GTM #534 Build Log

[ohmygosuness]

Hi everyone,

My name is Fei. I'm 33 and I live in Texas. I'm a very inexperienced builder. A lot people said the GTM kit isn't beginner friendly at all. But I enjoy being hands-on and I love performance cars, so I said **** it and pulled the trigger. I took delivery of GTM#534 around February 2022 (I made a post about it last year saying the delivery driver told me it was the last one). I've been working on it on and off, mostly during the winter times when my garage feels more comfortable than an oven.

I've been reading you guys' post pretty much word-for-word for the past 2-3 years. So, I decided it would be a good idea to post here about my progress. Everything I'm posting will be my first time doing it. Also, to make the "beginner experience" worse, I got a C6 donor instead of a C5. I feel like I possibly shot myself in the foot with this decision but I'm pretty optimistic that I'll eventually make it work (with a ton of research/modifications, of course).

I've seen a lot of yall's build and they're pretty amazing. If the things I post looks like I have no idea what the hell I'm doing, then you're probably right. So, please feel free to offer some pointers. I'll try to be as detailed as I can with my posts/replies. I'm currently at work. I'll start posting later when I'm at home. Thanks!

Fei

[VRaptor SpeedWorks, LLC]

Welcome aboard! Looking forward to seeing your progress...

[ohmygosuness]

Hi Shane. Thanks!
I believe I still owe you some dimensions for the location of the shifter (if I remember correctly). I know it's been a while but it's always in the back of my head.

[ohmygosuness]

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I've worked on the build very little since delivery, but a lot more last few months. The only things I have on it so far is the suspension, C6 steering column, 3 reservoirs.
C6 front suspension works on the GTM. Rear upper control arms don't work.
C6 steering column needs a little adjustment. I grinded off a lot of material for it to fit.
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I have the c6 corvette sitting next to the GTM. Taking it apart piece by piece as I put them into the GTM. Engine will be a stock ls2 with 65k miles.
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Cleaned every piston from carbon build-up. Got all new gaskets/piston rings, gapped all the piston rings, honed each cylinder, etc
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While uploading these pictures, I came to a realization that I've spent more time prepping the engine than actually installing parts onto the GTM. But I'm at the final stages of putting the engine together. Just waiting for the paint to dry on the cylinder heads before re-assembling the engine.

[VRaptor SpeedWorks, LLC]

Yes.....I was looking thru my orders spreadsheet the other day and saw that I still showed that I owe you that plate. Whenever you're ready, just let me know.

That C6 steering column sure looks like a whole different beast than the C5!

[Shoeless]

Looking forward to the posts!! We'll gladly let you know if something is wrong LOL ;). On a serious note, the recommendations and pointers from the group are pretty solid, so feel free to ask away.

[ohmygosuness]

Looking forward to the posts!! We'll gladly let you know if something is wrong LOL ;). On a serious note, the recommendations and pointers from the group are pretty solid, so feel free to ask away.

Hi shoeless. I like what you did with your build! I've been following it carefully as I'm building mine. Mine's just not as detailed :D

[ohmygosuness]

Here's another thing from the C6 that don't fit as good as C5 for the GTM - the Gen IV LS valley cover. I grinded off that big pipe sticking above the valley cover to clear the throttle body. Still trying to figure out how I should cap off that hole. I'm wondering if a bolt will do the trick?
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Here is the part I got to relocate the oil pressure sender. Anyone has a recommendation on which sensor I should get?
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[VRaptor SpeedWorks, LLC]

http://vraptorspeedworks.com/ls-engine-valley-cover-oil-pressure-boss-modification/

As for the oil pressure sender, you need to use the one that comes with the oil pressure gauge in the kit. If that block you have above the filter is to relocate the OEM sensor, it probably won't work for the gauge sender as the gauge sender is 1/8" NPT and the OEM sender is....I believe a straight metric thread with a crush washer? For the gauge sender, I normally take the OEM cast aluminum bypass piece and drill and tap it to 1/8" NPT.....

[ohmygosuness]

http://vraptorspeedworks.com/ls-engine-valley-cover-oil-pressure-boss-modification/

As for the oil pressure sender, you need to use the one that comes with the oil pressure gauge in the kit. If that block you have above the filter is to relocate the OEM sensor, it probably won't work for the gauge sender as the gauge sender is 1/8" NPT and the OEM sender is....I believe a straight metric thread with a crush washer? For the gauge sender, I normally take the OEM cast aluminum bypass piece and drill and tap it to 1/8" NPT.....
Drilling through the OEM cast aluminum piece is a good idea. I think I should have done that instead...

As for the relocator I bought, I do believe they sell an adaptor to 1/8" NPT. But I'm not sure if the transducer will be able to mount directly above it after using the adaptor. I think i may have to get one that's angled.

As for the hole on the valley cover, would it work if I just fill it up with some metal filler/epoxy? :D

[VRaptor SpeedWorks, LLC]

As for the hole on the valley cover, would it work if I just fill it up with some metal filler/epoxy? :D

As long as the epoxy you use is completely unaffected by oil and heat and you create something inside the hole for it to hold to....like get a dremel down in the hole and grind some grooves into the aluminum so that the epoxy is not just a smooth sided plug that could pop out under pressure......that might work?

[Ajzride]

As for the hole on the valley cover, would it work if I just fill it up with some metal filler/epoxy? :D

I wouldn't risk it. Tap the hole and fill it with a screw in plug.

[crash]

I wouldn't risk it. Tap the hole and fill it with a screw in plug.

THIS.

If you want to make it permanent use epoxy on the threads.

Are you sure you have to remove the sender cast piece? I seem to recall I did this the first time I did a build and flipped the intake around. Then on a second engine I recall just trimming the intake manifold to clear the casting and using a plug in it. Yes you still have to relocate the sensor, but no cutting, tapping/welding of the valley cover is needed...IIRC. I haven't done a flipped intake in a long time though.

There are also available valley covers with the sensor blocked off...

https://www.summitracing.com/parts/icb-551646

For $42 it saves a bit of work and looks nice and clean.

[VRaptor SpeedWorks, LLC]

The oil pressure boss on the LS3 is really tall......no way to avoid cutting it off. You can see in the top photo here just how far it holds the flipped intake up off the heads:

http://vraptorspeedworks.com/ls-engine-valley-cover-oil-pressure-boss-modification/

Even with it cut down so it only sticks up an 1/8" or 3/16", you may still need to trim a bit of the plastic webbing from the bottom of the intake to clear it.

[ohmygosuness]

Shane, Ajzride, crash, thanks for the response. After reading your inputs, I believe I'm going with thread tap then plug option. Still waiting for the plug to arrive (hope I ordered the right size).

Shane, I do have some epoxy for exhaust repair, so it is heat resistant. I may end up putting epoxy on the threaded plug like crash suggested, to make it more permanent (if that's what he meant). I'll definitely post pics when it's done.

Question about power steering pump on the engine: do we use it on the gtm? If not, do I need a shorter belt?

[beeman]

I am aware of an early build that used the C5 power steering rack, but 99% use the manual rack from FFR.

[ohmygosuness]

I am aware of an early build that used the C5 power steering rack, but 99% use the manual rack from FFR.

Hi Beeman. Yes, I do have the manual rack from FFR installed. So, I don't think there's a need for the power steering pump. I was wondering if I need an aftermarket belt or a power steering delete bracket to make this work.

[beeman]

Lots of ways to run the belts depending on your accessory locations, mainly the alternator. Where are you running your alternator?

[VRaptor SpeedWorks, LLC]

All of the belt/relocation brackets should be included with the GTM kit to mount the alternator and install the donor belt tensioner. The other options are to use the Cadillac CTS-V alternator mount instead of the FFR mount since the FFR mount is not great. I also offer a belt tensioner kit that replaces the FFR bracket....which, once again, isn't great but can work.

[rolfer]

I have Shane's belt tensioner kit and can say it works very well. I would recommend it!

[Shoeless]

Hands down the best setup is the CTS-V Alternator and bracket with Shane's belt tensioner. Especially if you are going with a bit higher HP.

Make sure you get the right alternator as Cadillac changed over mid year and the old one needs a PWM signal to turn on and that's the one I got as I can control the output voltage with my ECU. There are a few large threads on the other forum with details you can read up on.

[ohmygosuness]

All of the belt/relocation brackets should be included with the GTM kit to mount the alternator and install the donor belt tensioner. The other options are to use the Cadillac CTS-V alternator mount instead of the FFR mount since the FFR mount is not great. I also offer a belt tensioner kit that replaces the FFR bracket....which, once again, isn't great but can work.

Sometimes I'm just waiting for orders to come in and I'll be day dreaming about how am I going to put everything together on the engine. I may be thinking way ahead of myself. Thanks for letting me know that they provide a bracket in the kit to adjust the belt.

I just noticed I'll need a C5 AC bracket as well as a C5 AC compressor. I just have them ordered, currently waiting for them to come in before I start thinking about dropping in.

What's wrong with the FFR alternator relocation bracket?

[ohmygosuness]

Hands down the best setup is the CTS-V Alternator and bracket with Shane's belt tensioner. Especially if you are going with a bit higher HP.

Make sure you get the right alternator as Cadillac changed over mid year and the old one needs a PWM signal to turn on and that's the one I got as I can control the output voltage with my ECU. There are a few large threads on the other forum with details you can read up on.

I'm assuming the main reason to use CTS-V alternator is for the voltage output adjustment?

Currently the engine is a stock LS2, should be making around 400 HP. I do have plans to make a bit more power, with something along the lines of AWD. I'll definitely look into the CTS-V. Still waiting for the C5 AC compressor/bracket to come in, so I can install it before dropping the engine in.

[Shoeless]

The main reason for using the CTS-V alternator and bracket is the rigidity. When compared to what the kit wants you to use, it’s far superior. Pair that with Shane’s Belt Tensioner, again superior rigidity, you have a solid setup.

Unless you are going with an aftermarket ECU and doing your own engine harness, make sure to get the one that is NOT PWM Controlled.

[beeman]

Main reason is that the FFR supplied bracket /pulley is not rigid enough and prone to making noise, and I believe jumping belts.

[ohmygosuness]

Been working on the hole sticking out on the valley cover. Got a 3/8" NPT plug then tapped the oil pressure sensor hole with 5/8" threads. Screwed in the plug up-side-down so the flat end is flush with the top of the cover. The plug width (thread-to-thread) is slightly wider than 5/8", something like 21/32. This allowed me to torque the plug into the thread really tight. I was going to add epoxy to the thread to make it more permanent, but seems unnecessary. Although, I could fill the underside of the cover with epoxy just so it could be flat.
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[ohmygosuness]

Thanks you guys for the heads up. I'll definitely be looking into CTS-V alternator/bracket.

[crash]

Been working on the hole sticking out on the valley cover. Got a 3/8" NPT plug then tapped the oil pressure sensor hole with 5/8" threads. Screwed in the plug up-side-down so the flat end is flush with the top of the cover. The plug width (thread-to-thread) is slightly wider than 5/8", something like 21/32. This allowed me to torque the plug into the thread really tight. I was going to add epoxy to the thread to make it more permanent, but seems unnecessary. Although, I could fill the underside of the cover with epoxy just so it could be flat.
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DO NOT fill the underside with epoxy. You need to be very careful with anything that is in the oil system on the engine. ANY contamination, like little bits of epoxy that might break off, can cause catastrophic engine failure. Avoid putting anything into the engine oil system after the filter that could even possibly be an issue. If the plug is tight enough I might recommend a bit of Teflon tape to make sure there are no leaks, but again, be double sure that you clean any excess off the threads before installing the cover. This is critical.

[ohmygosuness]

DO NOT fill the underside with epoxy. You need to be very careful with anything that is in the oil system on the engine. ANY contamination, like little bits of epoxy that might break off, can cause catastrophic engine failure. Avoid putting anything into the engine oil system after the filter that could even possibly be an issue. If the plug is tight enough I might recommend a bit of Teflon tape to make sure there are no leaks, but again, be double sure that you clean any excess off the threads before installing the cover. This is critical.

Noted. No epoxy. I do have Teflon tape, I'll probably try that instead. Thanks.

Man, am I glad I posted it on here before trying something stupid :D

[ohmygosuness]

Been waiting for some stuff to come in, like the AC bracket. Can someone confirm if I got the right one?
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Also, this water pump came with the engine. Would it work for the GTM or do I need one from LS1?
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[VRaptor SpeedWorks, LLC]

Not positive on the AC bracket, but looks like it's the right one to me. There may be a boss on the bracket or the engine block that will need to be removed for that bracket to fit an LS3. Same with the the motor mount brackets.....they bolt up and appear to fit, but there is interference between additional bolt bosses on the block and the bracket that need to be ground down for a proper fit.

You will need an LS1 water pump with the large bell-shaped pulley (1999 Corvette fitment). The pump you have is a newer pump and will hit the chassis at the t-stat housing.

[Shoeless]

It may or may not need to be said, but it tripped me up, so I'll share here.

When I got my LS3, I bought the LS1 water pump as Shane mentioned above, but kept the LS3 T-Stat housing as it appeared to fit. That's a no go as I had about 1/16" clearance to the frame. You need to get an LS1 T-Stat housing as well.

[ohmygosuness]

Not positive on the AC bracket, but looks like it's the right one to me. There may be a boss on the bracket or the engine block that will need to be removed for that bracket to fit an LS3. Same with the the motor mount brackets.....they bolt up and appear to fit, but there is interference between additional bolt bosses on the block and the bracket that need to be ground down for a proper fit.

You will need an LS1 water pump with the large bell-shaped pulley (1999 Corvette fitment). The pump you have is a newer pump and will hit the chassis at the t-stat housing.

I hope this is the right AC bracket. It supposedly came from the LS1 and looks way different. It looks similar to the one in Shoeless' build log :)
There is a boss on the bracket that I had to tap it with M10 to fit the M10 bolts that came with the LS2 AC compressor. Maybe that's what you're talking about. But I haven't installed it yet. Will definitely let you know if I something that don't fit (fingers crossed).

Yes, you're right about the motor mounts! I had to drill a hole into each of the spacers so that little 1/4" nub sticking out below won't interfere when mounting the engine.

I got a new water pump.
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[ohmygosuness]

It may or may not need to be said, but it tripped me up, so I'll share here.

When I got my LS3, I bought the LS1 water pump as Shane mentioned above, but kept the LS3 T-Stat housing as it appeared to fit. That's a no go as I had about 1/16" clearance to the frame. You need to get an LS1 T-Stat housing as well.

Thanks shoeless. Noted.

[ohmygosuness]

Here is the AC compressor with bracket.
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[VRaptor SpeedWorks, LLC]

That does look like the correct AC bracket.....and I don't think it will bolt up to an LS3 without grinding either the bracket or the engine block to make it fit. Same with the aluminum brackets that bolt up to the engine block that the motor mounts attach to. Where the alum brackets meet the block, you may be able to get all of the bolts started and seems like everything fits, but if you look, the bracket is not sitting up against the engine block like it should....this is on the pass side bracket.....there is a bolt boss on the engine block that sticks out and holds the bracket out away from the engine block. You will need to grind something to make it fit. I've seen this dozens of times with cars we've worked on here where the previous owner just bolts the bracket up to the block and then goes to install the engine and wonders why the motor mounts don't line up with the chassis.

[Shoeless]

I did a little blending on my motor mounts like Shane notes, an it worked perfectly.

[ohmygosuness]

I've been working on making the FFR alternator bracket stronger by welding on some gussets since you gentlemen mentioned it's a bit fragile.
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I was recommended to get the bracket from CTS-V, not sure if I needed the alt from CTS-V as well. But it would ended up costing a lot more. This project only costed me $12 (replaced the aluminum bushing on the 1/2" pulley bolt to steel and fishing up some scrap metal from work for the gussets). If this bracket still gives me issues down the road, I'll go for the alt bracket from CTS-V.

PS: some of my welds look like boogers because this is my first welding project. But I made sure it had good penetration :)

[ohmygosuness]

I'm working on routing the brake lines. The cylinder on the left appears to be interfering with the frame after I snugged the fitting in the front. Is this suppose to happen or am i just being dumb?

Also, I know all the cylinders are the same but is there a preference as to which one to use for which (front/rear) brakes in terms of giving maybe slight advantage in the routing process?

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[doug_porsche]

I suspect that is the MC you are using for the front brakes.
On my, and all the pictures I can find of others, the front port is for a "bleeder" and the top port is run to the calipers.

The front mc has the line coming out of the top port, going to a tee, and then to each front caliper.

[crash]

I suspect that is the MC you are using for the front brakes.
On my, and all the pictures I can find of others, the front port is for a "bleeder" and the top port is run to the calipers.

The front mc has the line coming out of the top port, going to a tee, and then to each front caliper.

I have discussed this quite a few times on the forums. The bleeder on the high port is the CORRECT way to have the bleeder setup. If the bleeder is not the high point, then how is air expected to leave the system without pumping it all the way through to the calipers? At that point there would be no need to even have a bleeder at the MC. Many, if not most, GTM builders do this incorrectly because it is hard to get the lines to fit because of the frame interference. I would try using low profile banjo fittings.

As far as which master to run to which set of calipers, it should not matter unless you are running staggered size calipers, and/or staggered sized MCs. The only other reason would be if you run a bias adjuster, in which case you would want the "Front" and "Rear" on the adjuster to correlate to the MCs. We run this adjuster on the race car and the center MC is for the front calipers.

[ohmygosuness]

I suspect that is the MC you are using for the front brakes.
On my, and all the pictures I can find of others, the front port is for a "bleeder" and the top port is run to the calipers.

The front mc has the line coming out of the top port, going to a tee, and then to each front caliper.

Thanks, Doug, for the input.

[ohmygosuness]

I have discussed this quite a few times on the forums. The bleeder on the high port is the CORRECT way to have the bleeder setup. If the bleeder is not the high point, then how is air expected to leave the system without pumping it all the way through to the calipers? At that point there would be no need to even have a bleeder at the MC. Many, if not most, GTM builders do this incorrectly because it is hard to get the lines to fit because of the frame interference. I would try using low profile banjo fittings.

As far as which master to run to which set of calipers, it should not matter unless you are running staggered size calipers, and/or staggered sized MCs. The only other reason would be if you run a bias adjuster, in which case you would want the "Front" and "Rear" on the adjuster to correlate to the MCs. We run this adjuster on the race car and the center MC is for the front calipers.

Crash, I believe you're right. The top port is the bleeder, at least according to the user manual. Either way it doesn't look like I can get the lines to fit on the inner-most MC, at least without a fitting that's 90 degrees or low profile.

[crash]

Crash, I believe you're right. The top port is the bleeder, at least according to the user manual. Either way it doesn't look like I can get the lines to fit on the inner-most MC, at least without a fitting that's 90 degrees or low profile.

Again, the banjo fittings are your friend here.

https://www.anplumbing.com/a-n-male-banjo.html

EDIT: Looking at the picture and the adapter you are using it looks like the MC is either an internal flair or the housing uses pipe thread. This may present an issue as the banjo fittings use straight threads. Let me look at some options tonight and I will get back. Could always drill out and retap, but then you would have to disassemble the MC. Have you tried a low profile tube nut and just bending the tube? Our MCs on the race car have moved a bit but I know I have seen others do this on a stock GTM where they make the lower hole work. Banjo is the tightest 90 you will get, it's just going to be a matter of getting it threaded in the MC.

[ohmygosuness]

Again, the banjo fittings are your friend here.

https://www.anplumbing.com/a-n-male-banjo.html

EDIT: Looking at the picture and the adapter you are using it looks like the MC is either an internal flair or the housing uses pipe thread. This may present an issue as the banjo fittings use straight threads. Let me look at some options tonight and I will get back. Could always drill out and retap, but then you would have to disassemble the MC. Have you tried a low profile tube nut and just bending the tube? Our MCs on the race car have moved a bit but I know I have seen others do this on a stock GTM where they make the lower hole work. Banjo is the tightest 90 you will get, it's just going to be a matter of getting it threaded in the MC.

I took some more pictures. It does appear that the threads are straight in the MC. Also, the fittings Wilwood provided also have straight threads.

From the pics, the front may look like a tight fit, but I believe the banjo fittings you linked would go in. The only thing I'm afraid of is that the bolt going through the banjo bore may interfere with the frame.

It's interesting that you mentioned using just a tube with a nut. I used a 20" tube from FFR to test it out and it seemed like it would work nicely. I just need to get a shorter tube so I can T it off.

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[crash]

Thanks for the shot down the thread bore. Unfortunately if it does not have an internal flair, which it looks like it does not, then the direct tube and nut option will not work. I took a picture of what we have, which is all banjos, but am having issues sharing the photo. The good news is that the banjo fitting should just work with no mods on what you have there. Simply use what I linked to, along with the properly sized and threaded banjo bolt and then put the tube and flair nut directly on the flared end of the banjo fitting.

[crash]

Finally got the picture to upload.

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[ohmygosuness]

The banjo fitting looks really solid. BUT, it's still unable to clear the frame.
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The only thing that I could barely get it to fit was a 90 degree bend fitting. But it doesn't look as reliable as the banjo fitting.

[ohmygosuness]

Actually, I may have the banjo fitting installed the wrong way (in the above pic). Here is what it looks like with banjo installed on the 90 degree fitting. It's just enough to clear the frame. Someone please let me know if this works.
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[beeman]

A GTM build will hone your problem-solving skills, any other car projects you take on will be a piece of cake!

[ohmygosuness]

A GTM build will hone your problem-solving skills, any other car projects you take on will be a piece of cake!

I completely agree. I've learned so much already. The GTM pushed me to become a better man :)

[crash]

Sorry to send you down a rabbit hole. I'll buy the fittings from you if you like. As you can see, they are what we use.

Now back to the issue. The problem I see with your proposed solution is that I believe the fitting you are using is pipe thread and you have it screwed into straight threads on the MC. I don't believe this will work. I have seen others connect up the proper way so I know it is doable. Too bad none of them have provided any pictures or insight.

Have you spoken with anyone at ANPlumbing.com? One of the reasons I use that vendor is because they have people there that will work with you and get you what you need. Prices are pretty close to Summit and Jegs but their searchability is much better. Maybe a lower profile banjo/bolt will work...maybe not, but it might be worth a phone call to ask what they have available?

Then, of course, there is always frame member modification...if you are willing and able. I seem to remember a small modification was done on the other setups I saw with the tubes coming out the front.

[Shoeless]

I completely agree. I've learned so much already. The GTM pushed me to become a better man :)

This damn build will definitely humble you LOL. But when you get a portion of the work or a major milestone complete, its very rewarding.

[ohmygosuness]

Sorry to send you down a rabbit hole. I'll buy the fittings from you if you like. As you can see, they are what we use.

Now back to the issue. The problem I see with your proposed solution is that I believe the fitting you are using is pipe thread and you have it screwed into straight threads on the MC. I don't believe this will work. I have seen others connect up the proper way so I know it is doable. Too bad none of them have provided any pictures or insight.

Have you spoken with anyone at ANPlumbing.com? One of the reasons I use that vendor is because they have people there that will work with you and get you what you need. Prices are pretty close to Summit and Jegs but their searchability is much better. Maybe a lower profile banjo/bolt will work...maybe not, but it might be worth a phone call to ask what they have available?

Then, of course, there is always frame member modification...if you are willing and able. I seem to remember a small modification was done on the other setups I saw with the tubes coming out the front.

Crash, I do like the banjo fittings. I could definitely use them for the MC's, you don't have to buy them from me lol.

Here is the link to the elbow fitting I got. It's 3AN female to 3AN male:

Podavelle 3AN Female to 3AN Male Flare 90 Degree Elbow Swivel Fitting Adapter Coupler Aluminum Black https://a.co/d/6IZjW98

Let me know what you think. Also, I'm thinking about getting more banjo fitting for the other MC's. They just seem very reliable.

[crash]

I think I see what you are getting at. You are suggesting using the male flare to bottom on the inside of the MC threaded area. I can't tell from the pictures you sent for sure, but there may be a flared or chamfered area on the hole where the fluid comes out of the MC? You are suggesting seating that -3 straight threaded male flare up against that chamfer and then hoping the 90 degree fitting comes out in a usable position. Then using a single flare hard line with a tube nut in the female side of that 90? I have never seen AN fittings used in this way. I think I would try just using a single flare hard line down in the MC with a proper length tube nut and then that should give you the ability to turn the tube right out of the nut and it should result in a very short setup. If you are going to try a single flare setup, I think this is how I would do it and not with all the AN adapters.

[crash]

I don't know if this has the correct thread, but this fitting looks WAY smaller than what you have on there.

https://www.lethalperformance.com/tilton-racing-fitting-banjo-inlet-78-series-mc-an4-male-78-3400.html?msclkid=1301a8c2e992162dac2fcc8aa8df7ee6&utm_source=bing&utm_medium=cpc&utm_campaign=OB%20-%20Smart%20Shopping&utm_term=4582558340765433&utm_content=Catch%20All

I went and looked at the Tilton catalog and this is listed for use in the reservoir side. Thread is 9/16 18, probably too large, but very low profile, made out of steel, so I wouldn't worry about high pressures, but I would change the orings out for copper washers.

https://tiltonracing.com/product-category/brake/master-cylinder-pedal-assembly-parts/fittings/

[ohmygosuness]

I think I see what you are getting at. You are suggesting using the male flare to bottom on the inside of the MC threaded area. I can't tell from the pictures you sent for sure, but there may be a flared or chamfered area on the hole where the fluid comes out of the MC? You are suggesting seating that -3 straight threaded male flare up against that chamfer and then hoping the 90 degree fitting comes out in a usable position. Then using a single flare hard line with a tube nut in the female side of that 90? I have never seen AN fittings used in this way. I think I would try just using a single flare hard line down in the MC with a proper length tube nut and then that should give you the ability to turn the tube right out of the nut and it should result in a very short setup. If you are going to try a single flare setup, I think this is how I would do it and not with all the AN adapters.

I believe I may go with what you suggested about using a tube instead of the AN fitting. But I think the tube end may need to be bubble flare since the threaded area in the MC has an inverted flare/chamfer. I could be wrong, but I think it would be something like this? https://www.force10brakes.com/home/3-16-Stainless-Steel-Brake-Line-10mm-x-1-0-Bubble-flares-both-ends-pre-cut-to-length-6-to-84-p286498003

[crash]

Yes, that is what I meant by a "single flare". It is referred to as a single flare because when you are making a flare on the end of a tube, it is the first step of a two step process to make an "inverted flare". The "bubble flare" or "single flare" is known to not be able to hold as much pressure or nut tightening force, so the "double flare" or "inverted flare"(same thing) is most commonly used. A single or bubble flare should work though, as long as there is a seat on the MC for the bubble to mate to?

[ohmygosuness]

Did the driver side brakes using banjo fittings. Had to order another 6" brake line for the inner-most MC because the one I ordered came with wrong fittings :(

184120

184121

184122

[ohmygosuness]

184166

[crash]

I would not have thought of doing it like that. Cool to see people trying new stuff and sharing.

[ohmygosuness]

I would not have thought of doing it like that. Cool to see people trying new stuff and sharing.
Okay. That kind of makes me nervous now :). I would have stacked 2 banjo's (like how you have it) if it wasn't for the MC thread being flared the way it is, where I need to screw the banjo thread into the MC, instead of screwing the banjo bolt into the MC. I just hope there's nothing wrong with this setup. I also like how the banjo is able to redirect the lines downward.

[crash]

What I might be worried about is that I try to avoid having solid elements at 90 degrees to a screwed in element because this gives leverage to allow the screwed in element to be unscrewed. Does that make sense? Just curious...why not use the "bubble flare" like you discussed previously?

[ohmygosuness]

What I might be worried about is that I try to avoid having solid elements at 90 degrees to a screwed in element because this gives leverage to allow the screwed in element to be unscrewed. Does that make sense? Just curious...why not use the "bubble flare" like you discussed previously?
That makes a lot of sense. It's actually one thing I'm worried about while putting this together.

I'm planning on using the bubble flare line on the inner-most MC. Because that's the one interfering with the frame. Other 2 MC (middle and far right) will have a banjo.

I may have to come up with a solution to prevent the T from unscrewing due to vibration or other effects over time...

[Shoeless]

My concern is the banjo may leak requiring you to torque it down more and you can't because you have the bolt going straight down.

When I put my brake lines together all the fitting felt really tight, until I filled them with fluid and tried to bleed the system. I had a few leaks that i had to chase around fittings.

[ohmygosuness]

My concern is the banjo may leak requiring you to torque it down more and you can't because you have the bolt going straight down.

When I put my brake lines together all the fitting felt really tight, until I filled them with fluid and tried to bleed the system. I had a few leaks that i had to chase around fittings.

That does sound very concerning. What did you do to fix the leaks?

[Shoeless]

That does sound very concerning. What did you do to fix the leaks?

I simply torqued down the brake/clutch lines more until the leaks stopped. For lines that simply connected to an end fitting or a straight coupling, it was really no problem, just torque down, but where my T fitting was, it caused a minor issue. I had to tighten the T fitting about 1/4 turn from where I mocked it up and the 90 deg output line had to go along for the ride so to speak. Thankfully I had some give in that particular line with a service loop in the line close by so I was able to re-bend the line as I tightened the fitting.

Just something to think about. Not saying it won't work, but I'd fill the lines and try to blead the lines ASAP (I ended up delaying this for some reason) to see if you have any leaks. That way you can address this now instead of further down the road in your build when you get more stuff installed and in the way.

[ohmygosuness]

I simply torqued down the brake/clutch lines more until the leaks stopped. For lines that simply connected to an end fitting or a straight coupling, it was really no problem, just torque down, but where my T fitting was, it caused a minor issue. I had to tighten the T fitting about 1/4 turn from where I mocked it up and the 90 deg output line had to go along for the ride so to speak. Thankfully I had some give in that particular line with a service loop in the line close by so I was able to re-bend the line as I tightened the fitting.

Just something to think about. Not saying it won't work, but I'd fill the lines and try to blead the lines ASAP (I ended up delaying this for some reason) to see if you have any leaks. That way you can address this now instead of further down the road in your build when you get more stuff installed and in the way.
I just ordered a liter of brake fluid. Going to use it to check for leaks. Good call on doing this early than later :)

[crash]

Good call on this as I almost ALWAYS have to tighten to stop leaks on newly installed parts. I would rather do this than over tighten at first and damage something, so I snug everything, then pressurize, then tighten until no leaks.

[ohmygosuness]

Good call on this as I almost ALWAYS have to tighten to stop leaks on newly installed parts. I would rather do this than over tighten at first and damage something, so I snug everything, then pressurize, then tighten until no leaks.

That reminded me. I do have an air compressor sitting around. It's not much, only 150 psi, but it's less messy than having oil leak everywhere. Is it possible to do a leak test first with just air?

[Shoeless]

That reminded me. I do have an air compressor sitting around. It's not much, only 150 psi, but it's less messy than having oil leak everywhere. Is it possible to do a leak test first with just air?

Negative, the hydraulic pressure present in brake lines is well over 150 psi. Would be a waste of time.

[crash]

I want to say we are seeing brake pressures of around 800 psi...with spikes to over 1000 psi.

[Shoeless]

I want to say we are seeing brake pressures of around 800 psi...with spikes to over 1000 psi.

I figured it would be in this ballpark, but don't measure it on my setup so no factual numbers to share.

[ohmygosuness]

Making a good-looking bubble flare was probably one of the more difficult things I had to do so far with this build (apart from pulling the engine out the Corvette).
185482

A direct line to the MC fits perfect. I just hope my bubble flare pass the leak check.
185483

[crash]

Yeah making either type of flare sounds simple and looks easy when you see the mass produced tubes sitting on the shelf at the parts store, but, as you said, they are rather difficult to get right. The nice thing about the double flare is that if it is not perfect, as you tighten the nut during assembly it will crush the flare to seal on the fitting. This is not the case with the bubble flare. The single, or bubble, flare must have a really nice sealing surface when you are done making it as there is much less "wiggle room" when seating it. Looks good and I hope it seals properly also. Anything that has to do with brake fluid is on my "least favorite" list when working on cars.

[beeman]

The auto parts store rental tools are junk, and anything that style struggles with steel lines. You might be able to flare copper lines. I finally found a tool that works! Need the chamfer tool too.

https://a.co/d/3Q3IYAj

https://a.co/d/74VoszG

[crash]

Here is the one that I use...

https://www.ebay.com/itm/175737920489?var=0&mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338767525&toolid=20006&customid=4581664967841095_377870104_o.0399ea9fcc4f 1a9389518e188d4d9c60&msclkid=0399ea9fcc4f1a9389518e188d4d9c60

[ohmygosuness]

I appreciate you guys sharing what you use. Now that I think about it a bit more, I should've invested in a tool that's more expensive (assuming I get what I pay for). Braking is quite important, at least to me, since my life will depend on it.
This is the bubble flare tool I bought. It's inexpensive, but seems to get the job done. Although, it does grab the line a bit hard. Hard enough to leave marks. Hope that won't cause any issues down the road.

https://a.co/d/6UgA5e0

[beeman]

I have only had intermittent success with the style that crash and ohmygosuness posted above, hard to keep the brake line from sliding in the clamping mechanism. I've used vice grips on top of those devices, ground down the flats to allow a tighter clamp on the line. I've always used steel lines which are harder to flare, could probably do fine with softer metals with any flaring tool.

[crash]

I have only had intermittent success with the style that crash and ohmygosuness posted above, hard to keep the brake line from sliding in the clamping mechanism. I've used vice grips on top of those devices, ground down the flats to allow a tighter clamp on the line. I've always used steel lines which are harder to flare, could probably do fine with softer metals with any flaring tool.

If you used the Bluepoint tool I referenced and had an issue with grip, then you didn't tighten the wing nuts enough. This tool WILL leave marks on the steel lines, but the line will not move in the tool if you clamp it into a vise to use. The funny looking wing nuts are designed to be used with the tightening bar so you can get some significant leverage on the nuts without the use of a separate wrench. With the tool clamped in a vise and using the included bar on the wing nuts, it gets very tight. Only issue I have had is breaking the double flare mandrel if the tube is not perfectly flat. Using a file after the tube is clamped in the device to make sure the tube end is at the right height and flat to the bar surface reduces the risk of breaking the insert. I do tend to keep 2-3 extra mandrels in the kit because breakage does happen. Make sure to blow out the line after filing.

[ohmygosuness]

If you used the Bluepoint tool I referenced and had an issue with grip, then you didn't tighten the wing nuts enough. This tool WILL leave marks on the steel lines, but the line will not move in the tool if you clamp it into a vise to use. The funny looking wing nuts are designed to be used with the tightening bar so you can get some significant leverage on the nuts without the use of a separate wrench. With the tool clamped in a vise and using the included bar on the wing nuts, it gets very tight. Only issue I have had is breaking the double flare mandrel if the tube is not perfectly flat. Using a file after the tube is clamped in the device to make sure the tube end is at the right height and flat to the bar surface reduces the risk of breaking the insert. I do tend to keep 2-3 extra mandrels in the kit because breakage does happen. Make sure to blow out the line after filing.

I literally did break a mandrel on my first attempt :D (you could probably see it in the picture, first attempt on the far left barely showing a metal piece stuck inside the brake line).
I didn't have a tightening bar, I had to use a wrench. But yea, this tool won't clamp tight enough with just bare hands.

I tested the front brakes for leaks. It had a leak on one of the banjo crush washers because it was over torqued. Thankfully they gave me 2 spare washers. Replaced them, torqued them very gently. Pressure tested over night. No leaks so far. One thing I noticed was that my brake rotors would scrape the brake pad even when there's no pressure applied on the brakes. Is that normal? I haven't installed the wheels yet.

[beeman]

clamp it into a vise to use

One benefit of the tool I linked to is the ability to make good flares on installed lines, I had to do this on my Esprit.

[crash]

I literally did break a mandrel on my first attempt :D (you could probably see it in the picture, first attempt on the far left barely showing a metal piece stuck inside the brake line).
I didn't have a tightening bar, I had to use a wrench. But yea, this tool won't clamp tight enough with just bare hands.

I tested the front brakes for leaks. It had a leak on one of the banjo crush washers because it was over torqued. Thankfully they gave me 2 spare washers. Replaced them, torqued them very gently. Pressure tested over night. No leaks so far. One thing I noticed was that my brake rotors would scrape the brake pad even when there's no pressure applied on the brakes. Is that normal? I haven't installed the wheels yet.

There will always be a bit of contact by the pads to the rotors. However, if you have not done a final bleed and gotten ALL the air out the air in the system will compress and then not allow the pads to retract properly. Just make sure all the air is out.

I usually put fluid in, crack the furthest bleeder screw, and wait for the fluid to gravity feed to that point. I put a bleeder bottle on and sometimes it takes hours for this to happen. Once the fluid is to the furthest point, then I go around and bleed the brakes as normal. Once no air is visible I go and run a few laps. Then I almost always have to bleed again to get everything up to operating readiness.

[ohmygosuness]

There will always be a bit of contact by the pads to the rotors. However, if you have not done a final bleed and gotten ALL the air out the air in the system will compress and then not allow the pads to retract properly. Just make sure all the air is out.

I usually put fluid in, crack the furthest bleeder screw, and wait for the fluid to gravity feed to that point. I put a bleeder bottle on and sometimes it takes hours for this to happen. Once the fluid is to the furthest point, then I go around and bleed the brakes as normal. Once no air is visible I go and run a few laps. Then I almost always have to bleed again to get everything up to operating readiness.

Yea I bled the front brakes. It did take me several hours to catch all the leaks. Currently there's no more air bubbles. However, I still think about what you said about having a 90 degree element right after a connection may cause it to "unscrew" over time. I'll try to come up with a solution to fix that.

Does the Mendeola clutch line go down the driver side or passenger side?

[Mark Eaton]

For what it's worth I bought this Eastwood brake flaring kit with my MK4 and am now using it on the 818C. its spendy but works really well, saved me alot of headache...

https://www.eastwood.com/professional-brake-tubing-flaring-tool.html

Also used it to replace all lines in a 1970 Land Cruiser.

[crash]

Does the Mendeola clutch line go down the driver side or passenger side?

The Mendeola slave is on the passenger side. I don't know if my car has the clutch line in the stock location but it is on the drivers side. If I did this over I would likely run the clutch line down the passenger side.

[ohmygosuness]

It's been around 110 degrees here in the past couple of months. Had difficulty to motivate myself to get some work done on the GTM in this heat. But I got all the brake lines in place. Bled them. Pressure tested. So far, no leaks. Next will be mounting the radiator and AC coils from C6 corvette. I wonder if it's going to fit as well as the C5.

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189216

[ohmygosuness]

Good news is c6 vette radiator/AC fits the GTM. Only had to make minor modifications to the mounting bracket on the frame rail.

Although, I'm having the hardest time fitting the corrugated radiator hose into these rubber adaptors.
190145

[ohmygosuness]

After hours of trying to fit these FF corrugated lines into these adaptors with not much progress, I'm thinking about replacing the FF lines with something else. Anyone have any suggestions? Maybe silicone or aluminum lines?

[VRaptor SpeedWorks, LLC]

You don't need any of those separate internal sleeves in the adaptors with the corrugated lines. That's the problem you have there. Yes, you can ditch the corrugated stuff and switch to stainless or alum tubes and silicone elbows, but you will have to bead the ends of the tubes so that the coolant system pressure can't push the joints apart.

[ohmygosuness]

You don't need any of those separate internal sleeves in the adaptors with the corrugated lines. That's the problem you have there. Yes, you can ditch the corrugated stuff and switch to stainless or alum tubes and silicone elbows, but you will have to bead the ends of the tubes so that the coolant system pressure can't push the joints apart.

Thanks Shane, you're right! It fits good without the sleeves. The sleeves are only for the aluminum hard lines (according to the manual). I may just stick with the corrugated hose for now, and use the FF provided aluminum hard line for the long, straight section inside the tunnel.

I'm also thinking about insulating the crap out of the outlet of the water pump going through the tunnel, since I heard that heat in the cabin may be an issue.

Something on the manual doesn't seem to make sense on this part. It's basically saying to connect the 1.5" diameter hard line to the upper port of the water pump (about 1.25" diameter). While connecting the 1.25" diameter hardline to the lower port (1.5" diameter). Why are the lines not connecting to ports with their corresponding sizes? (1.25" line to 1.25" port, etc)

[VRaptor SpeedWorks, LLC]

Not sure of their thinking on the sizes of the coolant lines, but it works. As far as insulating goes, I've found that the most effective way to do that is to insulate both hard lines with some form of "sleeve" insulation over the tubes, then once all of the coolant and AC hoses are in place, make a "blanket" that spans from one side of the tunnel to the other and seal the blanket to the chassis with foil tape. I've used the foil-faced bubble wrap stuff for this and it works very well....dome it up so that it doesn't contact the tubes......and then use louvered belly pans so that all of the heat from the coolant tubes, heater hoses and AC hoses all gets vented out the bottom of the car.

[crash]

Since we are back to discussing coolant lines, I will tell you that I just finished redoing the entire cooling system on the FFR PDG GTM race car.

I was able to fit a GM truck standard radiator in the front framework. 19 X 31 double row. All aluminum, Griffin radiator. $200-$250.

190261

You may also know from previous posts that we pioneered the outside the car water lines in the rocker panel area. I would never build a GTM without doing this upgrade. It takes all the heat issues outside of the cockpit.

Now the truck radiator has a cooling system design standard 1.5" inlet and a 1.75" outlet. Because of the size difference there will naturally be a pressure difference designed into the system...as it should be. I went ahead and put a 1.5" line on the top water pump outlet and ran it to the 1.5" inlet on the radiator, and then changed all the radiator out lines right up to the thermostat housing to 1.75" with a reducer at the thermo housing.

I also redesigned the header tank and overflow tank systems.

The result? I had to put a 190 degree thermostat in the water pump housing and also put duct tape across the front radiator opening in order for the engine to not run too cold. And this is with the Katech engine that we recently put in that has got a considerable higher output than the crate 525 LS3 we have been running previously.

I also upped the oil cooler to a pretty large Fluidyne unit.

Bottom line...engine runs right where we set it, the driver is cooler, and we don't have to worry about cooling...EVER.

Unless, of course, we go to something like a 1200 HP mill. That is not happening though.

For the record, we run an entirely closed bottom car with no venting or air flow to the tunnel or engine compartment from under the car.

[ohmygosuness]

Not sure of their thinking on the sizes of the coolant lines, but it works. As far as insulating goes, I've found that the most effective way to do that is to insulate both hard lines with some form of "sleeve" insulation over the tubes, then once all of the coolant and AC hoses are in place, make a "blanket" that spans from one side of the tunnel to the other and seal the blanket to the chassis with foil tape. I've used the foil-faced bubble wrap stuff for this and it works very well....dome it up so that it doesn't contact the tubes......and then use louvered belly pans so that all of the heat from the coolant tubes, heater hoses and AC hoses all gets vented out the bottom of the car.
As long as the setup in the manual works, I'm cool with it. Wrapping the whole thing in a blanket (or even adding a layer of heat shield on the tunnel aluminum panels) was exactly my thought of going about insulating this. I've also thought about building a fan on one end of the tunnel, or even a couple fans in the back of the engine bay to suck out as much air as possible. Kind of simulating a wind tunnel.

[ohmygosuness]

Since we are back to discussing coolant lines, I will tell you that I just finished redoing the entire cooling system on the FFR PDG GTM race car.

I was able to fit a GM truck standard radiator in the front framework. 19 X 31 double row. All aluminum, Griffin radiator. $200-$250.

190261

You may also know from previous posts that we pioneered the outside the car water lines in the rocker panel area. I would never build a GTM without doing this upgrade. It takes all the heat issues outside of the cockpit.

Now the truck radiator has a cooling system design standard 1.5" inlet and a 1.75" outlet. Because of the size difference there will naturally be a pressure difference designed into the system...as it should be. I went ahead and put a 1.5" line on the top water pump outlet and ran it to the 1.5" inlet on the radiator, and then changed all the radiator out lines right up to the thermostat housing to 1.75" with a reducer at the thermo housing.

I also redesigned the header tank and overflow tank systems.

The result? I had to put a 190 degree thermostat in the water pump housing and also put duct tape across the front radiator opening in order for the engine to not run too cold. And this is with the Katech engine that we recently put in that has got a considerable higher output than the crate 525 LS3 we have been running previously.

I also upped the oil cooler to a pretty large Fluidyne unit.

Bottom line...engine runs right where we set it, the driver is cooler, and we don't have to worry about cooling...EVER.

Unless, of course, we go to something like a 1200 HP mill. That is not happening though.

For the record, we run an entirely closed bottom car with no venting or air flow to the tunnel or engine compartment from under the car.

Crash, now you have me day dreaming and scheming about a new setup. Rerouting the lines sounds like a great idea. Though, I am curious about how you get them into the rocker panel area. When you said "outside," is it exposed to the outside air?
Do you have both lines sitting next to each other? Or do you have the cooled water line through the tunnel, while the uncooled line outside?

[crash]

Hot water on driver's side under rocker panel and cool side on passenger side.

It does require quite a few 90 degree and 45 degree both soft and hard bends. I also have the advantage of having a tube beader so I cut to length and then beaded the ends of the tubes.

I did every connection with double hose clamps for two reasons:

1) It is a rule requirement for the racing sanctioning bodies we run under
2) I also used a 30 pound cap that allows me to run the cooling system to 250 degrees without boil over

Double hose clamps is not a big deal if you have the normal 4 hose connections. 8 versus 4 hose clamps used. But when you have a GTM...holy crap I ordered fifty 1.5" and fifty 1.75" clamps. I used 10 silicone elbows on each side so two ends equals 20 single hose clamp connections, equals 40 double hose clamp connections!

If you are just running a street GTM you can use regular rubber elbows and single hose clamps. It is a bit of work though. Just be prepared.

I will note that the fuel tanks are not in the stock location on this race car. I know people have done the conversion to outside lines with the stock fuel tanks, but I am not sure how they ran the water lines around them. I would think the hot would be easy to go over the drivers tank and then down to the rocker area. The cool line I am not sure how that was done on a stock GTM. Maybe someone that has done it can share?

[ohmygosuness]

Which port on the pump is the in/outlet? And which port on the radiator is the in/outlet? I would assume the port on the pump with the larger diameter (bottom) is hot water to radiator, is this correct?

[crash]

I believe the Corvette runs what is termed a "reverse" system. In other words the cool water is at the thermostat and the hot water comes from the port at the top of the pump.

https://www.bing.com/images/search?view=detailV2&ccid=%2b4a9r6OH&id=E0A430173421B6EA5661A16EE05C3405266DC025&thid=OIP.-4a9r6OH2CIFQkYrH12jqQAAAA&mediaurl=https%3a%2f%2fwww.pirate4x4.com%2ftech%2f billavista%2fCooling%2fimages%2fLS%2fLS+cooling+sy stem+-+numbered+-+pressure_resize.jpg&cdnurl=https%3a%2f%2fth.bing.com%2fth%2fid%2fR.fb8 6bdafa387d8220542462b1f5da3a9%3frik%3dJcBtJgU0XOBu oQ%26pid%3dImgRaw%26r%3d0&exph=255&expw=350&q=ls3+cooling+system+diagram&simid=608013334969852993&FORM=IRPRST&ck=8C8E91913549D8154E0729F364A0C60C&selectedIndex=0&ajaxhist=0&ajaxserp=0

[ohmygosuness]

Crash, you've inspired me to relocate the hose (at least the hot one). I've been thinking about it all day. I may have the cold line going through the tunnel and just relocate the hot one somewhere else. Problem is I'm still very early in the build and am still not 100% sure what will be in the way if I were to route this through the passenger side (my preference).

I may have to get back to this later in the build (at least until after I have most of the parts in the car) to know how I can route it and, if necessary, make any modifications to the chassis.

[Ajzride]

Cold is relative, the cold pipe is still a heater to the cabin. I would relocate both.

[ohmygosuness]

Cold is relative, the cold pipe is still a heater to the cabin. I would relocate both.

I suppose relocating both shouldn't be a big problem, just a little more work.

[ohmygosuness]

Hot water on driver's side under rocker panel and cool side on passenger side.

It does require quite a few 90 degree and 45 degree both soft and hard bends. I also have the advantage of having a tube beader so I cut to length and then beaded the ends of the tubes.

I did every connection with double hose clamps for two reasons:

1) It is a rule requirement for the racing sanctioning bodies we run under
2) I also used a 30 pound cap that allows me to run the cooling system to 250 degrees without boil over

Double hose clamps is not a big deal if you have the normal 4 hose connections. 8 versus 4 hose clamps used. But when you have a GTM...holy crap I ordered fifty 1.5" and fifty 1.75" clamps. I used 10 silicone elbows on each side so two ends equals 20 single hose clamp connections, equals 40 double hose clamp connections!

If you are just running a street GTM you can use regular rubber elbows and single hose clamps. It is a bit of work though. Just be prepared.

I will note that the fuel tanks are not in the stock location on this race car. I know people have done the conversion to outside lines with the stock fuel tanks, but I am not sure how they ran the water lines around them. I would think the hot would be easy to go over the drivers tank and then down to the rocker area. The cool line I am not sure how that was done on a stock GTM. Maybe someone that has done it can share?

I've been wondering if it's outside (or under the car) what happens if it hits a rock on the highway. My car may see some tracks but it's mainly for the streets, and the roads in Houston are VERY bumpy.

Do you have any pictures?

[crash]

You should not have to change any frame components. We did not.

The tubes are still very much enclosed, just not in the drivers compartment.

They go in the area where the rocker panels are, just outside the frame on each side.

You may note that the next car that FFR built, the 818, the cooling tubes were kept outside the driver's compartment and run along the sides of the car.

The only drawback that we saw to moving these out to the sides was that the tubes are more exposed to an impact in any potential side impact incident. They are VERY low, especially compared to other street car bumper heights, and so this doesn't seem like it is that big of a concern.

[crash]

Here is a picture before the current redo. It is really pretty straight forward. It just requires a bit of finagling around, particularly on the front, to get through the frame work and hooked up to the radiator.

[ohmygosuness]

Here is a picture before the current redo. It is really pretty straight forward. It just requires a bit of finagling around, particularly on the front, to get through the frame work and hooked up to the radiator.

It looks like you have it routed through the wheel well. I'll have to put a wheel on the car to check the clearance.
Did you have any issues when putting the body on the car?
.

[crash]

It looks like you have it routed through the wheel well. I'll have to put a wheel on the car to check the clearance.
Did you have any issues when putting the body on the car?
.

Nope. There is lots of room. I did put aluminum shields over the tubes where debris would hit them from the spinning front wheels as a precaution.

[ohmygosuness]

Nope. There is lots of room. I did put aluminum shields over the tubes where debris would hit them from the spinning front wheels as a precaution.
This is good info. I was also wondering about the debris. Thanks.

[ohmygosuness]

So, I noticed on top of the C5 vette radiator (passenger side) there are 2 ports for heater hose. One connects to the vent tube on cylinder head. The other one connects to the surge tank. The radiator I have from C6 vette only have 1 port. Can I still use this radiator? Or do I have to get a different one.

190704

[VRaptor SpeedWorks, LLC]

It's just a port to the top of the radiator.....nothing special about it, so there's not going to be any difference whether you hook 2 hoses to the top of the radiator or install a T there and hook one hose to the radiator and the other hose to the T.....

We always relocate the surge tank to the engine bay and hook a short hose and petcock or shut-off to that port on the radiator (and plug the 2nd port) and use the petcock/shut-off to purge the air out of the top of the radiator.

[ohmygosuness]

Thanks, Shane. Good to know it's nothing too important. I'm assuming you also do nothing with the vent tube on the cylinder head and plug off the port on top of the surge tank?

[crash]

Head vents must be used. Not doing so can lead to severe engine damage. Another reason surge tank/header tank is moved to engine compartment. Tank needs to be the highest point in the system for system to function properly.

[ohmygosuness]

You're right, Crash. After doing a bit of research on the LS forums, it appears that the best place to plumb the head vents would be the highest low-pressure point of the system (water pump inlet) or into the surge tank. I believe the easiest way for me is to plumb it into the port on top of the surge tank. Correct me if I'm wrong.

190788

[VRaptor SpeedWorks, LLC]

Yes, the steam vents on the engine need to connect to the surge tank if you have the surge tank mounted in the engine bay. As Crash stated, this is the #1 reason we usually move the surge tank to the engine bay and mount it so that it's higher than the engine......so that any air trapped at the top of the engine can vent to the surge tank so that the engine is completely full of coolant with no air pockets.

With the surge tank mounted up front in the FFR location, you would need to attach that steam vent hose to that port on the top of the radiator, since the surge tank is mounted lower than the engine. The top of the radiator should always be full of coolant since the radiator is lower than the surge tank....so with the vent hose connected there, the engine shouldn't ever be able to suck in air at the steam vents. If you hook that vent hose to the upper port on the surge tank, the steam vents will pull air in from the top of the surge tank and it will be trapped there and your engine will overheat.

[ohmygosuness]

Thanks for the details, Shane.
Where exactly, in the engine bay, should I relocate the surge tank? Only place I'm seeing is on top of one of the panels right behind the fuel tanks, above the wheel well.

[crash]

I generally suggest that the tank go as high up as you can get it and therefore it should be up towards the engine firewall. I have always put them on the left side as it is less busy as far as wiring goes.

I should note that Shane's tank fits a stock GTM better than the universal tank that I use, although I don't think it gets up quite as high. As I do not currently have the universal tanks in stock, I would highly recommend Shane's model.

[crash]

Header tank pic...190807190808

I know I said as far forward as you can get, but in the second picture you can see how much fuel system stuff ended up in front of those tanks. This setup, now that I look at the pictures, is probably not much if any higher up in the car than what Shane does.

The three lines connected there are radiator bleed(blue hose), water pump bleed(-3), and steam vent bleed(-4). The return line is off the bottom of the tank and goes back over to the water pump heater hose connection.

[crash]

I also put a "bulkhead" in for easier engine changes...190809

I ended up having to add a 4th fitting on there. The fittings you see are steam vent, water pump bleed, and fuel supply. I ended up having to add the fuel return. The fuel return was on the passenger side of the car previously and I was hoping to keep it there, but ended up having to move it to the driver side.

[ohmygosuness]

Looks like this step (relocating surge tank) would be something I should do towards the end, after I have all the wiring in place. Also, I just bought the stock C5 vette tank from Amazon. It seems a tad wider than the one you have. I may have to play around with the fitment location after everything else is in place to be able to decide where it will be mounted.

I like your setup, Crash. Very practical. And those AN fittings looks sweet! I think I might get me some. The welds look clean too. My welds look like boogers being smeared.

Where is the bleeder for the water pump? Or is it one of them heater hose ports. It's mentioned in the manual that both heater port connects to the surge tank. I don't see a bleeder.

[crash]

We have been looking at issues as they occur on the GTM setup.

I want to put coolant into the system when I put an engine in, fill up the coolant tank, run the engine just long enough to circulate the fluid, top it up, and then not worry about it again.

I don't want to have to start it repeatedly, use a vacuum cleaner to suck fluid to where it should naturally want to go in a properly designed and built system, and I certainly don't want to jack the car up to try and get the cooling system to work properly.

This is why I redesigned the cooling system on the GTM and passed the info on to this community. There is really nothing special about the system once changed over to what I recommend. It is simply changing things to what every vehicle manufacturer uses in every one of their vehicles.

Now, that said, we have seen cavitation issues in the water pump. While a water pump bleed is pretty standard in a racing vehicle, the Vette does not have one from the OEM. I will have to get a picture for you but what I do is put a -3 bleeder hose at the top of the chamber where the water pump impellor is. This allows a small amount of fluid, and any air that could be trapped, to return to the header tank...automatically since the tank is higher than the pump.

There are two really critical areas that IMHO need to be air free. Those would be the cylinder heads, and the water pump. I left the radiator bleed in the system just because the line was already run from a previous iteration of the cooling system, but it is not essential. You can simply bleed the radiator with a petcock valve and the small amount of air that may accumulate at the radiator will really cause no issues.

If the heads get air in them you can very easily lose a head gasket, and if the pump cavitates and fluid is not flowing, again, you can very easily lose a head gasket.

Just study your street car's system and replicate that and you should be good.

Do you need a water pump bleed? It does make the system more failure proof and easier to work with, but whether you use one or not is up to you. It certainly isn't a requirement to have a functioning system. You just may have to start and stop the engine a few times when initially bleeding the system of air. If you do not see a solid circulation of fluid thru your header tank it either is not hooked up correctly, or you have pump cavitation.

I think Shane offers a mounting bracket to relocate the stock tank to the rear? Don't know for sure, but I do know that his aluminum tank installs look really good. You may want to just purchase his entire kit.

Also just a heads up on AN fittings. There is roughly $10,000.00 of AN fittings and hose in the FFR PDG GTM race car. It is not a cheap alternative.

The key to welding, like painting, is prep. Can you screw up a nicely prepped job? Yes. Can you have a beautiful finished job without good prep? No. Make sure to clean everything really well and then you will eliminate that as a cause of bad welds.

[VRaptor SpeedWorks, LLC]

Here is the link to the bracket I sell that allows you to mount the donor 'vette reservoir in the engine bay:


http://vraptorspeedworks.com/vette-coolant-tank-relocate-bracket/

‘Vette Coolant Tank Relocate Bracket – $23

It's just a flat plate that welds to the round tube and the 1x1 square tube above the fuel tank. Gets plumbed up the same as it was in the donor Vette. As mentioned in the description, the only lines attached to the radiator are the main feed and return to/from the waterpump....and then at that top RH corner where there is normally 2 hose barbs moulded into the radiator, we plug one of those off and hook up a short hose with a petcock to the other port. This is just to bleed the air out of the top of the radiator. Once you bleed it out initially and then drive the car a few times and bleed it out again, it shouldn't ever need to be messed with again.

[ohmygosuness]

Crash,

I saw a post on the LS forum about people tapping a hole into the OEM water pump, I'm not sure if that's what you did, a picture would definitely help.
I did not expect $10,000 worth of AN fittings and hoses. I know these things ain't cheap and it adds up quickly, but damn.
Speaking of the cooling system, I found a place in the front where I could possible route the radiator hose towards the sides of the car. I'm not sure if you modified your wheel well or because it's a Gen 1 GTM, I can't route it through where you have it without cutting away a big chunk of the panel by the wheel and also relocate the brake line bracket. But I found a small gap between the foot well and the lower control arm where it's just wide enough to feed a hose through. I put a 1.25" diameter silicone elbow there and turned the wheel as far left as I could, it is VERY close to touching the tires (like 0.5" away).
190850
190852

[ohmygosuness]

Shane,

This part you're selling for the surge tank, does it require me to weld it on to the chassis? I'm tempted to make my own part since I get a bunch of scrap metal from work and it's not an important piece of the car. But I know for sure 100% it won't look anywhere as good as yours.

[VRaptor SpeedWorks, LLC]

Yes, the bracket gets welded to the chassis. No....it's not difficult to make...the biggest PITA with the donor tank is that the mounting locations are recessed, so the bracket has to be shaped so that the mounting bosses fit into the recesses in the tank. Making that work with cutting out a nice custom piece on a CNC plasma table is easy......but to fab one out of scrap, I'd be tempted to just weld something like a piece of small angle iron between the tubes and make some tabs to weld onto that to sort of recreate what FFR did up front.

[crash]

An inch or a mile, as long as the tire doesn't hit you are good.

Not trying to come across as a Shane Fanboy (which I guess actually I am since I buy some GTM items from him as well) but is your time worth $25?

[ohmygosuness]

Let me know if you received the payment, Shane.

[ohmygosuness]

You're right, Crash. I'm definitely losing time and money not buying Shane's parts.

[VRaptor SpeedWorks, LLC]

Let me know if you received the payment, Shane.

Shoot me an email....

vraptor@centurylink.net

Thanks!

[crash]

Here's the water pump bleed.190885

I use an early LS1 style pump for space considerations and you can also see there how I modify the cover bolts to clear the block. I countersink and change over to countersunk screws.

[crash]

Crash,

I saw a post on the LS forum about people tapping a hole into the OEM water pump, I'm not sure if that's what you did, a picture would definitely help.
I did not expect $10,000 worth of AN fittings and hoses. I know these things ain't cheap and it adds up quickly, but damn.
Speaking of the cooling system, I found a place in the front where I could possible route the radiator hose towards the sides of the car. I'm not sure if you modified your wheel well or because it's a Gen 1 GTM, I can't route it through where you have it without cutting away a big chunk of the panel by the wheel and also relocate the brake line bracket. But I found a small gap between the foot well and the lower control arm where it's just wide enough to feed a hose through. I put a 1.25" diameter silicone elbow there and turned the wheel as far left as I could, it is VERY close to touching the tires (like 0.5" away).
190850
190852

Looking at these pictures and I have to ask, have you done an alignment on this car yet? If not, you will be moving the front lower control arms as far forward as you can in order to get as much caster as you can. This will increase the space at the rear of the tire.

[ohmygosuness]

I have not done an alignment yet. I'm happy to know the wheel won't be moving anymore backward, since there's very little room to work with already. Are you talking about adjusting the toe in? Because I don't see how I can possibly move the lower control arms anymore forward, or anywhere for that matter.

[crash]

The alignment is done by turning the eccentric bolts in the inner suspension mounting points, or using a shim kit like I sell. It actually moves the lower control arm mounting points either in or out depending upon what is needed for alignment. Because the GTM suffers from a lack of built in caster, you will be running these bolts to where the rear suspension mount is almost all the way out and the front is almost all the way in. This will effectively move the lower control arm outer ball joint forward and thus give you max caster, which will only be in the 3 degree neighborhood. The secondary effect will be to move the tire away from the rear of the fender/fender well area.

[ohmygosuness]

Hey Crash, speaking of wheel alignment. I've been wanting to ask how does the steering feel on the GTM without power steering? Do I need to go to the gym to train my arms? :)

[VRaptor SpeedWorks, LLC]

IMO, the only time that you'll probably notice the lack of power steering is at a full stop....and even then, I don't even give it a second thought.

[crash]

I used to sell power steering components for the GTM that were developed by a couple early developers of the GTM. I do not personally run that system as I feel, especially in the race car, that simpler is better, and we just do not run the car at slow speed, where it would really be needed. The other thing about power steering is that it is nice when it is working, but if there is a failure, then the car is darn near impossible to turn.

[ohmygosuness]

Got the part, Shane. It fits perfect! Looks pretty much leveled already. Don't even need much grinding.
191142

[ohmygosuness]

I got the driver side radiator pipes pretty much mocked up, just need to clamp the elbows. I decided to stick with FFR supplied corrugated hoses for now for the bends and turns. Save me some money on buying 20 silicone elbows. Also, I believe the ribs on them corrugated hoses help with heat transfer (maybe?).
191143
191144
191145

I'm not connecting the pipe to the water pump until I have the fuel tanks in the car. Still in the process of taking them off the vette.

[VRaptor SpeedWorks, LLC]

Got the part, Shane. It fits perfect! Looks pretty much leveled already. Don't even need much grinding.


Thanks! Glad it worked out for you!

[crash]

One of the issues with the corrugated line is that it makes the flow turbulent in the lines. Is this an issue? Not sure, but I chose to keep all the lines smooth in order to keep the flow as smooth as possible. I had an engine builder recommend against corrugated lines many decades ago for this reason, and I have always chosen not to use corrugated because of that.

[Ajzride]

One of the issues with the corrugated line is that it makes the flow turbulent in the lines. Is this an issue? Not sure, but I chose to keep all the lines smooth in order to keep the flow as smooth as possible. I had an engine builder recommend against corrugated lines many decades ago for this reason, and I have always chosen not to use corrugated because of that.

From a thermodynamical engineering standpoint we always want to achieve the most turbulent flow possible because it increases heat flow. I don't know why we see so many myths in automotive hobby that make no sense from a scientific standpoint.

Edit:

Here is an article on why to use corrugated heat exchanger tubes:

https://www.hrs-heatexchangers.com/us/resource/comparison-of-laminar-and-turbulent-flow/

[VRaptor SpeedWorks, LLC]

There are 2 different issues here. Yes, the corrugated lines and turbulent flow might exchange more heat.....no doubt about that.....but what happens when there is so much turbulence that it restricts the flow to the point where you no longer have enough coolant circulating to keep the engine cool? All the heat exchange in the world won't help you if your engine needs to flow (just pulling this number out of my ***) 10gal/minute to keep it cool, but the long distance to pump the coolant thru corrugated lines and turbulent flow causes your WP to only be able to flow 3gal/min.

Think about the donor 'Vette. Coolant pretty much dumps right out of the WP into the radiator and right out of the radiator into the WP.....there is no "heat exchange" between the engine and radiator. 100% of the heat exchange is in the radiator. Why should the GTM be any different? The only difference is the distance and # of elbows that the WP needs to pump the coolant thru.

[rolfer]

From what i have been reading every 90º bend is like adding 4-6 feet in lenght worth of resistance.

[crash]

From a thermodynamical engineering standpoint we always want to achieve the most turbulent flow possible because it increases heat flow. I don't know why we see so many myths in automotive hobby that make no sense from a scientific standpoint.

Edit:

Here is an article on why to use corrugated heat exchanger tubes:

https://www.hrs-heatexchangers.com/us/resource/comparison-of-laminar-and-turbulent-flow/

Yep, turbulent flow in a heat exchanger is desirable because if there wasn't turbulent flow then only the outside layer of liquid would have maximum heat transfer. There are many ways to deal with this though. Separating the water into smaller amounts does this...i.e. having a lot of very small volume tubes such as in most radiators. Turbulent flow when you are just trying to move fluid from one location to another wouldn't seem to make much sense to me.

Again, I have upped the size of the water tubes in order to try and compensate somewhat for all the bends that are added to the system, and I use 45s instead of 90s where I can. Good example is from the water pump down to the drivers side supply tube. I use two 90s and two 45s instead of four 90s. Same in water pump return area. I use two 45s and one 90 instead of three 90s.

[Ajzride]

If there are concerns about the water pump not having enough head to overcome the corrugated pipes or 90s then I understand the reasoning for wanting to eliminate them.

[ohmygosuness]

I completely agree with Crash and Shane that I should just let the radiator do its job, which is being 100% responsible for cooling. And let smooth pipes do their job, which is simply carrying the fluid.

Ajzride, I understand where you're coming from with the scientific view. Having worked in the heat-exchanging industry in the past was the reason why I mentioned ribbed lines might help. But some times when I'm talking around folks with a lot of car-building experience, I feel like throwing my degree out the window.

I did a bit of research on the corvette forum about having corrugated lines - it appears that the cons and pros are close to 50/50. Some say they had it for decades with no issue. Others wouldn't go anywhere near them. Most of their reasoning behind were more about looks and durability. There were not many reasons regarding engine cooling. One guy said he took temperature readings around the engine to see if there's a difference between corrugated hose and stock rubber hose and there were no noticeable difference.

Couple things I'd like to point out is that there will only be corrugated hose before and after radiator (where flowrate should be at the lowest). I'm using smooth lines on the sides of the car, all the way to the inlet/outlet of WP. I think the section right after WP is the most important to be smooth, because that's where flowrate should be at its highest. The corrugated section could act as a "transitional phase" going in and out of the radiator.

Either way, I do like Crash's setup with having mostly aluminum pipes. I may just have the corrugated hoses there for now as a place-holder until I possibly replace them later down the road if it causes any issues.

[crash]

I am partial to the saying that there is "nothing so permanent as temporary". Meaning you will likely never get around to changing those once they are in and working. Be careful heading down this path as those things can snow ball and at some point become over whelming.

My wife asks me why it takes me so long to finish some projects? Simple answer is that I would rather not do them than do them half way or not in the best fashion I know how to do them.

[ohmygosuness]

So, one other option I had in mind to replace the corrugated ones were silicone hoses. That's what I'm thinking of going for the WP inlet/outlet. But I do prefer that the plumbing near the radiator to be mostly metal, since it's at a location of high airflow, it would allow heat to be transfered as much as possible.

[ohmygosuness]

After making some measurements and brainstorming, I'm going to switch corrugated hose to aluminum pipes. It just seems like the better way to go. I thought I'd have to get a ton of elbows, but it's actually not too bad. I only need 2 more 45 degrees to complete the driver side. Maybe a couple of 90 degrees on passengers side.

[ohmygosuness]

I've been working on passenger side aluminum panels to check if there's enough room between the foot well and lower control arm to route the radiator pipe. I can't help but notice gaps between aluminum panels and I'd like the car to be as waterproof as possible. The FFR manual suggests using caulk between panel and frames. What about 1-2mm gaps between panel and panel? Feels like caulking won't be enough. It makes me want to get an aluminum welder.

[crash]

Caulking will be enough. I use a very tough product called M-1 sealant.

https://www.amazon.com/Chemlink-M-1-Structural-Adhesive-Cartridge/dp/B071V67V4B/ref=sr_1_1?crid=Z5VB4KU5F0ZL&keywords=m1+sealant+chemlink&qid=1698684382&sprefix=m1+seal%2Caps%2C171&sr=8-1

[VRaptor SpeedWorks, LLC]

Yes, good caulk will fill the voids and be fine. You can back one side up with something like foil tape and then fill the gap from the other side. Since you have to stick carpet/vinyl to the inside....and carpet and vinyl don't like to stick to silicone caulk, keep the beads small so that it doesn't get smeared all over.

[ohmygosuness]

Quite a bit of physical labor.
191796

191797

191798

Will be making splash guards next for the pipes close to the wheels.

[VRaptor SpeedWorks, LLC]

Nice work! My only concern is with the top radiator inlet. If that elbow sticks up above the aluminum panel, the hood will hit it. Looks like you might need to trim that elbow down quite a bit to get enough clearance for the hood to close.

[ohmygosuness]

Hi Shane. Yes, that was one of my concerns too, actually. I haven't rivet the radiator in place yet. I thought about cutting the current radiator bracket and weld a new one so it can be mounted lower.

[crash]

You can see how short the inlet elbow is on the previous pictures I posted on my setup. I believe you will definitely need to cut that down significantly.

Also, unless you are changing the sheet aluminum significantly, it appears you are actually running the water lines into the cabin foot well area, and then back out to the frame rails? Kind of defeats the purpose of running the lines outside the cockpit to keep temps lower for the driver and passenger by doing this. Might want to mock up all the sheet metal and make sure you are doing exactly what you want at this stage. Also this may have space issues around the pedals. Not what I would recommend.

[ohmygosuness]

You can see how short the inlet elbow is on the previous pictures I posted on my setup. I believe you will definitely need to cut that down significantly.

Also, unless you are changing the sheet aluminum significantly, it appears you are actually running the water lines into the cabin foot well area, and then back out to the frame rails? Kind of defeats the purpose of running the lines outside the cockpit to keep temps lower for the driver and passenger by doing this. Might want to mock up all the sheet metal and make sure you are doing exactly what you want at this stage. Also this may have space issues around the pedals. Not what I would recommend.

Just FYI, the pipes do not enter the cabin. It fits into a very tight gap (no more than 1.5" diameter) right beneath the end of the foot well area and right before the lower control arms. No aluminum panels were modified or cut. Everything is outside the cabin. I posted a pic of that area a few posts above. I'll see if I can post a better pic when I get home.

The driver sider port on this radiator isn't perpendicular to the surface, it points directly upward. I had to find a 135 degree elbow to direct it downward instead of a 90 degree. I tried using a 90 degree and it created a kink. I'll see what I can do to lower the radiator.

[crash]

Just looking at picture 3 and all I can say is that it appears you are running a different radiator and fan setup than what has been historically run on the FFR PDG GTM. Until the change that I mentioned here recently we ran a C5 setup and the radiator and fan configuration looked significantly different from what you have there. Two fans and the vents and inlet/outlet on the radiator looked quite a bit different as well. Is that C6? or something else?

Thinking if you are able to rotate that radiator 180 degrees it might help your situation considerably? The outlet would then already have some directional change towards the direction you want, and the inlet being down from the top of the radiator tank would help the hood clearance issue it appears as well.

[ohmygosuness]

Just looking at picture 3 and all I can say is that it appears you are running a different radiator and fan setup than what has been historically run on the FFR PDG GTM. Until the change that I mentioned here recently we ran a C5 setup and the radiator and fan configuration looked significantly different from what you have there. Two fans and the vents and inlet/outlet on the radiator looked quite a bit different as well. Is that C6? or something else?

Thinking if you are able to rotate that radiator 180 degrees it might help your situation considerably? The outlet would then already have some directional change towards the direction you want, and the inlet being down from the top of the radiator tank would help the hood clearance issue it appears as well.

Yes, this came from a C6 Vette. I wanted to keep the radiator since it worked for this engine.
Interesting that you mentioned rotating the radiator. I thought about that too. Only problem would be the port will be pointing downward, I'll see if that works when I get home.

[beeman]

I don't know how you are going to get the air pocket out of this tubing arch, it is the highest point in your front system. You may need to replace that coupler with an aluminum elbow and a 1/8npt bleeder.

191804

[ohmygosuness]

Hi Beeman. You might be right. But if we're including the surge tank as part of the system, after relocating the tank to engine bay, the bottom of the tank is about 0.5" higher than that elbow. But, I'll still need to find a way to mount this elbow lower, somehow.

[ohmygosuness]

Correction: after looking at it again, turning the radiator 180 degrees would cause the port to face directly towards the passenger and it's right up against a frame rail. This way would work, only if I move the radiator forward a little, which may still (or may not?) cause some interference with the hood.

[ohmygosuness]

Here's a couple more pics to help clarify the foot well situation

191810

191811

[crash]

Here's a couple more pics to help clarify the foot well situation

191810

191811

That is interesting. Very different setup than what is on the FFR PDG GTM. Granted my GTM is very early, number 29 I believe, and the kit sheet metal may have been different at that point, or a previous owner may have changed things, but I don't believe I could run the water lines the way you have them there. Looks good the way you have it though.

Beeman, every GTM built has this hump in the radiator inlet line. It does not seem to be an issue. Again, I will also add that IMHO having a small amount of air in the system at the radiator is a minor issue. Only thing it will do is reduce the cooling ability of the radiator slightly. Not like having an air bubble where the heat is being generated, which can lead to engine failure.

[beeman]

Hi Beeman. You might be right. But if we're including the surge tank as part of the system, after relocating the tank to engine bay, the bottom of the tank is about 0.5" higher than that elbow. But, I'll still need to find a way to mount this elbow lower, somehow.

The surge tank is only going to collect air that can find its way to it, there's going to be air trapped at the upper elbow, don't know if it will be enough to screw up your cooling though. Ideally the whole system is free of any air.

[ohmygosuness]

The surge tank is only going to collect air that can find its way to it, there's going to be air trapped at the upper elbow, don't know if it will be enough to screw up your cooling though. Ideally the whole system is free of any air.
I'll keep that in mind. Might look into crash's idea of flipping the radiator 180 degree. My question is - Does it matter which side of the radiator (passenger/driver) connects to the inlet/outlet of the WP?

[ohmygosuness]

So I rotated the radiator, seems like it could work. Just need to rotate the radiator shroud, otherwise I'll have to trim it. I may need to elevate the radiator mounts a bit since that elbow is right up against the bracket.

Only thing I see is that the vent tube now becomes the drain. And the drain may become the air vent.
191832

191833

[crash]

You generally want to put the hot coolant to the top of the radiator and the chilled coolant coming out the bottom. I think the new arrangement still qualifies. The only other thing might be hose diameters? Looks like they may be equal in your case?

[ohmygosuness]

You generally want to put the hot coolant to the top of the radiator and the chilled coolant coming out the bottom. I think the new arrangement still qualifies. The only other thing might be hose diameters? Looks like they may be equal in your case?

Just out of curiosity, why is that better? Is it because hot air rises and cold air drops?
With the setup I have now, the driver side port was going into the thermostat. If it's better for chilled water to coming out the bottom of the radiator, then rotating the radiator definitely helps.
Yes, both side fits a 1.25" ID coupler.

[crash]

I believe it is along the same idea but has to do with the temperature of the coolant. The hotter coolant would naturally rise and the cooler coolant would naturally fall. Thus, this would ensure that the cooled coolant is what is drawn back into the engine.

On my GTM the driver's side line is the out of engine hot line and the line that is on the thermostat side is the cool line from the radiator. Remember, the LS engine runs a "reverse" cooling system.

[ohmygosuness]

I noticed this radiator has a built-in trans fluid cooler. Now, is this going to be needed for the mendeola trans? Or should I plug them up and not use them.

191853

[Shoeless]

The advice I got was if you are going to track the car, best to have trans fluid cooling as well.

I'll have both engine oil and trans oil cooling on mine, but do not have the trans oil cooler in the radiator. That's just one more thing to run from the back of the car to the front.

[ohmygosuness]

The advice I got was if you are going to track the car, best to have trans fluid cooling as well.

I'll have both engine oil and trans oil cooling on mine, but do not have the trans oil cooler in the radiator. That's just one more thing to run from the back of the car to the front.

Hi Shoeless. That's a good point about running less things from the back to the front. Where is yours mounted? do you need to run another fan?

I saw the go-cart pics you posted. Looks really nice. Makes me want to work on the car even more!

[crash]

Not to open another unintended project tangent for you, but I run a heat exchanger in the water line coming out of the engine for the transaxle cooling. It is a 13 plate C&R product. This puts the transaxle heat into the water to be dissipated by the radiator, yet does not require running any more lines up to the front of the car. This is one of the reasons I upped the radiator capacity by 65% over the stock C5 radiator. This also reduces complexity in the rear of the car because it gets rid of a radiator and all of the associated ducting. Every little thing you can do to get heat out of the rear of this car and save space in the back is important. It is not a cheap alternative to a radiator in the rear, but it solves a lot of problems.

[ohmygosuness]

Not to open another unintended project tangent for you, but I run a heat exchanger in the water line coming out of the engine for the transaxle cooling. It is a 13 plate C&R product. This puts the transaxle heat into the water to be dissipated by the radiator, yet does not require running any more lines up to the front of the car. This is one of the reasons I upped the radiator capacity by 65% over the stock C5 radiator. This also reduces complexity in the rear of the car because it gets rid of a radiator and all of the associated ducting. Every little thing you can do to get heat out of the rear of this car and save space in the back is important. It is not a cheap alternative to a radiator in the rear, but it solves a lot of problems.

When I bought the GTM kit, I was prepared for a ton of "unintended" projects to come my way!
From what you just told me, I'm leaning towards using this trans cooler in the radiator. Since it's built-in, I would assume GM already included extra capacity in this radiator for cooling to account for the heat from the trans and a bigger engine on the C6 over the C5. Only thing is I believe the trans cooler is on the cold side of the radiator. And since I'm flipping the radiator 180° - unfortunately, the stock lower port becomes the upper port (which is going to be the chilled side). I hope this doesn't make a big difference in cooling.

When you said you run it in the water coming out the engine, doesn't the engine run hotter than the trans, thus, potentially heating it up?

[Shoeless]

Hi Shoeless. That's a good point about running less things from the back to the front. Where is yours mounted? do you need to run another fan?

I saw the go-cart pics you posted. Looks really nice. Makes me want to work on the car even more!

I'm using Shane's solution for mounting a couple Setrab coolers on the rear diffuser of the car. One for engine and the other for trans. I'll have about every scoop or heat abatement option that Shane has so I'll have a lot of cool air coming in and pulling heat out. Only downside is these coolers are on the diffuser and will take warm air and pull it out, so hopefully I'll manage to bring in more cool air and get hot out and it will function as intended.

If I had it to do all over again. I'd go with a full MoTeC PDM setup versus the Infinity Box setup and run a couple fans and the pump controlled by that. But that will get very expensive for you very quickly.

Glad you like the go-cart pics, this thing is so damn fun to drive!!!!!

[crash]

When I bought the GTM kit, I was prepared for a ton of "unintended" projects to come my way!
From what you just told me, I'm leaning towards using this trans cooler in the radiator. Since it's built-in, I would assume GM already included extra capacity in this radiator for cooling to account for the heat from the trans and a bigger engine on the C6 over the C5. Only thing is I believe the trans cooler is on the cold side of the radiator. And since I'm flipping the radiator 180° - unfortunately, the stock lower port becomes the upper port (which is going to be the chilled side). I hope this doesn't make a big difference in cooling.

When you said you run it in the water coming out the engine, doesn't the engine run hotter than the trans, thus, potentially heating it up?

Yes. Thermostat is a 190 and engine coolant from radiator and into engine block runs at around 190-206. I see about 225-250 or so on the trans because the exchanger is on the hot side of the engine cooling. This is fine as the transaxle used to run 275 or so without the heat exchanger and using the rear trans cooler/radiator. Mendeola recommends about 225 or so for transaxle temp so this gets us right in the ball park and much cooler than it used to run. It actually also helps warm up the transaxle as well, as when the engine coolant warms up the transaxle also sees this heat from the engine without the car moving. Not really much of an issue on a street car, but useful for a race car where we might get only one lap to get everything up to operating temperature. I run the transaxle pump whenever the ignition is on.

Unfortunately we have gotten to the point where the start up process for this race car is about an hour long thing that has to be done in the paddock before the car even moves.

[ohmygosuness]

Yes. Thermostat is a 190 and engine coolant from radiator and into engine block runs at around 190-206. I see about 225-250 or so on the trans because the exchanger is on the hot side of the engine cooling. This is fine as the transaxle used to run 275 or so without the heat exchanger and using the rear trans cooler/radiator. Mendeola recommends about 225 or so for transaxle temp so this gets us right in the ball park and much cooler than it used to run. It actually also helps warm up the transaxle as well, as when the engine coolant warms up the transaxle also sees this heat from the engine without the car moving. Not really much of an issue on a street car, but useful for a race car where we might get only one lap to get everything up to operating temperature. I run the transaxle pump whenever the ignition is on.

Unfortunately we have gotten to the point where the start up process for this race car is about an hour long thing that has to be done in the paddock before the car even moves.

If you suggest that the hot side is fine, then I'll keep it on the hot side. I have no idea how hot this trans runs.

[crash]

My thinking on this was that I wanted the transaxle heat to be in the system before it saw the radiator so that the more efficient radiator could do its job with the extra heat. If you put it on the cold side of the radiator, then there is no way to remove that extra heat until after it has gone through the engine. Probably would be fine as the thermostat would do its job as long as the coolant going to it was cool enough, but I had to choose one side or the other so I chose the hot side knowing that this transaxle had seen much hotter temperatures previously than it has seen with this setup. It was kinda a "try it and see" thing though to see how hot the transaxle would get. All seems good so far.

[ohmygosuness]

My thinking on this was that I wanted the transaxle heat to be in the system before it saw the radiator so that the more efficient radiator could do its job with the extra heat. If you put it on the cold side of the radiator, then there is no way to remove that extra heat until after it has gone through the engine. Probably would be fine as the thermostat would do its job as long as the coolant going to it was cool enough, but I had to choose one side or the other so I chose the hot side knowing that this transaxle had seen much hotter temperatures previously than it has seen with this setup. It was kinda a "try it and see" thing though to see how hot the transaxle would get. All seems good so far.

That's good enough for me. I believe you're running an LS3? That's slightly bigger than my LS2. If your trans runs cooler, I don't see why mine would run hotter. And mine would mostly be for the street.

[ohmygosuness]

192011

192012

[crash]

Just something to think about...my shields are open on the bottom so that debris cannot be caught in them. Might not be an issue for you, but we run long races and the potential for rocks that are kicked up from the tires to lodge in with the water lines did not seem like a good idea to me, so I designed mine attaching from the top and open on the bottom.

[ohmygosuness]

I showed this to a coworker and he said the same thing about opening the bottom. That's not a problem since it's just a mock up right now.. I can definitepy close the top and open the bottom.

By the way crash, do you run an oil pump for the trans cooler?

[crash]

Yes to the pump. The big one that Tilton offers...

Tilton part number TIL-40-527

[doug_porsche]

Yes to the pump. The big one that Tilton offers...

Tilton part number TIL-40-527

I have read, but don't know so I am asking, that running the trans cooler pump all the time is actually good for lubricating some of the gear sets that get a bit lube neglected in a flipped trans. (Street car, not track car)
Is this good information or just "someone on the internet saying"?

[crash]

I guess you could say that I am just some guy on the internet, but here are the reasons I run it 100% of the time.

1) It lubes the areas of the transaxle that need to be lubed. I have a line run to the R&P and another run to the gear stack.
2) Running it all the time means that we never forget to have the lube circulating once things get busy and we hit the track surface.
3) I don't use a temperature sensor to turn on the pump because that sensor is just another potential failure point to what I consider a critical system.
4) As I was explaining earlier, because I run a heat exchanger from the trans fluid to the engine coolant, the opposite is also true. As the engine coolant warms up rapidly, because of the heat exchanger, this causes the trans to also be warmed up along with the engine...without the car even moving while we are warming it up under the tent.

I do have a shut off switch so that when we are doing things on the car like data downloads, computer adjustments, or anything else that requires the ignition to be on but the car to not actually be on the track, we don't have to listen to the pump running.

I would guess that lube distribution would be just as important or maybe more so on an inverted trans since it wasn't designed to run that way. The Tilton pumps can easily handle the lower viscosity of cold fluid without damage so I really do not see any draw backs to running it all the time, especially if you use this particular pump. If you run a radiator and a cooling fan, then I would put the fan on a temp sensor, but not the pump. There will be some pump noise, but most GTMs will drown that out with engine noise as soon as started.

Just a heads up, these pumps claim to be self priming, but in my experience they are not. Mine is mounted with the pump part of the unit BELOW the transaxle and the scavenge line a direct shot to the pump and down hill, but I still have to crack lines to get it to prime the first time after trans/pump install. Prime it and be sure fluid is flowing.

[ohmygosuness]

I'll take a better look at how I can put together the trans cooler once my Mendeola arrives. Although, I don't know when that will be. It's been 2 years and 4 months since I ordered it.

[ohmygosuness]

I may (or may not?) need to trim the top of the fan shroud.

192154

192155

Do you guys tie these pipes down to the frame or just leave them hanging?

[crash]

They are tied down with Adel Clamps.

[ohmygosuness]

Since the radiator is flipped 180°, I have the radiator vent capped off. On the FFR manual, it said the vent tube from the cylinder head was suppose to be connected to the radiator vent. But now, can I just connect the vent tube from the cylinder head directly to the surge tank?

[VRaptor SpeedWorks, LLC]

Yes....with the reservoir mounted in the engine bay, you route the steam vent directly to the reservoir tank. With the radiator flipped, you can now use the petcock to vent all of the air out of the top of the radiator. After the first couple times you drive it, park with the front of the car downhill a bit and let it cool off and then pull the cap off of the reservoir so that the system isn't under pressure or vacuum and then open the petcock a bit to let out any air. Once you do this a couple times, you should be good to go and air really shouldn't ever be able to get into the radiator again.

[ohmygosuness]

Yes....with the reservoir mounted in the engine bay, you route the steam vent directly to the reservoir tank. With the radiator flipped, you can now use the petcock to vent all of the air out of the top of the radiator. After the first couple times you drive it, park with the front of the car downhill a bit and let it cool off and then pull the cap off of the reservoir so that the system isn't under pressure or vacuum and then open the petcock a bit to let out any air. Once you do this a couple times, you should be good to go and air really shouldn't ever be able to get into the radiator again.

Being able to start the car still feels like a dream!
Since the radiator is flipped, the vent tube is at the bottom now. I think the only place I can vent out the air is using the radiator drain plug, since it's now on top.

[beeman]

I don't recall, was there a reason you didn't use the C5 radiator?

[ohmygosuness]

I don't recall, was there a reason you didn't use the C5 radiator?

My donor is a C6. Will try to reuse as many parts from it as I can. Also, I'd prefer to use a radiator that already works with the engine from the C6.

[beeman]

C5 radiators are plentiful and cheap, might prevent some future trapped-air headaches etc. My Lingenfelter C5 ran a stock radiator with 490 NA HP LS1, ran cool.

[Shoeless]

Being able to start the car still feels like a dream!

I’ll be brutally honest here and you’ll understand once you get to that dream day of firing it up for the first time. Between now and then you will have many sleepless nights, frustrations, and challenges, but that first time you fire it up and then drive it, is TOTALY worth it. Just take it one or two steps at a time and you’ll get there :cool:!!!

[crash]

I don't know. It looks like to me this C6 radiator setup could be superior to the C5. It has the driver's side hose coming in not at the front end of the tank so interference with the hood is reduced, and the drain becoming an air bleed actually seems like a plus over the C5 arrangement. I really don't see any down sides to using this radiator.

[ohmygosuness]

C5 radiators are plentiful and cheap, might prevent some future trapped-air headaches etc. My Lingenfelter C5 ran a stock radiator with 490 NA HP LS1, ran cool.

I don't know the main difference between the C5 and C6 radiator other than the built-in trans cooler in C6 radiator. The LS2 from the C6 is 6.0 L vs LS1 being 5.7 L. I'm going to assume the C6 radiator is (maybe?) slightly larger to accommodate for the engine size. But 0.3 L may have no noticeable difference at all. If I keep running into unsolvable fitment issues, I may consider the C5 or look into Crash's radiator.

[crash]

Just a heads up on the radiator I used...it is simply a 19" X 31" GM truck radiator. The only issue with using it is that I had to weld a plate onto the radiator cap filler neck to delete the cap. If you can weld aluminum, then this isn't an issue, but if you have to take it to someone then TIG welding this block off plate on could get a bit expensive.

If I was building a street GTM I think I would stick with the C5-C6 stock radiator, and after this thread I would probably lean towards the C6 variant.

[ohmygosuness]

I forgot to mention I did not flip the fan shroud. I had to make 3 new mounting brackets on the radiator to keep the shroud at the same location, otherwise it would interfere with the hood. Not an unsolvable fitment issue, but still required some work. That just reminded me, I also need to make new mounting points for the AC coil too.

[beeman]

Trans cooler was standard on the C5 automatic transmission radiator, you probably have an auto trans c6 rad.
Crash, did you mean to say lean towards the C5 variant?

[ohmygosuness]

That I did not know. Yes, I got an automatic C6.

[ohmygosuness]

Welded on the surge tank bracket. A little embarrassed about my welding skills. But with a little clean up, I'd give it a solid 5/10.
I like the bracket. Fits perfect! Only trimmed the edges very slightly. Thanks again, Shane!
192452

192453

[beeman]

I've seen much worse welds. Besides, it's not structural so no worries about penetration, etc.
Are you using a flux core MIG?

[ohmygosuness]

I've seen much worse welds. Besides, it's not structural so no worries about penetration, etc.
Are you using a flux core MIG?

Thanks. I would definitely think twice about doing it myself if it was structural. Yes, it is a flux core MIG with 0.035" wire. I'm not too experienced with welding, so, I'm not sure if it's me or the welder but I get a lot of spatter...

[beeman]

Flux core gives some splatter, and is less forgiving to any impurities on the metal surface. I'd remove a little more of the mill scale with a flap disc so it's not so close to the weld, then wipe the surfaces with acetone before welding. Remember acetone is flammable so let it dry and keep the rag and container far away from where you are welding.

[ohmygosuness]

Flux core gives some splatter, and is less forgiving to any impurities on the metal surface. I'd remove a little more of the mill scale with a flap disc so it's not so close to the weld, then wipe the surfaces with acetone before welding. Remember acetone is flammable so let it dry and keep the rag and container far away from where you are welding.

Good advice. I definitely should have spent more time preparing the surface before welding.

[VRaptor SpeedWorks, LLC]

Glad it worked out! Yeah, it's pretty tough to get nice looking welds from flux-core. Looks like it's not going anywhere!

[beeman]

Previously looked at the pics on my phone, thought it was mill scale, but it's powdercoat that is next to those welds. You really have to take all of that off, a good inch or more back from the weld, down to shiny metal. It's nasty stuff, it smokes, catches fire, toxic fumes, and will get into the weld pretty easy.

[crash]

Previously looked at the pics on my phone, thought it was mill scale, but it's powdercoat that is next to those welds. You really have to take all of that off, a good inch or more back from the weld, down to shiny metal. It's nasty stuff, it smokes, catches fire, toxic fumes, and will get into the weld pretty easy.

Also because of the heating process of powder coat the material can get down into the pores of the metal. It is for this reason that I DO NOT powder coat frames on a race car. I have found that no matter how much you clean the metal surface the PC can still contaminate the welds. Pont is, don't beat yourself up. Welding on previously powder coated metal usually has issues, at least for me, no matter how much I clean it.

[ohmygosuness]

Previously looked at the pics on my phone, thought it was mill scale, but it's powdercoat that is next to those welds. You really have to take all of that off, a good inch or more back from the weld, down to shiny metal. It's nasty stuff, it smokes, catches fire, toxic fumes, and will get into the weld pretty easy.

You're right about it catching on fire! Good thing I always have a fire extinguisher nearby.

[ohmygosuness]

Been fighting the donor to reuse some parts. Cut a hole on the side of the vette tunnel to pull the parking brake out. The FF manual didn't mention where to mount this bracket. What's a good location to mount it? Do the cables need to be adjusted or is it good to go from the donor?
192502

[Shoeless]

For some reason your pic attachment isn't coming through. There should be a bracket or place on the passenger side of the tunnel to mount the e-brake, that should be in the manual.

As for cables, I had a whole new set made by California Push Pull so I can't comment on the donor ones, let along C6 donor cables. You may find it easier to just measure where you want them and have new ones made. They came out perfectly for me. I made one small single cable (maybe 8-9") that went from the handle to the distro bock, then measured the left and right cables where I wanted them to run under the motor and back to the brakes.

[VRaptor SpeedWorks, LLC]

The donor brake cables are really too short to use as-is. The only way I've found to use them are to route the cables and that "splitter box" underneath the oil pan on the engine....which means that the first speed bump you roll over, will probably tear them off since they will be the lowest part of the car. That's why I created the e-brake kits on my website. The combination of brackets and "extender links" lengthen the stock cables enough to be usable and mounts them up out of the way instead of under the oil pan.

https://vraptorspeedworks.com/e-brake-bracket-kit/

https://vraptorspeedworks.com/emergency-brake-mounting-kit-batwing-oil-pan/

https://vraptorspeedworks.com/emergency-brake-mounting-kit-mendeola-crate-oil-pan/

As Shoeless mentioned, the other option is to order new custom cables. I've also done this in the past (before I developed my own solution).

[Shoeless]

Shane definitely has elegant options available based on the configuration.

[ohmygosuness]

Not sure why the pic didn't show. It's the bracket that connects the 1 wire to 2. Shane's part is very appealing, indeed.
192517

[Shoeless]

That looks to be exactly the same as the C5.

[VRaptor SpeedWorks, LLC]

Hmm....pretty sure I've been here before. If memory serves, the "splitter" link that is swaged to the end of the single cable on the C6 is different than the C5 and the swaged ends of the 2 brake cables that interface with that are a bit different? The cables come in from the sides of that link instead of both on one side like the C5? For my kit to work, I think I just ended up putting the "extender links" of my kit in a vice and twisting the ends 90 degrees to make them fit into the C6 link?

[ohmygosuness]

Hmm....pretty sure I've been here before. If memory serves, the "splitter" link that is swaged to the end of the single cable on the C6 is different than the C5 and the swaged ends of the 2 brake cables that interface with that are a bit different? The cables come in from the sides of that link instead of both on one side like the C5? For my kit to work, I think I just ended up putting the "extender links" of my kit in a vice and twisting the ends 90 degrees to make them fit into the C6 link?

Yes, the 2 cables comes in from the sides of that small tab to connect to the 1 cable.
Last night, I roughly put everything in place where they generally should be. The linking bracket ended up hanging around the side of the engine between the starter and the motor mount. It does seem like the wire going to the driver side rear wheel is a bit short. I wonder if I just drill a couple holes in the current linking bracket and mount it on the side of the engine, will that be enough? Although, I am a little concerned with the current length of the cables. I'll take some pics when I get home.

[VRaptor SpeedWorks, LLC]

In my experience, if you try to stick with the donor "splitter box".....if you use the longest brake cable on the RH side of the car (assuming you're thinking of mounting the splitter box to the RH side of the engine), you can make that work, but then the LH cable is way too short and is kinked over hard at the wheel hub. If you try to use the long cable for the LH side, it's still kinked over at the hub, but not stretched tight.

[ohmygosuness]

This is the location of that splitter box right now. It's currently facing down, just hanging by the starter.
192597

I mounted the lever slightly lower than recommended so the cable can reach slightly further back. The one solo mounting hole (on the bottom of the lever) did not fit anyway. In the end, I'll still have to make modifications to the stock mounting points.
192594

Shane, you were right about the cable going the opposite side of the engine being a bit short. With the lever mounted slightly lower, the kink is much less. Fun fact, apparently both LH/RH cables from the C6 donor are the same length.
192595


Here is a top view.
192596

[Ajzride]

Another way to skin the cat of e-brake is to go electric. Quite a few cars these days have them so you can find electric calipers on eBay or in a junk yard. Pololu makes a shield for Arduino that controls them. I put a Tesla e-brake on my mustang and VW on my 818. Eliminates all the cables and the handle. You can even interface the Arduino to the ECU to pick up engine speed so you can can control how fast the electric brake locks up allowing it to still function as an eBrake and not just a parking brake.

[ohmygosuness]

Another way to skin the cat of e-brake is to go electric. Quite a few cars these days have them so you can find electric calipers on eBay or in a junk yard. Pololu makes a shield for Arduino that controls them. I put a Tesla e-brake on my mustang and VW on my 818. Eliminates all the cables and the handle. You can even interface the Arduino to the ECU to pick up engine speed so you can can control how fast the electric brake locks up allowing it to still function as an eBrake and not just a parking brake.

That's an interesting idea! I definitely thought about incorporating some gadgets in the build with Arduino, just don't know where yet. It would definitely be a fun project.


Will there be any reliability issues, though? And I hear it can be quite costly to repair if something breaks.
I also like the feel of manual brake. Maybe even use it in drifting :)

[Ajzride]

That's an interesting idea! I definitely thought about incorporating some gadgets in the build with Arduino, just don't know where yet. It would definitely be a fun project.


Will there be any reliability issues, though? And I hear it can be quite costly to repair if something breaks.
I also like the feel of manual brake. Maybe even use it in drifting :)

Obviously neither a 65 mustang or FFR 818 are daily drivers, but I've had never had any issues with them locking and unlocking when I hit the switch going on 5 years now.

[beeman]

I didn't care for the struggle to make the Corvette E-brakes work either

https://thefactoryfiveforum.com/showthread.php?23183-Making-progress-on-my-build&p=342963&viewfull=1#post342963

[ohmygosuness]

I didn't care for the struggle to make the Corvette E-brakes work either

https://thefactoryfiveforum.com/showthread.php?23183-Making-progress-on-my-build&p=342963&viewfull=1#post342963

Nice! That e brake lever looks a lot cleaner than the Corvette's.
I wish I have my trans delivered already, so I have an idea what that area looks like.
Where do you have the splitter bracket mounted?

[beeman]

Nice! That e brake lever looks a lot cleaner than the Corvette's.
I wish I have my trans delivered already, so I have an idea what that area looks like.
Where do you have the splitter bracket mounted?

It's in the tunnel right where it comes off the E-brake, splitter is part of the kit.

[ohmygosuness]

So, I've been reading the section in the manual where it talks about getting into wiring. It said to "prepare donor harness." Now, am I reusing the harness from the donor for both the engine and the dash or just the engine?

[VRaptor SpeedWorks, LLC]

There's a whole section at the end of the donor tear down section of the manual that goes into how to prep the donor parts and wiring harnesses. If you're using the donor engine and harness and ECU, then you'll need to follow the manual on how to hook all of that stuff up. If you were using a crate engine and crate harness/ecu, then pretty much everything changes and you won't be able to follow the GTM manual for much of the wiring besides the lights (headlights/tail/turn/brake, etc) and gauges. The majority of the rest of the wiring is going to be determined by the crate engine harness.

[ohmygosuness]

There's a whole section at the end of the donor tear down section of the manual that goes into how to prep the donor parts and wiring harnesses. If you're using the donor engine and harness and ECU, then you'll need to follow the manual on how to hook all of that stuff up. If you were using a crate engine and crate harness/ecu, then pretty much everything changes and you won't be able to follow the GTM manual for much of the wiring besides the lights (headlights/tail/turn/brake, etc) and gauges. The majority of the rest of the wiring is going to be determined by the crate engine harness.

Yea, I'll be using the donor harness, engine, and ECU. Probably won't be getting anything aftermarket unless absolutely necessary.

[Ajzride]

I elected to cut my OEM harness down to just ECU and engine, and buy a dedicated harness for the chassis (lights, fans, windows, radio, etc). Kind of depends on what your plans for the car are. If you want a dedicated chassis harness I love my Coach-1.

https://coachcontrols.com/index.php?main_page=product_info&cPath=36&products_id=123

[ohmygosuness]

I elected to cut my OEM harness down to just ECU and engine, and buy a dedicated harness for the chassis (lights, fans, windows, radio, etc). Kind of depends on what your plans for the car are. If you want a dedicated chassis harness I love my Coach-1.

https://coachcontrols.com/index.php?main_page=product_info&cPath=36&products_id=123

I suppose my question is, what's the advantage of going for an after market harness as opposed to just reuse the harness from donor? Other than to include buttons/gadgets outside of the stock donor.

[Ajzride]

Way less wiring, much simpler to troubleshoot, more flexibility in how you route and place things.

[beeman]

Do you have the wiring diagram for your Corvette harness, and do you understand it?

C6, right ? You basically need to get rid of all non-essentials. You can also add in new circuits after the fact . You should be able to run your gauges off your C6 harness.

[VRaptor SpeedWorks, LLC]

I suppose my question is, what's the advantage of going for an after market harness as opposed to just reuse the harness from donor? Other than to include buttons/gadgets outside of the stock donor.

I would say the main advantage is complexity. On the donor harness....especially since you're using a C6 harness(?).....I'm guessing that the GTM manual might not be of much use, and if you're not good with reading wiring diagrams, it might be quite a challenge figuring out what needs to be hooked up and what to hook it up to. Some of the wires out of the engine harness run to the ECU, some to the main fuse block, some to some misc connectors that connected up to the transmission or fuel tanks or emissions stuff, etc.

On a crate engine harness or custom harness, generally, you're just going to have a dozen or so wires that come off the engine harness to hook up and they will be labeled as to what they need to hook to.....ignition power, battery +, fuel pump, cooling fans, tach, etc, etc. As Ajzride said, much easier to hook up and diagnose.

[ohmygosuness]

Between getting a new job, having to commute 60 miles each way for work on weekdays, chasing women on weekends, and now trying to find/move into a new house. Life has been kicking my ***. Feel like I've been neglecting this project. Trying to work on it again. Definitely will have more free time after moving closer to work.


I would say the main advantage is complexity. On the donor harness....especially since you're using a C6 harness(?).....I'm guessing that the GTM manual might not be of much use, and if you're not good with reading wiring diagrams, it might be quite a challenge figuring out what needs to be hooked up and what to hook it up to. Some of the wires out of the engine harness run to the ECU, some to the main fuse block, some to some misc connectors that connected up to the transmission or fuel tanks or emissions stuff, etc.

On a crate engine harness or custom harness, generally, you're just going to have a dozen or so wires that come off the engine harness to hook up and they will be labeled as to what they need to hook to.....ignition power, battery +, fuel pump, cooling fans, tach, etc, etc. As Ajzride said, much easier to hook up and diagnose.

I've decided on getting an aftermarket harness to make my life easier. Is there a brand that you recommend?
Also, from research, it appears that OEM ECU may be the way to go over aftermarket ECU's (?).

[Ajzride]

I can highly recommend a Coach One for the chassis (non-engine) harness:

https://coachcontrols.com/index.php?main_page=product_info&cPath=36&products_id=123

https://thefactoryfiveforum.com/showthread.php?32777-Coach-1-Wiring-Harness


I've done 3 cars with American Autowire products and thought the Coach was in a different league.

[ohmygosuness]

I can highly recommend a Coach One for the chassis (non-engine) harness:

https://coachcontrols.com/index.php?main_page=product_info&cPath=36&products_id=123

https://thefactoryfiveforum.com/showthread.php?32777-Coach-1-Wiring-Harness


I've done 3 cars with American Autowire products and thought the Coach was in a different league.

And it's reasonably priced! I'll definitely look into it. Thanks.

[VRaptor SpeedWorks, LLC]

I've decided on getting an aftermarket harness to make my life easier. Is there a brand that you recommend?
Also, from research, it appears that OEM ECU may be the way to go over aftermarket ECU's (?).

It's been a few years since I've installed a new engine harness....so not sure if anything has changed or improved in the past couple years....but here are some things that pop to my head....

1. Using the donor C5 ECU had the huge advantages of being able to control the cooling fans and AC compressor thru the ECU....which means that the ECU would automatically control the cooling fans when you kick the AC on and also compensate the idle control with the AC on and also control the AC compressor. The over-rev and WOT features in the ECU also work so that you don't over-rev and explode your AC compressor and also cut the AC compressor off under WOT.

2. Since you're using a C6 donor, you won't be able to use the C5 ECU....and last I checked, the C6 crate engine ECUs did not have the capability of incorporating the AC control.....so no idle compensation, no AC compressor control and no cooling fan control for AC use. Without that control, a lot of times, with the AC engaged, when you push in the clutch and come to a stop, the engine will die because it can't compensate for the load of the AC compressor.....and you have to figure out a work-around to control the cooling fans. Also need to figure out a work-around so you don't red-line your compressor and explode it. I think the C5 ECU cut the compressor off at around 4700 rpm.

3. I've installed quite a few of the GMPP crate engine harnesses with the later ECU's and they're generally pretty easy to work with and have the inputs/output wires labeled so you know what needs to be hooked up. As long as you have the MAF sensor installed per the instructions, they will generally start right up and run fairly well as-is. Might take several starts and time to learn idle, but eventually they do. The downside of these (like most) is that they're set up to have the main harness bundle come off the rear of the engine.....which means you'd have the harness from the engine to the ECU going right over the hottest part of the car near the exhaust at the back corner of the head. You can strip them down a bit and re-wire them to route the main harness at the front of the engine instead, but of course that takes some work and time.

4. You can order a custom harness from somewhere like Speartech and have them assemble the harness so that it comes off the front of the engine and over to the ECU with a custom length to reach the ECU....so all of the work is already done for you and you just have to install it. Of course, custom is going to cost a bit more $$$ than a generic GMPP crate harness.

[Shoeless]

With regard to your question of OEM ECU compared to aftermarket ECUs, the answer is, it depends.

Do you want to be able to use advance tuning method, adding items like launch control, traction control, and data logging? You better going with an aftermarket ECU then. Going with an aftermarket ECU comes with its challenges. You need a competent tuner to take care of you and you are likely on your own to build your own harness. There are some DIY kits out there across all the aftermarket brands, but you will still need to be able to build it to make it really work with the mid-engine GTM. All of the items that Shane mentions above are super simple for an aftermarket ECU to control. I can choose the temps to start my fans, what RPM to shut the AC Compressor off, and actually a lot more.

Then it comes down to what aftermarket do you get. Depends. How much money do you want to spend. Do all the above items sound cool and you want top of the line, then save your pennies and go full MoTeC. I ended up starting with AEM (still have all of it for sale) and then learned I should have just went MoTeC to begin with. I also build my own motorsports grade harness from scratch. I wanted to learn the process and skills to do it, so this was fun for me. I can't say everyone shares my same enthusiasm.

Do you really not care about the above items? Then find an OEM ECU that takes care of you.

[crash]

So to recap...

OEM/Crate LS = cheaper, easier, and more people can tune it.

Aftermarket Motorsports ECU = Expensive, relatively harder to deal with, but gets you anything and everything you could ever want in an ECU.

Choose the one that best fits your needs.

I am personally using a very advanced motorsports ECU, and would likely not use this particular one again. MoTec ECU would likely be my choice going forward.

[ohmygosuness]

I do like to have data logging and I want my AC to work. I've never driven a car with this kind of power/weight ratio, so I'm not sure if I need traction control (yet). But it sounds like something that's nice to have. Based on what you guys are saying, MoTec + custom harness is the way to go (say I'm willing to spend a bit more on ECU).

Why MoTec over other brand? Is it easier to tune?

Does "full MoTec" include the ECU+harness? I looked up their harness pricing. I rather build my own harness if their harness costs almost half a GTM kit lol.

[Shoeless]

MoTeC is essentially a top tier motorsports product that outperforms all other "hobby" ECUs in every aspect.

Is it easier to tune, absolutely not. I have taken some classes online for tuning and specific to MoTeC and still had issues. I got some help to get mine running and idling in a reasonable manner to at least move the car around and will be having an experienced tuner finish it off for me.

When I say full MoTeC, for me that is an M170 ECU and C127 Dash.

If you are interested in building your own harness, than you and I should talk. Depending what level of wiring you want to do, TXL wire, Tefzel wire,...? Than you will spend a boatload in tooling. I spent over $3,000 just in tooling to build mine and am about to open a tool rental business.

[beeman]

Tuning is actually not an enigma. I just got done street tuning a Honda RBB (K24 VTEC/VTC). Self-taught with Youtube videos and HP Academy course. I'd much rather tune an LS. With VTEC/VTC, you have to tune separate fuel and ignition tables for low and high cam (VTEC), as well as 5 different cam degree tables (0-50 degrees cam rotation, tune every 10 degrees!) for both low and high cam. Just did a 1600 mile trip in that car running it 10/10. Yes, I couldn't find absolute peak HP/TQ without a dyno. Might find 5 more HP on a dyno (NA 200hp engine).

Most ECUs will give you a basemap for the engine you are using to get you started.

[Shoeless]

Love my HP Academy videos and looked around long and hard for someone to rent me dyno time on an load bearing dyno. Closest I found was a non load bearing dyno, but that's just not the tool you need to do it properly.

My AEM Infinity Series 7 (still for sale with my CD-7) offered an LS3 base map and I was able to get my engine to fire up in about 3 minutes. Cleaned some things up and was able to drive it. I had my knock detection setup and tried some left foot breaking and logging, but trying to hold a 625 HP engine in the cell long enough to get a good reading was difficult :cool:. But I did get it to the point it was drivable and to the tuner.

I don't think MoTeC had any base map available. I essentially copied my AEM tune into my MoTeC, but the logic in the MoTeC is different so I struggled a bit. Even with the HP Academy video on MoTeC idle tuning didn't help me much. Oh its worth saying I went with JRR software package in the MoTeC, so that's pretty different from the GPR package. JRR added a few functions that I thought worked better for me. One cool function in the MoTeC was Quick Q. Once you set your base VE table you can run on any cell and it measures the lambda against the target, hit the Q key, and it automatically tunes that cell for you. I did pretty good with this feature, but nowhere near max HP and Torque.

[beeman]

Love my HP Academy videos and looked around long and hard for someone to rent me dyno time on an load bearing dyno.

Great points. I would not enjoy tuning a 650 hp engine on the street. 3rd gear pulls on a country highway were easily doable with 200 HP :cool:
The Honda engine is getting a turbo this summer, will be about 400hp, still plan to street tune.
Sorry for the thread hijack.

[ohmygosuness]

MoTeC is essentially a top tier motorsports product that outperforms all other "hobby" ECUs in every aspect.

Is it easier to tune, absolutely not. I have taken some classes online for tuning and specific to MoTeC and still had issues. I got some help to get mine running and idling in a reasonable manner to at least move the car around and will be having an experienced tuner finish it off for me.

When I say full MoTeC, for me that is an M170 ECU and C127 Dash.

If you are interested in building your own harness, than you and I should talk. Depending what level of wiring you want to do, TXL wire, Tefzel wire,...? Than you will spend a boatload in tooling. I spent over $3,000 just in tooling to build mine and am about to open a tool rental business.

Currently, I am leaning towards MoTec. What about Haltech or Holley? I hear good things about them and they're half the price.

Is there really no company out there that does custome length harness for a reasonable price? :confused:

I'd build a harness if I have to. It would definitely be a nice skill to learn. But I also like to keep my options open.

[ohmygosuness]

Sorry for the thread hijack.
Not at all. I appreciate all/any input.

[ohmygosuness]

Not to change the subject but does anyone have decent pics of how the fuel tanks should be mounted? The manual just show one pic of already installed tanks. It really doesn't look like anything is holding them in place other than maybe the seats and crossover tube.

[Shoeless]

Currently, I am leaning towards MoTec. What about Haltech or Holley? I hear good things about them and they're half the price.

Is there really no company out there that does custome length harness for a reasonable price? :confused:

I'd build a harness if I have to. It would definitely be a nice skill to learn. But I also like to keep my options open.

Haltech and Holley are considered hobby level ECUs and as such will be half the price. Can they work, sure there are successful builds out there, but in this instance you get what you pay for. This was a hard lesson for me to learn. I knew nothing about motorsports ECUs and wiring when I started my journey years ago. All I knew was that I wanted to learn how to build my own harness and do my own tuning (at least get it running and driving). So I chose AEM to begin with, in the end that was a mistake. AEM stopped supporting my ECU and they sold out to Holley. Once that happened I ripped it all out of my GTM. You won't see MoTeC playing any of those stupid games. They truly are a top tier company that stands behind their products and its a benchmark for high end performance.

Depending what MoTeC ECU you go with you will either have a Deutsch Auto Sports connector, like my M170 or the other Molex (I believe its a Molex) product for a plug like an M130. The takeaway here is you can run a GTM on a M130 or M170 but you may want to also add a C127 dash as it will allow you to expand the number of inputs and outputs. I have the tooling that will handle both of these plugs flawlessly (even with RaceSpecs new gold solid contact for the Molex connector).

I'm not aware of anyone that does custom length harnesses, especially at a reasonable price. I could make you a pig tail type harness that has the plugs and say 15 ft of wires attached, but we'd have to design your power management section as well. Planning on these harnesses is sometimes just as much work as building them.

[Shoeless]

Not to change the subject but does anyone have decent pics of how the fuel tanks should be mounted? The manual just show one pic of already installed tanks. It really doesn't look like anything is holding them in place other than maybe the seats and crossover tube.

The tanks are literally just stuffed in the opening and then the tank covers hold them in place. If you are going with Aluminum tanks you may need to add additional foam and supports, but if donor tanks, just set them in there and the tank covers hold them in place.

[crash]

Why did I say I would likely go MoTec with future builds? Because it is a race industry standard. I have no doubts that the full race ECU that I am currently running in the race car does everything and maybe even more than a MoTec standard unit, but the fact that there are only a couple of tuners here in the US that can work with the ECU is a much bigger draw back than I had anticipated. You will find multiple tuners in almost all major US cities that can work on a MoTec unit.

Harnesses. Ugh. My last one cost over $5k and the builder did not do it the way I had asked him so as soon as I got it installed and saw how the knock sensors wiring was run I got out my nippers and cut the harness apart! Really not happy about that, but needed the harness to make it to a race and so I had to "modify" it straight away. Sometimes it is very hard to get a builder to understand something when it is not assembled and in front of them. The way the knock sensor wiring was run originally caused it to run right next to the exhaust header, whereas the way I wanted it (not standard for an LS setup) ran everything down the bottom of the engine.

I have not done this, but given the fact that I have seen some "motorsports" harnesses available online for relatively low prices...like a few hundred $$...and they appear to have real mil spec connectors, I think I might give one of those a try and see if it fits okay and just needs minor modifications. Worst case scenario is that you overpay slightly for your connectors and have to repin them. Awesome wiring source, and the one I primarily use is prowireusa.com.

I can send you to the guy that made my custom harness, just expect $5k range for cost...and maybe not 100% the way you want it. LOL!

I did suggest to the guy I used that I thought he was missing out on a lot of customers that would happily buy a "standardized" LS motorsports harness that would be in the range of $2,500.00. His reply to me was "why would I do that when I am backed up for months at $5k-$10k for my harnesses?" Guess he's got a point.