Split Front Mounted Radiators

[Fraser D]

Thought it best to start a thread specifically about the progress and the modifications being made to install a split radiator system in the front of my GTM. Feel free to chime in with suggestions, comments, etc and I will try and be as detailed as possible with the modifications so that if everything works out the way that I am planning it will, fellow builders will have a good understanding to either copy or deviate from what I have done.
Please this is specifically about a front split system and not about installing radiators anywhere else on the car.
After the initial mockup I was able to determine where there was room to mount each radiator with enough clearance between the tire and the radiator itself. I did look at similar setups on production cars and was surprised how little clearance they were running between the tire and the radiator protection.
As with most modifications like this there is going to be a little trial and error.

[Fraser D]

The maximum available space was 18” tall x 15” wide which when doubled has the same surface area as the original Corvette unit.
I ended up purchasing this radiator knowing that the top inlet would need to be resized and moved while the cap will be removed in order to give enough clearance behind the headlight bucket.
The radiator is;

Overall Size: 14.37"x16.5"x2.5"
Core Size: 13.5"x16.5"x2.25"
1.25" Inlet & Outlet
3 Rows

Radiator Fan Spec:
Size: 12"
Thickness (Motor Height): 2.5"
Air Flow Rate: >1130 CBM/Hr
Speed: 2100 RPM
Power: 12VDC, 40W

[Fraser D]

The radiator is just sitting in place to give me an idea of what is going to be in the way.
The top fill tube will need to be moved to clear the back of the headlights and it looks like the radiator will need to be angled back a little as well due to the headlights.

[crash]

As I said on the "other" forum, just flip the radiator around, and your clearance problem will disappear. Probably also much more efficient routing of the lines this way as well. :)

[Fraser D]

Crash,

I am trying to keep the thread going on both forums so bare with the repeats.
While that helps with the top it does not with the bottom hose, but you bring up a good point about there being more clearance at the top due to the curvature of the wheel well. The top facing into the wheel well and against the frame and the bottom facing forward may be the cleanest solution.
It will not be hard to make the radiator guard curved to match the wheel somewhat.
I still need to play around a little this week if I have time, but relocating and resizing the ins and outs is not an issue as I have a TIG set up in my garage and enough ally stock to completely replace the tanks if I need to.

[crash]

As I said on the other forum, be ultra careful if the tubes are epoxied, as opposed to brazed, onto the tanks. They can be ruined easily from the heat of TIG welding.

[Fraser D]

Crash,

Thanks, understood regarding radiator construction and heat issues.
Stay tuned for photos of success or spectacular failure in a couple of weeks when I am allowed back in the garage to play!

[Fraser D]

85328533853485358536Snuck a couple of hours in the shed today and was able to make progress on the fabrication of the radiator mount. It is starting to look the part and I have been able to maintain clearances from the front wheel and the headlight connectors. The next challenge is mounting the condenser but I have verified that it does fit… just.

[crash]

Looks cool.

[Fraser D]

885988588860Drivers side mounted, now for the ins, outs and the condensers.

[Fraser D]

A small step forward today.
Passenger side radiator TIG'd together, (man I am out of practice with this welder) and have started on the driver’s side.
I think that I have the plumbing configuration sorted out and in the process realized that I have the tunnel tubes back to front. Correct as per the manual but not correct as per pump flow. I have 1 1/4" to the passenger side and 1 1/2" to the center of the tunnel. So I am debating if this actually makes a difference but will most likely nut up and take the hour or two to swap them.
The coolant flow will be coming into the bottom of both radiators and out the top.
Between getting rid of the original stainless hoses and using an engine bay header tank, getting the battery in and out is not too much of a struggle.
Currently looking for a Houston AC guy who can make up custom AC hoses for my condensers.

[kabacj]

Looking good Dave! That setup is will really open up the styling options for the front of the car. Keep up the good work.

John

[Fraser D]

John,

Thanks. I just think that the GTM front looks a little unfinished so let’s see if I end up making it better or worse ;-)
I am hoping to get the cooling system back together this weekend and go for a drive to see how the temp sits before the hood goes back on.

[mendo]

I think the flow should be "in the top, out the bottom". that way the pump always has water to suck.

[Fraser D]

Mendo,

I was initially concerned about getting all the air out of the system but I guess that with once the system has been purged there is no reason for the "in at the bottom, out at the top" orientation. With an engine bay header tank and an air bleed at the high point for each radiator there should not be trapped air issues so pump supply can be the systems priority.
Thanks and I appreciate the input.

[crash]

I concur. Hot water should be at the tops, and chilled water should come from the bottoms.

[Fraser D]

I concur. Hot water should be at the tops, and chilled water should come from the bottoms.
I sure am glad you guys pointed this out before I cut up my tubing.
Thanks

[Fraser D]

Radiators welded up, (starting to get the hang of TIG welding again) and piping run. I hope to get the header tank installed and radiator tubes beaded tomorrow so that I can start the engine to see if I have any leaks and if there is any difference in temps.
Once I know that there are no leaks I will frame out the trunk, mount the AC condensers and fans then tidy up the battery area.
Then the body mods start in earnest. :(

[Fraser D]

Ran the car around the block a couple of times this afternoon with only one small leak found.
Car temp ran about where it normally does but I don’t have the hood, ducting or fans set up yet so it is a little soon to tell if there is going to be any benefit or issues. The header tank set up made removing the air from the system very easy and I don’t believe that I had any vapor locks in the plumbing as all seemed to be getting varying degrees of warm.
Next is to fix my leak, do a little tidying up and make the debris guards between the radiator and the front wheels.
All in all a positive move forward today.

[kabacj]

Looks great Dave. Very neat install.

John

[Fraser D]

Thanks John, It's all starting to come together
Just a quick video of the first test drive with the split radiators.
I will tidy up the plumbing this weekend and install the wheel guards if the material is delivered in time.
Once the hood is mounted, secured and modified the radiators will be securly braced and connected to ducting from the front of the car.
http://youtu.be/31zo3FPyV4k

[Fraser D]

Well no leaks and no heating issues after a little spin around the block and a long run in the garage with the hood on and the hatch and glass installed.
Time to start mounting and modifying the hood.
The material for the wheel guards has not arrived yet so that will be next weekend’s task.
First go with the Go-Pro taped to the roof and an unsuspecting father-in-law who did not know that I was recording ;-)
The car is struggling to hook up well with the old set of 295’s on the back and a very rough chassis set up.


http://www.youtube.com/watch?v=G0c6ijqGqQ8

[Fraser D]

Two weeks ago I found a couple of spare hours to get the AC condensers mounted but not plumbed up.
I need to find some fittings compatible with the Honda Civic DelSol condensers and make some hoses.
The lower driver’s side radiator outlet needs to be moved inboard as it rubs on the hood.
I think that I will try the stainless steel mesh as the tire guards as I was not happy with the aluminum honeycomb that I picked up.
Mesh spec from McMaster Carr
9253T482
Extra-Rigid Type 304 Stainless Steel Woven Wire Cloth, 1/4" Opening Size, .063" Diameter, 24" X 48" Sheet

There is still lots of work to do with securing the tubing and bracing and detailing the mounting frame.

[Fraser D]

I have made a bit of a step back from my original design layout.
Spoke to a friend who is all about air movement and he pointed out a fundamental flaw with my original layout.
It is called roping.
In a nut shell I was loosing approximately 1/3rd of the radiator area due to the boundary layer of air created by the tire's rotation.
That boundary layer in theory would push air back through the radiator effectively stalling air flow through that portion of the radiator.
This set up may just work but I am not willing to take the risk with the changes that need to take place with the body,
I had originally avoided cutting up the chassis to install a different profile cooling system but now all bets are off.
I will be installing a pair of AFCO Racing Scirocco-Style Drag Racing Radiators 80107N set at an angle.
The original set up will work for a lower HP setup but mine will be 550-750hp
More photos to follow as I mount the radiators,
Hopefully this will be the reliable solution.

[Desertrunner]

I did not know you could do this, what gets me why don't you end up with holes in the radiator from stones etc being thrown up from the tyres.

Don't get why it would not have been better to tee the radiators so each operated seperatly, would have been less pressure loss in the system and also long residence time, slower veliocty in each radiator.
As for the need to send hot in the top and cold out the bottom, its a over stated benfit. In most cars the volume of the radiator is changed every 6 secs. That means there is no time for convection to work or have any effect.

Nice set up, well done.

Tony

[Fraser D]

Tony,

Guarding is still needed between the radiator and the wheel to prevent damage.
When you look up in the wheel well of most vehicles you will notice that there is very little/if any indication of debris strike in the front half of the wheel well.
Whatever has been picked up by the tire has been flung off in the first 200+ deg of rotation for the most part but there will always be that pesky little stone that did not take jnr high physics but is well schooled in Murphy.
As for the flow path of the coolant I don't know enough to calculate if the reduced fluid velocity would provide enough additional heat dissipation to compensate for the reduction in half of the heat transfer surface area so I just went with what made sense.
The original setup which is now sitting on a shelf in my workshop combined had the same frontal area as the stock C5 radiator with the addition of ally tanks/not plastic and being 3 row not the stock 2 row.
The new radiators have almost 50% more frontal area and are a lot further away from the wheels which should eliminate air packing and wheel debris issues.
Please by all means if you think that there is a better way or a different way let me know as I am currently working on version 2 and really don’t want there to be a third version.

[Desertrunner]

Hi Dave,
Up front I will say I have no experiance with the GTM but I have done a lot of work on cooling other type of systems. The major failing in cooling systems is caviation to the water pump. You would have seen suction pipes to water pumps with wire in them to stop the hose collapsing. That is a bad sign becasue it shows that the water pump if pushed will capaviate.
If it was my car I would tee in the hot to the top of both radiators and tee the outlets together. Every radiator has some friction and results in a pressure loss, it maybe only 5 psi but when you send it from one radiator to the next the loss maybe only 10psi but as pressure calcs are logarithmic to move the pressure from 5 psi to 10 you need 4 times the energy.
Don't want to get to complex unless you want me to. The surface area is the surface the direction of flow of coolant doesn't change that.
Last point the installation will be a lot neater.

If you want me to expand any points please ask I am happy to help in any way.

Tony

[Fraser D]

Tony,

I hope to have everything mocked up over the weekend and will post some more photos

[mendo]

I just saw a Lambo this week, it has both radiators mounted behind the rear wheels. there is ducting that starts right behind the door windows and the radiators vent straigh out the back. ???? maybe?

[Desertrunner]

14330Hi Dave,
Had a though this idea might help you develop the project. When I run tests I use a computer cooling fan (couple of buck worth) with long leads and attach a multimeter attached to the end. Need to check its the type of fan that when spun generates power. Set metter at 0 to 24v DC. Zip tie it were ever you want to read the air seed. You will be surprised what you learn from this simple test.

14331

[mendo]

Good Idea Runner!

[Fraser D]

That is a good tool to have.
Thanks for posting.

[Fraser D]

Rev 2 Mounting completed. I have to break out the TIG to finish up the radiators then plumb them in. Still finalizing the fans and AC condensers.
I like these way better. A lot more work but......
There is a heap more photos in my photo bucket link below.

[Fraser D]

Radiators plumbed up and leak tested OK.
I used the material from the original set of radiators but later on I will replace the tubing assembly with single piece mandrel bent items.
Fans on order and I will enclose everything with aluminum sheet once I am happy that everything is running Ok.
AC condenser will be mounted in a novel place with photos to follow once I sort it all out.
I should have the hood mounting completed this Sunday.

[OZIGTM]

Great work Dave, it's looking really good.

Rohan GTM# 285

[Fraser D]

Great work Dave, it's looking really good.

Rohan GTM# 285

Thanks, where have you been? DOT Engineers haven't pissed you off have they?

[chronies5]

Extra-Rigid Type 304 Stainless Steel Woven Wire Cloth, 1/4" Opening Size, .063" Diameter, 24" X 48" Sheet

There is still lots of work to do with securing the tubing and bracing and detailing the mounting frame. .


Mcmaster is charging an arm and a leg for this stainless steel wire cloth material - if you are not into wasting money check out some more sources, like the following:

www.grainger.com

http://www.bwire.com/index.html

They will beat the pricing and shipping costs of mcmaster. hands down.

[OZIGTM]

Thanks, where have you been? DOT Engineers haven't pissed you off have they?

Hey Dave,
I'm still going, as you know with projects like this life gets in the way; the balance of keeping everybody happy.
Engineers are OK if you follow the rules, there is really only two main issues; beam / torrsional test and emissions test plus every state has different rules.
One more GTM arrived last week into OZ, which is good more the better I think that makes 7.
Cheers,

Rohan

[Fraser D]

Extra-Rigid Type 304 Stainless Steel Woven Wire Cloth, 1/4" Opening Size, .063" Diameter, 24" X 48" Sheet

There is still lots of work to do with securing the tubing and bracing and detailing the mounting frame. .


Mcmaster is charging an arm and a leg for this stainless steel wire cloth material - if you are not into wasting money check out some more sources, like the following:

www.grainger.com

http://www.bwire.com/index.html

They will beat the pricing and shipping costs of mcmaster. hands down.

At the time I purchased mine there was about $5 difference between the two vendors and I had an order to place with McMaster anyway.
You are correct in that you really need to shop around because prices can vary greatly.

[Fraser D]

I was able to get a couple of things completed today with the biggest milestone being getting the hood brackets progressed and the hood mounted.
The hood opens and closes like a champ!
The hood brackets still need to be powder coated and the base plates glassed into the hood.
The tube work has been cleaned up ad painted so it is time to start putting things together for the last time and finish off the aluminum close out panels.

[kabacj]

I was able to get a couple of things completed today with the biggest milestone being getting the hood brackets progressed and the hood mounted.
The hood opens and closes like a champ!
The hood brackets still need to be powder coated and the base plates glassed into the hood.
The tube work has been cleaned up ad painted so it is time to start putting things together for the last time and finish off the aluminum close out panels.

I like your hood hinge setup Dave. I have been thinking about the hood hinges on the stock car. Since the pivot point is behind the light buckets, as the hood tilts up the area below the pivot moves downward. This is fine if you have the stock splitter. I wanted to hinge the hood but also run a solid floor that extends out to the splitter. I think your idea of hinging the hood at the lower edge would solve this problem. Thanks for sharing your design.

John

[Fraser D]

I like your hood hinge setup Dave. I have been thinking about the hood hinges on the stock car. Since the pivot point is behind the light buckets, as the hood tilts up the area below the pivot moves downward. This is fine if you have the stock splitter. I wanted to hinge the hood but also run a solid floor that extends out to the splitter. I think your idea of hinging the hood at the lower edge would solve this problem. Thanks for sharing your design.

John

John,

I will take some detailed photos when I disassemble for final install to give you a better perspective.
One key, (for my application anyway) aspect that is missing is the slide limiter which allows the assembly to slide forward a little over 3” to clear my splitter tray and ducting before tilting up. I will update the thread once I complete those pieces.

[Fraser D]

I was able to squeeze a couple of hours in today and completed the screens/mounts for the radiators.
This is the stainless steel wire mesh that I purchased for the first attempt at split rads.
These are the ones that will protect the radiators from big bits of rock.
I will just wait and see how much trash ends up between the screen and the radiator before I take any further action.
Installing louvers once everything is closed out will not be a big deal if it comes to that.
My plan this weekend is to get all the close out panels made and installed along with the radiators themselves for the modified front end. Hopefully get the headlights installed and wired but lest see how far I can get.

[Fraser D]

Well four more panels to make, a few hundred 1/8” holes to drill, a little painting and lining and it’s done! Maybe ;-)
Oh and I now have a trunk.
Getting close now.

[Aman]

whoa, nice work! Great idea, that is going to be very handy

Aman

[Fraser D]

A little progress this week.
Panels coated and installed for the final time.
The trunk is insulated but I will wait until I am further progressed with the body work before installing the carpet.
Radiators installed, filled and car run with no leaks in the system.

[GTM]

This is likely going to be on my list of "must-do's" Going to go through the photobucket and may ask for more info later. Thanks for sharing!!

[Fraser D]

This is likely going to be on my list of "must-do's" Going to go through the photobucket and may ask for more info later. Thanks for sharing!!

Thanks and let me know if you need any dimensions or closeups.

[Demthios]

Looks Like you might have started something here, I can see my self attempting to follow in your foot steps with this set up as well. Thanks for spear heading it for us! Keep up the awesome work

[Fraser D]

Looks Like you might have started something here, I can see my self attempting to follow in your foot steps with this set up as well. Thanks for spear heading it for us! Keep up the awesome work

When you get serious about taking this path get in touch as there are some improvements that I can share.
Once I finish I intend to write a bit of a write up covering the pros, cons and improvements .

[Taz Rules]

I don't even have a kit yet, but I'm thinking seriously about following your lead on this when I get one. I have a few questions though.

1. Where will you pull the airflow from? Will you duct it from the center hood opening? Or close that up and open two intakes closer to the corners?
2. Where will you vent the hot air to? Will you channel it up over the wheel to fender vents? Or duct it to central vents as exist now on a Gen 2? I'm assuming you don't want to vent that hot air past the front brakes and out the wheel well.
3. Where is the AC condenser? Can you split it in two and set it up with the twin rads? Or do you still plan to have a single, center mounted unit?
4. Will there be room for the battery forward of the new trunk? This could create some much needed space behind the steering rack for AC and electronics packages. Also, as I understand it, bringing weight forward on a GTM is a good thing, handling-wise.
5. How will the weight of the radiators being further outboard affect steering and handling?

As a final note, check out the Photoshop stuff I did on the FFR forum in collaboration with Mike on his interior. If you like it, let me know and maybe we can work together on some front end designs. This concept really intrigues me.

[Fraser D]

I don't even have a kit yet, but I'm thinking seriously about following your lead on this when I get one. I have a few questions though.

1. Where will you pull the airflow from? Will you duct it from the center hood opening? Or close that up and open two intakes closer to the corners?

DF. I still need to fiberglass the intakes/duct but this should give you an idea.

2. Where will you vent the hot air to? Will you channel it up over the wheel to fender vents? Or duct it to central vents as exist now on a Gen 2? I'm assuming you don't want to vent that hot air past the front brakes and out the wheel well.

DF. For now the hot air will just flow into the wheel well but at some point I intend to duct it around the wheel and through the wheel well vents. I need to get a better idea of flow rates etc to make sure that I don’t create a heating issue. More time with a beer in hand while scratching my head plus some time on the road to see how it is all working out.

3. Where is the AC condenser? Can you split it in two and set it up with the twin rads? Or do you still plan to have a single, center mounted unit?

DF. I am going to try the center condenser approach to see if I can get enough heat exchange with the air exit being via the brake cooling ducts that I am installing. A plus is that there will not be any heat soak from the engine or radiators for the condenser to contend with.
The center air intake has not been cut yet. You could split your condensers and run one with each radiator as this will work.

4. Will there be room for the battery forward of the new trunk? This could create some much needed space behind the steering rack for AC and electronics packages. Also, as I understand it, bringing weight forward on a GTM is a good thing, handling-wise.

DF. If you did not have your AC condenser in the center then you could utilize that location for a battery.

5. How will the weight of the radiators being further outboard affect steering and handling?

DF. The mathematical answer is yes but I doubt that I would notice any difference either good or bad.
I want to add a couple of smallish canards in the same area as the Gen 2 hood to help with the high speed aero.

6. How is the headlight clearance?

DF. This photo does not have the top of the radiator closed off but the finished gap at its smallest is ¾” between the radiator and the light bucket.

As a final note, check out the Photoshop stuff I did in collaboration with Mike on his interior. If you like it, let me know and maybe we can work together on some front end designs. This concept really intrigues me.

I would appreciate that as the original openings were for the previous radiator setup which would have been a gradual profile and now look a little odd for rev 2.
Let me know if you have any other questions as I learned a lot through this process and I have no issues passing on how I would make this design better that what I have.

[Fraser D]

Well I had a go at making the radiator intakes today and only glassed up the passenger side intake along with the hood mount backing plates.
I would appreciate any feedback and comments regarding how this looks as I am afraid the style gene is completely absent from my DNA.

[Fraser D]

Well I took Ash (AKA Taz) up on his offer to play around with the front options in photo shop and this is what he came up with. He took a little of what I have already and added a couple of options of his own and I have to say that the results really helped me to fully picture the end result.
There are still a couple of technical issues to resolve in order to make the best looking version work, (large center intake for the AC condenser) and that primarily is how to pass as much of the air as possible that that hole will collect.
Current plan is to run dual 3" brake ducts (4 x total) from that cavity and let them both exhaust into the wheel well for now then later hook one up to each of the front brake calipers.
I have found a few options regarding bar LED Fog lights that I am looking to install under the top edge of the radiator intakes.
Thanks Ash for taking the time to help me out. Very much appreciated.
For the builders like me who are not afraid of making something different but are challenged in the style department I strongly recommend using tools like this and talented folks like Ash.

[Fraser D]

I had a quick hour and a half this morning and knocked out the drivers side intake.
One more thing tick'd off.
Still need to clean them both up and smooth them out.

[Desertrunner]

Dave I ment to post a couple of weeks back were I found some Porsche have split front radiator and they run them in parrallel. If its important I can go look for it a again.
Tony

[Fraser D]

Tony,

I am interested to see how they do it if you come accross that information again.
Thanks

[Desertrunner]

Its diagram of the plumbing, hope it helps Dave. What I also think is interesting is the way the oil coolers work.
Tony
17740

[Fraser D]

Its diagram of the plumbing, hope it helps Dave. What I also think is interesting is the way the oil coolers work.
Tony
17740

Tony,

Thanks for the diagram.
Interesting how they run the pump so that it pushes through the engine.
I am still running with temp plumbing so may see how this compares to the temps I am getting now.

[Desertrunner]

Hi Dave,
Yes its a interesting doc,

Both Subaru and Porsche have 2 things in common, they have the pump pushing through as you say which I tend to agree is a good idea, the other which I don't agree is they both have the thermostate on the suction of the pump.
Both Porsche and Subaru get cavitation and poor cooling control due to this point. In the case of Porsche they have tank 7 to get rid of the air.
The logic behind having the thermostate on the suction of the water pump is that the engine will always get in spec tempreture controled coolant. Which sounds great but in reality doesn't work for a whole lot of reason I won't go into here.
The Porsche oil coolers are really smart becasue once you have your engine at the right temp the coolers make sure the oil is at the right temp as well. People fail to realise that with the Porsche oil cooler design they are infact temp controls as they both heat the oil and cool it. The problem with normal external oil coolers is that unless they are fitted with a thermostate you can blow the engine from oil being to cold.
Keep well, great project.
Tony

[Fraser D]

Starting not to look like a jigsaw puzzle anymore.
Still a ways to go. Wheel vents next on the list.

[Fraser D]

Actually got a couple of hours in the shed today.
The front is almost done. There is a lot of detail work that the photos don’t really show but all the front wiring had to be completely redone and re run, (which is now done except for a few weather pack connectors).
The splitter tray is now mounted and I have one of the fan shrouds completed and the other shroud cut out ready to bend.
The hood mounting brackets have been cleaned up after being fiber glassed into the hood and bolted back together.
The hood itself still needs some cleaning up with a couple of spots on the radiator intakes to be filled with resin.
I have a different style of bulb seal ariving during the week as the FF5 stuff is simply falling apart.

[Fraser D]

Getting very close to completing the front section and the split radiator modifications.
Wheel well vents installed with the fan shrouds and AC condenser to complete before track testing to see how the cooling and aerodynamics have been changed.

[RM1SepEx]

Dave, where did you get your wheel well/fender vents? I'm considering a similar twin radiator mod for the 818...

Thanks

Dan

[Fraser D]

Dave, where did you get your wheel well/fender vents? I'm considering a similar twin radiator mod for the 818...

Thanks

Dan

Dan,

The Factory Five GTM shop sell them for $199 + shipping and handling
http://www.factoryfiveparts.com/gtm-fender-louver-set/

[Fraser D]

I made some modifications to the fan shroud to allow at speed air flow to bypass the fan opening.

[RM1SepEx]

Dan,

The Factory Five GTM shop sell them for $199 + shipping and handling
http://www.factoryfiveparts.com/gtm-fender-louver-set/

Its a pretty sure bet that they won't fit the 818 fenders...

[WIS89]

Dave-

Build is looking pretty awesome! I really enjoy watching your progress on the split radiators. I hope it exceeds your expectations on the track! Thanks for documenting it and putting it here for us to see. Really great work!

Regards,

Steve

[Fraser D]

Its a pretty sure bet that they won't fit the 818 fenders...

Dan,

A couple of folks have made their own version, (or their body guy did) and I think that one or two of the shops will sell them.

[Fraser D]

Dave-

Build is looking pretty awesome! I really enjoy watching your progress on the split radiators. I hope it exceeds your expectations on the track! Thanks for documenting it and putting it here for us to see. Really great work!

Regards,

Steve

Thanks Steve,
It did not end up being the configuration that I started out with which is the fun of starting out with only half an idea :-)
I am shooting for a track day during the 3rd week of August at one of the local tracks with still plenty of work to complete.
As I still consider this to be a bit of an R&D project a couple of aspects will remain unrefined until I am completely happy with the setup, (especially the front aerodynamics).
Bondo and undercoat will be the paint scheme for a while I am afraid.
So if I have not forgotten something stupid I will have some real data on the setup after that event.

[kabacj]

Dave the setup looks excellent.

I am sure if the setup works well on the track it will also work well on the street. The track is a great way to both push yourself and your design.

One thing I found on the track that I did not expect might help you out.

I was surprised by all of the rubber bits that end up finding their way into cracks and crevices. I have not yet installed the splash guards on the front fenders and i end up with a pile of rubber bits in the foot wells after every weekend.

When you plan on hitting the track you might want to consider using a fine mesh screen to keep the rubber bits out of the radiators both front and back.

John

[Fraser D]

Dave the setup looks excellent.

I am sure if the setup works well on the track it will also work well on the street. The track is a great way to both push yourself and your design.

One thing I found on the track that I did not expect might help you out.

I was surprised by all of the rubber bits that end up finding their way into cracks and crevices. I have not yet installed the splash guards on the front fenders and i end up with a pile of rubber bits in the foot wells after every weekend.

When you plan on hitting the track you might want to consider using a fine mesh screen to keep the rubber bits out of the radiators both front and back.

John

Great advice John

I was planning on repurposing the FF5 mesh from the original radiator hood exhaust for my radiator intakes
Do you think that the mesh size will work for the rubber issues?
I had not planned on any other mesh other than the stone guard that I currently have for the back of the radiators but will change that now
Funny that you mentioned getting rubber inside the cabin as Linxs and I were going over the car looking for heat entry points and the foot boxs especially around the top are wide open.
I need to invest in an assortment of different seals to take care of that.
Thanks for the feedback

[kabacj]

Great advice John

I was planning on repurposing the FF5 mesh from the original radiator hood exhaust for my radiator intakes
Do you think that the mesh size will work for the rubber issues?
I had not planned on any other mesh other than the stone guard that I currently have for the back of the radiators but will change that now
Funny that you mentioned getting rubber inside the cabin as Linxs and I were going over the car looking for heat entry points and the foot boxs especially around the top are wide open.
I need to invest in an assortment of different seals to take care of that.
Thanks for the feedback


Hey Dave,

yes the factory five mesh has roughly 1/4 inch holes if I remember correctly. That might be just a little big to block everything but the vast majority of the bits are 1/2 to 1 inch long by 1/8 to 1/4 inch in diameter.

I ended up using duct tape to block all of the openings where the aluminum touches the bodywork in the front wheel wells. Bulb seal would most likely work in these places.

I wanted to maintain the vent where the leading edge of the door and the front fender meet.I would think you also would want to keep this airflow path open as it exhausts air from the front fender. I can tell by the amount of brake dust on the leading edge of the door that air is definitively following this path.

The down side of not having splash guards of course is water in the rain and the rubber bits.

The other thing to consider is the aluminum you might add under the nose.

Without any aluminum you are going to have plenty of airflow as air will exit under the car and any debris just falls out on the ground. If you add aluminum to channel the air then you might need to be more concerned where the air exits and what enters that area.

You are going to have a blast on the track.

John

[LCD Gauges]

Awesome! I just realized by glancing through your first page that you've redesigned the rad layout. Version two looks much better!
You may be the only one that will have effective use of the louvers over the tires.

By the way, I'm jealous of your trunk space.

[Fraser D]

Well there is something to be said for spending a little time recuperating from surgery to get the creative juices flowing. The bad part about recuperating from surgery is that I can’t do the work myself for the next couple of months.
Continuing on from the physical mounting of the radiators it became a challenge to make the brake ducting and the AC condenser operational while the hood was in one piece.
I looked at the different approaches to making the hood two piece that have been tried on GTM’s so far and different production cars and decided on the approach in the below photos.
A jig was made to align the hood when in two pieces to allow the fiber glassing of the weather-strip and any reinforcing, (although the pieces are very thick and did not move once cut).
The pieces are just laid in place with no alignment or positioning and I was surprised to see that the natural lay of the main hood piece is almost perfect.
Having the front piece separate from the hood itself gives me a lot more options for the radiator intakes, (profile will change) and the center AC and break intake, (yet to be cut).
So what stands between me and success right now will be my ability to not backseat drive and piss off the help
It is early in the process but I am very happy with how it is turning out.

[Fraser D]

Taking the next step in fiber glassing in the weather strip overlap and I am not sure if the panels or my jig have moved some or both but the two pieces are not settling in as well as they did previously. I will leave them on the jig overnight and all day tomorrow to see if the alignment gets better.
If not I will pull them back into position with some screws and glass in some reinforcing strips to hold the shape.
I have all the mounting points identified for the two pieces and some design drawings for the hood hinges which are just waiting on material.
The process of putting things on the car then pulling them back off is getting old but I only have myself to blame.

[Fraser D]

The day started off with a thunderstorm and local flooding so I was not very optimistic at getting anything done today but managed to get the fiber glassing for the weather strip completed.
I will trim the fiber glass back in the morning, finish the mounting of the nose section then make it all pretty.

[Fraser D]

My shoulder is starting to feel good enough to do a little light work so I made some progress with a few things.
The AC condenser is ready for a date with the TIG to weld in the fittings and mounting brackets.
I have rough cut the center opening that will supply air to the AC condenser and cooling air for the front brakes via some ducts. The opening still needs to be finished with a lip fiber glassed in.
The radiator opening are getting a little tweaking. The shape is having all the angled corners replaced with radiuses so I made up some fiberglass pieces to graft in. One corner down two to go.
The internal frame for the mounting and support of the front clip is almost done along with the hood hinges.

[Taz Rules]

I think the rounded corners will really make a difference. They make it look more refined. I like it

[kabacj]

Looking good Dave. I am looking forward to joining you creating some custom GTM bodywork features.

[Fraser D]

I think the rounded corners will really make a difference. They make it look more refined. I like it

Ash,

After I made them I was not very impressed by how the profile turned out. My skill level did not match my imagination very well and while it bugged me I was happy to keep in way down the list of priorities.
A couple of months ago a friend drove my car while I followed in my truck as I wanted to see how bad the oil seal blow by was on one of the turbo’s. I led the GTM onto the freeway and I looked back in the rear view mirror and was not happy how the intakes violently contrasted, (in my mind at least) to the rest of the car. It’s a small change that I should have finished over the next couple of weeks but it should allow me to get back to the important stuff.

[Fraser D]

Looking good Dave. I am looking forward to joining you creating some custom GTM bodywork features.

Thanks John.
Your posts on aero enhancements have added a couple of items to my list.

[Fraser D]

Slowly chipping away at the hood.
The ally plate bonded to the hood still needs to be glassed in.
A little more bracing to be done from the hinge back to the chassis and from what I am seeing I may not need additional reinforcing in the hood but I have a few ideas if it looks risky.
I used rod ends to give the hood some alignment flexibility.
The gas struts supplied by FF5 for the hood are too strong and cause the hood to bend when closed and latched so I am looking at some lower or zero rated units.
The range of motion is enough to get decent assess to the trunk and battery etc.

[Fraser D]

The hard part is done and the hood works.
Still some adjusting to do along complete welding out the frame work, the body work and painting but it operates very well. :cool:
I will have to do a little reinforcing of the hood but I am very happy with how this is turning out.
So glad that I was able to spend a couple of hours in the shed today.

[Taz Rules]

That looks really nice and clean, Dave. Did you bend the hinges yourself?
That's a really elegant solution.

[Fraser D]

That looks really nice and clean, Dave. Did you bend the hinges yourself?
That's a really elegant solution.

Thanks Ash.
I bent the hinges myself and will post photos once I have them cleaned up, pre and post powder coating.

[Fraser D]

I have a couple of days of vacation to burn so what better way to pass the time than to spend it than in the shed.
Got the fiber glass work completed, (radius’ d the corners) on the radiator openings and will start the body filler in the morning to make it pretty.
I increased the center opening and have started marking out the mold so that should be glassed in and smoothed out by the end of tomorrow.
Fingers crossed for paint on Friday.

[Fraser D]

Tried using the florist foam for the center section mold and I have to wonder why it took me so dam long to try it. Magic stuff!
The recess for the AC condenser and front brake cooling ducts is molded and I think turned out pretty good.
Ran out of time to do any body work on the front but I did get the hinge brackets tweaked and ready to powder coat tomorrow.
I tried to stay as true to Ash’s photoshop idea as I could but the size of the number plate forced a slight change.
Looks like tomorrow is a Bondo day!

[kabacj]

Great progress Dave

Your idea of using the December vacation for GTM work is a good one.

The floral foam sands nicely. The pink insulation foam works reasonably well also. It's stiffer and more dent resistant but is harder to sand smoothly.

At least you guys have nice enough weather to do dusty work outside. I've spent the last few weekends installing heat in the garage. I have always used a space heater. But wow thermostat controlled heat is awesome. Now I can live in the garage 24/7 year round.

After you finish up this mod are you going to paint? Oh and since you are tracking your car. You might want to add a tow strap somewhere on the front of the car. Just something to think about. I've been towed in twice already. Ran out of gas once. No gas guage at that point. And spun off the track stalled it and my old small racing battery could not crank the hot motor. You don't need the toe strap or hook, but is sure nice to not worry when they pull you back to the pits.

[Fraser D]

John,
What have you used to cover the foam that is good for reasonably complex profiles? I have been using aluminum foil and painters tape but it has it limits.
I am in no hurry to paint the car mainly because my toy budget has to include a 2nd school tuition, (why do I pay taxes again?) starting this year and my list of suspension and engine upgrades has a higher priority. Unfortunately I really like those $600 double adjustable shocks that quick racing sells.
Re tow point… I knew that I was forgetting something! I looked at that about a month ago and meant to incorporate that into the front design. Thanks for the reminder. I will make it work somehow.

[Taz Rules]

The recess for the AC condenser and front brake cooling ducts is molded and I think turned out pretty good.
...
I tried to stay as true to Ash’s photoshop idea as I could but the size of the number plate forced a slight change.

Actually, Dave, I think I like your way better!
(Damn big license plates...how come everything in Texas is oversized? :) )

Glad I could help out, even if only minimally. Make sure you plug my vendor status so I can do this for others, too! (Shameless self promotion! :o)

No, seriously, I really like what you are doing with your car! You deserve a lot of credit for your originality and design/fabrication skills. This is a truly unique build.

[kabacj]

John,
What have you used to cover the foam that is good for reasonably complex profiles? I have been using aluminum foil and painters tape but it has it limits.

For a one off part like you are making I do the same with foil and tape over foam. This method definitely takes more filling and working the final shape. Its almost like you are sculpting the part as opposed to producing a copy off the foam plug. For the more complex part that I might want to make more than one of I cover the foam with fiberglass, then body filler, then gel coat and make a re useable mold. I think both methods work and the foil method is far easier.




I am in no hurry to paint the car mainly because my toy budget has to include a 2nd school tuition, (why do I pay taxes again?) starting this year and my list of suspension and engine upgrades has a higher priority. Unfortunately I really like those $600 double adjustable shocks that quick racing sells.

I am in the same boat with two kids in school paying once in taxes and again. I feel your pain on that one. Yep I would also concentrate on the go fast parts instead of paint. Im going with a simple single stage paint job for this season. As fasthings has shown us you can get an incredible finish with single stage and its far more friendly to the garage paint job.





Re tow point… I knew that I was forgetting something! I looked at that about a month ago and meant to incorporate that into the front design. Thanks for the reminder. I will make it work somehow.

Yeah im sure it will be fine. The only thing to consider is when you are pulled off the track many times the sideways load is greater then the load that goes in line with the car. The tow truck is never in front of you so its a sideways pull till you get going then you are dragging the brakes to keep the tow line taught.

My setup is strong enough to lift the car if the front wheels were unable to roll. I dont think you need to go this far. I think you can easily use a red nylon strap attached to a hard point under the body as long as the sideways load is not going to crack any fiberglass.

[Fraser D]

Actually, Dave, I think I like your way better!
(Damn big license plates...how come everything in Texas is oversized? :) )

Glad I could help out, even if only minimally. Make sure you plug my vendor status so I can do this for others, too! (Shameless self promotion! :o)

No, seriously, I really like what you are doing with your car! You deserve a lot of credit for your originality and design/fabrication skills. This is a truly unique build.

Thanks Ash!
I am almost done with the body work for the front and am saving the next set of photos for the final product probably around mid this week.
It was your concept that solved the problem of both form and function and I can’t emphasize the benefits enough of having a few variations of a concept on paper to help guide the process.
Very glad that you are now able to offer this as a service to fellow builders.

[Fraser D]

John,

It looks like we are on the same page regards to the foam molds.
I am trying very hard not to ***** about our education system……… but occasionally distain seeps out.
I think that I have a tow hitch option that I will share soon. Just need to fabricate it to make sure that it will actually work..

[crash]

I would recommend shooting the foam with a build up type surface primer. You have to make sure it is compatible with your foam by trying it on a test piece, but once you get the right combo of products, this is definitely the easiest way to make a quality mold from a plug. Or even a one off from the plug, such as you did there. The primer will fill in any small imperfections and is easy to sand. Once everything is ultra smooth, then the primer is shot with a gloss surfacing coat to make it slippery. Some primers will also allow just sanding until "polished". Then a release agent, such as wax, can be applied and it is ready to make a plug or use as you did.

[Fraser D]

It was a busy weekend with a lot of good progress made.
The two piece hood modification is done bar the final assembly after the entire car was primered then plasti dipped. I was getting tired of the primer grey look so purchased some plasti dip then bribed a couple of friends who had the spray equipment with booze and food.
All that is left is to install the mesh in the openings and bolt the bits back together.
As I am so close to getting back on the road so here is a teaser pic.

[Edgeman]

That looks amazing~! very nice work on the 2 part hood.

[LCD Gauges]

Agreed, it does look amazing. Being on Ontario, I've thought about 'glassing in some sort of bracket the rad opening for the license plate.

Your design, or something similar just might work (depending on air flow to the rad).

[Fraser D]

That looks amazing~! very nice work on the 2 part hood.

Thanks, It took a bit of head scratching but it got there eventually


Agreed, it does look amazing. Being on Ontario, I've thought about 'glassing in some sort of bracket the rad opening for the license plate.

Your design, or something similar just might work (depending on air flow to the rad).

Thanks, it may be a way to reduce the original radiator opening without looking to goofy

[Fraser D]

We I have finished messing with the body for a little while. Just a couple of bits and pieces to tidy up then the focus will be on the mechanicals for upgrades.
Unfortunately the only photos that I have from this weekend the car was either covered in dirt or rained on.
Now back to the track.

[kabacj]

looks great Dave! When are you back out on the track?

[Fraser D]

Thanks John.
I am looking at a couple of opportunities to run in late March with a goal of running at Texas World Speedway before they turn it into a housing development around the middle of this year.

[crash]

WOW! I am in love with your lower nose modifications!

Looks really great.

I would be tempted to change the hood a bit, but that is probably just me, I have never liked the way the radiator exit ducts looked.

On a precautionary note, I would highly recommend putting some metal screens in front of the radiators to keep them from being damaged by small stones. Pretty much a requirement if you are going to be running it at speed on a track. I can't tell from the pictures, maybe you have this already?

[Fraser D]

WOW! I am in love with your lower nose modifications!

Looks really great.

I would be tempted to change the hood a bit, but that is probably just me, I have never liked the way the radiator exit ducts looked.

On a precautionary note, I would highly recommend putting some metal screens in front of the radiators to keep them from being damaged by small stones. Pretty much a requirement if you are going to be running it at speed on a track. I can't tell from the pictures, maybe you have this already?


Mike, Thanks.
I know what you mean by the hood but I don't have a clear picture in my mind what to do with it.
There is mesh over the rads but I am using 75% opening, not the supplied 50% from FF5

[Fraser D]

Putting the hood to use :)