Lewma's Gen3 Coupe Almost Built Thread

[lewma]

All

Should have done this a long time ago.

https://photos.app.goo.gl/3ZyXcduhUmDeDQZD8

That's my ongoing pic album that is documenting my build. No words, just pics. Hopefully the pics can provide help to other builders.

-Gen3 Coupe
-Blueprint GM427LS + T56
-IRS, AC, Power Steering


mark

[JimStone]

This is great, thank you! That's the Blueprint engine/trans combo I am interested in and there's not a bunch of information available for that in a Coupe.

Which sized driveshaft is needed?

Did you have any issues with the motor mounts or trans mounting?

How much clearance do you have under the hood? Would there be enough for an aftermarket high ram intake or a supercharger?

Thanks in advance

- Jim

[JimStone]

Also, it looks like the oil pan hangs below the frame. Did you have a solution for that?

[lewma]

This is great, thank you! That's the Blueprint engine/trans combo I am interested in and there's not a bunch of information available for that in a Coupe.

Which sized driveshaft is needed?

Did you have any issues with the motor mounts or trans mounting?

How much clearance do you have under the hood? Would there be enough for an aftermarket high ram intake or a supercharger?

Thanks in advance

- Jim

Hello Jim

- If you contact FFR and tell them the engine package you are using, you should get the correct length. I can check my inventory list when I get home for a part number
- Yes, all kinds of fitment issues when it comes to engine mounts, trans mount. Had to grind a little off the mounts and the trans plate mounts. Nothing too much but just a little with the grinder. Had to design a completely new trans mount plate as the one provided in the kit did not work for this combination. My son drew up a design and we sent it to sendcutsend.com and they did the rest. We have the designs somewhere but I'm hoping by now that FFR supplies the correct plate.
- There seems to be quite a bit of room under the hood. I can take measurements if you like

[lewma]

Also, it looks like the oil pan hangs below the frame. Did you have a solution for that?

Yes, the stock pan from Blueprint hangs a good deal below the frame. Worked with BluePrint and had to order the following:
Oil pan:

12624617

Pickup tube:

12624497

Windage tray:

12558189

Dip stick:

12570788

Dip stick tube:

12570787

Pickup tube o-ring:

12557752

Gasket:

12612350 or Improved Racing Part No. HGA-1001

It still hangs below a little.

[JimStone]

Thank you Mark

The engine sounds great in the videos. Are those the kit supplied side pipes and headers or did you go GAS'N?

I assume you got the ECU from Blueprint. How is the tune out of the box? Idle okay?

Which gear ratio did you go with for the diff? Thoughts so far?

- Jim

[Its Bruce]

What's the story on the throwout bearing?

I just recently fired up my BPE 427 LS3 and the tune is good enough to fire up, but it's very far from being good enough to count on as-is. The first ECU had a corrupt VIN and wouldn't let me flash a tune. They sent another ECU and I was able to get in. The STFTs were immediately adding fuel due to a lean idle condition. I've since turned off all fuel trims and started MAF tuning at idle. I'll be driving it over the next few weeks to dial in the MAF before going after the VE table.

[lewma]

Thank you Mark

The engine sounds great in the videos. Are those the kit supplied side pipes and headers or did you go GAS'N?

I assume you got the ECU from Blueprint. How is the tune out of the box? Idle okay?

Which gear ratio did you go with for the diff? Thoughts so far?

- Jim

Jim

Those are the standard FFR pipes, I just had them ceramic coated to fit the theme of the car

ECU seems fine with the tune that is in there however I'm planning on a Lund tune once the car is on the road

The diff is what comes with the IRS option from FFR. 3.55

[lewma]

What's the story on the throwout bearing?

I just recently fired up my BPE 427 LS3 and the tune is good enough to fire up, but it's very far from being good enough to count on as-is. The first ECU had a corrupt VIN and wouldn't let me flash a tune. They sent another ECU and I was able to get in. The STFTs were immediately adding fuel due to a lean idle condition. I've since turned off all fuel trims and started MAF tuning at idle. I'll be driving it over the next few weeks to dial in the MAF before going after the VE table.

The throwout bearing was leaking. After working with BluePrint and McLeod, they sent me a replacement bearing.
I managed to separate the engine and transmission without lifting the whole assembly out and was able to replace the bearing

No leaks so far with the new bearing

I have some MAF codes that the ECU is throwing. Still tracking those down

[JimStone]

I see you mounted your reservoirs on the firewall behind the engine. I like that because it's out of the way but do you have trouble accessing them when the body is mounted?

And is that a coolant expansion tank? Was that recommended by Blueprint?

[lewma]

Its a little tricky with the body on but I wanted them out of the way

Yes, that's an expansion tank. I read the cooling system diagrams on the engine then plumbed it in. Its likely larger than needed. Once I have more experience with this engine I may relocate it or use a smaller tank

[JimStone]

I was wondering: the LS 427 is rated at 625 hp, 565 ft-lb. So far, would you say that much power is useable as a street car? Would you choose something different if you could do it again?

I'm thinking about the 427, but I also don't want to kill myself.

[lewma]

Jim, its not street legal yet. We've just had it running around the street in go-kart mode. Yes its a step up from the coyote we have in our roadster, hopefully its not too much for street use but we'll have to wait until its running.

mark

[JimStone]

Thanks Mark. Good luck on the rest of the build

[Namrups]

My coupe has a SBF Boss 427 crate bored out to 460 cu in. 500 hp at the crank with 580 ft lbs of torque and a Sniper EFI. IRS with 3.55 gears. 18" tires. It is a beast in a 2600 lb car but IMO that's what these cars are designed for. Is it streetable ... again, IMO yes. Will I ever get it's full potential street driving? NO! By the time you shift into third you can be into triple digits. You most defiantly have to respect it but it is the most fun I have ever had in my 55 years of driving.

Having said all that, you can have a blast in these cars with a mild 302! That motor is more than enough for a 2600 lb car. But if you want to take the dragon by the tail go with the 427 and hang on!

[JimStone]

My coupe has a SBF Boss 427 crate bored out to 460 cu in. 500 hp at the crank with 580 ft lbs of torque and a Sniper EFI. IRS with 3.55 gears. 18" tires. It is a beast in a 2600 lb car but IMO that's what these cars are designed for. Is it streetable ... again, IMO yes. Will I ever get it's full potential street driving? NO! By the time you shift into third you can be into triple digits. You most defiantly have to respect it but it is the most fun I have ever had in my 55 years of driving.

Having said all that, you can have a blast in these cars with a mild 302! That motor is more than enough for a 2600 lb car. But if you want to take the dragon by the tail go with the 427 and hang on!

Scott, your SBF Boss is a monster! The torque is ridiculous and that engine sounds mean as hell. You're right, the car is designed to handle it. It's more the operator I'm worried about. I doubt I have enough restraint to not put the pedal down at every opportunity, and those Michigan trees are oh so close to the road.

Just from the re-sale standpoint the 427 makes sense though - if (gasp) selling ever was necessary. It gives that extra "fizz" factor.

[Namrups]

Scott, your SBF Boss is a monster! The torque is ridiculous and that engine sounds mean as hell. You're right, the car is designed to handle it. It's more the operator I'm worried about. I doubt I have enough restraint to not put the pedal down at every opportunity, and those Michigan trees are oh so close to the road.

Just from the re-sale standpoint the 427 makes sense though - if (gasp) selling ever was necessary. It gives that extra "fizz" factor.

Jim Your right. It is all operator. You learn real quick what 1/4 throttle is. 1/2 throttle scared me the first time. I have not even considered full throttle yet!

[lewma]

Getting closer. This is a sample of the paint color we're going with. Porsche dolphin grey.

20231030_160722.jpg

[JimStone]

Haven't seen many coupes in lighter colors. I'm excited to see how it turns out

[lewma]

Started on the dashboard. Carpeting will start this weekend hopefully.

20231105_145256.jpg

[JimStone]

Very cool custom design! Looks like a lot of work, haha

What material did you use on the top of your dash and around the digital instrument panel?

Have you had it out on the road much to have any more thoughts on the LS 427?

[MSumners]

Looking great. Are the steering wheel buttons functional? Did you add a slip ring?

[lewma]

Very cool custom design! Looks like a lot of work, haha

What material did you use on the top of your dash and around the digital instrument panel?

Have you had it out on the road much to have any more thoughts on the LS 427?

Hi Jim. Its a work in progress

The material is an alcantara. This is the first dash I've done using that and i'm still learning how it likes to stretch in some ways but not in others.

Still not got much time on the 427 apart from go-karting around the street. Seems like it will be 'exciting' to drive

[lewma]

Looking great. Are the steering wheel buttons functional? Did you add a slip ring?

I have plans on making them functional at some point. Still sourcing a coiled cable and quick disconnects so I can hook them up.

[Its Bruce]

I have plans on making them functional at some point. Still sourcing a coiled cable and quick disconnects so I can hook them up.

https://www.motionraceworks.com/prod...-wiring-system

[Papa t]

What did you use on the hood around the edge to build it up. Looks like sound kind of plastic channel. I need to do the same. Thanks

[lewma]

What did you use on the hood around the edge to build it up. Looks like sound kind of plastic channel. I need to do the same. Thanks

Papa, that's standard drywall plastic corner that you can get from Home Depot or Lowes. My hood needed extending so I used that to form the shape but lined the inner sides with packing tape. I then filled the gap with HSRF but left it a little low on the surface. Removed the channel then filled the remaining with rage gold filler. Came out great. here's a pic of the hood today.

20231107_152618.jpg

[Papa t]

Looks great. Thanks for the idea.

[MC Builders]

Mark,
I am in the midst of a similar LS3 build and I see you disassembled the engine fuse box(you are braver than I am). Did you eliminate the box altogether? I have been scrolling this AM as I was about to mount the fuse box on top of the panel over the master cylinders but without the body on I am afraid there isn't enough clearance.

[lewma]

Yes, I deleted the fuse box altogether as I'm using a digital fuse system. Not entirely sure if there is enough room for the plastic fuse box above the master cylinders but you could test fit then use the firewall as a height guide. You should be able to open that box to replace fuses once the nose is lifted.

mark

[lewma]

Painter is done, hopefully bringing her home tomorrow if not raining
20240123_073247.jpg

[JimStone]

Awesome! I'm a big fan of grays and blacks, so loving your color combo. Don't think I've seen one like that. Exciting to get her home

[rhk118]

Painter is done, hopefully bringing her home tomorrow if not raining
20240123_073247.jpg

Great color combo, congrats!

[JimStone]

Lewma, your recent Google album photos and videos are amazing! The sound is just insanity!

[lewma]

Thanks Jim. It was fun ( and loud ) driving her around the neighborhood.

DMV is the next task

Mark

[JimStone]

Hey Lewma,

The Google album pics of your coupe out on the road look fantastic.

I was wondering if you've had enough seat time to make any comments on the LS 427?

When I picked up my Coupe kit a few weeks ago, Dan Golub really tried to talk me out of the stroked LS - said it'd be too much power and I'd just be driving scared instead of having fun. So now he has me questioning doing the 427 vs the non-stroked 376 (still 530 hp).

I would be giving up that extra mean stroker sound, and the bragging rights of 600+ hp.

Much appreciated!

- Jim

[lewma]

Jim

The car is a beast. We set out to build something different from the MK4 ( Gen2 Coyote ) and we've certainly reached that goal. Is the 630hp LS too much ? probably? If you control your right foot you'll be fine. It is loud, hot, loud, hot and loud but we expected that up front.

I wish I could comment more on the drivability but I've had limited seat time. I can't get my son out of the drivers seat. The car is half way through the California DMV saga but has a moving permit. We've taken it for brake and light inspection, then to the CHP for their inspection and vin assignment. Now just waiting on the smog gods to give their blessing then we should be good to get plates and be done with DMV.

The engine as received from Blueprint has a rough tune. When we took it to the CHP, the car was stalling on the drive back home. Mainly due to 1) the bad MAF intake tube I originally built ( too short and had a vacuum leak ) and 2) although Blueprint says the VSS signal from the transmission does not need to be fed to the ECU, it actually does and allows decel / idle to behave better.

The pics we just added this weekend were from the tuning runs we were doing. I spent the money and bought the HPTuners adapter and software. Also rebuilt the intake tube per GM specs. We've got MAF tuning very close, and started on VVE / Speed Density tuning too ( lots of Youtubes ). We were out for about 3 hrs, did multiple runs/tunes and the engine is behaving very nicely. Still go to do more tuning, and especially idle tuning which is challenging due to the cam that is used in the engine.

Its still a beast but its so much fun driving that thing ( I got to drive 1 run when I wasn't driving the laptop ). At one point I glanced at the clock and it said we were doing over 93mph and I was sure the GPS calibration was wrong. Checked it on both our phones and yes we were going 93mph on a back road and I though it was 50 ish. It gets up there so easily.

More engine tuning to come and there's a boat load of tidy up tasks to do as well but so far no regrets at all with the LS engine choice.

thanks!
mark

[Alan_C]

https://www.motionraceworks.com/prod...-wiring-system

Very interested in this product and looking forward to you installing and using it. I plan to install a 10R80 into my coupe and I want operational paddle shifters.
I have seen this kit which looks like a decent quality solution for a good price.
https://www.seemslegitgarage.com/pro...n=freelistings
I would like to see the mono-cord steering wheel wiring system and these paddles working together.

I had been looking for a more conventional clock spring type adapter for the paddles, but nothing out there I have seen was designed for aftermarket columns like those from Ididit. The Factory Five column is simpler but has support for the same steering wheel I will put into my 70 Mustang restomod. Looks like I will have to buy these two kits and see if they will work with the FF column and then possibly the Ididit column.

[JimStone]

Jim

The car is a beast. We set out to build something different from the MK4 ( Gen2 Coyote ) and we've certainly reached that goal. Is the 630hp LS too much ? probably? If you control your right foot you'll be fine. It is loud, hot, loud, hot and loud but we expected that up front.

I wish I could comment more on the drivability but I've had limited seat time. I can't get my son out of the drivers seat. The car is half way through the California DMV saga but has a moving permit. We've taken it for brake and light inspection, then to the CHP for their inspection and vin assignment. Now just waiting on the smog gods to give their blessing then we should be good to get plates and be done with DMV.

The engine as received from Blueprint has a rough tune. When we took it to the CHP, the car was stalling on the drive back home. Mainly due to 1) the bad MAF intake tube I originally built ( too short and had a vacuum leak ) and 2) although Blueprint says the VSS signal from the transmission does not need to be fed to the ECU, it actually does and allows decel / idle to behave better.

The pics we just added this weekend were from the tuning runs we were doing. I spent the money and bought the HPTuners adapter and software. Also rebuilt the intake tube per GM specs. We've got MAF tuning very close, and started on VVE / Speed Density tuning too ( lots of Youtubes ). We were out for about 3 hrs, did multiple runs/tunes and the engine is behaving very nicely. Still go to do more tuning, and especially idle tuning which is challenging due to the cam that is used in the engine.

Its still a beast but its so much fun driving that thing ( I got to drive 1 run when I wasn't driving the laptop ). At one point I glanced at the clock and it said we were doing over 93mph and I was sure the GPS calibration was wrong. Checked it on both our phones and yes we were going 93mph on a back road and I though it was 50 ish. It gets up there so easily.

More engine tuning to come and there's a boat load of tidy up tasks to do as well but so far no regrets at all with the LS engine choice.

thanks!
mark

Mark,

Thanks for the response. Lots of good info there.

Happy to hear you and your son are enjoying the end product of your labors. It certainly looks and sounds like a beast. Whether it's 625 hp or 530, it'll be a handful and require a delicate right foot.

You do have me worried about all the tuning concerns. I'm a complete novice when it comes to that. I am planning on using Terminator X Max EFI/ECU which has self-learning capability, but I'm sure that opens a whole other set of potential problems and won't be just set-it-and-forget-it. I hate farming anything out, but I'll probably need profession help when it comes to that.

[lewma]

I'm a complete novice too when it comes to tuning but I'm reading a lot and taking it slow. Documenting each change then reverting the change if needed. There's a load of videos to watch where they explain it step by step. I can already see the improvement and the logs say I'm moving slowly in the right direction.