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