🔧 BUILD Turbo 3800 T56 Swapped G-body Grand Prix w/ Holley EFI

[Mr_Roboto]

90 bucks at the Joliet U-pull gets you a diff assembly. If it will work (I think you may have less splines) I'll donate my 3.23s your way if/when I swap the Astro to something else. They had a ton of 3.42 and 3.73 axles at the yard, that'd be my choice in your case.

At the very least I'll try to check the g-body they have there to see what ratio it is.

 

[bs009]

It'd be really cool to find a g-body with a good ratio. It seems like they're pretty hard to find though. Something in the low 3's would be perfect I think too.

I'm trying not to put much money into the 7.5" axle I have since it probably won't hold up in the longterm. I don't quite want to swap to the 8.5" yet either though since that will need a new driveshaft.

If I can get something cheap though then that would be really cool! There's a yard around here that has a few g-body's sometimes. I might have to stop by there to see what they have.

 

[Dirty Vegas]

Did you get the trans out of an F-body? There are some significant differences between the V6 3800 4L60e and the V8 4L60e's. There is also a difference between the LT1 and LS1 4L60e's. I know the V6 4L60e has a weaker input shaft with less splines, and there are mostly shitty converter options out there for it. I had a PI converter in my 2000 Firebird V6, and it worked fine at a much lower power level than it sounds like you're running. I had a cam and nitrous. It would 60' in the 1.6x range with the stock 3.42 gear on a 150 shot.

A very good friend of mine has a 2000 Camaro 3.8 with a custom built twin turbo setup, and she has smoked countless transmissions in that car over the past 10+ years. I know she was having them built by FLT for a while, but I'm not sure they are around anymore. They used to be based out of Naperville.

 

[bs009]

Did you get the trans out of an F-body? There are some significant differences between the V6 3800 4L60e and the V8 4L60e's. There is also a difference between the LT1 and LS1 4L60e's. I know the V6 4L60e has a weaker input shaft with less splines, and there are mostly shitty converter options out there for it. I had a PI converter in my 2000 Firebird V6, and it worked fine at a much lower power level than it sounds like you're running. I had a cam and nitrous. It would 60' in the 1.6x range with the stock 3.42 gear on a 150 shot.

A very good friend of mine has a 2000 Camaro 3.8 with a custom built twin turbo setup, and she has smoked countless transmissions in that car over the past 10+ years. I know she was having them built by FLT for a while, but I'm not sure they are around anymore. They used to be based out of Naperville.

It did come from a 97 Camaro that had a 3800 in it. I'm not sure of the differences in years myself, but when it comes time to rebuild it I'll be sure to put in whatever updates the later designs had as much as I can. It seems like the only thing I might not be able to update is the input shaft unless I find a way to get a special torque converter with 30 splines and the v6 engine side.

I'm not sure what really goes on these things yet but I guess I'll find out.

 

[bs009]

So I found that the 98 and 97 tunes have some differences in the TCC tables. I used the 98 tune to copy the changes over to mine and didn't think to check the 97. (The trans is from a 97)

could this be why I'm having a tcc code? P0742

97 on the left, 98 on the right:

again, 97 on left, 98 on the right:

It seems like the apply rate table is very different between the two. Looking up part numbers though it looks like the 97 and 98 use the same solenoid. I'm not sure what else could be different to account for the change here.

 

[Dirty Vegas]

So I found that the 98 and 97 tunes have some differences in the TCC tables. I used the 98 tune to copy the changes over to mine and didn't think to check the 97. (The trans is from a 97)

could this be why I'm having a tcc code? P0742

97 on the left, 98 on the right:

again, 97 on left, 98 on the right:

It seems like the apply rate table is very different between the two. Looking up part numbers though it looks like the 97 and 98 use the same solenoid. I'm not sure what else could be different to account for the change here.

I'm not sure enough about that to give you a firm answer. I do know that 97 is kind of a bastard year because they were still fully integrating OBD2. Are you on any of the other forums? Camarov6.com? fullthrottlev6.com?

Have you confirmed the wiring pin outs? Cause I'm pretty sure I remember that you can't swap a 97 PCM into a later car. I know I sold a guy a 2000 harness and PCM for his 97 so he could run the later PCM. It wasn't straight up plug n play. Sorry I can't be of too much more help, as I was really into this stuff like 15 years ago... Do you know how much drinking & drugs happen in 15 years!??!! I'm lucky I still mostly remember my own name at this point!

 

[bs009]

Haha!

I could totally get that the 97 pcm tables would just be odd lol. I had a 97 Bonneville for a while and remember there being some odd issues occurring if I touched some tables or even changed the shift points.

I'm sure I have the pins right though. I followed my service manual for the 98 Camaro and did notice that some pins were moved from where they were on the 97 harness.

I'm on a few other forums, but neither of the two you mentioned.

It sounds like the 98 tables might be correct then, but I think I'll try these changes anyway and see if that makes a difference.

 

[bs009]

I'm hoping to take the car to the strip in the near future here before the season ends and see how much boost I can put into it before I start to see KR.

I have a cheapo ball and spring style manual boost controller that I'll throw on there to try and put some more into it. Right now it has 6 or 7 psi springs in the wastegates and I've been having an issue where the boost will build up quick and slowly start to drop after getting into it.

I think what is happening is that the wastegates aren't getting enough pressure in the bottom half soon enough to open to regulate at such a low pressure. It also explains why I have such a weird MAF curve. Here's what that looks like for a few of the pulls I made recently:

I think I'm going to see if I can put some larger hoses on the wastegates and put a little pressure in the top. Maybe if the bottom section of the wastegate is slow to build then the top will be slow enough to build too. I'm hoping I could push something like 15 psi out of this setup before something breaks or I see KR, or I guess max out the MAF.

I was originally thinking that I'd have to redesign my wastegate perches but it looks like I might be able to get away with not doing that if it's just a hose issue.

 

[Dirty Vegas]

Hopefully someone with more turbo knowledge than I can help you out with that issue. I do remember the L36's not taking much more than 10psi in stock form. There was a lot of weird bad information back in the day about turbocharging. Everyone was beyond paranoid of breaking any parts! It's much easier now to get used parts and repair engines quickly.

 

[bs009]

Yeah I've been stumbling on a few really old threads where people were talking about how dumb you would have to be to try and put boost in the L36 lol.
I'm sure mine will break eventually here, but when that happens I'll be replacing it with an L32 shortblock if I can find one cheap enough. If that happens it will be getting a lot of engine work.

My issues with the boost level have to do with my wastegate setup though right now. I think I do need to go back and redo the passenger side wastegate so the exhaust flows into it easier. Once I do that I want to get an electronic boost controller and different springs for the wastegates.

I'm running full E85 in it right now and a huge A2A intercooler so it should be able to take what I want without showing KR. Otherwise the motor is completely stock and it's been taking the boost really well. I've had it at the stock AFR's since I started driving it and very rarely will see knock, especially after I went to E85. I'm also giving it 18-19* of timing too and it's been super happy.

When I go to the strip and turn the boost up I'll drop the AFR's down to the 11's or 10's to see if it likes it if I start seeing knock.

 

[bs009]

I wasn't able to get the car to the track around here since they closed early on what was supposed to be the last weekend of the season.
I did put the manual boost controller on the car now though and that solved the issue where boost was dropping off. It's now hitting 16 psi on the lowest setting on the boost controller which seems to be just fine for the motor.



Next year I'm going to have to really push this current setup and see how much power it can make before I start doing valvetrain mods.
As it is this thing hauls even with AFR's as rich as they were during that run.
It was the last time out for the year so I didn't bother to look into the AFR's. I think that was just because of the winter E85 blend.

 

[SleeperLS]

I like it a lot

 

[bs009]

Anyone else going on Power Tour this year? Because this car is!

/tease

 

[bs009]

So I've been planning on taking this car on power tour for a while, but I've been waiting for other things to straighten out. I finally have my own place where I can work on the car though so I should be able to hammer everything out in the next 2 weeks.
I know it's going to be a long trip so everything needs to be straightened out and good to go. I should have all of the kinks worked out for it.
So between now and the trip I've been working on:
- adding air conditioning to the car
- adding a trans cooler
- replacing the radiator fans with low profile units
- ironing out radiator hose issues.
- fixing all of the exhaust leaks
- cleaning up some of the wiring

So here it is at its new home:

starting the teardown:

added a new evaporator:

and a new condensor and trans cooler:

I also flipped the intercooler to help reduce some of the extra plumbing. I still need to sort out how that will connect to the motor and the turbo but I'm pretty sure I cut out at least a foot of 3" plumbing.
Before:

After:

The next thing that needed to be fixed was the exhaust. Some of the v-bands weren't sealing properly and things just weren't lining up in general around the turbo causing some exhaust leaks. I took everything over to my brother's house to straighten it all out:

mounted up on a spare block to make sure everything fits perfectly in the GP:

New V-bands, 2 new flex pipes, and the downpipe is now braced much better:

The biggest challenge now is adding A/C to the car. I'm going to try to use the entire factory system from the G-body but use a compressor from a Camaro. This means I just need to find a spot to put the compressor and get the manifolds for it adapted.
This also means deleting the factory tensioner bracket and finding an alternative to the coolant elbows. We're still working on a solution for intake manifold port but I think we have it figured out now.

This is a bracket I dreamed up that hopefully will work out:

plasma cutter is amazing btw!

Test fitting it after many cuts and tweaking:

Seems like the biggest challenge is going to be getting the a/c hoses conneected and fitting properly in there along with a belt tensioner and the heater core lines.
This will be make or break for the A/C system and will determine if I've wasted weeks on this.

Here was the solution for the heater core lines: welded in 1/2" NPT fittings into the timing cover

planning on plugging this hole in the intake and tapping another one elsewhere since there's no way we could fit a tap there. Seems like the best solution so far but we'll know tomorrow if that'll work or not. It should work but welding on aluminum is tricky:

Also these fans should be pretty nice:

 

[bs009]

Really getting down to the wire here now. I need to leave Friday morning and there's still a lot to do


intake port plug:

Finally welded in. This was a hug PITA and I still don't know if it will leak yet.

I tapped the UIM to move the heater core fitting there. I misjudged how close it would be to the throttle body so I had to modify my fitting too so I could go WOT.
I also added the factory sensor for the Grand Prix so my coolant gauge actually reads properly.

I also replaced all of the radiator hoses and added this sweet looking stainless pipe that moves the radiator outlet to the other side of the car:

New gauges finally added:

I've gotten the A/C compressor bracket pretty much finished now assuming I don't have any issues with the belt alignment.

I also relocated the PCM to the cabin so there would be room for the A/C components.

At this point the car is basically back together. I still need to:
- add a serpentine belt and make sure it's the right length
- route and plumb the heater core lines.
- make my own A/C compressor hoses.

Nobody local to me wants to touch these AC hoses for whatever reason. I ordered 4 different hoses trying to find something that fits close enough and nothing has.
Today I ordered an overnight shipment of individual fittings from Summit and hopefully I can get those lined up enough that a hydraulic shop can just crimp them for me.


It's really up in the air right now as to whether the car will have working A/C or not. The new bracket might not line up properly, the fittings might not work, and I might not be able to get the fittings done in time.
The weather looks like it'll be hot and rainy so I'm really hoping I can sort this all out.

Today I'm hoping to fire the car up again and get it up to temp to make sure there are no leaks from the trans cooler or coolant lines. I'm leaving early on Friday so everything has to be ready and there's a lot that can go wrong.

 

[Mr_Roboto]

Power Tour? Majorly jealous. This car is still cool AF, and it's neat to see the incremental improvements.

 

[10sec]

Plenty of time! Scary doing all of that work and then leaving for PT

 

[Mr_Roboto]

Plenty of time! Scary doing all of that work and then leaving for PT

That is why he will have glory.

 

[bs009]

I know it's a late update, but the car did pretty well on the trip and actually made it the whole way!

Leaving home in the car I thought for sure this was a mistake, but I couldn't think of anything that would go wrong during the trip so I kept going.

The car is actually really good on the freeway! the 2.41 gears and the 4l60 netted some really great gas mileage (22-ish on E85) and the thing rides relatively smooth for its age. The gears in it though made it sit around 1800 rpm around 70 though so pretty much any time I needed to accelerate it would have to be in 3rd gear. It was just a little annoying but it had tons of power in 3rd since boost will build from as low as 2200 rpm.

Here it as at the first hotel:

The first stop in Bowling Green was one of my favorites. They had drag racing there, autocross, and the venue had tons of shade and was laid out fairly well. It did rain there but that wasn't too bad.

The biggest issue though was the car overheated going into the event with all of the traffic. It was pretty close to 100 degrees out that day and sitting in traffic around all of the other cars putting out their own heat did not help the cause. The motor hit a little over 230 before I shut it off. That was pretty much a constant battle for the whole trip.
Needless to say, the fans will need to be addressed again now that the car is home.
The car also started to leak some oil after sitting at a stop too long or in traffic too long. That made for a lot of weird glances sitting in traffic while trying to get into the venues. It's probably just leaking valve stem seals though so that should be a quick fix.

Here it is at the first venue:

This was basically my view though for the whole trip.

Not too bad IMO

The drive coming into Chattannooga was awesome! Lots of twisting back roads and also some really great views:

btw, I removed the muffler and added a blow off valve before the trip and the sounds this car made were AWESOME imo



Here are just some random shots at some of the venues:

At this point I finally spent some time polishing the chrome on the bumpers lol:

I thought this was pretty cool too!

Finally punched the whole card:

And my car was also part of an article from Car Craft too!
https://www.hotrod.com/articles/car-crafts-top-10-rides-hot-rod-power-tour/

Some of the info in there was wrong, but who cares?! The guy who interviewed me probably didn't take the best notes.

All in all it was a good trip, if I did it again though I would plan on doing my own thing in each city or on the drive rather than relying on their own itinerary.
On the way back I took the car through the mountains in west virginia and this thing was amazing through there! The turbo made driving up the grades so easy, it felt like the car didn't give a shit.

Now that the car is home I'm planning on putting a fresh tank of E85 in this thing, going to the dragstrip and turning up the boost until it starts to knock or something breaks! lol

 

[Mr_Roboto]

Got some miles under your belt and some ink too. Totally awesome.

 

[CMNTMXR57]

Nice man!

 

[CHI2000GTP]

Awesome trip man! Glad you documented it with all the photos.

 

[10sec]

Read everything and enjoyed all pictures, awesome trip!

 

[IDAFC21]

Nice!

 

[SleeperLS]

Awesome man!