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

[Mr_Roboto]

My Astro has a 2.5T L-L box in it if you want it, I believe that the stops would be compatible but do your due dilligence. Did you use the adjustment screw on the top to try and tighten it up? Worked wonders on my Escalade box but it took a few iterations.

Another thing is has your rag joint been swapped out? If it's loose AF doing a steering shaft upgrade isn't a bad idea.

 

[bs009]

I'm sure the exhaust note is due entirely to that downpipe routing.

Oh yeah I agree 100%, crazy how much of a difference it made!

My Astro has a 2.5T L-L box in it if you want it, I believe that the stops would be compatible but do your due dilligence. Did you use the adjustment screw on the top to try and tighten it up? Worked wonders on my Escalade box but it took a few iterations.

Another thing is has your rag joint been swapped out? If it's loose AF doing a steering shaft upgrade isn't a bad idea.

I haven't adjusted the new box yet, but it's definitely on my list of things to do. I was hoping it was pretty much ready to go out of the box though since I bought this one new. I'll do some testing with it though before I try a new one.
I'm using the jeep shaft now though so no more rag joint to have to deal with haha!

 

[bs009]

Well the spark plugs fixed the misfire, car runs great now!
Only problem is that now the tee for the turbo feed and oil pressure sensor decided to break itself where the threads bolt into the oil sender. I don't have a new tee or time to really dig out the old one so the car is going to get some rest here this weekend instead of driving its way to Michigan.

Here's a short unedited video of the noises this thing makes though. The videos don't really do it justice in my opinion though lol

 

[Mr_Roboto]

Good on the plug fixes FU on the tee. I've been living vicarious through you 3 3800 Turbo RWD guys on the wrenching side.

 

[GTPpower]

Sounds just like the beginning of 2fast2furious when Paul walker is rushing to the race in his skyline.

 

[sktchy]

Ugghhh hearing that makes me want mine done and back together

 

[bs009]

Got the oil tee replaced today and took the car out for another drive. Was really foggy out though so I couldn't really do much with it.
Managed to get the car a little sideways though without really trying too hard It was a little wet out but I can tell I'm going to get into a lot of trouble now with the new rear end

This car is finally starting to feel like a quick car and it's so much easier to drive with the new rear end! Absolutely a night and day difference! Can't wait to get this thing on the road again this weekend

 

[bs009]

So I'm fighting a misfire at idle in this thing right now and tried a lot of different things to solve it. Definitely no vacuum leaks that I've been able to find, fueling changes don't seem to make a difference and I've tried a lot of wild changes.
Put a new MAF into it too, then went and got another set of 80# injectors just in case these ones that have been in the car for 6 years are having some sort of issue.

Learned how to make my own plug wires today too which was way easier than I thought it would be

I can finally get rid of the rainbow of plug wires I've been running for the last year

old injectors had some oxidation on them, probably from the tank or the fuel rail. This car always has E85 in it even when it would sit for 4 months in the winter time.

new fuel injectors made no difference though so I'm confident the issue is spark related now.
I had the plug gap down to the 25 ish range, so I adjusted it up to 32 tonight. I'll see how that goes tomorrow but it seems like it helped a little. I'll need to see how that gap handles 20 psi though before I try to go bigger.
I might even try a case learn since I've been hearing about it from you guys a lot lately. Never done one before so it's probably worth doing.

Also finally installed the fuel pump I bought for it a year ago when I needed an excuse to spend $100 at summit for Cleetus pay per view tickets for the 2.4 hours of lemullets
Just realized that it's pretty much exactly a year ago that I bought this thing lol

new 450lph walbro on top, old 255lph on bottom

old fuel pump somehow got some crud past the sock on it

Never noticed any issues with it though. This pump has been a trooper but I think with the 1.9's and the new turbo it's not going to be able to keep up

 

[bs009]

Car's been working great for the last few weeks. At one point the fuel tank sender's harness melted from the new pump though so I had to drill a hole and just run wires through a grommet with fuel safe RTV to fix that. It's been pretty good lately, this car has come so far in the last year and it's so much more enjoyable to drive. The best part of driving this thing is that everytime I try to get gas in this thing there's almost always someone there who has a story about an old GP like this or they're just a fan of it haha!

Finally got around to testing out the 2 step again at least without actually trying to launch it.

2 step might need some tweaking though but every 3800 needs to sound like this thing

 

[bs009]

2022 Season Prep

So it's looking like 2022 will be a year of some small changes for it, nothing too crazy yet. I'm currently in the process of having a house built so I'm trying not to go too crazy on the car this year. I've been really hoping to switch the car over to Holley EFI this year but I think that might have to be a mod for next winter when I hopefully have some more garage space. If this year goes well though then I may still try to squeeze the Holley in the budget. ?

I picked up a few parts from somebody I know who's been out of the 3800 world for a while but still had a few things left over. Got some things that I'm going to use that should be pretty cool for it so I'm pretty excited about it.

This is just a stock short block of his old motor that I was planning on using but it looks like it's going to need a bit of work to get it going the way I had hoped. Some of the cylinders have some rust and the cam bearings look like they need to be replaced and I just don't have the tools to do that right now. Might still look into that though depending on how the other motor looks.

This is just another junkyard engine that should be pretty much ready to go.

Now for the gooder stuff:

Those are heads that were ported and then sent to a machine shop for larger valves and some cleaning up. Not sure if they're as good as some of the other heads out there but they look better than the heads I ported so far and have larger valves in them. That and the cam should really wake the car up even more.

As for the cam I know what cam it's supposed to be, but it's also possible it's a stock cam too since the part number at the end of it came back with nothing in Google.
It's not an ST5 cam and it's not the cam I had planned on running but it's still a really good cam on paper. If anyone wants to guess I'll leave a hint that this cam gets a lot of hate pretty much everywhere it's mentioned in the 3800 world . This one is an OG cam
I also have another cam as a backup that should be coming in the mail some day if they ever decide to ship it out. I ordered it a long time ago but I figure if this happens to be a stock cam then that other cam should be good to go as a backup. Otherwise that'll be for the next project instead.

I'm a little worried about my current motor and heads, I know the engine block has been overheated at least once and I've blown a headgasket on it, probably 2 now honestly since I think I used the L36 head gaskets instead of the L67 gaskets. So the plan is to build one of the other engines on the side while I still drive the crap out of the car to local events. Then once the engine is ready I'll just swap it in and start getting the current engine refreshed as a backup or to get it ready for the next project I've been wanting to do.

So this car should be getting some lope in its idle for Power Tour! I can't wait to hear this exhaust with an engine that (hopefully) revs to 7,000 rpm!

 

[bs009]

Took the GP out to my first ever autocross event. I was kinda iffy on even going but oh my god I'm so glad I did!
I've never had so much fun behind the wheel of the car before and I think I'm hooked now!

I started off the day with a 74 second run, then managed to work my way down to a 70 second run, then worked it down to 64 seconds.
Fastest run I saw of anybody all day was 53.8 seconds. Most of the pack was around 58-70 seconds though that I saw. Huge turnout and I was able to get 5 or 6 runs in before I called it a day.

I never left 1st gear in this course and towards then end I had some trouble getting the transmission out of gear. I'm a bit worried the synchros might be unhappy but it could also be that the clutch isn't getting released all the way.
I managed to bend the rod for my clutch master cylinder or at least this was when I noticed the issue.

The car has some suspension upgrades: lowering springs, KYB GR2 shocks, 19mm hellwig pro touring rear sway bar, 34mm 3rd gen f-body front sway bar, and the boxed frame. But It still needs a lot more to really be competitive. The body roll is a little insane lol
The rear end is going to need more tire too because this thing really likes to kick the tail out coming out of the corners, the new rear end really woke the car up big time and it was extremely noticeable on the track!

I managed to get some video without audio of one of the runs but the gopro mount wouldn't hold it very well. I'm going to order a suction cup mount though now. I have no idea why the gopro didn't capture audio, I've had nothing but issues with it





Here's my bent clutch master cylinder rod.

I'm going to try and revisit the whole pedal situation, maybe just redo the whole brake/clutch pedal assembly because it's really tight between all of the pedals and I know the clutch pedal has some flex in it that probably caused the bend. I'm sure the stage 5 clutch isn't helping either.
I think I'll just cut out a chunk of firewall too because the master isn't exactly lined up with the pin on the clutch pedal. Then I'll just weld in a thicker piece at the same area maybe.

I've also thought about going with something like a Wilwood pedal assembly but I don't want to take out the whole dash again in the garage I'm at. Would love to find a strong pedal assembly that just bolts in though.

Also saw this badass Malibu there that has me really wanting to stick a huge tire in the back of my car now.

I really don't want to have to cut up my frame though lol

 

[Shawn1112]

Holy fuck, how did I miss this? That’s fucking sick AF

 

[bs009]

Realized I hadn't updated this thread in a while.

I fixed my clutch with a quicker fix for now to get through a while longer. Eventually I'll brace it against the pedal box but for now it's holding much better than it did before.
I cut out the firewall where the master bolted in and rewelded in a piece of thicker sheet metal with holes that aren't ovals and it's been much better since.

So I'm finally getting over to doing the cam swap and the plan is to use a spare motor I have, prep the whole thing as much as I can and then transplant the engine into the car to minimize downtime.
This was a great theory until I realized I will absolutely have to reuse my old intake manifolds and timing cover because I need to use my threaded heater core ports. So some of it's can get done on the side but I'll need to wait until I can disassemble the old motor before I finish assembling the next one.

So here we have a mysterious junkyard L67 short block I picked up from a friend of a friend:

I went and assembled the new ported L67 heads. These were home ported a long time ago and then had larger valves installed by a machine shop. The car these were in was supposed to be pretty quick for a supercharged car and I'm sure with the larger valves they'll flow more than mine. It also looks like the valve guides are already cut for more lift.
I'm also reusing his old camshaft too so it's a bit like his old motor is being resurrected with a big turbo instead of a supercharger.

Heads assembled with new valve springs, lapped valves, and new stem seals:

MLS gaskets and ARP head studs:

3/8" Pushrod clearance is a bit tight by the stock rocker pedestal. This cam has tons of lift otherwise I'd go with a different rocker arm

This is the most I've ever actually put into an engine now and it's pretty much going to be the penultimate engine "build" for this car.
- MLS head gaskets
- ARP 12 point head studs
- PAC 150# valve springs
- 3/8" pushrods
- LS7 lifters (the expensive AF ones, p/n 12499225)
- double roller

I also bought yet an even bigger turbo for this thing. Hoping to make 600+ whp with this thing and that would be stretching the limit of the one I just installed. New turbo is a GT45 knockoff with a 69mm wheel. I'm hoping it basically bolts up where the current turbo is since they're very similar.
Side by side of this new turbo vs the first turbo I was running back when I first put this car together:

I'm also going to be working on converting the car over to the Holley EFI system. I bought a Terminator X a couple months ago and just haven't had the time to get anything done since February. Eventually I want to rewire the whole engine management system but I'm planning on just making as few changes as possible to the power distribution under the hood. It looks like I might have to still use my current PCM as a way of sending a speed signal to the speedometer and to enable/disable cruise control.
I'm really short on time to get all of this done so the wiring is going to be really frankensteined to get it converted quickly.

I'm using the LS1 harness since I figured a lot of the connectors would fit 3800 stuff. I'm going to have to splice a lot of things like the crank, cam, IAT, coolant temp, knock sensors, and a few other small things to make it work. It's a bit more than expected but it's not a big deal at all.

With the Holley conversion I'm also going to be switching to LS coils and at the moment I'm working on getting them mounted on the engine.

Driver's side fits nicely:

Passenger side is going to be tight with the AC bracket and the oil fill there but this should work

 

[v6buicks]

Oh man. You're getting serious!

You're also making me worried that I'll need to get my valve guides ground down for my ST5. I keep hearing more and more about this and didn't know it was necessary.

 

[SleeperLS]

I love this car. The two step sounds awesome

 

[bs009]

Oh man. You're getting serious!

You're also making me worried that I'll need to get my valve guides ground down for my ST5. I keep heart more and more about this and didn't know it was necessary.

Yeah the valve guide thing is still a bit of a mystery to me, I've heard the stock heads can take like .515" of lift and the ZZP modded retainers are advertised to add .050" of lift so it might be okay without milling down the guides for the ST5 cam.
I noticed I still have a good bit of room, but I'm not sure what that will look like once the lifters get pumped up. It seems like there's too much room on my heads for these to be stock though. I might have to measure them tonight and compare to a set of heads I have.

 

[sktchy]

I can't remember where I saw it but I rember seeing the modded retainers were .080 of extra clearance? May have been on the intense site. I don't think I ever saw where zzp had the extra clearance listed but I guess we'll see if I run into issues with the intense stage 4 turbo cam. If it'll clear the st5 will be fine as it's just a touch less lift iirc.

Take that with a grain of salt we all know how I slapped mine together. I love where this build is heading tho

 

[v6buicks]

Maybe the new ones have more clearance than the old ones? I remember being pissed because I bought my retainers right before they were updated in some way or another.

 

[sktchy]

Thats probably what it is but i dont wanna say i know for sure. I do believe I have the updated retainers and pretty sure I spent a night or two rabbit holin to figure out if I could make it work or not

 

[bs009]

Cleaned up the car and took it the GS Nationals for its last run with the engine it's had for the last 2 years. This is the cleanest the car's been in a while and man do these wheels make me happy when they're clean!

Really cool to finally see the Camaro behind this thing in person!

Went ahead and pulled the engine out last night. Had some hiccups figuring out what to unbolt around the bellhousing since I have the adapter plate, bellhousing, and transmission bolts I could've unbolted. Seemed like the trans bolts were the easiest thing that would come loose.

I think I found my exhaust leak(s)

Made the bracket for the new coils finally:

passenger side is crooked but nobody's going to ever see it anyway

Managed to fit the fuel rails and figure out where the lines will fit around the Camaro intake and the coil bracket. I notched the coil bracket so the lines would fit down the valve cover but I think I'm going to see if I can tuck it behind the intake instead of over the top of it

1" NPT oil drain into the new pan for the turbo:

-12AN valve cover breathers into 3/4" barb fittings. Since the valve covers are fiberglass now with the L67 heads I had to buy bulkhead fittings instead of threading into the valve covers. Seems like it'll work pretty well but it's going to be a tight fit

Hoping to have the motor assembled today but there's a lot that can go wrong.

 

[Mr_Roboto]

Racecar engine right there.

 

[SleeperLS]

Those coil brackets turned out really nice.

 

[v6buicks]

NICE! That picture of our cars turned out better than mine.

Do you have an NPT bung welded to the inside of your pan? If you're just threading that fitting into the stamped sheet metal then I think it's doomed to leak even with sealant. If its a steel fitting you can just weld it in place too.

I agree that those coils are sexy. The valve cover breathers are cool too! I wish I had room between mine and the firewall to do something like that.

 

[bs009]

I have a few more pictures of our cars like that haha!

I agree about the coils, really excited with how all of this stuff is starting to look!

So I did just thread the npt bung and wasn't sure if there was enough meat there to actually allow it to seal. I'm thinking of just using RTV instead of sealant though, that shouldn't leak right? lol
I'm going to be adding another sensor to the pan below the oil level to measure the oil temperature so I'll need to do the same with that. I could weld a small plate on the pan so it has more meat for that and then tap the plate... or just RTV the sensor too

I'm going to be adding a few more sensors to this thing while it's out and I'm getting pretty excited for that haha!
- oil temp
- coolant pressure
- exhaust manifold pressure pre-turbo
- flex fuel sensor
- dome pressure

Going to be a ton of wiring that I'm looking forward to.
I'm not looking forward to pulling off the oil pump cover though, last time I had the timing cover off the torx bolts would not budge at all. Probably going to have to use the torch or weld a nut on them to get them to come off

 

[v6buicks]

Eh. I guess the RTV would work as long as you don't give the fitting any reason to wiggle in the pan. Just make sure it gets reasonably tight.

Do you already have a fuel pressure sensor? That's probably my next piece of instrumentation. Also, what's dome pressure?