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

[v6buicks]

I'm so happy to see this car getting attention again. I was scared that you were going to give up and move on to another project.

22 lbs! Nice! Any idea on your quarter mile time?

 

[bs009]

I haven't bothered to go the track in forever because it still has the 2.41 gears and an open differential ?
I'm thinking it should be trapping a little over 110 with that amount of boost and if it could actually launch it should be in the mid to low 12s

That does remind me though, I learned this car actually weighs a little more than I thought it did. I found a local person doing corner weight testing for pretty cheap so I had it weighed late last year

She's a big girl for a g-body

I'm pretty sure I'm reaching the limit of what this turbo can do up there though, it honestly feels faster to me at around 18 psi than it does at that boost level. Could also just be the valve float issue everyone is always talking about but I'm not sure.
With the head gasket failing too I'm a bit afraid to take it back up to that level of boost again until I can get the heads and block decked and some MLS gaskets in there. Ideally even a set of fire rings there too to help keep things in place haha!

For now I'm going to keep the boost down a bit so I can feel more comfortable revving it out though.

 

[v6buicks]

Oh yeah, I keep forgetting that you still have the stock 7.5" rear. I'll have to keep my eyes peeled for some decent deals on 8.5"s for you. Haha

I know there are people who are going to say forget about MLS. I'd probably be more scared about breaking a piston or something with well sealed MLS, but I'm nowhere near ready for that much boost either.

 

[bs009]

If you can find a good one for cheap I'd probably be all over it, but I haven't had much luck finding anything that I felt good about. I had a 3.73 axle in here at one point but it needed a new gear set since it was howling so bad

I'm pretty much at the point where I'm ready to just start saving for one of those ebay 9" axles made for these cars

I think the most likely next step for me for engine power would be to put a bigger cam in here so I don't have to put so much pressure down the tubes, but I think I'll need a way to get a bigger compressor wheel in there before I can do that. It's so stupid fast as it is though already, enough that every time I run it hard I'm worried about breaking another transmission or something else in the engine ?

I'll just go ahead and stop thinking about more power , reliability and drivability are going to be the mantras for this car this year ?

 

[v6buicks]

Lol! You still just have the stock cam right? I saw a guy selling an ST5, LS7 lifters and 150# springs for $600 or something and I started liking my chops a bit... I love the way the ST5 sounds, but I'm pretty positive that I'd end up regretting it when I leave a whole bunch of low end torque on the table.

 

[bs009]

yuuup I am right now. I like the ST5 but I really want to try a custom grind with a lot more duration though. A lot of the modern LS cams have a ton more duration than what any of the 3800 cams have so I want to try something like that especially considering how bad these heads flow in comparison to other engines.
I would probably have jumped on that deal though if I had seen it, especially if it had the timing chain and machined oil pump cover too

 

[bs009]

Won't need any help finding a rear end now. It'll be a while before it gets here but I finally caved and ordered a brand new rear end!
Should be a no fuss solid unit compared to the last few I've been wasting time with.

Probably won't be here in time for power tour though. 8 week lead time to get it produced supposedly

 

[v6buicks]

Hell yeah! What gear ratio did you go with?

 

[bs009]

Settled on a 3.50 ratio for this round. Didn't really put a lot of thought into the 3.50 ratio, but I know that a 3.42:1 would be ideal for this with the current tire size, trans ratios, and rpm limit for the 1/4 mile. Apparently Ford uses different ratios though so I settled on 3.50 instead. I figured I can always get a taller tire for the strip if I need to.
Differential is going to be a Eaton Truetrac since it seemed like the best option for autocross, twisty roads, racing, and everything else.

really hoping it arrives early though, would love to be able to have some burnout action at the hotels with both tires participating instead of just one!

 

[RebelGTP]

God Damn, I am way late to jump on the nutswinger's bandwagon for this G Body... But nonetheless, here I am now!

 

[Rdrnnr]

God Damn, I am way late to jump on the nutswinger's bandwagon for this G Body... But nonetheless, here I am now!

Same

 

[bs009]

Going to be a good time to start following for sure, lot of things in the works for this thing finally!

Started working on the car now. Settled on replacing a lot of the front suspension, front brakes, and will be getting a transmission refresh in addition to the already mentioned rear end!

New digs:

Barely fits in the garage... she's tight!

Really looking forward to buying another house with a proper garage in the next year or 2 once if real estate ever calms down.

Trans is out today now

new parts!

New front suspension parts:

Brakes:

Going to start working on getting one of these ready to be installed soon. Just waiting on a few parts:

 

[Turbocharged400sbc]

God I need to get rid of the hydrostatic 700R4 and go with one of the 4l60e's
I'll give you pocket lint and a crushed cigarette butt for that core LOL

 

[bs009]

God I need to get rid of the hydrostatic 700R4 and go with one of the 4l60e's
I'll give you pocket lint and a crushed cigarette butt for that core LOL

Next time I'm passing through Illinois I'll keep that in mind! ?

 

[Turbocharged400sbc]

Id be very much obliged sir

 

[bs009]

Started on some of the suspension and brakes. I can't actually run the new brakes until the new wheels arrive so right now it's kind of just a test fit. The wheels are supposedly getting shipped in 2 weeks or so. But with the way everything else has been going with finding parts I'm not holding my breath.

Learned that g-body knuckles and blazer knuckles have different bolt hole locations. For some reason I thought they were 100% identical.

kore3 c5 brake swap kit for the blazer knuckles:

new ~13" c5 rotors compared to the Blazer rotors:

niiiiiice

swapped out the stock steering box with a Monte Carlo SS box

TRZ bump steer kit! which apparently might need to be cut short on the inner tie rod end because it's so long. We'll see but I think it's going to be close

out with the old stock springs too! No more bouncy boatlike front end hopefully

New springs in the front have a higher spring rate and should lower the car from factory height a little bit. The old springs were so worn though that it'll probably actually raise the car ?
That spring compressor did not participate in today's activities. What a PITA that thing was, way easier to install the new springs without it.

Was going to swap out the control arm bushings but realized my vise isn't quite big enough for the job. Now just need to do all of that to the other side.
Right now I have so many things that I'm waiting on shipping for though. One is coming from Australia so I have no idea how long that'll take. Supposedly it was shipped out though today. ?

 

[v6buicks]

All the shipping and shortage stuff is just killing me right now. If I had my transmission delivered in reasonable time the Camaro would be done by now, and the Volvo would be undergoing major surgery. The GN probably never would have gotten the much deserved love, so I guess that's a plus. However it wasn't exactly part of my "regime". lol

Anyway, its cool to see somebody doing some of the G-body mods that I've always been interested in doing. I forget. The S10 knuckles are pretty much just to open up brake options right? Do they raise or lower the car at all on their own?

 

[v6buicks]

I don't wanna muddy up your thread, but how's Nashville? What was your motivation for the move? As much as I appreciate the low cost of living in Indiana, it's so friggen lame here. We're considering moving up to WI or MI in a few years because we like the year-round activities up there better than what we have here. Plus, we would still not be too far from family. I hear that auto insurance is virtually unaffordable for multi-car owners in MI due its "no fault" BS. Not to mention the other government issues. Was it more of a push or a pull for you? You can PM me if you want to take it somewhere else. lol I'm just really curious to hear from somebody who actually made the move.

 

[bs009]

The blazer knuckles don't change anything with the suspension or ride height, but they benefit to me was the sealed unit bearing separate from the rotors and the dual piston front calipers with .5" larger brakes iirc.
When I first decided to go that route I thought that everything was the same with the brake caliper mounting brackets so it seemed like a good way to get ready for big brakes without having to modify the stock spindles or pack bearings.
The downside I've found so far is that brake upgrades are a bit more expensive with the blazer knuckles for something like Brembos because the brackets cost so much more money. The C5/c6 bracket wasn't too expensive and should give wayy more stopping power than even the blazer brakes so I'm still happy with my decision so far.

I'll PM you about the move, but there was a lot that went into my reason to move for sure. Pushers, pullers, and the covid stuff really pushed me over the edge. I do love Michigan and would still go back there again, but there's a lot of things that were starting to bother me about it, some were more unique to where I'm at in life though.

 

[v6buicks]

Ahh, yes. Packing bearings has to be one of my least favorite automotive maintenance jobs. That seems worth it if it's all coming apart for upgrades anyway.

 

[bs009]

Took a lot of L's this weekend.
Got nothing done at all, in fact took a step backwards instead. New steering box I installed has a LOT of slop in it. Turning the input shaft on it does nothing to the pitman arm for like 20* of steering wheel movement. Steering shaft itself is nice and tight so that's not the issue. Apparently you can adjust these so I took it back out of the car to try and do that only to find that it can't be adjusted anymore than it is. You'd think they'd ship it already adjusted properly. Sending this one back in the morning hoping a different one is a lot tighter. Hopefully summit can exchange it quickly

Also had another transmission part arrive with no foam in the box to protect it and its case was bent and cracked. Hoping I can get that replaced ASAP from Summit. I've had bad luck with getting exchanges done quickly with them.

This is a thing though at least

 

[Mr_Roboto]

Did you try the adjuster screw on it to see if it tightens up? Just curious.

 

[bs009]

Yupp, I tightened down the one on top that seemed like it only affected the way it felt when the wheel was in the center position. I then learned there's another nut at the front too that you can adjust and I tried tightening that one too, but couldn't get it to tighten any more. I was able to loosen it so it wasn't seized or anything from what I could tell, just wasn't letting it go any tighter

 

[Mr_Roboto]

That sucks. I've always heard reman boxes are a mixed bag though. I still have the original gear off my 89 Astro, I'm saving that bad boy. I think it's variable rate but it's 3.5 L-L so it's not like the Astro RS box I stuck in my 92.

 

[v6buicks]

What's in the picture?! Bellhousing?