🔧 BUILD Queen: 4T80e Turbo 2001 Park Avenue

General Information

So this car has a ridiculous amount of work already put into it. Overtime I'll try to highlight some of the big points with the transmission swap and some of the other really cool details, but for now I'm going to briefly explain what the car looks like when I bought it and what's going on right now with the build.

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I bought the car earlier this summer in very poor condition. All the high $$$ parts were already on the car, I've put less than $500 into it as of now. Bought the car for a great price, even if I had known everything wrong with it I still would have paid that much in a heartbeat.

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The 4T80e conversion was incomplete (car wouldn't shift into 3rd gear), everything was leaking except the rear suspension air bags, lots of misfires, horrible squealing from the engine due to improper belt routing, and other things I'm probably not thinking of.

Here's what the car came with:

Engine:
-VS Cam with new GM timing chain
-Cobb Racing one-off turbo kit
-Camaro intake for beautiful routing of the charge pipe through the air/air intercooler
-(Unsure of what turbo is on it)
-No coolant overflow
-Stock Camaro TB and MAF (MAF was getting maxed out with the springs that came in the wastegate and blowoff)
-LS3 MAF installed but not wired up or tuned

Transmission:
-Stock rebuild 4T80e from a 2000
-3.11 gears
-700+ ft-lb rated LSD
-GM axles
-Cheap transmission cooler mounted in front of the driver's side wheel (effectiveness unknown)

Suspension:
-Stock parts, maybe some stock spec aftermarket stuff
-Broken away bar links in front (makes for an extra "exciting" ride when attempting to tame 400+ HP)
-Worn out 225 mm tires

Exterior:
-Rust
-Body panels in two different shades of green
-Rust
-Front end body panels are not from an Ultra (the car is an Ultra)
-Rust

Interior:
-Bone stock with a boost gauge and wideband.
-Lots of broken interior panels
-Heat and heated seats work :)

Fast forward to a week ago...

My friend Daniel has had possession of the car ever since we got it. He's been dailying while stress testing and taking care of little details, repairs, tuning tweaks, and some diagnostics. It's a win win for us because he doesn't need to spend money for his own car, he really enjoys the project, and I didn't have storage space or time for another project lol...

Anyways, even though we knew the mass airflow sensor was getting maxed out, we didn't really worry about it because we weren't getting any knock. During an extended 20 plus PSI pull he blew out one of the head gaskets. I'm sure the AFR was quite lean and I'm thankful we didn't lose a piston. We will be keeping a close eye on the afrs until we rework the mass air flow sensor system.

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Before we can rework the mass air flow sensor, we need to finish getting the car running good. The afrs are all over the place at idle because the oxygen sensor hasn't really been working and the used one I had laying around that we tried to put in when doing the head gaskets also isn't working. While doing the head gaskets we found that the spark plug gaps were very inconsistent from 24 thou all the way up to close to 40. After finishing the head gaskets and regapping the plugs, the misfires are gone at idle and full throttle.

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Next steps will be to convert the ignition system to LS coils and try another oxygen sensor. As soon as the AFRs are good and the misfires are completely gone at the same time, we will be putting a mini AFC on the stock Camaro mass air flow sensor currently being used.

turtleman

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Sep 6, 2009
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Objective today is to hopefully franken-swap in a new junkyard driver seat base because the whole side of the one in the car has been weirdly hacked away so your left ass hangs low sitting in it and it's awkward. Also the seat elevation doesn't seem to be working.
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The above, of course, won't hold the button assembly in. It should look like this and still not hold the button assembly in like all the proper buicks from this time.
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new billet ss fender-bumper cover bracket because overkill everything
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spotted this disaster waiting to happen while underneath - that goes right to the fuse box ?
lovin the cutting style

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turtleman

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Sep 6, 2009
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I'm slowly poking at this big ole pile of car that i've sorta started taking apart.. and it's not putting itself back together so.. i guess i have to do things again.
Item #1 : trans mount
The 4T80 swap in this later H-body chassis required a fabbed up front trans mount. The other three are oem parts. The one that was originally made unfortunately ended up failing so I designed a decently mass-produceable replacement.

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You can see the strap that's supposed to be surrounding the bushing let go and then Travis, in order to kinda fix it, ended up just drilling through vertically and putting a bolt through to hold the bracket down which insulates it one way and hard-stops it the other direction which was very noticeable in the car :LOL:

I was dying to fix that whole deal so I took it out and then noticed they welded that lower insulator bracket to the subframe (instead of bolting in like stock) which sucks. Had to cut/grind that whole thing out to replace it. They did use a two-piece bushing so if the strap didn't fail, that would have been ok but... yeah

here's a progress shot of cutting that all out - this is the point when i had to just stand there bent over and start grinding
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Here's the comparison shots between the old fabbed mount bracket and my functional prototype. I should point out I'm using a northstar performance mount which is a direct oem replacement.
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turtleman

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Sep 6, 2009
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Villa Park, IL
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o_O Whyyy did I do this to me...
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Ok I guess there's a chance this could be an issue. This is the remnant of the plug that went to the boost control solenoid. It sure does look like there could have been some shortery goin on. (The picture looks like one wire but that's two wires right there) At least I'll tell myself that to justify the hole I dug myself into now.
I'm just gonna comb through all the wiring and make sure things are ok, remove all the unused wires, retape and loom up, and add some legit heat protection. The turbo zone is definitely trying to cook things. I'll probably wrap the downpipe too before I put it back in.
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On another matter, my new coil mount brackets are lookin great. Hit up me or james if you are lookin for a set.
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The printed brackets are not liking the heat at all :LOL: The back one is worse
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turtleman

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Sep 6, 2009
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Villa Park, IL
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*post under construction while I post pics the right way or whatever*

sequential turbo setup almost done
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...no not really but i'm very happy I got the whole turbo setup back in the car today.
I just need to make a longer turbo oil feed fitting so you can actually get a wrench on the AN line properly... Or I'll just install the old one and stop trying to be an overachiever. we'll see

Designed a new turbo support link bracket. The old one worked well enough but it looked like garbage
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the old one
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turtleman

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Sep 6, 2009
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Villa Park, IL
Real Name
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Ktj100 Ktj100
My man, turns out the pins to the map sensor were all wrong. To be fair the colors are kinda wonky. The 2001 Park Ave wiring diagram says they're supposed to be LT GRN, ORN/BLK, GRY. That's not quite exactly what we have there but once I swapped around the pins in the MAP plug, it's readin right. None of the wiring work I spent almost two months on-and-off doing really mattered but I'm still happy.
Also the rev limiter on this thing is like a two-step compared to the 1997 riv I was used to tuning. Sounds cool as hell! I've swapped in another PCM with a 2000 PAU osid so I can open-source tune it with DHP/Tiny so I'm kinda starting over with a freshy tuning-wise.
I'm gonna try to kinda transfer in what I can from your tune table-by-table and then get hard with makin power once I get the water-meth kit and boost controller put in.
It'd be nice to schedule some dyno time and get a solid new big maf and maybe VE table built this spring-summer and then this thing should be a proper bastard
 

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