I might be interested in a Turbo V6 swap in my 1991 Pontiac Firebird. I think I remember someone on here doing that (I think it was a red thirdgen). Just curious on what is involved in the swap. I have a built 700r4, would it bolt up to that? I also heard that I have to "dimple" the shock towers. What is involved in doing that? And usually, how much money does this kind of project suck up? Thanks.

Depending on what you want to turbocharge. Contact Fly89 he's done the 3.8 TTA swap. Parts are available to do the conversion. If a/c matters it's more hassle, but doable. I'd go with a non a/c blower box and stick in the GN engine and trans. You'll need a custom crossmember, Buick mounts, harness, and driveshaft..

Also IC and good fuel pump. All this could be salvaged with the exception of the fuel pump from a GN/Ttype.

Good luck

If its the GN motor, U need the th200 trans.. sinse it requires
the BOP bolt pattern..

Cost could add up quickly.. sinse u have to modify what
u have to make something non original fit.

not true. TCI makes an adapter plate that allows you to run a BOP motor and a chevy trans, and vice versa

I'm running a 700r4 behind my motor...

There isn't that much to modify...the swap is easier than most people think.

Hey Fly that beast up and running yet? What'll you expect from it? Undergoing rebuilt and combo changes for me right now, hoping for some very decent times by next season. Gotta get a converter by next season to fully exploit this new combo.

I know the TTA used 89 FWD LeSabre heads. Not sure if that was because of the need to create some room for the A/C setup, or if those heads are even necessary in the swap. I'm sure fly can elaborate on this.

yeah you hit the nail on the head there...they were used to clear the AC stuff

I haven't even started on it yet Still gathering parts...my ATR downpipe and external wastegate will be next week, I have my TE60 turbo sitting here, gotta get my injectors..my rebuild kit...probably a set of MSD 50's. Yeaaaah I still have a lot of parts to buy lol

Yeah me and Tony already talked awhile back. This post was before we talked. He has set me straight and so far I am saving the dough and I think this is gonna be the plan.

86-87 GN Engine Complete
Custom Downpipe
Aftermarket wiring harness
port/polish the heads
Get adaptar for 700r4
Get ideas for custom scoop for intercooler
Do small aftermarket modifications and rebuild the engine before dropping it in.
Get some aftermarket headers jetcoated.

Get it runnin right before I do anything major and go from there.

My combo consists of Or will consist of. Stock block bored .030 trw forged pistons, mild street port/port matching, cam I haven't decided(212/206 or 210/210)yet,3in. DP, deltagate mounted on crossmember(bleeder in cockpit in ashtray), MSD 50's, Orange stripe 12" converter(only cheap raised stall 12" I could find, old one was toast),Pt-51 is on there now, but will possibly be changing it before the spring along with converter(they have about 150 miles on them combined), Extender chip, maf trans+ with 3" LT1 maf,electronic dump cutout,Trans has been out before, but don't know what's in it(TC cover was missing and stainless steel braided tranny lines were installed, I'm sure it'll break next) Other than gauges that's about it, converter will be addressed next. Looking for mid 11's on this combo and the new combo I have in the back of my head will be to scratch the 10's.

Good luck with the rebuild and never ending project(aren't they all). I finally gave up trying to repair other peoples mistakes with this car and took it in for a complete tear down and rebuild. Awaiting news on how bad it actually is inside there.

Here's my setup as of right now

TE60 turbo(already have)

ATR 3'' downpipe and ATR external wastegate(on its way)

50 or 55# injectors

LT1 MAF and T+(already have)

Stock TTA heads with some bowl work and minor porting

Port matched intake

214-210 cam

Stock pistons, rods etc but with billet main caps on #2 and #3

Mease big necks added to the TTA intercooler

Impala SS 140 amp alternator(already have)

Some type of dual solonoid electronic boost controller

Freshen up the 700r4 and add a ACT 3K stall converter

hmmm more stuff but that's all I can think of off the top of my head

My goal is to run as fast as possible on good 'ol 93 or 94 pump gas...I'm hoping for very low 12's, easy mid 11's on alchy

That's just the drivetrain, I won't even go into the suspension and brakes

Already have the suspension done minus the adj tourqe arm i'm looking into. If you haven't done it, the tubular LCA's and panhard bar made a noticeble difference in the bite with my nittos. Last car was a HT and it didn't do as much for it for some reason. Gotta put the sfc's on as well, car is very mushy with these t-tops(AKA CRAP). Where is Ben Salem? Got a buddy and we wouldn't mind another 3.8turbo car to meet up some time. It's hard being the bastard child of Pontiacs. Some third genners don't bother with the TTA guys and the Buick guys look at us like we have two heads(until we bank a turn at 80 when they have to slow to 35mph )

Are you planning on studding the rods and caps? I'm looking into the little extra insurance it provides, especially on these motors where 600lb/ft isn't very hard to come by. The bearings may thank me in the long run.

Again good luck Bro!

Pete

Bensalem is 5 minutes outside of NE Philly

I haven't checked into the studding much..I've thought about it..gonna wait for the machine shop and see what they say

My uncle has an 87 GN and I am quite sure that he said that the 700R4 isn't near strong enough to handle the torque that the turbo 3.8 in going to put out. Might want to check into getting a 2004r. Save you on some headaches down the line.


Check the boards on this site for lots of info purtaining to turbo 3.8's.

http://www.turbobuick.com/


Skull Leader

A 700r4 can be built to handle power as well. The 200-4r has problems in stock form just like a 700r4...both need to be addressed

His 700r4 is built up pretty good...as is mine...I'm running a 700 with no problems. I wouldn't trust EITHER trans in stock from once you start making real power.

.........Whats the real difference between the two anyhow?

TH-700 Vs TH-200?

I've been debating to do this swap, and I think I'm in. But just got to line up an 87 GN 3.8 Turbo w/ complete set up. PCM, tranny, motor, etc. If I can find a 3.8 TTA motor, that would be nice....

The TH700-R4 has ratios of 3.06-1.63-1.0-0.74 and the TH200-4R (not to be confused with the TH200C) has 2.74-1.57-1.0-0.70

The TH200-4R is also slightly shorter, about the same length as a TH350.

Those are the only two things I know different between the two, maybe someone else can think of more things.

the 200 has 27 splines while the 700 has 30(84+)

There are more differences but I forget them

Hey, what types of intercoolers are u guys running? Aftermarket or stock?

I'm running the stock TTA intercooler. Steve is running a CAS V2 Front mount(I think it's a V2, might be a V4)

I see.

I am just worried about detonation and I heard by having the proper intercooler, you won't have to worry about that. So what size would be good for the setup I want? I want to make around 450-500hp at the crank.

the stock IC is efficient into the 11's. If you want a little more flow add the big necks to the ends. There is no need for a front mount until you're deep into the 11's

Well no matter what type or how large of an intercooler you have you can always detonate a motor - especially when your trying to tune in the fuel maps or pushing to make max power.What a front mount or better stock location intercooler lets you do,for the most part,is be able to run a little more boost at a certain octane level and make some mroe power even if you keep the boost level the same.

But never think your free from detonation,cause thats when it'll get ya and pop your motor.

Steve

Thanks Steve.

Hey another question, I found an 89 TTA wiring harness but the guy turned my offer down. He said he has turned down 500 offers. So what kind of wiring harness did u guys use in your swaps?

a TTA harness, it came with the motor

A TTA harness in my car too,I actually found and purchased two.One was used in really good shape for around $200 and another was a brand new NOS harness for $350.

Caspers Electronics used to have them brand new for around $650-700 which I know is expensive but a TTA harness is the only way I'd do it.

Steve

Oh and I saw the ad for the harness,he also has a ton of other stuff for sale but wont list a price on anything.I know TTA stuff cost a pretty penny and I dont think he really wants to sell what he has unless he gets top,top dollar.

I could be wrong,it's the impression I get

Steve

Yeah, its a used harness and he turned down 500.00 bucks. So I am screwed. You guys gotta keep an eye out for TTA harness for me.

holy ****, it's used and he wants more than $500? Damn...

Spend the money for the GM manual(not haynes or chilton crap) the dealer repair manual for what year you are using and splice your harness together. It takes a while, but if you can read and operate a soldering iron you can do it. The schematics are quite easy to understand. GM kinda made them idiot proof by color coding and numbering each terminal. You'll also need a 6 cylinder tach don't forget.

I dont think that a 6 cylinder tach will work.. Just because of the DIS. I "think" the signal is different.

Kat

I know someone that tried the V6 tach idea and it didn't work...his TTA was a theft recover and they took the gauge cluster. He put in a V6 cluster and the tach didnt work.

So my guage cluster isn't going to work?

Could just be having to try out a different tach filter. I don't think it's the signal since the GNX used off the shelf Stewart Warner gauges. Or just run the gauges directly from each sending unit, a pita but should work.

Mine may be up for sale if you're interested . Currently waiting on my builder to get it done. I've always had the urge to do a turbo camaro

Just the tach

I found an 89 TTA guage cluster from a friend. Wohoo.

The different valve body that the turbo versions use of the 220R4 change it into a different animal, as compared to a v8 version. With a turbo application there is no need for a low first gear since EGT is what spools the turbo, the extra load of the gearing just quickens the spooling.

The FWD heads have much better exhaust ports then the RWD versions. But, it's rather moot since with the turbo motor all you need to go faster is twisting up the boost. If you have a set of the 89 exhaust manifolds, great if not dumping the A/C and going with the GN exhaust is alot cheaper, and easier to find.

Turbo motors are about detonation control. The fuse in the Buick v6s is the headgaskets, too lean too long, and you get to change them.

Common mistake when going for HP is not going with a large enough injector. I'm running 55 PPH injectors and a full time 36 PPH 7th injector, and can use more. You can run smaller injector and go static but that raises issues with the injectors going erratic just as they go static, which is not a good thing.

Grumpy, what turbo are you running, I forget.

A 60.

I'll be running a TE60

Damn, you guys rock! Thanks for all the info. I'm afraid I'm still a ways behind 91Bird305 in getting my turbo V6 in my 3rd gen, but still. I want to reseach all the facts first, and post like this just helps point out all the pit falls and peev's when it comes to building up the turbo 3.8.

One question though: Where the heck can I find a used 1987 Buick Turbo V6, complete with ecm, motor, turbo, etc. ? Complete with TH-200 attached would be cool too!!

I got daily email searches that I get from ebay, and still nodda. Been snooping the different buick' boards, but cant find anything.

Thanks,

www.turbobuck.com


www.turbobucks.com


www.gnttype.org