GT35R...will it work?

[Phoenix_400]

Hey guys, this is my first post. I work as the office assistant/computer tech at a performance shop near Ft. Bragg. H&H Performance to be exact. We mostly deal with Imports (Subaru and Evo).

I've recently gotten my hands on an 85 T-Type for $300, most of the engine is in the trunk though. I've emailed Cotton's Performance for advice on my buildup, waiting to hear back. I'll be rebuilding the engine, swapping to an 86-87 setup. I'm going to be running XFI as my tuner guy will have an easier time with that than a chip. We have Cobb Tuning certified tuners and a Mustang AWD chassis dyno, so dialing it in once its running is pretty much gonna be free for me

Alright, background outta the way, now for my question. One of our customers is thinking about selling his GT35R turbo and step up some more. I was wondering if this would bolt in? (if doesn't, one of my guys could fit a flange for it) Also what would be a similar turbo in the TR scene? I'm looking to build this car with decent street manners. We've got some of these dang imports deep into the 300-400+whp range with these kits easy, so I'm hoping it will be a good match for my car once the engine goes back together.

Any advice would be greatly appreciated. I've been lurking on this board for quite a while and this place is great.

Also, are Labonte meth kits any good for these cars? I know everyone seems to love the SMC kits but we just became dealers for Labonte, so now I can get a good price on those.

 

[Eticket]

Technically, the turbo would work, but it would very soon run out of breath. It might even destroy itself, overspinning to keep up with the airflow requirements under high boost.

Remember that you're dealing with a much bigger engine to blow into - bigger than most turbo imports.. sometimes 2x the size. If you look the 35r up on turbobygarrett, it's rated for engines less than 3.2 liters.

Most of the upgraded turbos for buicks are 58mm+ (A te44 is 58mm I think).
You're better off, especially starting out, to get a turbo to fit your particular combo and hp requirements, and there are plenty that will bolt right up, instead of having to fab up a 4bolt turbine housing.

I would also say to do a little more research. Alot of things, like a Fast system, are kind of a waste of money untill you're making over 500hp to the wheels. There isn't much tuning to do with a "good" chip for your combo.

If you've chosen Jack to help you out. Stick with his help and don't deviate too much. Nothing more frustrating than 400 guys trying to make 1 combination work.

 

[RUQWKNF]

The GT35R would work, but only with a great deal of changes being made to your car, if equipped with the factory T3 3-bolt configuration.

Yes, the standard GT35R that most Evo and STis run, would not be suited for our 3.8L motors. This is mainly due to the turbine housing that they are stuck with using. Some STi guys are utilizing T4 .68 A/R housings tho. With a turbine housing change to the T4 .68 A/R on a 3.8L Buick, it would work fine. Now on a Supra application that has a very efficient head design and can move some air, it would not be suited. Even though there are some out there that chose to run it.
The GT35R comes standard with a T3 style Garrett turbine housing.

TurboByGarrett.com - Catalog

Precision Turbo offers T4 turbine housings for this turbo in .58 & .68 A/R T4 tangential style.

By changes being made, you would have to convert your factory setup, to be compatible with the T4 style turbine housing. Meaning, you would need a 3-bolt to 4-bolt adapter flange at the header, make provisions for an external wastegate either mounted on the crossover pipe, or coming off the passenger side header, and switch over to a custom 3" v-band style downpipe. Most T4 turbine housings available today use the 3 5/8" v-band flange on the turbine housing discharge. This can be a very costly and frustrating task, when it's much simpler to work from existing Buick 3-bolt housings that simply bolt up without modifications.

Saying that the GT35R won't work on a Buick is not correct. Look at all the PT61 users our there who have gone very fast on stock motors. The Precision Turbo PT6152E and PT6152S turbos, have been using the GT35R compressor wheel for years. Given they utilize a slightly less efficient turbine wheel than the one used on the out of box GT35R. The reason for this is there doesn't exist a PTE turbine housing for the GT35R, that is compatible with the Buicks' 3-bolt T3 style configuration. That would have required a completely new turbine housing and those are not cheap to do. A turbo manufacturer could have $30-$40K invested in a new casting. So you can see why it would be beneficial to utilize existing 3-bolt Buick turbine housings that are on the shelf. PTE used the GT35R compressor wheel with the readily available T350 turbine wheel, in a journal bearing T3 cartridge and a THB3-52 .63 A/R Precision turbine housing and called it a day. HP rating? 650 flywheel when maxed out.

To my knowledge, no one has ever tried to retrofit a T4 turbine housing equipped GT35R onto a '86-'87 Turbo Buick, but if someone would try, I would venture to say, you would see more power potential with it when combined with a .68 A/R T4 turbine housing. Quicker spool due to the dual ball bearing cartridge and more efficient turbine wheel, and less back pressure at higher boost levels. A win win scenario. Not trying to argue, just filling in some of the blanks.

Check out this post, that discusses the differences between the Buick T3 3-bolt turbine housings and the T4 style turbine housings.

http://www.turbobuick.com/forums/turbo-s-turbo-related-parts/209431-3-4-bolt-turbo-mount.html

Hope some of this helps.

Patrick

 

[Phoenix_400]

Thanks for the info so far guys. I'm waiting to get the specs and price from the guy to see if this would work. I'm pretty much building the engine from scratch with what I've found scattered through the car. Tim Bradham chassis works is right up the road so they may be able to fab up a good downpipe for me and a 4 bolt flange. Figured I'd go ahead and do TA Performance headers and was planning on going with an external w/g anyway. We'll see once I get to talk to the infamous Jack Inventoried the car today and I don't have a heck of alot to work with. Short block still bolted in under the hood, alternator in the p/s floor, heads in the back seat, intake with injectors, ignition coil, valve covers, most of the throttle body and ONE set of rockers on the shaft in the trunk. Think I may have found the wastegate and half the turbo too.This is an 85 hot air car too, so I imagine there would be alot I'd have to change over, might as well take my time and build it to rip from the get go.

So far all I know about this turbo is that it came from Perrin. Went on the website and had a look, found these(see below). We'll see once the guy gets back to me on his actual specs...okay, so I guess its a 30R Dangit, I oughta stick with carbs and v8's, all this turbo stuff is drivin' me nuts. Too many choices.

My boss had it right though, I oughta stick with proven combos that work for these cars. I know that too but our tuner guy keeps trying to put ideas in my head.

Garret GT3076R

-Maximum air flow 52lbs/min
-Approximate Spool RPM-2.0L 4800rpm, 2.5L 4000RPM
-Compressor Wheel size 76.2mm
-Turbine Wheel size 60.0mm
-Turbine AR choices .63, and .82
-Recommended for 2.5L and high revving 2.0L WRX's wanting to make 450WHP

Garret GT3071R

-Maximum air flow 46lbs/min
-Approximate Spool RPM-2.0L 4200rpm, 2.5L 3500RPM
-Compressor Wheel size 71mm
-Turbine Wheel size 56.5mm
-Turbine AR choices .63, and .82
-Recommended for 2.0L and 2.5L WRX's wanting to make 400WHP

 

[cracker]

in australia gt35/40s are weapon of choice on force feed v6's
with .70 compressors and 1.06 turbines.

 

[Eticket]

Patrick,

I misquoted - in the wrong way. When I looked up the specs on the GT35R, I clicked on the link for a GT3571, which is a 51mm turbo only capable of 390hp. That particular GT35 would have run out of breathe.

Thanks for clearing that up.
John

 

[pocoloco]

So far all I know about this turbo is that it came from Perrin. Went on the website and had a look, found these(see below). We'll see once the guy gets back to me on his actual specs...okay, so I guess its a 30R Dangit, I oughta stick with carbs and v8's, all this turbo stuff is drivin' me nuts. Too many choices.

My boss had it right though, I oughta stick with proven combos that work for these cars. I know that too but our tuner guy keeps trying to put ideas in my head.

Garret GT3076R

-Maximum air flow 52lbs/min
-Approximate Spool RPM-2.0L 4800rpm, 2.5L 4000RPM
-Compressor Wheel size 76.2mm
-Turbine Wheel size 60.0mm
-Turbine AR choices .63, and .82
-Recommended for 2.5L and high revving 2.0L WRX's wanting to make 450WHP

Garret GT3071R

-Maximum air flow 46lbs/min
-Approximate Spool RPM-2.0L 4200rpm, 2.5L 3500RPM
-Compressor Wheel size 71mm
-Turbine Wheel size 56.5mm
-Turbine AR choices .63, and .82
-Recommended for 2.0L and 2.5L WRX's wanting to make 400WHP

Hey everyone.
I'm new to the Buick scene however I have been playing with turbos for years. Here are some of my thoughts as I have used some of the turbo's in question in other projects.

A GT3076R or GT3071R will not have enough huff for your Buick.
I run a GT3076R on a 2.8 12valve VW engine as a "daily beater". Makes good power and spool is early 15psi by ~3200 and full boost of 18psi by ~3700.
A GT3582R would be a better choice on this set up as it would ramp smoother and be more efficient higher up in the rev band.

When Building my T-Type I too looked to a GT3582R in a T4 housing. This would make for a great "street" car. Quick spooling, good power but limited.
As others have pointed out there are lots of "bolt" on turbos available on the market. But if you are looking to be different or want to go make some impressive numbers I'd be looking at GT40's, GT42's.
Or if you are truely daring you could do like me and run a Bullseye turbo.
I have an S366 to start off on and then have a S372 for later

There are lots of options but don't just pick something cause its cheep or free. Look to the people who know these cars and have done the leg work for you. A plan Jane 62mm Turbo will take you into 10's no sweet.

Just my 2 cents. I have yet to prove any of this though on the Buick.
Good luck in your build.

 

[Black Power]

Toss a 6776BB PTE turbo on it, run some 10s and be done with it

 

[Phoenix_400]

Well I guess that's it for that then. I'll stick with the vendors on here for my turbos. Funny though, my guy at the shop doesn't wanna believe that a "big" turbo for an STi is a "small" turbo for a buick

Now for the real question...If I'm building my shortblock with a 206/206 roller cam and don't want to go any higher than a 2800-3000 stall lock up converter (I'm shooting for decent street car).....6157 or 6162bb turbo? or bigger? Wouldn't mind a little lag, just so I could actually hook up

 

[RUQWKNF]

With a roller cam and head work, I would go with the Dual Ball Bearing 6162, not the 6157. The turbine wheel in the 6157 could cause some back pressure issues at higher boost levels. A 2800 - 3000 stall PTC converter from Dusty and the dual ball bearing chra on that 6162 should be sweet with a built motor and a 206 roller cam. I'd hit it with 60# Mototron injectors, a hot wired "good" intank pump, one of Eric's Turbo Tweak chips and a good intercooler and have fun.
Just my O2's worth.

Patrick