What turbo for my stage ii?

[turbotwister]

Hi,
Im looking to upgrade my turbo.I have a 3.830 bore with a 3.625 stroke stage 2 with champion race ported heads,champion intake,224-224 solid roller,th-400 with a trans brake etc etc.when i upgraded from my 109 engine i left my 70hpq bb 3 bolt turbo on intially and now want to upgrade.the current combo runs quite well.

im undecided on what turbo to go with.the 2 options i am looking at is either a gt42/75 t4 with a 1.15 or 1.28 housing or a 76hps with a .81 or .96 housing.
i know the gt42 is capable of making more power but may be harder to make work.i am only looking to get around 9.0's from this combo and may feel the gt42 is overkill and may need more stall etc etc.id like to get some opinions.


Thanks,Nick

 

[2QUICK2B6]

I would call patrick @ precision or pm him on here

 

[oldtimer]

Why don't you get a 42-76 ball bearing unit. They spool up fast, can be used on the street and and strip and will go low nines all day.

I'd check with Cal Hartline. He knows his turbos as well as anybody in the business and can probably give you a smokin' deal on one.

George

 

[John Wilde]

You could probably get there with just the turbine housing change.
The fastest TSM guys have gone 8.8x to 9.1s with a 3 bolt 71 Billet.
The new billet 76 is nice, you may want to call and get the TSL turbo.
I think it has been mid 8s. Maybe Cal can chime in.

 

[turbotwister]

Ive been talking to cal about this.we all know he knows what he's talking about and i value his opinion.just trying to get a perspective from all angles and from previous experiences from other users.

 

[HighPSI]

Thank you guys! I have spoken to Nick about this. The 42-76 is the TSL turbo and will certainly meet his goals. His concern is spoolup. I know one of the TSL guys has a 265 ci motor and is having no problems spooling it with a 1.28 housing and journal bearing. I have this turbo in stock as a BB unit with a 1.28 housing, but was trying to find a used 1.15 housing a customer took off for him to try. I can call PTE to see if they will do a turbine housing exchange on the one I have if Nick decides to go that route.

 

[Trbobuick]

I second the gt42-76...i have it on my car and it is SWEET for a stage 2 street car .

 

[Quint]

Cal knows better then most, the 42/76 is a winner, but let Cal take you to where you need to be.

 

[bison]

For a 9.0 car id go with the 76 HPS. It will have a little backpressure but will spool a lot better than the 42/76 unless its a BB. Even the 70 GTQ you have with a .96 tang housing will get it done. Its up to you if you want to spend extra $ on a turbo. The e.t. gain to $ spent will not be spectacular if you are only looking to run 9.0 with this combo. Now if you wanted to run 8.6 or faster the 42/76 is a no brainer but not needed for 9.0. Spend the $ saved on the turbo on lightening the car or working on the suspension.

 

[HighPSI]

The dollar saving is not as much, since it is a brand new, never installed "used" unit complete with ALL the flanges and clamps I took in on trade. If you take into account what the clamps and flanges cost, I can sell him the BB 4276 basically the same price as a journal bearing 76HPS and a lot less than a BB76HPS. I know most Stage2 guys aren't happy running low 9's, if he sticks with his goals, I agree the HPS lwill work.

 

[Squid4life]

Great info here, but just for reference, what stall converter are you running in your setup? I know you mentioned maybe needing more, so was just curious.

 

[John Wilde]

We had no problem spooling two GT42 (74MM) on a 390CI motor.
There is 195ci per side...
Cal's deal is pretty inciting, I don't think you should pass it up.

 

[GNDriven]

I'm in the same crossroads there Twister. I do not compete in any classes, I am looking for the most turbo per dollar.

I am building a 27X stageII motor street setup, with similar ET goals as yours.
I have been calling everyone to find out what is offered right now in the 76mm compressor size BorgWarner, Turbonetics, Precision, Comp turbo, you name it.

All claim their billet wheels would roll Büchii in his grave. The more I dig the more I realize most turbos are a crafty collaboration of different company's parts.
I get so caught up on performance in terms of what which turbo does the best with the Buick stageII, while most turbo shops consider the serviceability, reliability, etc.

I think the Precision 76HPS is for a direct bolt in app.It retails about 1500
while the GT4276 has higher HP capability with the larger exhaust housing but is twice the amount (ball bearing). I am not sure exactly how much the GT is displaced from the stock location, but it does have clearance issues.

I do wish there was more accessible information regarding the larger turbos, I am understanding more and more the information tit dries up quick when you start approaching low 9s. Instead of "you have to pay to play" its "you have to pay to find out " Its just the way it is down here in the trenches I guess.

 

[bison]

The dollar saving is not as much, since it is a brand new, never installed "used" unit complete with ALL the flanges and clamps I took in on trade. If you take into account what the clamps and flanges cost, I can sell him the BB 4276 basically the same price as a journal bearing 76HPS and a lot less than a BB76HPS. I know most Stage2 guys aren't happy running low 9's, if he sticks with his goals, I agree the HPS lwill work.

I might be interested in the 4276 if he passes. Let me know. Im not sure exactly what im going to do as far as cam/turbo. The limitation will be the turbo and how much i crank it up.

 

[its2qik]

Do it once and do it right - put Precision's pt47-88 turbo on it and don't look back. Comes in a .96 t-4 housing and will make all the power you'll ever want. Will spool nearly as fast as a journal bearing GT42-76 with a 1.15 hotside housing.

 

[HighPSI]

Do it once and do it right - put Precision's pt47-88 turbo on it and don't look back. Comes in a .96 t-4 housing and will make all the power you'll ever want. Will spool nearly as fast as a journal bearing GT42-76 with a 1.15 hotside housing.

I would be nice if the 47/88 spooled that well I noticed a Turbonetics turbo in your stage2 pics, did you swap it to a 47/88?

 

[GNBRETT]

I might be interested in the 4276 if he passes. Let me know. Im not sure exactly what im going to do as far as cam/turbo. The limitation will be the turbo and how much i crank it up.

put it on ur stage motor butthead

 

[bison]

put it on ur stage motor butthead

Depends on how much of a "race car" i want to have ball washer. If i want to have low 8 sec power id go with a version of the 88. Cam/springs/turbo. Anyone of them not enough and you can have whatever bottom end you want but it will fall short when its cranked up.

 

[its2qik]

... did you swap it to a 47/88?

not yet.