Question:72 Q trim turbo on S2 headed engine

[turbodave231]

I am building up a 274 with S2 heads. I already have a deal pending on a 72Q trim J.Craig turbo. I have 84 # injectors, so I think I have enough fuel available. Is that turbo going to be big enough to get to 750HP?

My car is light at 3200# and I would like to run a 9.990. How many of you guys have experience with a setup like this?

 

[S2V6RACER]

Turbo

I think that is the turbo that Bruce Aldred is running. He has ran 9.8's for sure and I believe he has done better than that. I wouldn't hesitate jumping on that if that is all your goals are.

 

[Reggie West]

My dad has been down this road with a 72. His car is heavier than yours at 3500 lbs.

I would look at a 76 to do the job. The 72 we had, from John Craig and this is by no means a bad thing on his part, will not flow enough air to run that number.

After 25 psi or higher on a Stage 2 block with ported M&A heads the turbo simply ran out of air. It would not flow any more air.


The real problem with doing this combo is and has been the torque converter. We may actually have that solved pretty soon.

Your injectors will handle a 76 turbo, just make sure you have a BIG pump to back it up.

The most HP we ever got out of that turbo was 605 on a roller dyno. That is through the driveline. Our best ET was a 10.40 at 128.

Go bigger and you can always turn it down if you have to.

just my 2 cents
Good luck

 

[turbodave231]

How much difference in spool up time will I see between a 72 and 76?
I'm thinking the 72 ought to spool up quicker than a 76 (given the same exhaust housing).
Which brings me to another question:If I decide on the 72 what exhaust A/R should I consider?

What pump should I consider: Weldon? Bosch SX? Aeromotive? Cost is a consideration (of course)

Dave

 

[turbobitt]

I have a 76Q-BB turbo with .96 a/r and love it . Very streetable and fun to drive. I think you would be better off with the bigger turbo . Buy now or buy later , eventually you will want it.
Allan Gorneault

 

[EightSecV6]

Back in '96 when my car was still functional, I ran a PT70 and went 9.70's at 141, the car was 3410#, it would only make 22# of boost but at the time, that was enough to get the job done.
Bill Anderson

 

[Reggie West]

I dont remember the model number but the fuel pump is an Aeromotive unit.

Here is the problem with doing a turbo upgrade on cars going this fast. If you change the turbo you will more than likely have to restall the converter. Sometimes you get lucky and this is not the case, but it is the age old rule with these cars.

You change something here and all of a sudden you have to adjust two other things to compensate.

A bigger turbo takes more stall speed to spool it.

In any case the 72 turbo seems to be maxed out at 24 to 25 psi. I cant tell you why but there is no difference in mph on runs in the quarter with the boost set at 21 or 28 psi. The EGTs were no different, all in the 1590 range.

Hope this helps

 

[SPEEDSTAR]

Bills T70 - 9.70 car in 96

Hey Bill , I am putting together a stgII and I will be using a t70bb turbo for mostly street, I just ordered a TH400 / T- brake from ATI I would appreciate any help you could give on selecting the right ATI converter, maybe like the one that you used in 96. You can e-mail me the specs if you can help, oh by the way , did you ever do anything with the stgII parts I sold you at BG this past year.The crank that I kept turned out to be crossed drilled, if thats good for anything.

TIA JEFF WEEKLEY

 

[ChrisCairns]

Jeff,

Bill is a dealer for ATI. You should call ATI and cancel the order then order it through Bill. You'd get great support...Bill would get paid for his advise...and ATI would still get the sale. Everyone wins.

Chris

 

[SPEEDSTAR]

A WIN - WIN DEAL, I LIKE

I will do just that , Chris, I didnt send them any money yet, I just got all the info over the phone from BOB at ATI, and was going to send them the money this weekend, but I rather do the deal with Bill,...............thanks Chris. Oh yea, I have Bills cell phone # and shop# I will give him a call tommorro


JEFF WEEKLEY

 

[EightSecV6]

Thanks Chris
Jeff, of course we used the S2 stuff, I didnt buy it to look at!!!!! I can help you out on the trans and conv., prolly save you a couple bucks too.
Dont know BOB????

 

[SPEEDSTAR]

Bill , I talked to your dad today , he is going to e-mail me the total for the trans and conv. and yes it is a better deal from you, thanks again Chris , Bill , as soon as I get the total I will overnight the payment to you .

thanks JEFF

 

[ChrisCairns]

I'm glad you guys got the deal done. Now you both owe me a stage 2 engine.

Chris

 

[EightSecV6]

Chris,
Would you like that with 1 hole or 2???