Hey guys, for once a question (or three) that's not all about me . An f-bud of mine has a 97 Trans Am with an S-Trim. He's already rebuilt with forged pistons so he's ready to up the boost and add an intercooler. Here's the problem; he's already bought an ATI 3-core but that's all he has. He has no hardware or ductwork at all.

What all does he need to do and buy and/or do you all have pic's of this setup? If you have any info on a good place to buy the hardware that would be great too.

One last question; he is planning to run about 10 PSI through his Hotcam/mild heads/350 setup. He has 40# Accell injectors and will have Ed Wright do the initial ECM tune. He wants to go !FMU .....will he be OK to do so with 40's, Hotcam, and 10 PSI or does he have to keep the FMU? I would think the injectors would be close to their limit but he'd probably be OK ....I don't know how you all figure out what the duty cycle would be for a given setup so tell me what you think.

Damn! One more, what pulley sizes for 10 PSI? (or would 10 even be possible with an S-Trim through a Hotcam/mild heads motor?) .....ok, that's it

 

FYI, out of the last 10 sets of Accell injectors we've flow matched, each set had about 2 injectors that were WAY off in flow. Your friend should really think about having them flow matched or buy some Lucas, Delphi, etc. Hope this helps....

 

On my 350 with AFR head, cam, 1000CFM TB, I saw 10# of boost with 6" crank pulley and the 3.125 inch supercharger pulley giving 476rwhp. This is with the S-trim and the aftercooler.

But on my 396, with more flowing head, more aggressive cam, with the 6" and 2.75" pulleys, I only see 6# of boost. So I have installed a 7" crank pulley from ASP bought through Steve at PerformanceSS.com (great place to buy it! mention my name or Quang) Also installed in the Seimens 72#/hr injectors and LJ's impedance box ( www.acceleronics.com )

I think he may probably get by with the 40# injectors. According to the calculation, at 560bhp (476rwhp), BSFC at .55, 50psi fuel pressure he will be at 90% duty cycle with the 40#/hr injectors. http://www.rceng.com/technical.htm

 

Cool, ironically.... 90% is exactly what I had guessed but only through experience of reading what you all have said about it in different combos. How exactly do you calculate the DC? I don't know if I ever knew the formula.

Any info you all can provide will be appreciated, thanks for the tip on flow matching the Accels.....I was a little leary of them when I heard that's what he's using just because I've noticed hardly anyone uses them. Rich Krause, since you've had Vortech and ATI and you know almost everything .....any input is welcome.

 

Regarding your intercooler question.....

I believe he will have to re-orient the discharge tube to point down vs pointing up (in relation to being mounted on the engine) as Vortechs go straight up to the throttle body or to the aftercooler which is mounted above the drivers side valve cover.

It shouldn't be too hard to fab up, about the only thing he'll really need to get from Vortech is the elbow tube to connect to the throttle body (and hose to connect the tube to the throttle body) and a blow off valve. I am not sure about the Vortech elbow but ATI has a divider in the middle to split the incoming air as it goes into throttle body, before somebody just tells you get get the Trick Flow elbow I'd check to see if it had the divider first.

I got some 3" exhaust tubing at a local exhaust shop (they have different lengths and bends available) and fabbed up my tubing as I relocated my 3 core intercooler to the nose of the car. The link for pictures is http://www.geocities.com/marc94z/intercooler.html
He'll also need to drill a hole in the tubing and add a small tube so the blow off valve will have something to attach to (again refer to my webpage above for reference)

To connect all the tubing together get some 3" Green stripe hose (Gates mfg) # 24248 from a local auto parts store and some hose clamps.

I have seen Trans Am's with the intercooler mounted in the nose, if he's not interested in doing that then check out this link and look at the bottom of the page as it's the only picture I have of how ATI recommends mounting their intercooler http://www.geocities.com/marc94z/airscoop.html If he does want to go that way, let me know as I have the airscoop and black plate that is in front of the intercooler. All that is realy needed for mounting straps is some alluminum strips and nuts / bolts to attach it. I scanned my ATI installation manual and Brady posted them on his website www.turbocharged.net and look for the pics page.

Marc

 

"First and Goal" gave a good answer. My own experience isn't of much help, since I am not using an intercooler after all and will continue to rely on the water injection to cool the intake. If it doesn't work, I guess I will be figuring this out!

Rich Krause

 

Thanks for the info guys. I'm just TTTing once here just in case anyone has anything to add....I'm going to send him this link tomorrow. I believe he already has a bypass valve, that will suffice won't it? (addition of BOV not really needed for 10 PSI, right?)

 

IMHO Forget about the BOV. You tried it and I tried it. I still think it is a waste of time and money. If he really need to upgrade his bypass valve because it is not evacuating fast enough or leaking then I would just get the procharger or vortech race bypass valve. It will help driveability by preventing surging and won't have any leaks. I still have the HKS SS BOV mounted on a vortech tube sitting around.

cheers