bigpoppapump

I have a 91 Z28 with the 5.7 and around 35,000 orignal miles, I am looking into installing an ATI Procharger P-1sc. Here's all the mods I have currently, Edelborock High Flow Intake and Runners, Edelbrock/BBK 52mm Throttle body, Hypertech chip, 3" Flowmaster American Thunder Exhaust (with High-flow cats), Richmond 3.73 gears, 17" 275 Zo6 wheels on Firehawk tires, and an SLP Shift Kit.

I dont want to wear on the car to much, and as u can tell by the mileage its not driven much. I was thinking of going with the 12psi set up, and was wondering if u think this will be pretty safe for my car and how much horse do u think I will be making? Thanks guys

Rice Killer87

Not sure man,but I think 12 psi sounds like alot on a stock internal motor,even if you dont drive it much.

Im not a F/I specialist,but that might be border line to run on pump gas at that psi.

I would run like 8 psi first and maybe go up from there.

just my 2 cents

Rottluver

6-8 psi is the "norm" for a street car, especially one with stock internals/non-forged bottom end. 12 psi would probably not only tax your fuel system (injectors, pump, etc) but end up destroying that low mileage engine you have there. I would stick with the stock/standard 5-7 or 8 (at the most) psi for non-racing applications. Just my humble $.02.

Also, if you go with 12 psi, you will end up needing to replace/repair your tranny and rear end a LOT faster then you would like to think about I reckon.........

respectirocz

dont forget to have the engine mapped or a chip burned for that speed density system, or u wont get the best bang for your buck

bigpoppapump

Yeah this is the kind of advice I need, I have no idea what to do I am not very mechanically inclined. I have no idea what engine mapping or having a chip burned is. Thanks

Rottluver

Not to sound condescending, and I am certainly not at all the know it all of cars, but if you really have that little info about what is needed, I HIGHLY recommend AGAINST getting a blower (supercharger). IF and I stress IF you are bound and determined to do it....find a GOOD REPUTABLE speed shop that has LOTS of experience with 3rd Gens and just give them the money to do it for you.....otherwise you are going to take that awesome low mileage car of yours and turn it into a heaping pile of junk.

I know I don't want to see that car get destroyed due to a lack of information.......and I am sure you don't either.

AutoRoc

There's a local around these parts running 10PSI on a basically stock 350TPI IROC-Z. Intercooled Procharger D1 setup. Runs like a champ and has been for years. Maybe he'll chime in.

These engines have cheap parts just like 4th gens but a thirdgen has 9.5:1 compression vs. a higher comp. in an LT1. A Safe tune up will be needed but that goes for any engine that will be pushed to the limit.

Goodluck!

cc89formula

i dont know how it would be where you live, but here something like 13.3 or 13.6PSI will double your amount of HP (from what im told, im a NA guy) so 12 would be alot.

Marc 85Z28

It's a little more than that. Theoretically 14.7psi will double your power. However, that is not always the case, and is a little more complicated. Much of it has to do with blower effeciency. Intercooling, engine setup, and total power output all play major factors among others. An ineffecient blower at 14.7psi on a 300HP engine might produce 425HP, while a very effecient blower at the same 14.7 might produce 475HP on the same engine. An excellent real world example of this would be found in many late model Cobras. Switching from the stock blower to a more effecient blower can increase power tremendously, on several psi less boost. Typically 100HP at the wheels or more!

I believe ATI recommends the 9psi setup with the intercooler for reliability and long term use on the L98. 12psi is possible, but you would need a much more effecient intercooler. AND MAKE SURE YOUR FUEL SYSTEM IS UP TO TASK!

mako350Z28

From what I have seen with an L98, a little bit of boost goes a long way. For example, I'm sure most here have seen that episode if Full Throttle with the '88 IROCs. On the winning car, it went from 208 rwhp to 332 rwhp using only 6 (I think) pounds without a tune or an intercooler.

I wonder what it would do with 9 pounds + intercooler + a good tune.

Willie

My 1987 305 TPI IROC-Z's best stock E/T was a 15.91 @ 82 mph. After building up the 305 to handle almost anything (which pretty much includes everything), I have run a best of 12.00 @ 117.62 mph with a D1SC making 14-psig boost with a 3-core IC and water/alky injection. This is with all accessories and all emissions equipment pushing a 3,900 pound load.

The general rule of thumb is: 1 second reduction = 100 hp. I've taken almost FOUR SECONDS off my stock E/T with 14-psig boost.

In late 2003, I bought a new F1 head unit to replace the D1SC. With only 953 miles on the new blower, I had a "problem" with my new Scat 4340 crank and the car was down about one year. During that timeframe, I decided to go a different route and am now selling an almost complete system for a third gen. If anyone is interested, e-mail me. Oh, if your engine has a stock bottom end, you don't want my stuff. It's way too potent.

Willie
tplsz87@***.net

BOZS89IROC

Everything you just heard from all these people was, as far as I know, right on the money. Which is what makes this site so great. So just to add my 2 cents...

I would stick with lower boost levels until you reenforce your bottom end. Your tranny and diff. are only good for up to 450 h.p. (i believe). Putting more air into your system means more fuel needs to be added to prevent a lean condition. Which, in turn, means (maybe) a new, higher flow fuel pump, bigger injectors, AFPR (adjustable fuel press. regulator), etc...Like I said, maybe. Lower boost levels can be run on the stock engine but once you start getting up there in PSI you need to start looking at reenforcing other things also. Check with ATI, I'm sure they can give some useful info.

Marc 85Z28

"General rule of thumb" Just like the 14psi doubles HP "general rule of thumb".

If we followed that "rule", you would be making over 600 crank HP

100HP = 10MPH is MUCH better than 100HP = 1 second.