hi everyone, my brother recommended me to this site. it has a wealth of information, i have spend a few hours just searching and reading. i have a question though. i currently have a 1988 iroc-z that originally came with a 305 tpi and a 5 speed. it is now a 383 stroker with a t56 6 speed. it has 195cc trick flow heads. cam specs: 224/224 @ .50 .495/.495 112LSA. edelbrock headers. and the holley stealth ram intake with holley TB. the ecm/prom was edited to eliminate the egr so it runs fine without check engine light. now my question is.... is the holley stealth ram intake to much of an intake for this car? its a street car, and i dont really want to turn 6,000rpm to make good power. i was thinking with this size of cam/heads i should go with a bigger mouth intake like edelbrock and as&m runners. i have a few options that i can go with because i have several different intakes on hand already. i have the HSR, siamesed in 4 inches stock base, stock edelbrock base, as&m runners, accel runners, ported plenum, stock tb, 58mm TB. as you can see i have several different options, but i dont know which setup i should use. thanks. i also can get a different ecm/prom to put the egr back in place, so thats not a problem.

 

with that cam and the HSR you peak power sould come in around 5500 RPMs. so your redline would be at 6k. how does the car feel now, with the HSR on it?

 

it feels nice and strong durning the upper rpm's like 4000 and up, but below that it feels like a 305 motor. i can run it all the way up to 6000 no problem and shift, my brothers stock 350TPI auto feels like it has alot more power down low and all the way up to 5500. i was thinking i should be able to make more power through out the whole range with the siamesed intake and as&m runners but top out at like 5000. i also just did a few runs with my scanner hooked up and noticed that open loop aparently doesnt exsist on my car, not during warm up or WOT. oxygen sensor reads 0 during warmup and .780mV at WOT. i think thats a little to low. hmmmm....

 

Keep the stealthram but you need to tune the timing/AFR/etc for it to run to its potential. The HSR ain't going to have the low end torque grunt that the TPI will so if your more interested in the idle to 3k rpms band then you've picked the wrong intake. However, if your interested in the 2k to 6500 band then you've pick the right one.

What gears do you have in it? If you have the stock 2.73s then I would upgrade to 3.42s or 3.73s.

 

im pretty sure the gears are either 3.27 or 3.45. i know its a 9-bolt bw rear. i was actually going to check the ratio tomorrow by spinning the driveshaft. im not sure exactly what i want, i just wanted some input on what you guys have ran and how it turned out. i like the upper rpm band, but i would like to move it down a bit, so i dont have to turn 6000 rpm. do you really think that with a siamesed intake and as&m large tube runners that it will only pull to 3000 rpm? i figured at least to 5000 rpm, but then again i need to figure out my rear ratio first.

by rule of thumb what is the smallest cam you should run in a 383 if you are using a holley stealth ram?

 

I think I would keep the steath ram intake with the combination that you have. The TPI long tube runner intakes will boost low RPM power but they will give up too much at the top end (In my opinion). It really depends on what you want, the TPI runners will probably make more power then the HSR until about 4200-4500 RPM and then the HSR will pull away. If you shift at 6000 RPM the engine will not drop below 4500 on the shifts and the car will be faster with the HSR. If you want low end grunt and low RPM shifts (5000 or less) put on the TPI set-up.

You may want to consider picking up a Superram, it is a combination of the two intakes, it still makes great low end power and then pulls to about 5500 RPM. I am running the superram but I an considering changing to the HSR to add some upper RPM HP.

 

The extra HP/Torque provided by stroking your motor should more than make up for the shorter runners of the HSR I would think. That intake with those heads on a 383 ought to pull very nicely all throughout the RPM range. I would definitely check your prom for problems, I can't imagine a stock 350 TPI pulling harder down low than your setup.

 

As with any fuel injection tuning is where its at for maximum power and driveability. You will still feel 'sluggish' from idle to about 3k with your combo (compared to the LTR setup) but you will put down more overall power and torque with the HSR. Like driving an LS1 car compared to a L98 car.

I had my 383 HSR on the road twice and while it wasn't running correctly I defenitly missed the feel of extreme low end torque (makes stoplights fun) but know that as soon as I get on the x-way I'll never look back to LTR.

The LTR's will pull to about 5000 but then fall flat on its face after that, right when the HSR is waking up.

 

I have a 383 with a Miniram intake running thru a T-56 tranny and 4.10 gears. I also have the TF 23* heads and a ZZ409 cam (226/226) but with .554 .554 lift on a 112*. And HAD the Edelbrock TES, now have SLP 1 3/4.

I have soo much torque that 1st and 2nd gear are useless on the street. most of the time I start in 2nd gear driving on the street anyways. I just replaced my older 350 under the same heads and can definatly feel the extra torque of the 383. Since my combo is VERY simlar to yours minus 4.10 gears and a slightly larger cam, I would check your tuning on your chip or something inside the engine. Your HSR has longer runners than my Miniram, and your cam is smaller (more torque at a lower rpm) so you SHOULD have more torque than me! In theroy.

 

i say if you want to keep the revs that low then go with the LTR setup. with your cam and the AS&M runners with the high flow base your peak sould be around 5k. the HSR and superram will make more HP but if low speed tourq is what you want then you can't go wrong with the LTR. that cam is a very good match with an LTR, IF you do go with the HSR a larger cam will yield more power, as you may know.

 

alright i checked my rear end out a little while ago, it is a 3.45 9bolt. i also took it out for a spirited run, got it into 3rd at 1500 rpm and floored it, it was kind of sluggish, until about 4500 rpm then it had an insane pull. i guess how the car sits now, its a benifit for cruizin and high performance, but only in the upper rpm's, i dont know what to say or do about this, im just confused.

 

I had to jack the base timing up to 14 degrees with a stock chip to get it to pull right down low on a similar combo on a 355. It was sluggish even at 10 degrees. Once I jacked the timing up,, it pulled fairly well down low even with 28 less cubes and a little less gear than you're running. So unless the new chip has a more agressive timing from stall speed to around 4000,,,, I'm going to say your problem has more to do with the ignition curve in the chip than the intake system.

You should be just fine with the 383 and HSR,,, but if you never plan on racing the car and just want to show out and have a blast driving it,,, port the Edelbrock base and put on the AS&M runners. If you're running less than a 3000 stall,,,, it might generate similar ETs,, provided traction.

 

what about switching to the miniram?

 

BadSS - im not sure if the timing curve was changed or not, the previous owner said it was burned by some guy on here named kevin or something like that, and that the only thing changed was to eliminate the egr function, i dont know why everything else wasn't edited too because there is no cold start injector with the HSR and it is a bitch to start, and something is up with the open/closed loop, because open loop never comes in play, its always in closed loop. i think i will try your idea about moving the timing up, right now its stuck at 9 degrees, whoever put the distributor in put some wierd bolt on it to hold it down, so my distributor wrench cant get down there, its like a 11/16 bolt and my wrench is only 5/8 some imma have to get it off some how with a regular wrench/socket, cuz the distributor is really tight, i cant turn it. oh and the transmission is a T-56 6speed manual, so there is no stall speed

the mini ram i believe has an even shorter runner than the HSR. which would bring the power band up even higher.

 

I would get it on a dyno, or a dragstrip, and find out what kind of power it makes. Dyno would be best obviously, and get them to use the tailpipe O2 as well, (or yours), and log the O2 vs the RPM and power. Also see if you can figure out what timing curve it has on it.
Probably a lot left in it from tuning, sounds like you've got a nice system as far as hard parts go, i'd go as far as you possibly can with tuning your current setup, before you go changing anything.

 

Seems strange you don't feel that extra kick with the 383 at the lower RPM's. Think you best bet is to get it on the dyno or get a WB02 sensor hooked up and find out what's going on, my bet is it's in the tunning either with playing around with the AFR or adding timming that you will get that kick your looking for. BTW this guy that's doing your chips has he done more then just EGR change to your chip?

I have to agree with 3rdgenZ with that cam your peak should come in at mid 5k and redline around 6K, why you worried to bring her up to 6k? You could slap on that edelbrock base and as&m runners but reving to 4500rpm's kind of sucks lol especially since you have a t-56 in there.

 

You should look into getting a better rear gear if you plan on running the HSR. IMHO thats one of the reasons your car dosent "feel" as fast as it could be (that and tuning) right now with your 3.42's or what ever you think you have. That will get you into the engines powerband alot quicker. With your T-56 tranny 4.10's (like mine are not out of the question) or a 3.73 rear would help out alot. I run around 2400 rpm on the freeway doing 80 mph!