klumb15

I was wondering which would make more power.

350 block
L98 alum heads
mild port job
276HR cam
224/230 duration
.503/.510 lift
1.6 ration roller rockers

okay say thats the motor, which would make more power, that bottom end with HSR, or that bottom end with say a airgap intake, and 670 or so carb...

also this is banking on that the HSR is tuned near perfect, which mine is not, and rarely anybody's is...

So give a crack at it, how much HP will eash produce...

Also if you guys had to choose, wich would you pick, a perfect running carb setup, or a rough running HSR?

Dave89IROC

EFI will allow more power if tuned correctly

Zepher

both can create the same power, just that the carb will end up using more gas over all.

91-Z28-L98

EFI gives more precise fuel delivery at all RPMs, therefore will be more fuel efficient. Also, EFI has a higher degree of variability for intake manifolds. So basically, they both can give the same results, but with the carb you may have to use a big intake manifold which could require a cowl on the hood.

klumb15

i got the ss hood, gutted out it can fit a decent sized air cleaner....also i do agree the FI puts out more precise fuel delivery, and more precise combustion, but that all looks excellent on paper. In real life, trying to get it dialed in that precise is another problem. And that is the problem i'm having now, and now money is a big issue, and I'm startin to see that a carb setup might be better for me...i just wanna get this car done! anybody have an idea on what a loaded HSR intake would go for...it has like 5 hours of runtime on it....includes HSR, 26# injectors, AFPR, 58mm TPIS TB, and all the other little stuff that goes with it...would i seam crazy to get 1500 for it?

89385formula

Well, I would say that the HSR would be the way to go. Stay EFI, spend the money and reap the benefits of it. I believe the same setup with a carb may be a an easier tuned one, but a do believe it will fall a bit short on HP compared to a well tuned HSR setup. I believe this to be the case because of 2 reasons....1 I find the HSR to be a very good intake for making TQ and HP, also (2)you will be overcarbing the engine if you want to get anywere near the CFM that the 58mm TB flows, in a carb.....therefore less flow equals less power.

What is wrong with your car...there must be something if you believe its not tuned well. What is wrong with getting a dyno tune and getting it spot on? What has made you consider this....maybe we can help.

klumb15

well i've been working with pcmforless for some time now, they burnt me 2 chips, niether of them work. Both of them made the car run crappier and richer than the stock chip does. So I've been runnign it on the stock chip. the car totally sucks under 2500 rpms, like when you give it gas, it just like falls on its face, and wants to just spudder out and die. But once you baby it and get it above 2500 or so, it just screams, but you can tell its still outta tune. I've messed with the timing and fuel pressure alot. i've started at 6* base timing, and went to 15*..i think its at about 10 or so, it seeems to run decent, but still not that good. When i go to start it, it'll take like a minute to get it going, then another couple minutes of babying it to keep it going. And my buddy has almost the same setup, but with a race carb. pumps the pedal twice, the bitch fires up on the first little nudge of the key. Don't get my wrong i'd love to keep the HSR, but I keep dumping more and more money into it, and I see no results. My only other option would be to get somebody in my town that knows how do to DIY prom tuning(which I know nobody that does it) or bring it to the nearest dyno which is like a 4.5 hr drive. And i don't even know if they tune after the dyno runs. I just know they have a dyno. I'm a college student now, and money is really dwindling. I don't have the money to float around like I did in highschool, cuz i was working all the time. I'm just looking for the easiest way out to get my car running good so I can enjoy it before getting rid of it in a couple years. My first thought of this car when i started ripping everything out, is I'm gonna throw a carb on this thing. Then everybody convinced me to go HSR. So I did, and when I got everything done, it seemed like everybody at TGO who told me to get HSR just like abandoned me and never give me any pointers on how to get this thing tuned.

RedIrocZ-28

Hey, whats your setup? Is it like mine? I can't remember off top of my head right now.

355 HSR
AFR 195's
230* / .530" cam
3.73's
2800 Vigilante
1 3/4" headers and 3" exhaust.

Same as mine? My chip runs the car pretty well. And I am having mine tuned in a week. shhhhhh

EDIT: Don't mind me, I have been having a splitting headache at work here today. I didn't even notice the combo specs up top.

onefastgta

Are you sure you don't have some sort of mechanical problem? You have an '86 correct? The maf cars are easier to tune idle, part-throttle and wot. Set the initial timing at 6* like stock.

You also need to communicate with pcmforless about your needs/problems.

If you don't have a scanner or laptop to record data, then you are in the dark. You have to have information to tune a fuel-injected car. Find someone around there who has a scantool and borrow it. You need to give pcmforless info so they can adjust the chip. Nothing will work right out of the box.

I bet you have a vacuum leak or something else mechanical going on. Verify your TPS voltage and reset the IAC and initial timing and check for vacuum leaks. Check all the bolts on the intake and exhaust to make sure they are tight.

Start with this and then report back.

RedIrocZ-28

I agree, you either have an intake leak/vacuum leak, the TPS is set incorrectly, the IAC isn't set properly, and your timing is off. Make sure that you have the ESC wire unplugged when you are setting the timing. That wire, for me (and you) is on the passenger side strut tower thing. Its a black connector and a tan wire, unplug that before setting the timing. The TPS should be set to .55V with the throttle blades closed at idle. The IAC should be set after the TPS is set, there is a writeup over on thirdgen.org in the tech articles. And lastly, go get yourself a can of carb cleaner, spray that around the intake manifold, just like a spritz of it, don't douse it. If the engine rpm gets higher then you have an intake/other vacuum leak. If not, then well... this CAI system will take all your problems away

klumb15

hey rediroc, i tryed and pm you about that CAI, but it said your PM folder is full...so empty that so I can write ya back..i gotta talk to ya...

the timing is back at 6*, and yes I do adjust the timing with the ESC plug unplugged. I redid the whole vacuum system to make sure there was no leaks...thats the first thing I thought it was...absolutely no leaks now. i'll try that carb cleaner thing and see how that works. But i'm pretty sure its sealed really good...

Now as far as the IAC and TPS, how do I check those?

RedIrocZ-28

First things first, do you have a scanner? If you do, then look for the TPS voltage reading. Dude, if THAT is not set correctly, WOW that is a monumental problem. If you don't have a scanner then you need a volt meter. And my PM box is emptied out.

klumb15

no scanner...i can get a volt meter, how do i go about checking it?

iansane

Sounds like you're getting some help now but I'd invest in an ALDL cable (or make one yourself) so you can see what's going on with your car.

Keep the HSR. Have you thought about learning to tune it yourself?

klumb15

yea i've thought about...tryed to learn, and it all sounds like greek to me. And the people you talk to on TGO sound like I should know all the stuff on how to do it already. I don't learn by reading, I learn by somebody showing me.