02 s-10 with 4.3 question

[97cavalier]

ok my buddy has an 02 s-10 extream with the 4.3 and he wants to know what you have to do to take the speed limiter off? do you have to get the computer retuned? or is there a prom chip?

[GMMerlin]

Originally Posted by 97cavalier

ok my buddy has an 02 s-10 extream with the 4.3 and he wants to know what you have to do to take the speed limiter off? do you have to get the computer retuned? or is there a prom chip?

Why?

[Ducaire]

Originally Posted by GMMerlin

Why?

Why not?

[ZL1power69]

you need a programer like a hypertech or superchips to remove/raise the speed limiter.

[sreve]

hypertech will raise it to 128mph. you can not comlpletly remove it but it can
be changed to a max of 255mph. there's not much bang for the buck if you are paying retail for one check out there dyno numbers online. pcm for less or nelson are much better options. if you live close i can change it, tune it, or buy a hand held on ebay get it how you like it and i can unmarry the handheld and burn that tune back to your pcm and you can resell it on ebay.
f.y.i. gm obd2 cars and trucks use a eeprom (electrionicly erasable programableread only memory) and are flashed though the data link connector. good luck if you have any questions PM me.

[97cavalier]

ok thanx alot guys, see i have a 92 camaro and it is OB1 not OB2 and i have a "prom" chip for mine and i was just trying to answer his question.but sreve where are you located? I am by St.Louis MO, i am like 5 min from the JB bridge.

[sreve]

too wierd you are not more than twenty min. from me. PM me if he wants to change it.

[kielu84]

I had a 97 S-10 and I had a hypertech power programmer 3 that I paid $400 for awhile back. It didn't do much on the performance end but it did raise the top speed limiter. If you want to go fast in something get a car.

[Blue Bowtie]

Originally Posted by 97cavalier

92 camaro RS 305
Mods- Flowmaster exhaust, Open Maf air cleaner,TB spacer, American Racing rims with 295/50/15's.LT1 Cam in garage.

Is it just me (probably) but does that somehow seem inconsistent?

What is an "Open Maf air cleaner" anyway? I've only been doing this for a little over 30 years, so pardon me for asking newb questions. But a '92 RS should be a TBI, which means it would never have had a MAF. Coupled with the fact that is has "TB spacer" which would seem to confirm it is TBI, even if it were TPI, it wouldn't have a MAF since the '90-up TPIs were all speed/density. And even further, as if by some strange rift in the space/time continuum it were to have a MAF, having one "open" is seldom a good thing. I must've missed sometheing there...

Perhaps that is supposed to be an "Open element" air cleaner? Just checking.

[kielu84]

I noticed that you refered to ''newb". Were you refering to me because I am confused on your post. I am also curious to know and have always wondered on TBI units. How does the engine measure the amount of air being drawn into the engine? Also on the older 3.1's 95 and back they too do not have a mafs. How does it measure the air being drawn into the engine? I'm only 22 and I'm pretty much just a back yard mechanic doing what I can here and there and I am always trying to learn as much as I can. Thanks!!

[Blue Bowtie]

That "newb" reference was about ME, since I've only been doing this for 30+ years.

As for TBI (and other speed/density MPFI control schemes), the air entering the engine is NOT measured. It is calculated based upon a presumed volumetric efficiency of the engine, throttle angle, engine RPM, manifold pressure/vacuum (MAP), and intake air temperature. The most significant inputs are RPM and throttle angle (thus the term, "Speed") and manifold absolute pressure ("Density"). That usually gets the calculations close enough for any factory stock setup, and the final fuel trimming is done with input from the oxygen sensor. Since the factory spent considerable time determining the correct VE rates for a given engine and building appropriate tables, the systems are usually fairly reliable and work rather well.

The real problems with this type system are that significant variations in pressure don't always get reflected accurately enough in the MAP signal to reflect the true amount of intake air, and any modification which changes the volumetric efficiency (VE) of the engine renders the entire calculation almost useless. Driving from the Nevada desert to Denver can have enough barometric effect to really skew the mixture rich, and the ECM does not have adequate time to integrate BLM data to write new tables. Adding headers, a freer flowing intake, different heads, a different cam profile, altering the air cleaner, and various other changes which can affect VE will throw the whole thing into question. You'll notice that when emissions requirements got more stringent, the MAF reappeared along with a MAP, so that systems could actually measure the intake air mass and trim fuel accordingly and correctly.

[DelCoch]

Just a word of caution on increasing top end speed. I've heard several horror stories about this. It seems the factory specs are designed for the restricted speed and when it's surpassed strange things can happen. For example, it seems the drive shafts are only balanced for the restricted speed and when this speed is exceeded the drive shaft will viberate casusing the transmission case to crack and/or the drive shaft universal joint to fail. I imagine the restricted speed is in place so weaker parts can be used, thus saving money on the build.

[kielu84]

I agree with that last post. When i had my S truck I had it up to 120 mph and it took awhile to get there in the first place. But that damn thing was all over the road, floated like a hoover craft. I dont think even an S10 Xtreme is made to go that fast even if you can get it to do it.