My friend has an 88 IROC that uses original EPROM ABYA. About a year ago he purchased a jet chip, which he said didn't make a noticable difference. Recently for reasons, I increased the idle and for curious reasons, I used a compare utility on the original vs the jet perf chip. There are only four bytes that are different $002 to $005, the date code and sequence number. The checksums match. Can anyone else confirm this on there product?

No way!

What a rip off!

Didn't make a considerable difference eh? Is his IROC a manual? Is the chip Stage I or Stage II?

I own a '88 GTA and I felt awesome results. My car is auto and the chip I put in was Stage II.

I was told that you do not want to have your base timing set higher than 6 degrees. This is done by rotating the distributor either clockwise or counterclockwise. The chip supposidly resets the timing electronically rather than manually.

Ahh, the triumph of marketing over engineering.

But since this is the Thirdgen DIY-PROM forum, what are the parameters for "awesome"?

John,

PS: Bruce, you're awesome- you be kind to this man.

Im still amazed that no one believes me when i tell them off the shelf chips are garbage and a hosejob.......... Then next time they are over i boot up the puter and show them and there like no way! your kidding! lol

Live and learn
LAter
Jeremy
PS even the really $$$$$$$ ones when u tell them all your "specs" same deal there too

Add lots of timing, and fuel.
The car about allows feels fast that way.

It is possible to stumble into an aftermarket chip that works well in some given combination. After all they have to get them to at least feel a little faster or they'd be out or business. I wonder thou if folks bothered to use a stop watch before and after if they would be in business thou.

Gotta give them credit, stage one, lower fan temp enables. Woo, now there's some engineering.
Stage II good for 3 MPH and .2 according to Hotrod, but of course they hardly ever do one mod at a time. But, you have to be an english major to work for the magazines, so that you don't laugh as you write the TRUTH, LOL.

I had a Hypertech stage 2 and the only thing changed was the fans temp was lowered and they used the ARAP main spark table.

First off I came into the DIY-PROM forum on a search... so I didn't know.

"the triumph of marketing over engineering"?
Isn't it hard to modify your motor without the use of aftermarket parts and aren't these aftermarket parts that are offered the results of such engineering? (no need to answer)

I was simply stating that I had outstanding results from my off the shelf chip. I'm not saying that a custom chip wouldn't be better. I apoligize if "awesome" wasn't the appropriate wording.

Okay then, what are the parameters for "outstanding"?

Grumpy has described a couple of potential parameters- MPH and ET improvement, but left open the question about where the extra air came from to take the spark and fuel changes the chip dialled in. Possibly they left the air filter out who knows? Your standard PROM carries a program that can cope with say 10% more air without too much fuss and that may make 10% more power. But what has your magic chip supplier done to your "Stage 2" chip that has this impact, and how much MPH or HP is "outstanding or awesome".

E-man has shown you what most of us here believe to be the case about these "off the shelf performance chip manufacturers"- at the best, they've just taken a good BIN (you can get one off the 'net or just pick the right memcal) and cut and pasted the spark table, and turned the fans on a bit earlier like Grumpy said. But their marketers have produced slick web sites which illustrate how awesome the results will feel and it's marketing you're buying, not rocket science.

Once the basics are right (as in good factory BINs) every time I burn a new chip and it doesn't make the ECM light come on it "feels awesome"- checking stuff you can measure never gives results that feel as good. That is, unless you've done something else to the motor to get more air through. Then you need a custom chip. That's not an "off the shelf performance chip."

What you get with those is not rocket science, it's a ripoff and that's what Don416's original post was designed to establish.

Welcome to the DIY-PROM forum

John