Shibbyfbird

just out of general curiosity and my need to win an arguement, theoretically you could by an aftermarket chip, read it into a BIN, then burn it onto a new chip? keep in mind i don't plan on doing this, since it probably wouldn't be worth it anyways, plus it's gotta be hella illegal anyways, just a simple inquiry!

:hail: PEOPLE WHO KNOW WHAT THEY'RE DOING

V8Astro Captain

iTrader: (1)

yes

Grim Reaper

But those "off-the-shelf" eproms/bins are so horrible, you're wasting your time doing it. In fact, a few are so poorly done that you loose performance - not gain.

The best place to start is always with a KNOWN GOOD stock GM eprom designed closest to your engine and modify from there.

Grumpy

Not all aftermarket chips are copiable.
I gave up watching what they were doing years ago, after seeing what they were trying to pass off as improvements.
At one point in time, I believe hypers were trimming a pin off of the chip so you couldn't read it.

Shibbyfbird

so those aftermarket chips aren't the magical things they seem? lol what exactly adds hp while changing the chip? i mean i know it's good for raising idle speed when using a big cam, fan turn on, etc... but where does the horsepower come in? spark plug timing? i read the tech article and all the pages in it and this didn't answer my question. thanks for the help.:hail:

Grumpy

The oem chips are designed for the average Gobber and to keep the EPA happy. Performance ain't spoke by either crowd.

When you get into off-road use, you can add or remove fuel, and play with the timing. There are some strategies in the stock cal that are there so the gobbers don't over heat the converter so the engine runs way rich, and as a side note, it's easier to replace plugs then pistons when under warranty.

Then they also figure your might swing thru Alaska on your way to the Mojave desert. While alternating between 85 and 100 Octane gas.

The oem cal is a compromise, designed by committee.
(ie a camel is a horse designed by a committee)

Shibbyfbird

so what is the first things that should be changed??? what changes will yield the most hp increase? i understand you guys can't say "poof, do this" but what is the first things you usually do to get the power up a lil bit? thanks

kevinc

Poof, do this:

Read the tuning articles posted by TRAXION, get a scantool or laptop setup so you can read the ECM's data and see where things are less than optimal, and start adjusting.

Grumpy

The first thing is investigating what all you can edit.
Then read thru some of the tuning articles.
Then estibalish an accurate baseline, and way to repeatedly measure your performance.
Then using that info., experiment.
There's a boat load of info., and you need to sit down and start studying it.

Grim Reaper

POOF! Do that.

Exactly as Bruce is saying, you need to play with the fuel and the timing. But there is no "magic" specific number - every engine EVEN when seemingly identical likes something just a little different.

There are "ranges" to play with, but the specific amount of spark advance or exact AF Ratio will vary from engine to engine. It requires "testing, testing and more testing". So it is tough to give generalizations.

Some generalizations with a "stock" GM F-body/Y-body heads is they seem to not like too much spark advance - PERIOD. Forget trying to run 36* of spark advance. Even on 94 Octance you'll be detonating like crazy (if you've capped or disabled the knock sensor) or have so much timing pulled out that you'll probably have only 20* of spark advance anyway.

Stock GM heads just don't like lots of spark advance. Clean up the combustion chambers and remove "casting flash" and you'll get a couple more degrees, but that's about it. With my "never been off the engine" iron L98 heads, I can't run more than 25* of Total Effective Spark Advance (that's after subtracting the knock retard, or capping it to 0* - does the same thing) - or I get detonation. And this is with 94 Octance. Guys who've "cleaned up" the combustion chambers get maybe 28*.

Conversely, I have a buddy with AFR 195s (Competition Porting) and he can run spark advance as high as 38* without any detonation. What we haven't figured out is the "optimum" spark advance in his case as you only want to run the least amount of spark advance the gives the best performance. I suspect in his case, the optimum number is somewhere between 34-36* depending on the AF Ratio (which we are now making a WB O2 Sensor for). But, as you can see, we need to do "testing, testing and more testing".