Is this the truth, the whole truth; and, nothing but the truth ?

A friend was telling me this morning that Corvette's from 80's upward came with a factory oem computer chip which already had High Performance settings programmed into them; but, that they where only set at the factory for normal performance.

If the owner wanted to boost performance this chip some how could be reset to the high performance settings by a tech.

I haven't gone onto Snope's to verify this, and since I'm definitely not a techie I figured it would be quicker coming here.....

 

Short answer, no! The chips have on program on them and you cannot reset it by a tech to a different program.

 

thanks -
I didn't think so, especially considering the years referred to...
now today with the technology what it is might be another story,
but I don't own a C7 so it doesn't really matter to me.

 

There is no real need to reprogram a stock L98 unless you want fans to come on sooner, or have deleted AIR, or EGR and need them turned off, and a small MAF adjustment. Some benefit can be made from spark mapping, but it's such a small gain it's only worth it if you have the extra coin.

 

MrWillys, i will be the first one to disagree with you. You can still make gains with a stock L98. Sure, you can change or modify the ancillary parameters, as you mention, but there are still gains to be made by changing the fuel and spark tables. Now the stock GM settings are certainly decent, but they are still conservative. You still have to know what you are doing. If someone wants to learn to do their own chips, you should not discourage them. Burn on!

 

So how much more horsepower is your stock L98 putting out after your tuning?

 

Mike,
I'm not trying to discourage anyone, and if we were talking about a Camaro I'd say go for it. However, for the most part the Corvette uses a much more performance based spark map. The $32B did use some weaker ones, but it was corrected by $6E. The OP was talking about buying performance programming and not doing it himself. My opinion is the money would be better spent elsewhere. Buy 1.6 roller rockers and he'll get more than a reprogram.

 

O i would say at least a hundred or more HP. But that was measured with my Butt-O-Meter. My engine dyno is broke, and my chassis dyno is out of calibration, waiting for parts..........LOL!

Tuning your own chips is not just about more HP, there are lots of things you can do. What about reliability, driveability and fuel economy? But I digress, since the OP wanted more hp. The stock L98 tpi might have 250hp at its highest peak, which in reality is not that much. Today's 6 cyl trucks have more hp than that. Most folks modify their tpi for more power. That is where you need a PROM burn to take advantage of it.

 

Good info there. I am still learning about my C4, since i have only owned it about a year and half. I am trying to keep it mostly stock, but have done a few things. Mainly just a lower t-stat, K&N filter, and 24 lb injectors. So you gotta tune some things for the changes. I have the MAT to IAT relocator kit, but have not installed it yet.

I started my tuning career on my '88 IROC camaro, with L98. Now with that i am quite sure i have gained some hp. Started running in the mid15s with it, now i am in low 14s. I have done alot to it, but still have stock block, and never pulled a valve cover. The camaros always got de-tuned Corvette stuff, and the iron heads are another story. I am running the $6E setup, with the ARAP bin (modified). they say that is a Vette bin, so it might be too aggressive for an F-body.

 

I wonder if that does anything useful on later cars.

In my car the only thing the MAT is used for is to enable EGR when it gets over 0.5°F. This is the ONLY place in the code that the MAT temperature is used:

 

You are absolutely right about that, Cliff. On MAF tpi cars, the MAT only controls the EGR enable. Now on the SD cars, which have a MAP sensor, the MAT value is most definitely used in the fuel calculations. There are several different tables, and some need to be changed when you move the MAT to and IAT. But for a C4 tpi, the only years that use it are 90&91. I am not so sure about how the LT1 motor works.

On my 88 IROC Camaro, i did the relocation several years ago, before I learned what the MAT did. But it is done, and looks cool, so i am leaving it alone. And just recently, i did away with my EGR, so now i have no need at all for the MAT!

Now, ask me how i know all this. Over on the Camaro forums, namely TGO, there are some really sharp chippers, who have all this figured out. And they have the tables which need to be changed for an SD car. So that is a project for my '90 someday. Supposely you can get some gains if you do this mod, but the tables MUST be changed in order for it to work. I am really not so sure how it all works, since the calculations get busy. I have over 10 years on the camaro boards. Now need to get some miles here on the C4 boards!