What is a chip and what does it do?

[Dave C. '04 Z06]

K&N and filter lid shouldn't make a difference.

The headers, depending on how well they match your car (how well they are tuned to scavenge), the computer may or may not be able to compensate for it.

I am not too familiar with the older PCM's such as in your '88. I know the newer ones (OBD-I and later) can compensate over time for that stuff to a degree. But the problem is that rarely does someone drive at part throttle at 5000 rpm, so that the computer doesn't know that there is a sweet spot there where the headers are really yanking in that fresh charge. That's where PCM tuning helps alot, because it tells the computer what is expected, so it can calibrate itself better. Also if the headers are scavenging well, you may have to slightly retard your ignition timing to prevent detonation if you're running on the edge. The computer just does what it's told as far as timing is concerned unless the knock sensor triggers. It has no way to measure for optimal timing like it measures for fuel mixture.

-Dave C.

ALSO: as far as someone earlier hoping that someone wasn't taking a shot at Jeff, if refering to me, no..I don't take shots at people. I don't know Jeff, but I'm sure if you guys have respect for him then he does a fine job at tuning PCM's. I'm sure he does the best he can for you. I'm just saying that if you go to McDonald's and ask them who makes the best hamburgers, they're going to say McDonalds. It's business.

 

[rrubel]

Couple things, Dave and Whalepirot...

First off, an honest 1/2 mph gain in trap speed in the 1/4 mi is definitely worth something. If you get that speed early on, and keep it the whole time, that's worth a tenth or two.

Second, TPIS did studies on a flow bench regarding just how much better a MAF with no screens flows. I don't have their numbers handy (lent out my book) but it's a decent amount. With respect to losing MAF protection, think about this: any particle large enough to be blocked by the screen still had to pass your air filter, and if it did, you've got bigger problems than a dead MAF. Also, why put it on both sides of the MAF if it's just for protection? I can understand protecting it during installation or maintenance, or perhaps expecting the screens to smooth airflow, but not protecting it while driving.

And finally the coolant bypass. It's not just the throttle body that gets hot; I've noticed the intake plenum is cooler in front where the TB is; the heat must get conducted from the TB. And yes, I realize the plenum gets plenty hot when the engine is running, but it doesn't seem AS hot. I can rest my hand, in a mechanics glove, on the top of it where I couldn't before. If you count most of the plenum, that's a longer distance for the air to get heated in...

[RICHR]

 

[Dave C. '04 Z06]

You don't get it early on. You get it after a 1/4 mile.

-Dave C.

 

[Bob Yates]

Hey everybody..... I have enjoyed reading what everyone has to say about the subject at hand. I've been in the automotive field for 37 years and it just hit me! The grass in my field is no longer greener, what a dummy I am next to some of you guys. I guess now the only chip I'll be buying is the ones on my cookies.... And the only burnning I'll do is my hambrgers on the grille.... I'm going to leave my vette the way it is. It's pretty darn fast as it is....Bob Yates