: Performance Chip on Ebay



mnymaker
04-10-03, 03:04 PM
Has anyone heard anything or actually purchased the alledged Performance Chip for 1994-2002 Northstars on eBay. I know it has to be a fraud or gimmick of some sort because its only $8.95. Just wondering if anyone has tried it or know of someone who has?

Heres a link to the current auction although its listed all the time:

Ebay Auction for Northstar Performance Chip (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2410241480&category=6764)

Katshot
04-10-03, 04:11 PM
This isn't a performance chip. It's a resistor for the MAT sensor. As the seller claims, you MAY notice a small performance increase after installation but it WILL NOT LAST. As long as you retain the OEM flash in the PCM, the O2's will still pick up the fatter mixture and trim it out. If you want to do "basically" the same thing, just pull the fuses on the PCM, or disconnect the battery. This will erase the short-term memory and set the fuel trim back to a slightly fatter starting point. Of course the PCM will "learn" and readjust the fuel trim back to where it was. The days of just adding a little fuel or air to gain some quick power are long gone. The PCM will compensate for a number irregularities in order to maintain a pre-programmed A/F ratio.
BTW, the OEM flash on most cars I've seen tends to be a little fat anyway, so adding fuel generally doesn't give you power. Matter of fact, you could lose power. Most dyno tuning sessions I've seen end up getting some extra power via leaning the A/F. the problem with that is it can get dangerous to the engine due to the leaner mix being more prone to detonation.

mnymaker
04-11-03, 11:17 AM
Thanks...

jadcock
04-11-03, 11:18 AM
Good info Kevin,

In fact, I think most OEMs run full rich at WOT, or close to it. Some of the performance chips lean it out a little bit at WOT to gain more power, but at the expense of possibly burning a hole in a piston. That's one of the reasons why they "recommend" 92/93 fuel with a chip -- because you run a much greater risk of hurting your engine.

The OEM did a pretty good job IMHO of accounting for everything, and making the performance pretty consistent across the board, either just off idle or at WOT.

elwesso
04-11-03, 05:04 PM
I dont think performance chips actually do that much to compensate for the cost. It has more of the placebo affect.

Katshot
04-11-03, 05:34 PM
Most GM programming is pretty good with respect to fuel management. Even spark timing is usually pretty good. On a "stock" engine, the most performance gains can usually be found in reworking the shift tables IMO.