: "0-60 Performance Mod"????



N0DIH
04-11-05, 12:17 AM
Anyone ever hear of this?

http://www.chevyavalanchefanclub.com/cafcna/index.php/topic,20281.msg307625.html#msg307625

Any clue what is REALLY going on? Knowing what I do on the operation of the PCM, this doesn't make sense from the fuel delivery standpoint.

So, anyone game to try it on the FWB and see if it works?

Honestly, I'm not expecting it to, but you never know!!

I do know my 94 FWB tends to feel better if I am a little more agressive on the throttle, where as if I am gentle on it "like normal", trying to get better mileage, it tends to get a little doggier (like a V4P car can be considered "doggy"!)

Thoughts?

illumina
04-11-05, 12:48 AM
Kind of like a "re-learn" process for the MAF, right? Well the best thing I can tell you is to get a G-Tech like I have, try a run before the trick, and then do what is suggested on that forum and see if there is any improvement.

If it were me I would get at least three runs before the trick (right term for it?), so you can see where the G-Tech accuracy is, such as tripple 0-60 runs all within two tenths or something so you know where your car stands. Apply MAF trick and see if there is an actual performance gain to it...It'll be interesting to see if it really works.

N0DIH
04-11-05, 01:08 AM
I guess assuming the "trick" doesn't make it learn it and improve it. I don't know if shutting it off makes any difference anyway. But then again, who knows.

I was always under the impression that NO learning can take place when you are in PE Mode or WOT mode. Learning only takes place in the lighter throttle modes. So, what is going on? Something "else"?

Katshot
04-11-05, 08:48 AM
The "trick" is something that has been common in these cars for years. There IS a degree of learning in the PCM (it has nothing to do with the MAF). The problem is that the PCM will keep learning and resetting after the "trick" and subsequent acceleration tests, and eventually take all the settings back to where they were prior to the "trick", which is really just resetting the PCM to the base default settings. I've tried resetting the PCM just prior to making a pass at the track and cannot verify whether it does anything or not.

N0DIH
04-11-05, 04:54 PM
Kat, your are correct, it is likely that learning. The learning that I am familliar with is nothing more than the Integrator/BLM value. Nothing more. It is purely for emissions to offset a bad injector or a vacuum leak, and resets itself fairly quickly. Like in minutes. Test it, watch the BLM value, note the average (Illumina, you can on the 4.9L, P.2.0) and then pull a vacuum line, now note the BLM value. Then reconnect the line. Note again the BLM value. It should return within a minute or so.s

Heck, you would have better and more predictable results of you could make it richer somehow and then "fix" it just after you leave the burnout box, and then by the time you nail it for the 1/4mi, it would be at a fixed BLM value for the remainder of the 1/4mi. Maybe like a propane injection just before you get to the burnout box, make it rich enough. Remember, our cars run rich to protect the converters, so leaning them does gain power, but can damage the converters if you get it too lean.

Sorry, I don't think it is worth a whole lot. The car uses BLM values as an offset when at WOT, then goes back to learning. Watch your BLM values and see how fast they "learn". You will be very surprised.