MAFT results so far
Thread Starter
Melting Slicks
Joined: Jul 2001
Posts: 3,284
Likes: 3
From: Southwest Florida
MAFT results so far
I think I'm getting closer. With 5% rich on the base and 6% rich on the WOT I was getting about 7.5 degrees of knock retard and only about 22 degrees of timing. I bumped the WOT up to 12% rich today and let it learn for a little while and did another two WOT tests. On both tests this time, I got no KR and the timing was up to 30 degrees with a sample or two even higher. It looks like I gained 10-15 lb/ft of torque over the entire lower part of the curve but lost just a little on the top. In my experience though, the bumps in the curve that show at around 4,600 RPM will smooth out with a little more learning so I would expect the top end to improve a bit anyway.
I suspect that I needed so much enrichment because I'm running a stock MAF that has no screen and has been ported (no divider). In any case, I think I'm pretty close now. The interesting thing was that with the 5%/6% setting, my O2's were .92 to .93. Now after going from 6% rich to 12% rich on the WOT setting, the O2's are *down* to .89 to .90. I have no idea why that should be but I've about decided that you should ignore the O2 readings because they are unreliable and focus on the timing.
I also don't think you need to drive from coast to coast three times to let the computer learn. ;) I found that about 10 miles of driving was all it took to allow the LTFT's to stabilize completely. I figure if they settled on a number and stay there when you've been driving it at different speeds, different throttle positions, etc., it's done all the learning it's going to do. Mine ended up settling on 2.3% for one bank and 0.0 for the other. That's about as close as I'm going to get with a 5% resolution on the base adjustment.
Here's the before/after dyno graph:
Mike
[Modified by mchaney, 12:13 PM 8/31/2001]
I suspect that I needed so much enrichment because I'm running a stock MAF that has no screen and has been ported (no divider). In any case, I think I'm pretty close now. The interesting thing was that with the 5%/6% setting, my O2's were .92 to .93. Now after going from 6% rich to 12% rich on the WOT setting, the O2's are *down* to .89 to .90. I have no idea why that should be but I've about decided that you should ignore the O2 readings because they are unreliable and focus on the timing.
I also don't think you need to drive from coast to coast three times to let the computer learn. ;) I found that about 10 miles of driving was all it took to allow the LTFT's to stabilize completely. I figure if they settled on a number and stay there when you've been driving it at different speeds, different throttle positions, etc., it's done all the learning it's going to do. Mine ended up settling on 2.3% for one bank and 0.0 for the other. That's about as close as I'm going to get with a 5% resolution on the base adjustment.
Here's the before/after dyno graph:
Mike
[Modified by mchaney, 12:13 PM 8/31/2001]
Race Director
Joined: Mar 2000
Posts: 17,602
Likes: 20
From: Palm City Florida
Re: MAFT results so far (mchaney)
That little dip has me concerned. You lost more than you gained at that point.
Since the BASE and WOT are additive. Just try a little different combo.. You may want to try 10% on the BASE and 0% on the WOT. Give it a shot to see if you can get rid of that dip.
But Always Always Always get the BASE set 1st. Keep WOT at 0 till the BASE is perfect. Then Add the WOT 1 click at a time if needed...
Since the BASE and WOT are additive. Just try a little different combo.. You may want to try 10% on the BASE and 0% on the WOT. Give it a shot to see if you can get rid of that dip.
But Always Always Always get the BASE set 1st. Keep WOT at 0 till the BASE is perfect. Then Add the WOT 1 click at a time if needed...
