cablebandit

iTrader: (37)

I am tuning my turbo car. Here is the problem. If I stomp the gas....downshifts...rpms shootup with my stall and I can see the a/f ratio on the wideband. Adjust in pe vs rpm...no prob. My maf is maxed out but this seems to work pretty well. NOw....I want to dyno so I have locked the converter in 3rd.....floor it at 2000 rpms and it gets WAYYYY lean around 3500-4000 rpms. Adjust pe vs rpm but seems to make no difference? at those rpms, I am still getting input from the maf. Do I need to richen my VE table? I made sure I am in cell 22 after it is floored so i ASSume it is in PE mode. Kinda lost here and could use some input.

wait4me

iTrader: (10)

nice sig, that is funny!! now i wanna get twin electric ones!! lol you could try ve, but did you mess with your open loop fa table yet? and on your maf table is the very last setting 510?

jimmyblue

iTrader: (11)

You should also be looking at your injector pulse
widths, convert to duty cycle and make sure there
is anything left to give.

cablebandit

iTrader: (37)

ok, it has 60# injectors.....no prob running 10.50s all day at the track.....you stall up and rip...no probs. I am trying to basically get the tune right from 2000-5000rpms before the maf is maxed. After that it pegs the maf @ 68 lb/min (maf table is extended) and all is good. In 1st at the track, it only sees this rpm for a sec plus the alky is prolly making up for some of the tune...after 1st gear the converter keeps the rpms around 6k and that is tuned fine. I am wanting to lock the converter in 3rd around 2000 rpms and dyno. This is the part I can't get richer...2000-5000 rpms. I will watch more tomorrow and see if I can figure out why I can't get that richer when my pe vs rpm table responds perfectly to adjustments for 5000+ rpms

wait4me

iTrader: (10)

what year is your car? maybe i can hex in an extended range maf table to it???

cablebandit

iTrader: (37)

i have the maf range extended from 5? lb/min to 68 lb/min. It is a 2000.

Another_User

Ditch MAF when HPTuners comes out with support for 2 and 3 bar MAP sensors. Benefits: more airflow to engine with less intake restriction, more accurate than your MAF.

Adding to your VE table shouldn't do anything. That RPM range is right about where the MAF takes over completely, besides, if you are boosted you are beyond the kpa at that point for the table to do you any good.

cablebandit

iTrader: (37)

so you are saying that something in my fueling is wrong...not pcm because of boost? Under boost my map shows 105 I think it is and stays there. This would fall under pe vs rpm?

Another_User

Exactly. Around 3000-4000k RPMs your MAF is pretty much all the PCM is using for fueling. Changing the VE table won't help. If you are out-flowing your MAF then you are screwed there too. But if you go MAFless with a 2 or 3 bar map sensor and program a new VE table, you'll be in great shape. Or if you can find somebody that can program your MAF table further.

cablebandit

iTrader: (37)

I will make sure tonight I have good fuel pressure and adjust pe vs rpm. it is tough to look at stuff when this bitch is spinning tires at 70-80mph on the interstate. I locked the converter in 3rd so it would come up on the rpms slower but the cold highway isn't helping. Thanks for your help. Like I said....my a/f at 5000+ where I stay at the track is perfect...just need it right at lower rpms for the dyno pull

Another_User

I suppose that, since the VE is used for error checking the MAF, maybe there is a huge difference between where each one wants to put your fuel (because MAP is maxed out and the MAF is reading way up there), and maybe the PCM is freaking out. I am surprised nobody saw anything like that before though...

cablebandit

iTrader: (37)

I think it was my extra fuel pump not kicking on......my hobbs switch seemed to be acting up and SEEMS to be ok now. I did a wot tonight and it didn't get over 11.5 a/f so it may have been that. Thanks for the help though!!

cablebandit

iTrader: (37)

man this is nuts. I logged it and at about 3200 my a/f starts going up to 15:1 and then at about 3900 it just drops down to 11.5:1 and the car takes off. I can't figure out where this lean spike is coming from. Fuel pressure is good......I just don't get it.
my a/f does like this
rpms a/f
2000 13:1
2500 12.5:1
3000 11.5:1
3200 12.5:1
3500 13.5:1
3750 15:1
3900 16:1
4100 10.5:1 it looks like the maf is maxed here and then all is good via pe vs rpm
4400 10.51

Another_User

Are you sure you are going right into PE at WOT. Maybe a setting is holding you back.

cablebandit

iTrader: (37)

hmmm....I dunno...all i know to look for is cell 22.

Slowhawk

iTrader: (12)

The VE table can fix your problem in the lean area's.Try adjusting it in the problem area's and see the affects . I have a few cars maxing there meter's at 4000rpm and use the VE/PE table's to tune them in.

Another_User

How can the VE table do anything? At that RPM the MAF has pretty much taken over. Besides, with the boost he would have far exceeded his MAP table.

cablebandit

iTrader: (37)

Slowhawk..my VE table uses map from 15-105...this is ls1edit I am speaking of. So basically you are saying richen up the 105 area from 3000-4000 rpms? To be safe I will do 90-105 at those rpms if this is what you are suggesting. Hopefully this will fix it as I can't dyno with this huge lean spike. When the pcm switches (i assume)to the pe vs rpm fueling at 4000 rpms, it literally feels like a switch has been pulled and the car pulls like crazy. Thanks for all this...it is much appreciated. I want to dyno just to see where I need to be shifting.

cablebandit

iTrader: (37)

I THINK it's solved.....damn hobbs switch for 2nd pump was flakey and it was kicking on/off erratically.