Pro Mouse

iTrader: (15)

ok Here is my delema,When I auto-tap my WOT mv's my bank 1 is much lower(.865) than Bank2 (.900) by an average of .035 mv's.Now my question is do bank1 and bank2 have to be the same?It figures out to I need to go 1% more on bank1 to be even with bank2.Should I do this or leave it alone?Are they supposed to be close to the same?Thanks for your help...
Scott

WS6snake-eater

Your rich lean setting in HPtuners should be the same for both banks. Check for an exhaust leak before the o2 on the side that is reading lower.

Another_User

There may not be a leak. Mine are always off by about that much. They were with the stock manifolds, and they still are with shorties and new gaskets. I also swapped O2s from side to side with no change. Either it is a difference in fueling on one side, or the O2 on one side cools faster because it is further downstream, or a difference in resistance or something caused by wiring. You should check everything, but you may not find a problem.

Pro Mouse

iTrader: (15)

Ok thanks guys,This thing has always been consistantly close with my 224 cam with mac Mid length headers and Now with bigger cam and heads and Kooks LT's my readings are now slightly different?I dont know...

JimMueller

iTrader: (9)

Same experience as AnotherUser here. I've always had a minor bank discrepancy from day one. Hmm, I wonder if it's worthwhile to tune on the leaner bank?

Pro Mouse

iTrader: (15)

My thoughts exactly Jim ,I was wondering if I give bank 1 1% higher numbers if it would even things up with Bank2....

JimMueller

iTrader: (9)

The PCM doesn't isolate fueling per bank - or if it does I haven't seen the tables to isolate banks.

My thought was to tune based upon the readings on the leaner bank to prevent that bank from accidentally being too lean if you tuned based upon the richer bank. Hmm, I think that makes sense

Pro Mouse

iTrader: (15)

Well Jim ,I think you are correct,But you know how you can change B1/B2 rich/lean mv's...I was wondering if I just do bank 1 maybe this would even it up?I really dont know..Has any one with HPTuners ever found that out?

JimMueller

iTrader: (9)

I haven't began playing with that yet. I've asked for feedback but received none at this writing.

Pro Mouse

iTrader: (15)

Ok Jim,I wish someone would chime in and help us out....
Scott

Another_User

I have never seen anybody do it. I have toyed with the idea of doing it plenty of times. Getting it right would be pretty much "hit or miss", unless you have a wideband sensor added on each bank and tune your O2s R/F numbers until both match at most RPMs. It's not worth your time. As long as you are not getting positive trims at WOT, both banks will get the same amount of fuel (injectors permitting) at WOT. So there will be no impact on horsepower.

Pro Mouse

iTrader: (15)

Thank you for that info Another_User This was the Kind of answers I am looking forI Have my Recent A-Tap log and my LTerm were B1 0.8 and B2 0.0 is the .8 at wot good or is there a way I need to tune it down to 0.0?
Thanks!

Another_User

To get the trims to zero at WOT you need (most of the time) trims that are at 0 or less for both banks (not average). Some people have seen 0 trims at WOT with slight positive trims, but we have not really figured out why. I think it has something to do with the last cell that you were in (whether it is positive or negative) right before you go WOT. So you would probably tune your VE (or MAF table, or IFR table, depending on which is your choice) to put you a hair more rich.