LTrims - difference between B1 and B2 -- what are yours?
Thread Starter
On The Tree
Joined: Jan 2002
Posts: 110
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From: Suwanee, Georgia
LTrims - difference between B1 and B2 -- what are yours? I have been doing alot of logging lately and have noticed that my Bank1 and Bank2 LTrims are always split by about 6-7%. When Bank1 is -2.3%, Bank 2 will be -8.5% or so....
I assume this must be due to a difference between the two O2's?
I am curious what a "typical" spread is between the two banks... what are yours?
Thanks In Advance for any responses.....
I assume this must be due to a difference between the two O2's?
I am curious what a "typical" spread is between the two banks... what are yours?
Thanks In Advance for any responses.....
TECH Apprentice
Joined: Nov 2001
Posts: 317
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From: Humble,Tx
Re: LTrims - difference between B1 and B2 -- what are yours? When I had the stock headers on the car I usualy had about a 5 to 6 split. Now that I have headers on the car they come pretty close to matching.
TECH Apprentice
Joined: Jan 2002
Posts: 384
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From: Murphy, TX
Re: LTrims - difference between B1 and B2 -- what are yours? Once upon a time I made some surface plots of histograms of B1 LTFT vs B2 LTFT and noticed the same systematic skew. One explanation could well be variation in sensors, but you would then expect about half the folks to favor B1 and the other half to favor B2. I've also heard the fuel rail being put forward as an explanation. Since most of the data that I've seen shows B1 numbers larger (i.e. more positive) than B2, I would tend to think the fuel rail effects dominate the variances due to the senors. So I'm thinking that generally (w/o being corrected by increasing PW) B2 sees more fuel than B1. This is counter to my intuition but I know squat about FI. <img src="gr_sad.gif" border="0">
Average diff on my 98 has been > 0.5% and < 1.8%, B1 larger, over a number of MAF/MAFT/filter combinations.
Average diff on my 98 has been > 0.5% and < 1.8%, B1 larger, over a number of MAF/MAFT/filter combinations.
TECH Addict
Joined: Nov 2001
Posts: 2,003
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From: Live Oak, FL - in the woods where the creatures lurk.
Re: LTrims - difference between B1 and B2 -- what are yours? Mine seem to stay within 2%, with B2 staying more positive. But at a steady cruise rpm of 1500 or so they usually stay at 0 a lot, depending on weather conditions.
This is with stock manifolds/cats/y pipe.
This is with stock manifolds/cats/y pipe.
Re: LTrims - difference between B1 and B2 -- what are yours? My B2 varies from 2-6 percent on the rich side. I've also heard it was the fuel rail damper but you'd expect B1 to be richer if that was the case. At any rate, I've cut out the center of the damper and haven't seen anything different so that's not it. I've got Mac headers for the record...
Staging Lane
Joined: Feb 2002
Posts: 52
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From: Virgin Beach, VA.
Re: LTrims - difference between B1 and B2 -- what are yours? This was a question I had but never got around to posting....
I have seen the same variences....B1 on A-Tap hovers around -1.7 and B2 around 0 to +3....I figured that due to the O2 differences and fuel rail that was normal.
I have 2000 TA with SLP LT headers/cats, ported MAF, lid and K&N, EGR mod, AIR, and MAFT.
Jeff
[ March 01, 2002: Message edited by: LS1pilot ]</p>
I have seen the same variences....B1 on A-Tap hovers around -1.7 and B2 around 0 to +3....I figured that due to the O2 differences and fuel rail that was normal.
I have 2000 TA with SLP LT headers/cats, ported MAF, lid and K&N, EGR mod, AIR, and MAFT.
Jeff
[ March 01, 2002: Message edited by: LS1pilot ]</p>
