Lean in Open Loop, need help
Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
Le Mans Master
Joined: Sep 2000
Posts: 6,303
Likes: 714
From: Bartlett IL
What is the PW and Duty Cycle for the Injectors at WOT? You need to see if you're injectors are going static. Playing with the O/L AFR tables won't affect anything if the Injectors are maxed out.
Le Mans Master
Joined: Sep 2000
Posts: 6,303
Likes: 714
From: Bartlett IL
Assuming you have an 8 cylinder motor with 8 30# injectors. Using the BFSC calc, 30#/hr x 8cylinders x 2 = 480hp. That's what this will support. Anything more than that, you'll need to increase size of injectors physically, or by increasing flow through higher pressures.
There's several assumptions in the calc I did above and would need to know more to make a more accurate assessment. But you can see why your AFR is probably going lean. Something tells me your producing more than 480hp.
There's several assumptions in the calc I did above and would need to know more to make a more accurate assessment. But you can see why your AFR is probably going lean. Something tells me your producing more than 480hp.
Thread Starter
Racer
Joined: Dec 2005
Posts: 361
Likes: 0
From: Russia, Moscow
'loop open % change afr vs map' High numbers lower AFR and will add fuel, I correctly understand?
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Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
ok, the dyno chart mislead me
correct, the higher the positive values=lower afr (yes, richer)
increasing fuel through injecter constant/s works as an inverted table, a lower number here will increase fuel, higher number will reduce. I agree w/Dominic in knowing PW and duty cycle numbers. The other thought I had would be using PW factor vs temp or PW factor vs MAP, however if it is maxed and going static then this would be of no help.
I am guessing you are doing open loop tuning here (based on lower ve #'s, upper ve looks maxed out )? It might just become more practical to use a bigger injecter.
increasing fuel through injecter constant/s works as an inverted table, a lower number here will increase fuel, higher number will reduce. I agree w/Dominic in knowing PW and duty cycle numbers. The other thought I had would be using PW factor vs temp or PW factor vs MAP, however if it is maxed and going static then this would be of no help.
I am guessing you are doing open loop tuning here (based on lower ve #'s, upper ve looks maxed out )? It might just become more practical to use a bigger injecter.
Last edited by mseven; Sep 24, 2007 at 09:21 PM.
