OK, so with the talk about using CF as a better guide to tuning with Lemmiwinks than knock sensor...
02-07-2005, 06:41 PM
#1
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OK, so with the talk about using CF as a better guide to tuning with Lemmiwinks than knock sensor...
activity, I set out tonight to try to make my CF low. I have always had HIGH CFs - like 12's-15's.
My knock sensor activity has been fine (which is what I used to "tune" my car). And the car runs really strong. I did this more for curiousity than because I'm trying to fix something.
Here's my set-up:
KO4s, RS4 ICs, Piggie Pipes, green top injectors, Piggie 88mm MAF housing with K&N cone filter, X-chip, MBC (alone), TCD.
I was running 22psi tapering to 20psi.
I read tonight that some are running 20psi tapering to 18psi and have really nioce timing #'s.
I wondered if I was running too much boost so went out and did some logging with some interesting results. (It was 33F outside tonight)
First, forget all about FATS times - my primary goal was to make my CF go down.
For some reason, I cannot make that number lower.
Again, I've been running 12-15 on all cylinders.
Here's what I did to try to make the CF go lower:
1. Decreased boost to 20 tapering to 18 - no change.
2. Kept boost lower and went from my current primary fuel tweak at -16.8 up to -12 and then down to -20.9 - no change.
3. Put primary fuel back to my old -16.8 setting and pulled 5.25 degrees of timing - again, no change.
So forget about power here, lowering the boost and pulling timing resulted in a slower car, that was not the object - my CF would NOT change - still 12-15.
So, I'm really confused now - I figured even if the car was slower, I'd see CF in the single digits and I did not.
I need some guidance here - why the hell does my car have such high CFs and why can I not make it go down?
The next plan is to fill up with 100 octane just to see if the numbers go waaay down as I'd expect. Not that I plan to run 100 but just to see if I can make those CFs go lower.
Any ideas?
My knock sensor activity has been fine (which is what I used to "tune" my car). And the car runs really strong. I did this more for curiousity than because I'm trying to fix something.
Here's my set-up:
KO4s, RS4 ICs, Piggie Pipes, green top injectors, Piggie 88mm MAF housing with K&N cone filter, X-chip, MBC (alone), TCD.
I was running 22psi tapering to 20psi.
I read tonight that some are running 20psi tapering to 18psi and have really nioce timing #'s.
I wondered if I was running too much boost so went out and did some logging with some interesting results. (It was 33F outside tonight)
First, forget all about FATS times - my primary goal was to make my CF go down.
For some reason, I cannot make that number lower.
Again, I've been running 12-15 on all cylinders.
Here's what I did to try to make the CF go lower:
1. Decreased boost to 20 tapering to 18 - no change.
2. Kept boost lower and went from my current primary fuel tweak at -16.8 up to -12 and then down to -20.9 - no change.
3. Put primary fuel back to my old -16.8 setting and pulled 5.25 degrees of timing - again, no change.
So forget about power here, lowering the boost and pulling timing resulted in a slower car, that was not the object - my CF would NOT change - still 12-15.
So, I'm really confused now - I figured even if the car was slower, I'd see CF in the single digits and I did not.
I need some guidance here - why the hell does my car have such high CFs and why can I not make it go down?
The next plan is to fill up with 100 octane just to see if the numbers go waaay down as I'd expect. Not that I plan to run 100 but just to see if I can make those CFs go lower.
Any ideas?
02-07-2005, 06:57 PM
#6
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Couldn't hurt to clear codes and give the car a few miles to adapt between changes.
The ME-Motronic guide does indicate that correction factors are retained in NVRAM when the car is shut off.
-Dave Pramanik
-Dave Pramanik
