I have a stock intake, an ETS 3.5" and HKS/CPE BPV.
I am seeing long term fuel trims of -10 under load and -5 on highway.
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I have a stock intake, an ETS 3.5" and HKS/CPE BPV.
I am seeing long term fuel trims of -10 under load and -5 on highway.
- means its pulling fuel
if you had a leak it would be sucking in un-metered air while driving normally - ie out of boost. and this would require the ECU to add more fuel.
if you had a negative number while in boost, and a positive number while in vacuum, you would have a leak after your turbo. But you dont. So dont worry
When you say under load do you mean flat chat.. because it should be zero at WOT..
Doc
Sorry, I should try to use the right terms, eh?
Under load in this case just means what I'm seeing when I'm driving around town vs what I generally see when I'm on the highway.
Generally soeaking, I'm seeing 5 - 11 negatives when I look at LT.
Off the top of my head, I think it does move towards zero on open throttle.
So this time instead of just glancing at it and wondering, I'm going to take a log over a trip, and pick out the relevent bits.
OBD2 dash software is reporting a very consistent 9.9-10 l/100Km.
---------- Post added at 12:30 PM ---------- Previous post was at 12:24 PM ----------
Does battery removal zero all the trims?
Which it then quickly relearns I presume.
Is it best to zero the trims when a mod is applied?
nah no need really.. it will learn as it goes..
but yet d/c the battery will loose everything
if your seeing negatives while still in vacuum, dont worry..
Your ECU will re-establish itself in a meter of a few kms after a battery disconnect. BTW, too many people think that the "learning" process will fix a multitude of ills, mechanical faults and crappy tuning, but it doesn't work that way. It only configures itself for the settings it sees.
Yes, I would expect that the learning process only allows the computer to fine tune towards optimums - within set limits. (i.e. max boost etc), so Starting from zero, it will test and trim towards figures that account for subtle variation, but represent the OEM or tuner specified targets.Quote:
Originally Posted by Doug_MPS6
I know that prior to the ETS and HKS BPV, I recall seeing low figure LT trims. Now it as much as -11. Can an ETS and BPV account for that difference? Looking back at a pre-ETS log, my first thought is the LT trims appear 4 points further into the negative. As it's got a stock intake, how does a larger, higher flowing, more efficient TMIC cause fuel to be pulled from the tune?
What are the influences on trims one would expect to see from mods (such as +12 due to MAF housing :) ?
The ETS may be cooling better than std. The engine would require less fuel to get it to run within tolerance. Maybe be fuel evaporation?
Just some thoughts for the subject.
Oversize MAFs cause it to run lean, increasing the LTFT to + figures.
Thanks, great to have some guru's brains to pick!
I've observed BAT generally only a couple of degress higher than IAT when I'm looking.
The ETS seems to be a great improvement in terms of flow, pressure drop, and temp.
I have a Hyperflow TMIC and am seeing Boost Air Temps typically around 20C higher than Inlet Air temps.Quote:
Originally Posted by Nexus
"a couple of degress higher than IAT" intrigues me. Anyone like to comment please?
Leon
It varies, but cruising was seeing bat not might higher than iat. temp spikes when getting on boost, but not for long.Quote:
Originally Posted by Velocity Red
I'll do some logs after next service.