Quote:
Originally Posted by mad_sb
I thought about that but it is not a power issue. If you key on but don't start the engine the IAM and fine learning will still be there from the previous drive cycle. Once you start the car, it resets to the roms initial IAM value.
I will double check this afternoon when i leave the office.
EDIT: confirmed after sitting for 6 hours or so, keyed on, connected logger, refreshed learning view... same values were there from before I shut off the car at work this AM. Left logger connected, started engine, refreshed learning view, fine learning was reset to all zero's. I am back on E85 now and have initial iam set to 1 in the rom so there was no change to notice in the IAM but since fine learning was present prior to cranking i'm 100% sure this has nothing to do with power connections to the ecu.
Yup, most of us already posted that a couple pages ago..
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My working theory on this issue:
It is well documented that it was difficult during development to extract 200 hp out of this engine. In fact dynos of the stock tunes posted everywhere are really not indicative of a typical 200hp engine. I haven't seen any independent engine dynos but I suspect this engine is comparable to what most cars would be factory rated at 180-190 crank hp, I'd bet my last dollar its not a factory 200hp car on cali gas. The engineers probably had a solid 200hp before the emissions band-aides were applied and the chassis got heavier than initial design.
So they made it reset to 0.7 IAM, if you have good gas and don't cruise around in closed loop under load where there is a lot of knock it then IAM will improve, but they don't trust it enough to make it persistent, its sort of a small gimmick so they can call it a 200 hp engine.
I know this doesn't explain the reported cars with a persistent IAM, but I'm not sure those cars were turned off for a length of time or if they were JDM configured that slipped thru the cracks. I haven't a persistent IAM car around here..
Obviously this is speculation on my part but this is the take away:
Get rid of the manifold cat and tune it based on a 0.7 IAM. The key is to tune it such that the IAM is a non-factor just like scaling the map for low correction.
I have always considered a good tune one that doesn't rely on the knock sensor so much except for a rare bad tank
But I hope I'm wrong and its just the small battery dropping voltage during cranking, or maybe the cranking makes the knock sensor sing and we just need to silence it during cranking.
Just don't have the enthusiasm to really dig into it till we have a solid header on the market to really justify investing time and $'s into tuning.
JMHO