Some people claim that at WOT, the stock ECU does richen the mixture way too much (like 8:1). I'm personally not convinced, especially if you're flowing more air with your CAI and cat-back. Bear in mind that you need a richer than normal mixture at extended periods of WOT to keep combustion temps in check and for smooth power delivery, but that is not always the best mixture for power. Check to see if your throttle stop is letting the throttle plate travel past WOT (where it is 180 degrees to the air flow), and is actually starting to reclose the throttle. I had an old Mercury that used to do that. If that's not the case, and your car is actually making more power at 3/4, then it probably has something to do with open loop vs. closed loop operation, and could indicate another problem that the ECU is working around in closed loop operation, like an out of range coolant sensor for example. Often a sensor can be out of range far enough to affect performance but not set a code because it is still working, and therfore th ECU has no way of knowing it is out of range.
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Can the ECU detect any of those conditions or is it global? I run 94 octane fuel in a car that's usually empty (except for me
) and with just over 9k miles on the clock. Theoretically the state of tune should be pretty good, so timing shouldn't be pulling back too much. Of course, I may be assuming too much...I seem to remember reading somewhere that automakers purposely set maximum power at less than full throttle. I'm not sure if this is really the case. The article was in either C&D or R&T and if I remember right was about a Volvo they were testing. It seems strange to me, but if it's true, I'd be really curious to know why.
Same thing here
I have felt the same thing. It seems if you go to 3/4 and slowly depress the accelerator to WOT, you seem to have a stronger pull by seat of the pants feel. May be going straight to WOT dumps fuel into the cylinders faster than it can use it at first then balances out in a few seconds. This does seem like a good thing to check out at the track. Not sure how though, because there are too many factors that could incease or decrease times whether you mash the throttle or not, like reaction time. It doesn't feel like some thing that would drop 0-60 or 1/4 miles times a huge amount.
I have felt the same thing. It seems if you go to 3/4 and slowly depress the accelerator to WOT, you seem to have a stronger pull by seat of the pants feel. May be going straight to WOT dumps fuel into the cylinders faster than it can use it at first then balances out in a few seconds. This does seem like a good thing to check out at the track. Not sure how though, because there are too many factors that could incease or decrease times whether you mash the throttle or not, like reaction time. It doesn't feel like some thing that would drop 0-60 or 1/4 miles times a huge amount.
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