Why does my engine respond better at 90% throttle than 100%? Timing?
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TECH Junkie
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From: Republic of Texas
Why does my engine respond better at 90% throttle than 100%? Timing? Last night I nailed it from a 50mph roll. I gave it about 90% throttle. When I did, the trans instantly kicked down, the tires broke loose and I went sideways. Did it a couple of times, including today and it responded just as well. But, when I mash the throttle to the floor the rpm's shoot up and the trans kicks down but it seems to take a second before the car takes off. And from a 45-50 punch the tires won't break loose. I have always kind of noticed (it always responds better at about 90% throttle) it but never tested it at that speed. When the car went sideways at 45-50 last night I was like "daam". What's the deal? Does it have something to do with timing and throttle %?
Adkoonerstrator
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From: Deep in the seedy underworld of Koonerville
Re: Why does my engine respond better at 90% throttle than 100%? Timing? I've noticed the exact same thing your talking about.
Does anybody know why this happens?
I've ATAPd to try and see if it had something to do with timing. It didn't look like it though. The timing at ~90% was the same as 100%
Maybe we're hallucinating but, I don't do drugs do you? <img src="gr_images/icons/wink.gif" border="0"> <img src="gr_stretch.gif" border="0">
Johnnie
Does anybody know why this happens?
I've ATAPd to try and see if it had something to do with timing. It didn't look like it though. The timing at ~90% was the same as 100%
Maybe we're hallucinating but, I don't do drugs do you? <img src="gr_images/icons/wink.gif" border="0"> <img src="gr_stretch.gif" border="0">
Johnnie
Re: Why does my engine respond better at 90% throttle than 100%? Timing? Possibly torque management? I know it pulls timing pretty much instantaneously when you shift at WOT. If you go only 90% throttle, maybe the torque management isn't kicking in, allowing you to break loose the tires?
Only about 1 out of 5 times do I get to see the torque management effect, when I log with AutoTap. It happens so fast that it is usually missed. But I have seen it...as low as -2 timing on the shifts.
Dope
Only about 1 out of 5 times do I get to see the torque management effect, when I log with AutoTap. It happens so fast that it is usually missed. But I have seen it...as low as -2 timing on the shifts.
Dope
On The Tree
Joined: Nov 2001
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From: Hainesport N.J.
Re: Why does my engine respond better at 90% throttle than 100%? Timing? I know someone with the same 90% trottle problem with an M6 right now, Pewter00TA, might want to compare notes with him. Check your WOT fueling with A-tap for a possible answer?
Re: Why does my engine respond better at 90% throttle than 100%? Timing? one may also think that you get more weight transfer/more traction on the rear at 100 that at 90% throttle, but that combined with the timing retard may add up to what you guys are feeling...
TECH Regular
Joined: Jan 2002
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From: Austin, TX
Re: Why does my engine respond better at 90% throttle than 100%? Timing? I think it may be choking! More fuel is going in to the cylinders and the spark is not enough to burn the fuel good at that moment (for a second). Check your spark plugs and gapping.
I could be wrong
I could be wrong
Re: Why does my engine respond better at 90% throttle than 100%? Timing? Also check the TPS (throttle Position Sensor) voltage. If the voltage goes above 4.5, the computer does not know what to do. Ive had this problem on worked Throttle bodies before.
\chris
\chris
