Over revved engine
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Joined: Aug 2008
Posts: 66
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Billman & All,
Why are you quoting 1500 RPM for the over rev? Using the gear ratios on wikipedia I see that if the vehicle is at redline and mishifted:
AP2, redline 3rd then shift to 2nd = 8,000 / 1.481 X 2.045 = 11,050 rpm
AP1, redline 3rd then shift to 2nd = 9,000 / 1.481 X 2.045 = 12,425 rpm
Certainly the revs will come down a little as air friction slows the car during the shift, and as the car's kenetic energy is used to speed up the engine, but I doubt these can account for too much of change. 11k or 12k are both scary numbers!
I'm particularly interested in the facts since I did the 3-2 mis shift a couple years and about 50k miles ago myself, on my AP2. The car has been to the track 10 times since and has been doing fine. I adjusted my valves 10k miles ago when the engine started idling rough, and they were in desperate need of it (no clearance on some of the valves). I'm guessing the valve mis adjustment is a result of accumulated track time more than the mis shift, as symptoms didn't appear for a couple tens of thousands of miles afterwards. When adjusting my valves I didn't specifically look for problems with the retainers, but I didn't see anything broken and it all runs fine now.
Why are you quoting 1500 RPM for the over rev? Using the gear ratios on wikipedia I see that if the vehicle is at redline and mishifted:
AP2, redline 3rd then shift to 2nd = 8,000 / 1.481 X 2.045 = 11,050 rpm
AP1, redline 3rd then shift to 2nd = 9,000 / 1.481 X 2.045 = 12,425 rpm
Certainly the revs will come down a little as air friction slows the car during the shift, and as the car's kenetic energy is used to speed up the engine, but I doubt these can account for too much of change. 11k or 12k are both scary numbers!
I'm particularly interested in the facts since I did the 3-2 mis shift a couple years and about 50k miles ago myself, on my AP2. The car has been to the track 10 times since and has been doing fine. I adjusted my valves 10k miles ago when the engine started idling rough, and they were in desperate need of it (no clearance on some of the valves). I'm guessing the valve mis adjustment is a result of accumulated track time more than the mis shift, as symptoms didn't appear for a couple tens of thousands of miles afterwards. When adjusting my valves I didn't specifically look for problems with the retainers, but I didn't see anything broken and it all runs fine now.
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Joined: Jul 2002
Posts: 22,386
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From: Long Island, New York
Yes the number on paper would indicate that type of rpm.
By the time the clutch slips a little, the major slowing affect of the downshift on the car, the relaistic numbers are as I stated.
If the car were being pushed by a truck at a constant speed, then you would see those numbers.
By the time the clutch slips a little, the major slowing affect of the downshift on the car, the relaistic numbers are as I stated.
If the car were being pushed by a truck at a constant speed, then you would see those numbers.
Joined: Aug 2006
Posts: 1,330
Likes: 17
From: Long Beach, Ca
Bumping this.
Just money shifted on track. Top of 3rd back to second. Watched my video and it spiked at 9714 RPM from my G2X.
AP2 with supertech TI retainers and double valve springs.
Should I have it inspected?
Just money shifted on track. Top of 3rd back to second. Watched my video and it spiked at 9714 RPM from my G2X.
AP2 with supertech TI retainers and double valve springs.
Should I have it inspected?
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Joined: Sep 2013
Posts: 4
Likes: 0
As a two week old baby owner of a 2002 with 54,000 miles, I mis-shifted twice but hit the clutch immediately. The engine sounds/runs fine. What are the symptoms if damage was done? What are the risks of not inspecting it?
