How bad is 7500 RPM for half a second on the stock valve train?
 

I know it's not good, but how bad are we talking here? Always catastrophic? Usually fine if you only do it once?

Had a dreaded money shift; flat foot shifted 4->5 at about 6100 RPM. Started to let off the clutch and the HUD shot to max RPM. I knew instantly I must have hit 3rd instead of 5th, and clutched in as fast as I could, with thoughts of chaos running through my mind.

The car didn't seem to mind. I finished the track session without any weird feelings in the car. Went out for the next session after a check on oil level and for any new engine noises. Car felt just as strong in that session. Drove it home, and have put about 100 miles on it since that track day.

I finally got around to analyzing the PDR data, and I used PI Toolbox to get at the raw engine data for the run. According to it, the engine hit 7505 RPM before I got the clutch in and revs dropped again. The whole ordeal lasted almost exactly 0.5 seconds from the time I started to let the clutch out, to the time the engine spun down to 6500 RPM again.

Realistically speaking, what are the chances I have engine damage, given that it hit 7500 RPM (maybe a hair more before the PDR recorded the next update), but it has been running fine for over 100 miles afterwards, including another 20 minute track session? Is there anything I can do short of pulling the heads to check for damage?

I still can't believe I did that; first time in 16 years of driving manuals. I feel sick just thinking about it. I should trade in for an automatic since I apparently cannot handle a manual anymore.

I shift at 7200 many times I don’t think it will damage your engine .

On a stock valve train? What is your rev limiter set to?

What is stock redline

I dont remember exactly but its in the 6600-6700 range.


OP - i say its hard to know if you've done meangful damage or not. Its kind of a crap shoot. Good news- so far so good as your car is running fine.

7500 lol yes stock

On a LT1 V8? If so - you're brave!

it was a mechanical over rev and he didn't mean to do it....
doesn't matter what the rev limiter is set to.....

he's not brave because he didn't mean to do it...

I had one the other day and I never fully let out the clutch... I think that's the key and you should be fine...

My brave comment was not to the OP (Calubi) but was aimed to Carnage for his comments about regularly shifting at 7200 rpm on a stock valve train and having his redline set at 7500.

I fully understand what a mechanical over rev is and I feel for the OP as that had to be a scary moment.

I think you confused me (OP), with carnage SS.

Yea but got it dynoed and lowered it to 7k

The mechanical over-rev, like this, is harder on the engine than just spinning it up under acceleration is. One of the members was doing a mechanical overrev repeatedly by downshifting and letting the clutch out too early (not slowed down to correct speed for the gear yet) on a road course, thus mechanically forcing the engine to overev. That guy did actually blow up his engine in that case.

Whether or not a mechanical over-rev hurt the engine depends on how long and or fast you got the clutch back in and if the rear wheels had traction or if they slid instead of grabbing.

If you have no noise then count yourself lucky.

Thanks for the comments! I'll be keeping a close eye (ear?) on the car. So far no mechanical ticking (other than the annoying DI noises).