Hi everyone,
I have been reading through the threads on this forum and saw a lot of folks mentioning overrevs. Can anybody explain how can you overrev these cars when they have rev limiters? Is it when going from a higher into a lower gear that it can happen? Can dealers erase the overrev history from the computer or is it there forever?
Thanks

 

+1 on this

i can't see how this would occur with a rev limiter unless it's a "mechanical" over rev ie shift to 2nd instead of 4th

 

The DME is read on levels 1 through 6. Normal activity is levels 1 and 2 and some 3 but anything more is considered dangerous to the engine, this is what my service manager told me. The report indicates the levels and how many times the car reached that level. I am told it is primarily associated with misshifts and downshifting. Even though there is a rev limiter if one rams the rev limiter hard the car can still be harmed. I am told the dealer can not erase the information, which is great for 2nd owners etc...You must really have to screw up bad though because I drive my car rather aggresively from time to time and only have a level 2 readout on my DME. I have redlined and misshifted a few times, who hasn't.....Bottom line, if a TT has 4 or above walk away....

 

One easy way is to miss a shift. Say you wanted 4th gear but got 2nd instead. This will give you an over-rev. Hope this helps?

 

I may be wrong, but I believe that the limiter can slow down a very aggressive over rev, but can not completely and immediately halt all of them; i.e. staying too hard on the gas for too long when moving upward in gear selection. This is where you might encounter level 1, 2 or 3, I assume. With that said, the limiter can NOT stop a mechanical over rev; when you downshift with the rpms too high.

 

Most used modern 911 turbos will have many Type 1 and Type 2 over-revs if they have been driven with any intensity, like they should be. Missed shifts are not the only cause of over-revs - they can be caused by not shifting up or down quickly enough to match engine speed.