pcar928fan

Just don't rev the GT to redline EVER and you will probably be ok...accusump did not help my buddy with his second motor...

Bill Ball

This must be wrong. Every 928 running M1 has blown up except mine.

pcar928fan

Or mine...

mark kibort

And ALL I do now ,and often, and for the past few years, is shift at just a hair before the rev limiter. NO issues. all shifts at 6300 to 6590rpm

mk

pcar928fan

Amzoil to the rescue! Just giving you grief MK. Your car was not a GT though...I am not sure what the deal is with them. Maybe they have an even higher rev limit then the S4's (and what you were using), or maybe there is something about those cams (I think that is about the only diff. between the GT and S4 engine anyway) or maybe it all boils down to the shorter rear end gears... I have no idea. All I know is I have seen WAY more engine failures in GT's that are being tracked (DE or Auto-X) than I have S4's...

James Bailey

GT is more like 6,800 as I recall....

mark kibort

that could be a good reason to not drive to redline. (or the reason for the failures, ill give them that. 6800 seems to be a little on the high side for the limits we have with this motor design.

James Bailey

The Autothority chips also bumped up the rev limiter.... so would all the copies. Stock engines you are just making more noise anyway !

paul928s4

take it my conservative DE 6000rpm shifts have been to my benefit then, at least when using Mobil 1

On a few dyno runs, I had a few pulls done up to 6500rpm (using AutoThority chips). HP peak was around 6000 rpm, so that seemed like that was a safe limit for me.