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totle totle is offline
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Join Date: Oct 2008
Location: Norway / Miami
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Originally Posted by lucittm View Post
Is there a rev limiter on that engine? If the answer is no (or it is set too high), then you know what happened. Your well-intentioned friend either missed a shift (it happens when you change cars for a few minutes) or he just let the revs go past the safe point (possibly his car has a rev-limiter and he is used to it) and the valves floated for a moment; that's all it takes in an engine like that.

In any case, I would verify with JB Racing that the valve springs used in that engine were each tested and found to be up to the task at any RPM that could be expected (or unexpected). There is no indication of detonation in that engine in my opinion regardless of the fuel mixture or the ignition timing used (you said it was running well, things like that don't typically change suddenly).

The rev limiter is set in the ECU. Set to cut off at 6800 rpm

Well car was running well. But I am not sure that the mapping was done in a dyno. From what I remember the mapping was done with log files from road test.
If that was the case, I believe that the setup in high rpm was not set correctly when engine was under stress
Trond R.
1979 930: Garret GT35r turbo, EFI, carerra intake, Link EMS, custom GT2 cams, 98mm JE P/C, 964 crank (stroker), custom valves & ported (XtremeCylinderHeads) etc..etc..
1972 914-6 GT replica project
1986 944 Turbo
Old 10-09-2011, 10:43 AM
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