T10Chris

overrev reports are worthless on 996, you have range 1 and range 2, and range 2s can be hit by revving the car in neutral or running through the gears and shifting fast at redline in a completely stock car. It's nothing like the newer cars that have range 1 through range 6 or more that tell you a precise range for how high the RPM was.

Dock

I don't think that is possible.

neonshadow

T10Chris

I know it is. I tested it a while back when my car was stock, and others have also reported similar behavior. Especially in lower gears. Run to redline in 1st gear and shift quickly into 2nd like you're trying for your best 0-60 run and it will register range 2 on occasion. The clutch cant stop the inertia of the rotating assembly and rev limit isn't a hard stop at a set rpm. Rev limit not being a hard stop is the same reason why it will range 2 if revving it at a stop, it bounces if you are crazy enough to rev it to rev limiter and the ignition cut can't stop it before it incidentally has a range 2 ignition go through.. Granted, I consider revving in neutral to rev limit to be abuse, but accelerating hard and shifting fast, the car was made for it.

Some people have even reported having more range 2 revs than range 1 which is also theoretically impossible since you cant register a 2 without going through 1.

My point was that the overrev system on these cars is extremely primitive and often inaccurate, and even something incidental can show up as range 2 and there is no way to tell if it was 1 rpm over or 1000 rpm over.

T10Chris

neonshadow- apologies for the brief thread derailment, best of luck in your search. Do your due diligence and you will end up with a great car

Dock

The soft cutout is at 6750 rpm, and range 2 is triggered at 7250 rpm. That would be a 500 rpm overshoot while in the soft cutout. Additionally, if a normal shift at red line was accomplished, the driver would be manually reducing the throttle input as the clutch was being depressed. This along with the soft cutout would make it very difficult to continue another 500 rpm beyond red line. If the driver power shifted (throttle on the floor) and the soft limiter was not functioning correctly allowing the rpm to reach (exceed?) 7250, then I'd opine that this rev 2 event would be relevant as it could indicate abuse.

Dock

I care about the 1 rpm over.

And certainly people should be concerned that rpm might have reached 7500, where according to Kevin you get into valve float issues.

T10Chris

My car has a raised rev limit with my tune so I shift around 7000 with a rev limit of 7200, but I have found a datalog when accelerating in 1st gear indicating throttle was let out for the shift at 7050 RPM and the revs continued to climb to 7612 in .214 seconds- slightly faster than the average eye blink.. . Even when the throttle is let out there is still momentum in the rotating assembly and when load is taken off of the car with the clutch being depressed, there is less load from the drivetrain on the assembly to stop it from spinning higher. It's physics.

Also, consider this attached readout- more range 2s than range 1s. Should be impossible, but again- these cars can register phantom range 2 revs.



According to what you are saying here, the valvetrain is good to 7500 RPM- indicating the arbitrary 7250 RPM as abuse is irrelevant anyway.


I don't want to derail this thread anymore, so if you want to continue the discussion I'd be happy to do so in another thread. Otherwise, have a good afternoon

Dock

The valve issue starts at 7500. Why get near that?

In a properly coordinated throttle/clutch shift probably no more than 500 rpm. Hence the soft cutout-to-type 2 architecture.


Then pick a thread or start a thread.

Dock

Correction: I just found a post where Kevin states it is 7400 rpm depending on boost level.