Hi all, so i've been reading threads about over-revs and I had a quick question. When I first bought my 997.2 c2s it had about 12 over -revs total, all in category 1. I used the durametric enthusiast to check.

Now I have around 200 or so and I was wondering if this is normal? I think its silly that going to redline is damaging for the engine...why wouldn't they make the redline lower if it technically counts as a category 1 over-rev?


Also, after 1 and a half months of ownership, and going from 14k miles to 19k miles, I must say I love this car!

 

Last I checked, about a year ago I had over 20,000 range one overrevs. Don't worry about it, just means your driving right.

 

You need to read more about over revs - range 1 isn't damaging for the engine.

 

Range 1 means you just hit the rev limiter. Don't give it a second thought.

 

Sorry, I should clarify. People say not to worry about it; which common sense dictates and I agree. However, I saw that range 1 is considered "may cause damage" just in theory. I was curious what you all thought.

Thanks for the replies.

 

Where did you see range 1 is considered "may cause damage"? I've never seen or heard that comment about range 1.

 

Someone referenced it as (i assume from a porsche document or durametric doc?)

Over rev events are documented as follows in the VAL (Vehicle Analysis Log):

Rev range 1: 6,740 -1 ... to 6,940 -1
⇒ Maximum permitted engine speed exceeded; engine damage possible.

Rev range 2: 6,940 -1 ... to 7,140 -1
⇒ Maximum permitted engine speed exceeded; engine damage possible.

Rev range 3: 7,140 -1 ... to 7,340 -1
⇒ Maximum permitted engine speed exceeded; engine damage probable.

Rev range 4: 7,340 -1 ... to 7,840 -1
⇒ Maximum permitted engine speed clearly exceeded; engine damage probable.

Rev range 5: 7,840 -1 ... to 8,940 -1
⇒ Maximum permitted engine speed very clearly exceeded; engine damage very probable.

Rev range 6: over 8,940 -1
⇒ Engine damage has generally occurred.

 

Those perimeters don't make any sense. Both range 1 & 2 are below the actual redline at 7200 and range 3 with "engine damage probable" is just flirting with redline territory. Where did you get that chart from?

 

Sorry I think I posted the turbo version. Someone had the exact same graph on the .2s engine, but I am not sure where I saw it. It was posted by someone on Rlist somewhere. Anyways, I do remember the range 1 was the same wordage.

I really want to find the source document they are using.

 

It's my understanding that range one is just before the limiter. Range two is bumping up and range three is slamming it.

Even range three is considered acceptable since you're just taking advantage of the limiter's purpose.

 

Not sure exactly where the limiter cuts it off but all the ranges recorded including range 1 are above redline.


From this thread: https://www.6speedonline.com/forums/...ported-ok.html

Here are the range specs:

A 997-1 DME records the following rev ranges:
Range 1: 7300-7500 RPM
Range 2: 7500-7700 RPM
Range 3: 7700-7900 RPM
Range 4: 7900-8400 RPM
Range 5: 8400-9500 RPM
Range 6: 9500-11000 RPM

 

Type 1 over revs occur when you hit the rev limiter. Type 2 over revs generally occur when you miss a shift - something like hitting 2nd gear instead of 4th gear on a downshift. Type 2 over revs typically have the potential to do more damage. That being said, I know lots of people who track their cars regularly who have multiple range 3 and range 4 over revs. It happens. It can damage the engine, but it's not guaranteed to be damaged just because you've got over revs in this range.

 

On the 996 there were only two ranges - range 1 was rev limiter and range 2 was a mechanical over rev (missed shift). On the 997 it was explained to me that ranges 1, 2 and 3 were rev limiter and ranges 4, 5 and 6 were mechanical. Obviously if you have a missed shift you get over revs in 1, 2 and 3 before you get to 4 or higher.

 

That makes sense. I was talking to my brother last night about this - he frequently tracks his 987 Boxster. He told me that he has never had a mechanical over rev, but his car shows that he has thousands of recorded over revs. Not sure which type...

 

Interesting to note that my prior turbo had 17 range 3s and 1 range 4. Of course I bought it at the time and had no issues during my ownership. However, when I traded it in the dealer told me they couldn't cpo the car since it had a range 4 record. They ran the dme right away when I traded it. Interesting, particularly since I had no skin in the game, we had already negotiated the trade price. I think they probably overestimated my trade value!