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That is alot. On the 6GT3 with only 2 overrev ranges you don't actually know if the range 2's were 8000+ rpm ones or 9500 rpm ones...with later GT3's you could determine that. Leakdown and compression are good to do regardless but could still come back good and then bearings might be on the way out if the overrev was a high one. Oil samples if they have them could tell you something if high in lead (bearings). Also if a track car as you stated does it have AIM system/sensors as these can record the overrev and could be more specific on the rpm if went too. Bottom line if it was me i'd budget for an engine refresh at some point if the rest of the car is clean and build that into your offer.
Some of those Range 2 appear to have happened just a little while ago as well. At 666 hours. Report was at 672.
Also keep in mind that there are 3 ignitions per rev. So - if my math is right - at 8800 rpm (where range 2 starts) there are 440 ignitions per second. That report has over 12000 range 2. That’s almost 30 seconds of range 2 living at 8800 ROM. And, at 10,000 rpm, it’s still over 20 seconds of Range 2. No way to know exactly how it unfolded, but IMO, seems like a lot.
I’d definitely check the car out if this is a PPI.
That is a good question. I will have them check the rev limiter to see if it goes past 7800.
How do you interpret range 1 and range 2 over-revs if a tune has modified the rev limit?
I am curious about this, as my 996.2 GT3 has the EVOMSit 93 octane tune, and it is possible that this tune raised the rev limit from stock 8200 RPM to 8400 RPM.
How do you interpret range 1 and range 2 over-revs if a tune has modified the rev limit?
I am curious about this, as my 996.2 GT3 has the EVOMSit 93 octane tune, and it is possible that this tune raised the rev limit from stock 8200 RPM to 8400 RPM.
I would think they would be less concerning as you could easily do that without a mechanical over rev.
Some of those Range 2 appear to have happened just a little while ago as well. At 666 hours. Report was at 672.
Also keep in mind that there are 3 ignitions per rev. So - if my math is right - at 8800 rpm (where range 2 starts) there are 440 ignitions per second. That report has over 12000 range 2. That’s almost seconds of range 2 living at 8800 ROM. And, at 10,000 rpm, it’s still over 20 seconds of Range 2. No way to know exactly how it unfolded, but IMO, seems like a lot.
I’d definitely check the car out if this is a PPI.
-td
doesn't the number indicate total over revs in range 2? and the hour just lets you know when the last incident was? I which case it could've been 3 seconds at 10 different times for example.
I would think they would be less concerning as you could easily do that without a mechanical over rev.
Would a rev limit change by a tune really mean much of anything? If it is raised to 8400 RPM, then range 1 would be <8400 RPM and range 2 would be >8400 RPM right?
A car with a raised rev limit might theoretically have spent some time in the 8200-8400 RPM range just by hitting the rev limiter.
But 8400 RPM is not dangerous for the 996.2 GT3 engine, as I understand. Of course, if you do a money shift it's going to show up as range 2 either way.
The other possibility is that a tune might change the rev limit to say 8400 RPM, but the DME is still recording range limits at 8200 RPM.
If that were the case, you might end up with a lot of range 2 over-revs that are really only 8200-8400 RPM, and not that concerning.
The other possibility is that a tune might change the rev limit to say 8400 RPM, but the DME is still recording range limits at 8200 RPM.
If that were the case, you might end up with a lot of range 2 over-revs that are really only 8200-8400 RPM, and not that concerning.
On the car you're looking at, whether it has a tune or not, it appears to have had spirited driving fairly recently, last 5-6 hours.
I think you're right that you don't know if these recent events are just a few ignitions, or if they were several seconds worth.
A mostly track car wouldn't necessarily be bad, since some of them that I know of are exquisitely maintained, beautiful cars with fairly low miles.
But there's a possibility that some not-so-good things happened recently, so a good PPI along with trying to learn about the car's history would help.
12000 does seem unusually high for range 2. Ive heard of cup cars spending accumulative minutes at 10K plus but they have a more stout cam set up than the road going GT3. Leak down and compression definitely as others have said, but they still won’t tell you the full story. I’m more lax with overrevs than probably some others (I think there’s a lot of misunderstanding and overhyped DME reports out there) but I’d be doing all due diligence before proceeding with this one.
How catastrophic is the report. It is from a primarily track only car
65,535 is 16 bit max value. My DME had exact same number for range 1, I'm assuming then that range 1 is at max count? Mine also had large range 2 count at 4888 but after doing some research online, found a long posting on modified ECUs causing inflated DME readings,which some have stated here already. I later found an old online auction listing stating the car had a modified ECU so for myself, chalked the large range 2 up to that, but time will tell, may be the wrong conclusion...
Odd thing about my DME report, there was no 3rd line for operating hours counter and where the VIN usually is said GT2 unknown/2003. I'm assuming modified ECU results in this
12-29-2020, 04:51 PM
High number of range 2 ove revs
