scorcherjf

I'd take the 2nd one... it looks like it was driven enthusiastically but no hard money shifts (except some range 4's but that happened quite a long time ago). The 1st one was just recently money shifted all the way up in range 6. To even consider a car with range 6's (no matter how it's recorded since no one actually knows the inner programming of the DME), you'd need to have way more operating hours on it before it's considered safe, and even then you might want to do a compression and leakdown test.

Quadcammer

No, this car was not money shifted to range 6. use your head. you can't have the same number number of ignitions in a single event in 2 categories. the lower category will always have a higher ignition count.

These single digit "overrevs" are computer errors, nothing more.

Quadcammer

I'm not sure I get what you're trying to say. the computer tracks how many times the ignition fired at a certain rpm. if it just tracked rpm vs time you'd need an almost endless data storage facility and it would be useless for at a glance monitoring.

The system is fine

scorcherjf

If you know for certain how it records overrevs, then they must be errors. If someone were accelerating and went down a gear at redline intending to go up a gear, yet only let out the clutch slightly but then clutched in asap, would it not be possible to record range 5-6 but not ranges 1-4 for example? I'm curious to know exactly how the DME records ignitions there.

altonj

It looks like a glitch...

Quadcammer

No. to get to range 5 and 6 the engine speed had to "travel through" the 1-4 range. there is no jumping of rpm

Bruce In Philly

Look, I know I am deep in speculation land.... but isn't everyone here?

You could just count, like ignitions, the number of revolutions in a band. What is odd about the ignitions, is that you get three ignitions for every revolution, assuming you get spark every cycle.... I do know that cars in general "cut gas" when off the throttle, I am not sure about firing a plug when there is nothing to burn. Are the engineers more concerned about applying gas in those ranges or just the engine spinning up not under load?

I am skeptical of flukes or anomalies in these systems as engineers worked pretty hard to get anti-knock and other control systems down pat. I am just skeptical that because it may not make sense to us, that we can then conclude the data was bad.

Peace
Bruce in Philly

LexVan

Could be a missed shift.
Could be a glitch.
Could be a tune.
Could be a sign the DMW was laundered.

A DME Report is just one tool, of many, used to do your due diligence in the buying process.

You could always purchase a powertrain warranty as a hedge.

Tcc1999

To partially answer your question, there is a reason that 1 and 2 over-revs are not considered particularly alarming by PAG. When you hit the Rev limiter there is a very, very short delay between when the ECU detects the limit and shuts off power. It isn't so much an electrical signaling issue as it is the mechanical response. So, if you bounce off the Rev limiter the corresponding delay will trigger a Range 1/2 over-rev. So Range 1/2s are pretty much to be expected (unless PAG lowers the point at which the limiter kicks in to allow for the delay).

On the practical side, why would anyone want to hit the rev-limiter? It seems to me that this is poor driving more than spirited driving. Hit the rev-limiter and your engine just down for a moment. How is this fun. It's like, "lets see how hard I can push my engine and I don't care if it shuts down". Accidents/inattention happens but a better driver, driving spiritedly, might hit the limiter much less frequently. Lots of Range 1 and 2s speak more about how the car was treated than if there is any damage. And if this is axiomatic, then a car with a lot of Range 1 and 2s might have other wear related issues associated with hard (poor) driving that you also ought to consider.

You can buy a car with lots of over-revs (X) or one with many fewer (X-Y). What you really need to do is ascertain how much more the fewer Range 1/2 is worth to your pocketbook, peace of mind and potential for future repairs.

LexVan

One note to mention here, this range #1 is getting very close to the maximum count limitation. Someone here will know what that hard number is, but this one is very-very close. FYI.

mleddy

Guessing that the count should be good till 32767.

rickdogg82

My understanding is that selecting Sport mode (when you have SC option) changes the rev limiter characteristic so that ignition is not cut and you can "ride" the limiter. This could be advantageous for track days or autocross where a shift change would not be practical. I don't have sport chrono so I am only going by what I recall reading on RL.

scorcherjf

Exactly. There are some places on the track where it would be a waste of time to upshift then have to immediately downshift for the corner. I've hit the limiter and "ridden" it for a second or two and it still did not log any range 1 over revs. I have a durametric and checked before and after each track day and I know for a fact I hit the limiter.

docdrs

Here is some DME over rev info just to peak at

http://www.6speedonline.com/forums/9...tive-post.html

LexVan

Yep! Anyone that's spent time at Road America will hear cars banging the rev limiter all-day-long coming out of #5 up the hill into the left hander #6 at the top.