I know most of the details about DME reports and most cars have Range 1 and 2 hits and maybe even range 3. I've read many threads about the results.
My question is in respect to ECU tuned cars. The typical tune is up to about 600 hp and I suspect a slight increase in redline. How do DME reports typically look? Will there be LOTS of Range 1 and 2 and even 3, with possible hits at Range 4? How should a "clean" DME look on a tuned car?

 

Range 1 - 6800-7000
Range 2 - 7000-7200
Range 3 - 7200-7400

A slight increase in redline typically means 500RPM. Based on the figures above if you're frequently zipping the limiter you should expect to see overrevs up through range 3.

A clean DME on any car tuned or not should ready ZERO across the board but hey we all know how easy it is to add to the count.

 

Thanks. I know this is a very travelled topic, so I try not to repeat old news. I don't remember much discussion about over revs and tuned motors though. An additional 500 rpm takes you to Range 3 already. If you get overrun from there, I would guess you are easily into Range 4 as easily as a normal car gets to Range 1. So then even Range 5 wouldn't be extraordinary. This seems logical to me, but I've never heard it viewed this way. I can't imagine there is any way to be "careful about hitting the limiter" if you have a tuned car with a higher limiter.

Interested to hear what's wrong with my logic.

 

As far as I know overrevs are recorded when the rev limiter is exceeded. In a tuned 997 turbo that has a rev limiter set to let's say 7800 rpm then over revs are recorded when you go passed the limiter and over 7800rpm. In a few words you will still see range 1 and 2. Range 3 in that case would definitely send you to buy some connecting rods...
Also if someone wants to raise the rev limiter then he needs to have ported heads for pressure release in the cylinders or use GT3 heads...

 

That is not correct, at least for the tuned cars I have seen. I think Scott@Softronics made some mention of raising the threshold for over revs at one point and I do not know enough to comment on Softronics.

I know for a fact though that EVOMS raises the rev limiter and does not change the threshold for the over rev ranges. So, by raising the limiter by 500, you are in range 3 before you hit the new redline.

Lots of tuned cars with lots of cumulative miles seems to support that the slight rev limiter bump is relatively safe.

 

Well, I do not really agree. Are you sure about this? If you don't hit the rev limiter No overrevs are detected even you had your limiter set at 8000 rpm... If you change gear at 7800 NO overrevs are recorded... If you hit the limiter or go passed it then the car records overrevs according to the range.

 

We all call it over-revs but it is really ignitions within the defined range. Bouncing off the limiter is irrelevant. The limiter just keeps you from going much above the set value.

Now onto my soapbox. Even if you could redefine the ranges, why would you? The only reason would be to try to fool a prospective buyer or PCNA into believing the car was modified/driven in a way it was not. It really bugs me when some of the vendors say their flash is undetectable. Before anyone modifies their car, they need to assume that all flashes void your warranty and may be detected by Porsche, provided they look closely enough.

 

Good thread on the same topic:
https://www.6speedonline.com/forums/...ughts-one.html

Anyone who tells you they have never hit the rev limiter is either a liar or a grandma.

 

That's exactly right... I have been driving manual cars for almost 25 years. I can confidently say that I have only hit rev limiter 1-2 times in my other cars but I have already hit it 2 times since I have owned my 997 TT (14 months).

This car revs so damn quick that it's hard not to hit it the limiter

 

An interesting article indeed, but still inconclusive. What even becomes a bit disturbing is if the flash raises the indexes. What makes the internals SAFER because it is running MORE boost? What sense is there in raising the indexes simply because you've raised the rev limiter?

Certainly, if you're driving the car hard and bouncing it off the limiter and you have raised the limiter, you're going to get range 3 ignitions and maybe range 4 simply due to the engine overrun when you hit the limiter. I've read almost countless comments that people would not consider cars that had range 4 ignitions. Seems that either those people are too conservative or a tuned car with plenty of overrevs is probably destined to have a shorter life.

Interesting debate on the topic.

 

If all else checks out fine (color/specs/options/PPI) then get a compression/leakdown.

Once that's a green light then regardless of what people say here on the forum, the car is just fine.

 

I agree. It not as easy as plugging an OBD-II cable in but much more useful.

 

I am glad I found this thread . I have been aware that a tuned car is a different species.

So today i decided to pull my dme report for the first time. My car has 14K miles .

Here's the car history --
I have pampered it to no end . I have never tracked it . I have never money shifted it . Outside of a few sprints on an open road I mostly drove it in traffic going slow. I hate to admit this but i somewhat drove it like an old man much of the time. In short .. i can't think of any reason outside on a modified engine to explain the results . The car is running perfectly . In fact in 6 years the car has been the most reliable car I have ever had . I have never had an engine issue at all . In fact the only reason I was at the shop today was to check the battery which was getting weak from not driving it enough and out of curiosity I requested to scan the DME .

I had levels 1-5 . The 4 and 5 were only split second and only a few . The 1-3 revs were plentiful.

Most of my posts on DME scans hinged on normally aspirated 997 cars or stock 997 Turbos. Trying to interpret a high HP modified tuned car is something I never considered .

So --I did ask how i might interpret my results given the way that i know I drove the car .

I was told that the higher over revs were minimal time framed . I asked if there was a way to differentiate which over revs were modified codes . A simple scan does not show it but the manufacturer probably has equipment that can . Not that any of this matters as my car warranty was over two years ago to warranty concerns are not an issue .

In conclusion --I have 6 years of amazing reliabiolity without a hiccup even now . Whatever the DME scan says although surprising doesn't effect me .

Years ago when I selected my tuner/installer/technicians-- I had confidence in them enough to trust with my car to bring it to this level and still do . I figure i have many more years with this car .

 

Did you use a Durametric to pull your report? If so, I think there is a flaw in the software that lists small numbers of ignitions in the higher ranges (anywhere from 1-4 ignitions). I know I've never been anywhere near ranges 4, 5 and 6 yet I have ignitions there and my ECU is stock. Also, if there are 3 ignitions every revolution how can you get 1 ignition each in range 4, 5 and 6 - doesn't make sense. Someday I'll try and confirm my Durametric reading with a PIWIS reading. I've asked Durametric about this but never received a response.

 

To change the way the DME records ignitions requires a factory computer that is closely guarded. (i.e., you cannot erase the over-rev reports easily) The Durametric tool cannot change this. The PWIS at the dealer cannot change this. In other words, the ignitions are recorded based on engine RPM. What the rev limiter is set to does not matter.

So, for a 997.1 turbo, the ranges are:
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 ranges cannot be changed by an ECU remap. However, if the hard rev limiter is raised, the likelihood of recording ignitions in the lower ranges increases. As a general rule, Porsche will only deny warranty claims for ignitions in range 4 and above. It also depends on the time since the ignition, etc. If the car is out of warranty, then it really doesn't matter.