Hi guys.

Mindful over revs are checked by the dealers at one point when a car is CPO'd, (or subject to warranty claim) i'm wondering just how many 997tt owners are out there with tuned ECU's (and Durametric software) that have discovered ignitions (over rev spikes) exist in the 1 to 6 range counters. I recall this topic being discussed somewhere before and certain tuners had claimed there should be no spikes in any of the ranges even where the redline has been increased to 7000 or more.

Do your over revs show, or dont they? And, if so, how many and what ranges do they appear in? And how do you plan to get rid of them .

Tuners are welcome to chime in here and give their thoughts and explanations on what to expect with their particular tunes....

 

I wonder if the answer to your question explains how a tiptronic transmission records a range 3 or 4 over rev.

 

I'm assuming the rev limiter wasnt raised in the tune either?

 

My car is a tip.I happen to own boh piwis and durametric.Rev limit was always stock...My car has some over rev range 1 ignitions,only a few range 2 and one range three...This is explained as follows...
1)When you fully accelerate with 1st gear the rate of lateral acceleration of the engine is so great that the inertia of the engine lets it turn at a hihger rpm than limit...This can happen to a tip car when manual is activated with sport and psm off...
2)If you compare rpm from dashboard to rpm from piwis,you will see that tacho shows slighly lower than actual rpm indicated from piwis...
3)On another thread I ve written down the exact RPM setpoints for 997TT that indicates overrev 1,2,3,4,5 and 6...

 

You've lost me.
1) Ignition is killed the moment the engine hits the rev limiter. The inertia of the reciprocating mass is not going to spin on for another 1000rpm (or more) beyond ignition loss.
2) Can you please quantify "slightly lower".
3) Can you link it or reiterate the info thanks.

So skand whats your explanation how your tiptronic managed to hit a range 3...7700 to 7900 rpm? Redline is 6800 and the tacho cant surely be 1000 rpm out.

It looks to me that an AM tune somehow changes the game on the range settings. And if thats the case, which it certainly appears to be, then how do you combat that when you know for sure your engine has not seen those rpms and, you've had no money mis-shifts? I think the tuners need to explain their take on this. This is not good!. It is evident the marriage between the stock tune file and the rev range counter file is altered once an alien tune file is introduced into the ECU .

 

my car has something like 26000 "type 1" over revs, and something like 3000 type 2's

 

Im assuming yours is tuned? Manual or tip? And do you have any 3's 4's 5' or 6's showing?

I know the topic of ranges has been raised on other forums but i just cant see anywhere where anyone has explained what is really causing it outside of a crazy downshift mishap. And when you look at the number of spikes how many times can someone misjudge a down change? It just doesn't add up.

 

The stock 997.1TT ranges are:
range 1 > 6800 and < 7000
range 2 > 7000 and < 7200
range 3 > 7200 and < 7400
range 4 > 7400 and < 7900
range 5 > 7900 and < 9000
range 6 > 9000

The first 3 ranges are a very narrow band so I think that inertia could get you into ranges 2 and 3 even with the rev limiter kicking in. Range 4 and higher I believe would have to come from a misshift. I don't think the rev limiter would stop an engine exactly at 6800 especially if you were in a sprited run up. Don't have any answers for you on your real question though about tunes and modifed rev limits.

 

difference between piwis and tacho is arounf 300-400rpm at rev limit...
have a look here...
http://www.youtube.com/watch?v=90c-NVEWIIU

 

......

 

^^^Im sure im with you then. My car is at the dealer now getting some carbon trim replaced. They already are some nasty SOB's I dont dare to ask for a report. Ill worry bout that come sale time.

 

This is scary!!!!

 

Is this car tuned or stock? And if so do you know the rev limiter max?

Any 5's or 6s?

 

not yet

 

Funny how not one solitary tuning company chimed in to offer any advice or, offer any explanation why this occurs.

Hmmmm.....I wonder why no tune vendor mentions anything about this when selling you the tune . Something tells me an eery silence on this topic will continue indefinitely....

And when you consider the discussion that regularly crops up on this board from prospective buyers seeking advice from other Porsche owners/6speedonline members about used Porsches that show nasty spikes on the range counters, it would appear that installing any AM tune into your beloved car's ECU is effectively handing your car a death sentence. For when it comes time to trade it or sell into the used car market there will be problems of some sort. Now maybe one should factor that into the real cost of the tune when buying one .

Take a look at this:
https://www.6speedonline.com/forums/...ported-ok.html There are some telling responses regarding buyer sentiment .