[MikeyComputers]

I was just reading how someone in the general section over-reved his motor and bmw won't warranty his car... i was just curious since the cobb raises your rev limiter is that info stored in the ecu once the tune in uninstalled?

just curious im going to bring my car in for service in a few days for a hpfp

[Al Blue4.6l]

cobb covered this somewhere in the morass of one of the 35254615461 page threads.

generally, IIRC, they claim that it wont trigger the permanently stored code. still, as there is 0 point to increasing the rev limit, it seems like a silly thing to include in the tune.

[bulldog_yyc]

Originally Posted by Al Blue4.6l

cobb covered this somewhere in the morass of one of the 35254615461 page threads.

generally, IIRC, they claim that it wont trigger the permanently stored code. still, as there is 0 point to increasing the rev limit, it seems like a silly thing to include in the tune.

agreed and in my opinion it would trigger the overrev flag

[momstmg78]

^you seem to have alot of opinions!

[interpol]

Originally Posted by Al Blue4.6l

cobb covered this somewhere in the morass of one of the 35254615461 page threads.

generally, IIRC, they claim that it wont trigger the permanently stored code. still, as there is 0 point to increasing the rev limit, it seems like a silly thing to include in the tune.

That reminds me of a question that I've never asked. Since most people say to shift around/before 6500, has any tune LOWERED the rev limit on a 6AT so that it shifts before the factory redline?

[bulldog_yyc]

Originally Posted by momstmg78

^you seem to have alot of opinions!

at least i disclose them rather than making blanket statements

[momstmg78]

^ you have alot of opinions but no facts or data to back them up. Where is your proof about the overrev flag?

[OpenFlash]

Originally Posted by momstmg78

^ you have alot of opinions but no facts or data to back them up. Where is your proof about the overrev flag?

The few times people have mis-shifted and bent their valves, PUMA case investigations have been able to retrieve max engine speed data which they used to deny warranty coverage. This isn't unique to BMW as it is well known that almost every modern DME stores such min/max data. The debate is to where this data stored and if this portion of memory is reflashable in the field. Common sense would suggest no. But common sense doesn't always equate to reality.

[Kalud]

Originally Posted by shiv@vishnu

The few times people have mis-shifted and bent their valves, PUMA case investigations have been able to retrieve max engine speed data which they used to deny warranty coverage. This isn't unique to BMW as it is well known that almost every modern DME stores such min/max data. The debate is to where this data stored and if this portion of memory is reflashable in the field. Common sense would suggest no. But common sense doesn't always equate to reality.

Yup, and I also came across an INPA script that I used to get the stored max road speed, time spent above rpm limit and max rev value.

The script is not directly plug and play but with some reading of that thread and playing with INPA and Tool32 you can make it work. I don't have a Cobb AP neither know someone around me to test out what happens with the increased RPM limit.

Source: http://www.m5board.com/vbulletin/e39...ml#post1991958

[XJS]

GIAC for some reason raise the limiter on their 335 flash, and also on porsche turbos. The porsche crowd are allergic to overrevs, which they also classify in different types of overrevs depending on how many revs over the limit one went, and also how long time was spent while overreving. When buying a used porsche, that's the first thing you look at, and for GIAC to be able to deliver a flash to that crowd I can guarantee you noone would even look at it if their flash would register overrevs that can bring down the value of their car.

It would honestly surprise me if COBB would raise the limiter to 7200 and then allow the DME to register overrevs if you are between 7000 and 7200.

With that said, raising the limiter is quite the unnecessary gimmick.

[Jeff@TopGearSolutions]

I wouldnt bother shifting anything after 6500 RPM in the first place on this car there is No power up there. Not sure why they even raise the rev limiter.

[bulldog_yyc]

Originally Posted by momstmg78

^ you have alot of opinions but no facts or data to back them up. Where is your proof about the overrev flag?

Overrev your engine, do some damage and dealer it. Report results here and you can have first hand proof you are looking for.

Or you can apply common logic and rational reasoning (as Shiv has posted):

Its already a fact that a flag exists - only question is if it can be wiped. My opinion is that its probably stored in a portion of the ECU memory that can't be wiped. Simple logic tells you that an overrev event isn't something that the manufacturer would want to forget about - in fact, as others have posted here, its commonplace to check if vehicles have been abused (once method is to check overrev flag) before purchasing. Same deal with max vehicle speed. I beleive this is stored in an area of the ECU that records a flag if max vehicle speed has exceeded a pre-set value - didn't someone get their warranty voided this way since it was obvious their car was tuned to exceed the limited speed?

Originally Posted by Jeff@topgearsolutions

I wouldnt bother shifting anything after 6500 RPM in the first place on this car there is No power up there. Not sure why they even raise the rev limiter.

In stage 1 form, totally agree. May come in handy for those with upgraded turbos, IF the tuning software is ever released........

[XJS]

It sounds unreasonable that a flash would raise a limiter and then continuously delete a flag that the ECU records.

What is logical is that COBB, GIAC and alike has reprogrammed the ECU to think that the limiter is 7200 instead of 7000, and the recording of the flag you mention is only done if an overrev happens above the new limiter.

[Kalud]

Originally Posted by XJS

It sounds unreasonable that a flash would raise a limiter and then continuously delete a flag that the ECU records.

What is logical is that COBB, GIAC and alike has reprogrammed the ECU to think that the limiter is 7200 instead of 7000, and the recording of the flag you mention is only done if an overrev happens above the new limiter.

I don't know if Cobb can clear those values but

Those are logged, its a fact, I checked those on my car. Recorded in the DME:

• Max rev value in RPM
• Time spent over rev
• Max road speed

[Clap135]

The rev limiter increase is not there because the car makes power.
Its there for road racing people that need an extra 100-200 rpm to stay in gear before a turn.

Also I found it useful when you launch in 1st and light up in smoke, gives you an extra 200 rpm cusion for that instant redline shot/shit while spinning. So it does have advantages, small an duseless to most however lol.

[bulldog_yyc]

Originally Posted by Kalud

I don't know if Cobb can clear those values but


Those are logged, its a fact, I checked those on my car. Recorded in the DME:

• Max rev value in RPM
• Time spent over rev
• Max road speed

how did you check these values?

[XJS]

Originally Posted by turkish335

how did you check these values?

I would like to know as well, that is valuable information when buying a used car.

[Toker335i]

damn, i dont think ive ever shifted past 7k, hope not

[Alan l.]

Originally Posted by XJS

It sounds unreasonable that a flash would raise a limiter and then continuously delete a flag that the ECU records.

What is logical is that COBB, GIAC and alike has reprogrammed the ECU to think that the limiter is 7200 instead of 7000, and the recording of the flag you mention is only done if an overrev happens above the new limiter.

^^This^^

If you over revved the motor then you have to pick up the tab regardless if you are tuned or not. Highly doubt the dealer is going to pull this data for normal service unless they suspect overrev damage which is easy to tell.

However, i do agree that it is rather pointless to increase it at all since the N54 runs out of steam way before that point. Good for guys with upgraded turbos but useless for 99% of us.

Alan

[Kalud]

Originally Posted by turkish335

how did you check these values?

Originally Posted by XJS

I would like to know as well, that is valuable information when buying a used car.

See my post #9 above, there is a script that you can run in INPA, you can also poke the value yourself in the DME using Tool32. (See coding forum for more introduction to those bmw tools)

Originally Posted by Alan l.

^^This^^

If you over revved the motor then you have to pick up the tab regardless if you are tuned or not. Highly doubt the dealer is going to pull this data for normal service unless they suspect overrev damage which is easy to tell.

However, i do agree that it is rather pointless to increase it at all since the N54 runs out of steam way before that point. Good for guys with upgraded turbos but useless for 99% of us.

Alan

Yes and no, let say you have a brand new car with 0 km on it, and only rev it to 3500RPM, the max rpm value stored will be 3500, its not a trigger on if you over rev past a certain "configurable" max rpm that it log it... I tested on my own car...

[bulldog_yyc]

Originally Posted by Kalud

See my post #9 above, there is a script that you can run in INPA, you can also poke the value yourself in the DME using Tool32. (See coding forum for more introduction to those bmw tools)

any way of doing this with the BT tool?

[SennaZ]

Originally Posted by turkish335

any way of doing this with the BT tool?

I was thinking the very same thing - or see if Cobb could add an erase of the TNMAX and NMAX values to their diagnostic functions.