997 turbo / number of ignitions

[Redeem]

I have seen what seems to be a 997 turbo but I am worried it has been over rev. The test shows that it had 1 range 5 and 1 range 6 number of ignitions. Should I be concerned by these ranges 5 and 6 numbers ?
Thank you

[IMI A]

don't think you can have one ignition in each range so maybe not an issue. I walked away from a GT2 as it had 3 ignitions in RR 5 and it was £90k then. Same car now on sale for £160k!

These cars can sometime rev spike at start up and this has been known to sometimes cause anomalous RR readings.

[Redeem]

I was told that the 1 incident is probably as a result of an incorrect gear selection. If this explanation is correct how is it possible to have a range 5 and a range 6 incidents at the same time ?

[Redeem]

I was told that the 1 incident is probably as a result of an incorrect gear selection. If this explanation is correct how is it possible to have a range 5 and a range 6 incidents at the same time ?

[berty37]

IMI A is right..you cant have 1 in each. This is happening more and more times according to Steve McHale at JZM and Porsche themselves are aware of the issue. I looked at a 997.1 S that had similar data.
Also on the turbo and maybe other carreras there is also something called 'rev flair' that happens on start up very occasionally - when you start the car it revs very high. This was caused by a sensor or something I think it was a recall a while ago but I am not sure. There was a thread on here beginning of the year about it where Porsche themselves tested a car back at an OPC and it did produce over rev data by this start up flair.
Sadly I never went for the 997S in the end just purely because of the 1 ignition in rev range 5 and 6 - I just think come resale on a fairly common car just trying to explain it to someone that its a 'glitch' they just more likely to say thanks but no thanks.

[Bikeracer1098]

Redeem said:

I was told that the 1 incident is probably as a result of an incorrect gear selection. If this explanation is correct how is it possible to have a range 5 and a range 6 incidents at the same time ?

I was told by Porsche that the over revs are caused by downshifting rather than during acceleration and up shifts. During acceleration the rev limiter prevents the engine from over reving.

However over revs are caused when downshifting incorrectly and changing dine from 5th gear to 2nd gear (rather than 4th gear) causing excessive over reving of the engine which can cause damage to the engine.

Porsche will not offer extended warranty on an engine which shows excessive over revs unless the engine is stripped down and inspected and the seals are replaced.

Hopefully this helps

[IMI A]

Bikeracer1098 said:

Redeem said:

I was told that the 1 incident is probably as a result of an incorrect gear selection. If this explanation is correct how is it possible to have a range 5 and a range 6 incidents at the same time ?

I was told by Porsche that the over revs are caused by downshifting rather than during acceleration and up shifts. During acceleration the rev limiter prevents the engine from over reving.

This isn't correct actually. Porsche turbos and GT2s over rev for fun on upshifts when you're smashing into the rev limiter.

Taken from another thread courtesy of TB993tt.

Have a watch, this GT2 has increased rev limiter to ~7300rpm but watch the needle jump towards 8000rpm on gear change - they all do this needle jump thingy, I'm sure other owners on here can confirm ?

http://www.youtube.com/watch?v=Cocju-Ri9qY

A freeze from the 5th to sixth change, if you watch the vid you can see the guy rowing the gears in the reflection...




The over rev at gear change seems to be a "feature" of the 7GT2, checkout the Sport Auto driver at 3:39 he changes before the rev limiter put apparently the engine still manages to over rev


http://www.youtube.com/watch?v=OaRtdZ428HI

My 997 turbo has GT2 turbos courtesy of 9e it also does this! I'm probably now logging RR 4,5,6 every time this occurs and I have an increased rev limiter to 7000 RPM - engines never been above 7300/7500 RPM

[Bikeracer1098]

IMI A said:

Bikeracer1098 said:

Redeem said:

I was told that the 1 incident is probably as a result of an incorrect gear selection. If this explanation is correct how is it possible to have a range 5 and a range 6 incidents at the same time ?

I was told by Porsche that the over revs are caused by downshifting rather than during acceleration and up shifts. During acceleration the rev limiter prevents the engine from over reving.

This isn't correct actually. Porsche turbos and GT2s over rev for fun on upshifts when you're smashing into the rev limiter.

Taken from another thread courtesy of TB993tt.

Have a watch, this GT2 has increased rev limiter to ~7300rpm but watch the needle jump towards 8000rpm on gear change - they all do this needle jump thingy, I'm sure other owners on here can confirm ?

http://www.youtube.com/watch?v=Cocju-Ri9qY

A freeze from the 5th to sixth change, if you watch the vid you can see the guy rowing the gears in the reflection...




The over rev at gear change seems to be a "feature" of the 7GT2, checkout the Sport Auto driver at 3:39 he changes before the rev limiter put apparently the engine still manages to over rev


http://www.youtube.com/watch?v=OaRtdZ428HI

My 997 turbo has GT2 turbos courtesy of 9e it also does this! I'm probably now logging RR 4,5,6 every time this occurs and I have an increased rev limiter to 7000 RPM - engines never been above 7300/7500 RPM

Thanks for the info.

This is very interesting as I was assured by OPC Porsche in Reading and West London that this wasn't the case, and the rev limiter protected the engine during acceleration and while up shifting.

I was told that this was the reason why PDK cars don't suffer from over reving, otherwise the same would be true of the PDK turbo whilst using in manual mode. I've certainly hit some high revs whilst up shifting manually in my PDK turbo.

Will have to investigate further.

[Mark A S]

Watching the video's its the rev counter that jumps, not the engine itself, regarding these counters, do they work direct from the rev counter?

[IMI A]

Bikeracer1098 said:

IMI A said:

Bikeracer1098 said:

Redeem said:

I was told that the 1 incident is probably as a result of an incorrect gear selection. If this explanation is correct how is it possible to have a range 5 and a range 6 incidents at the same time ?

I was told by Porsche that the over revs are caused by downshifting rather than during acceleration and up shifts. During acceleration the rev limiter prevents the engine from over reving.

This isn't correct actually. Porsche turbos and GT2s over rev for fun on upshifts when you're smashing into the rev limiter.

Taken from another thread courtesy of TB993tt.

Have a watch, this GT2 has increased rev limiter to ~7300rpm but watch the needle jump towards 8000rpm on gear change - they all do this needle jump thingy, I'm sure other owners on here can confirm ?

http://www.youtube.com/watch?v=Cocju-Ri9qY

A freeze from the 5th to sixth change, if you watch the vid you can see the guy rowing the gears in the reflection...




The over rev at gear change seems to be a "feature" of the 7GT2, checkout the Sport Auto driver at 3:39 he changes before the rev limiter put apparently the engine still manages to over rev


http://www.youtube.com/watch?v=OaRtdZ428HI

My 997 turbo has GT2 turbos courtesy of 9e it also does this! I'm probably now logging RR 4,5,6 every time this occurs and I have an increased rev limiter to 7000 RPM - engines never been above 7300/7500 RPM

Thanks for the info.

This is very interesting as I was assured by OPC Porsche in Reading and West London that this wasn't the case, and the rev limiter protected the engine during acceleration and while up shifting.

I was told that this was the reason why PDK cars don't suffer from over reving, otherwise the same would be true of the PDK turbo whilst using in manual mode. I've certainly hit some high revs whilst up shifting manually in my PDK turbo.

Will have to investigate further.

Not so common on tips and pdk but they can also both be overevved. PDK actually easier to over rev but nothing severe only like a RR 2. My wife managed to register a RR2 in a 991 turbo S

[IMI A]

Mark A S said:

Watching the video's its the rev counter that jumps, not the engine itself, regarding these counters, do they work direct from the rev counter?

Not sure but data logging defo shows GT2 turbo cars going way past their electronic limiters under hard acceleration. May be a feature of the larger turbos

[Redeem]

Thanks regarding my original post should I be concerned although the number of incidents is minimal 1 range 5 and 1 range 6 ?

[IMI A]

Redeem said:

Thanks regarding my original post should I be concerned although the number of incidents is minimal 1 range 5 and 1 range 6 ?

My view was that if you can find one with no RR in 5 and 6 so much the better. No right or wrong answer tbh and as I said earlier they're probably erroneous. Come sale time the car will be a bit harder to sell.

[berty37]

I think Imran on PDK the car cannot be mechanically over revved? RR 1 and RR2 are just limiter bounces...yet to hear or see a PDK with a RR3 - dont think its possible - sure I'll be corrected though!!

[fredt]

Over revs are over-done to death. Yes it offers some guidance, but the main purpose is Porsche extracting money from customers.

I almost backed out of buying mine because of overrevs. But when you start talking to specialists who sell and maintain these cars, and teams that have raced them for years you start to get a better picture.

Mechanical over rev (mishifts) can obviously have disastrous consequences, but the consensus is that it will fail at, or very soon after the event.

My limiter is set to 7250(and this is where the ecu starts picking up RR2 hits), needless to say RR1 is maxed out and I have a few in RR2. 996 so RR2 is the top range.

So a couple of or RR like the car you are looking at is nothing, though come selling you will have a few people telling you the engine is toast..

[996TT02]

I don't understand ONE ignition. Do you mean one incident where the engine over revved or literally as the data is offered, ONE ignition?

[Redeem]

996TT02 said:

I don't understand ONE ignition. Do you mean one incident where the engine over revved or literally as the data is offered, ONE ignition?

Yes this is correct - 1 ignition in range 5 and 1 ignition in range 6.

In addition to the above:
Range 1: 4910
Range 2: 660
Range 3: 22
Range 4: 2

The above data is from 2012. Obviously if I buy the car I will ask and pay for a new and updated ignitions test. I do not want to spend money on a new test though if the 2012 test raises issues.
Thanks

[dariog]

"The over rev at gear change seems to be a "feature" of the 7GT2, checkout the Sport Auto driver at 3:39 he changes before the rev limiter put apparently the engine still manages to over rev "

Hallo

I guess it is connected with inertia of the both turbines when the shift clutch is pressed they are working without load, so the tachometer swings to continue. But the question is wheter it has any other implications than what we could see on the gauge? In my opinion "Mezger" engine is proof for over rev and its racing heritage confirms it.

For overrevs it is importent how many houres passed since it occured, as it was said earlier.

It is almost impossible to change the gear in GT2 when the yellow triange is shown and not to make it with "red line".

Greetings
Darek

Edited by dariog on Wednesday 26th August 18:23

[996TT02]

Redeem said:

Yes this is correct - 1 ignition in range 5 and 1 ignition in range 6.

In addition to the above:
Range 1: 4910
Range 2: 660
Range 3: 22
Range 4: 2

The above data is from 2012. Obviously if I buy the car I will ask and pay for a new and updated ignitions test. I do not want to spend money on a new test though if the 2012 test raises issues.
Thanks

It could not have got to the (highly improbable anyway) 1 ignition in range 6 with only one ignition in range 5. A bit beyond the laws of physics I would say. I.e. one piston power stroke at the start of range 5 delivers enough energy to accelerate (rev) the engine through all that rev range such than the next ignition (only one third of a crankshaft rotation away) is within the next rev range.

Unless that ignition ignited 500 grams of TNT, somewhat unlikely. Methinks all a load of garbage.

[Matt Seabrook]

Redeem said:

Yes this is correct - 1 ignition in range 5 and 1 ignition in range 6.

In addition to the above:
Range 1: 4910
Range 2: 660
Range 3: 22
Range 4: 2

The above data is from 2012. Obviously if I buy the car I will ask and pay for a new and updated ignitions test. I do not want to spend money on a new test though if the 2012 test raises issues.
Thanks

I would say range 4 is also suspect. 2 ignition events is equivalent to 5ms 0.005 seconds. And range 3 is only 60ms 0.06 seconds.

Rev range 3 is 7200 to 7400 on a Turbo so Rev range 3 is questionable IMO
Rev range 4 is 7400 to 7900 so to to do that in 5ms to get to Rev range 5, really?

I'm not even going to bother with Rev range 5 and 6.

I looked at a few turbos before buying my car and rejected them on Rev ranges as they where too high for my liking. That said the car I now have has got Rev range readings up to 5 but are too small for me to be worried about. They are greater than the ones above though.

Commen sense has to kick in with these Rev ranges. If they are getting in to three figures then it's getting believable. But to get to rev range 6 you have to go through all the other first. Just my opinion and I could be talking b.....ks