Carrera GT rev range report
10-17-2014, 02:11 PM
#16
Rennlist Member
We did an article in Excellence years ago about a Porsche fanatic who made his own shift interrupt setup for early 911s with sensors and servos. Was pretty nifty, if a bit crude. A manufacturer could make it work at a very high level, I suspect.
pete
10-17-2014, 10:11 PM
#17
Nordschleife Master
What I don't understand is why car companies don't do a money-shift interrupt for manual transmissions. Porsche already has the mechanism that could block 2nd from 5th (at the very least) in the way it blocks 7th from 4th in the 991 MT. We did an article in Excellence years ago about a Porsche fanatic who made his own shift interrupt setup for early 911s with sensors and servos. Was pretty nifty, if a bit crude. A manufacturer could make it work at a very high level, I suspect. pete
Very good point!
10-19-2014, 12:43 AM
#18
What I don't understand is why car companies don't do a money-shift interrupt for manual transmissions. Porsche already has the mechanism that could block 2nd from 5th (at the very least) in the way it blocks 7th from 4th in the 991 MT.
We did an article in Excellence years ago about a Porsche fanatic who made his own shift interrupt setup for early 911s with sensors and servos. Was pretty nifty, if a bit crude. A manufacturer could make it work at a very high level, I suspect.
pete
We did an article in Excellence years ago about a Porsche fanatic who made his own shift interrupt setup for early 911s with sensors and servos. Was pretty nifty, if a bit crude. A manufacturer could make it work at a very high level, I suspect.
pete
Manual transmission development seems to have halted in favor of more advanced autos, and bandaids like skip-shift are the only rare innovations as a result. I agree that technically a money-shift lockout would be easy, but "take rate" x "customers who'd benefit" must look tiny compared to the next PDK. There's probably not much profit in fighting yesterday's war. Unfortunately.
This was likely true even a decade ago. Isn't the story that an automated transmission was originally intended for the CGT, but it was dropped during development?
10-19-2014, 10:28 AM
#19
Drifting
Engineers had to decide early that the engine was part of the integral rigidity of the chassis. The reason the clutch is so complicated and unique. Recently found one on e-bay. From the date appears Porsche made a run in 2012.
11-03-2014, 08:46 PM
#20
Burning Brakes
Gentlemen. Just got the following info on a CGT I am interested in buying:
[B][The rev information for range 1 is 4792 and range 2 is 165 and 5 hours since the last occurrence. /B]
I was told by the service manager that the car is fine and I should not be concerned with the minor over rev that took place. I have also heard from two Carrera GT certified mechanics that almost every CGT they have come across has had some sort of over rev.
I would appreciate your inputs.
[B][The rev information for range 1 is 4792 and range 2 is 165 and 5 hours since the last occurrence. /B]
I was told by the service manager that the car is fine and I should not be concerned with the minor over rev that took place. I have also heard from two Carrera GT certified mechanics that almost every CGT they have come across has had some sort of over rev.
I would appreciate your inputs.
11-04-2014, 09:15 AM
#21
Gentlemen. Just got the following info on a CGT I am interested in buying:
[B][The rev information for range 1 is 4792 and range 2 is 165 and 5 hours since the last occurrence. /B]
I was told by the service manager that the car is fine and I should not be concerned with the minor over rev that took place. I have also heard from two Carrera GT certified mechanics that almost every CGT they have come across has had some sort of over rev.
I would appreciate your inputs.
[B][The rev information for range 1 is 4792 and range 2 is 165 and 5 hours since the last occurrence. /B]
I was told by the service manager that the car is fine and I should not be concerned with the minor over rev that took place. I have also heard from two Carrera GT certified mechanics that almost every CGT they have come across has had some sort of over rev.
I would appreciate your inputs.
So the timing of the ignitions is super small intervals. Those figures are minuscule. These aren't revs remember these are ignitions during one revolution. There are 10 ignitions per revolution. I've talked to techs across the country and there sentiments are unanimous. If the engine idles smooth and there's no odd sounds then it is fine. Use the report to look at major over rev events and faults. Other than that people worry a bit too much I'm afraid.
165 ignitions is something like 16 revolutions at 8600+ or whatever rpms. Do the math and you will find that to be an awfully short duration. Rev range one doesn't phase me at all. Just means the dude
drove the car as intended. Rather have a broken in engine anyway.
Go for it!!!
11-04-2014, 10:27 AM
#22
Burning Brakes
So the timing of the ignitions is super small intervals. Those figures are minuscule. These aren't revs remember these are ignitions during one revolution. There are 10 ignitions per revolution. I've talked to techs across the country and there sentiments are unanimous. If the engine idles smooth and there's no odd sounds then it is fine. Use the report to look at major over rev events and faults. Other than that people worry a bit too much I'm afraid.
165 ignitions is something like 16 revolutions at 8600+ or whatever rpms. Do the math and you will find that to be an awfully short duration. Rev range one doesn't phase me at all. Just means the dude
drove the car as intended. Rather have a broken in engine anyway.
Go for it!!!
165 ignitions is something like 16 revolutions at 8600+ or whatever rpms. Do the math and you will find that to be an awfully short duration. Rev range one doesn't phase me at all. Just means the dude
drove the car as intended. Rather have a broken in engine anyway.
Go for it!!!
11-04-2014, 10:47 AM
#23
Drifting
CGT's wind up fast - these instances offer no concern.
Doesn't appear the driver made a massive downshift error - simply ran it to the tach limit shifted a lil late which does no damage.
Doesn't appear the driver made a massive downshift error - simply ran it to the tach limit shifted a lil late which does no damage.
11-04-2014, 12:10 PM
#24
Burning Brakes
Just got off the phone with the 4th CGT certified mechanic and his response was that over revs in range 3 and range 4 are concerning.
11-04-2014, 02:10 PM
#25
5 ignitions per revolution? It's a 4 stroke?
Out of interest, does anyone know what the RPM limits for range 3 and 4 are on the CGT?
Out of interest, does anyone know what the RPM limits for range 3 and 4 are on the CGT?
11-04-2014, 04:02 PM
#26
Drifting
Talked to the local CGT service guys when I dropped off another car.
To address the over rev's and other common CGT's issues - sellers / buyers who prefer a Porsche PPI prior to a sale it's common for a full inspection that usually leads to an engine out service including clutch at 29.5 to address all issues as Porsche strongly recommends these car be in top condition.
Depending who you talk to - chances are they are going to want to give the 10 year old CGT a proper going over.
To address the over rev's and other common CGT's issues - sellers / buyers who prefer a Porsche PPI prior to a sale it's common for a full inspection that usually leads to an engine out service including clutch at 29.5 to address all issues as Porsche strongly recommends these car be in top condition.
Depending who you talk to - chances are they are going to want to give the 10 year old CGT a proper going over.
Last edited by nuvolari612; 11-04-2014 at 07:24 PM.
11-04-2014, 10:32 PM
#27
If my math is correct 9000 revolutions per minute divided by 60 seconds = 150 revolutions per second.
So, if there are 5 ignitions per revolution, thats 150 x 5 = 750 ignitions per second. So 165 ignitions is .22 seconds. Range 2 is anything above 9000? I haven't heard of Range 3 or 4 with a CGT. I thought there was only Range 1 and 2.
Now I'm not sure, but the 165 number is the total ignitions. And the number after that, is the last time (hour) the event happened. Could this be 1 ignition 165 times, or 10 ignitions 16.5 times, or some other accumulation?
There was another thread I saw months ago, but cant find it now.
So, if there are 5 ignitions per revolution, thats 150 x 5 = 750 ignitions per second. So 165 ignitions is .22 seconds. Range 2 is anything above 9000? I haven't heard of Range 3 or 4 with a CGT. I thought there was only Range 1 and 2.
Now I'm not sure, but the 165 number is the total ignitions. And the number after that, is the last time (hour) the event happened. Could this be 1 ignition 165 times, or 10 ignitions 16.5 times, or some other accumulation?
There was another thread I saw months ago, but cant find it now.
11-04-2014, 11:33 PM
#28
Found that other thread I couldn't find earlier. rennlist.com/forums/997-turbo-forum/597259-how-to-read-over-rev-report.html
