Went to Engine Cutout, ? Did I Hit Range 4-6
09-29-2015 | 05:23 PM
#33
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From: Austin
I am not doubting your knowledge at all Kevin. I'm sure that your personal experience with your car with tuning these cars is invaluable.
You say that the rotating assy has been over 7,400 RPMs from the stock setting of 6,750 if your car has recorded type 4s. If this is true and my car has recorded type 4 over revs, then I have exceeded 7,400 RPMs. My car isn't tracked, and it isn't tuned. It's a weekend cruiser. I've hit the rev limiter once, and I've never missed a downshift or had any mechanically induced over rev. Using logic once again, we are left with the following possibilities:
1. My car actually exceeded 7,400 RPMs at some point, and the most likely point would be when I hit the rev limiter.
2. There's some kind of anomaly in my DME; it shows type 4 over revs and they didn't actually occur.
3. There's some doubt as to the accuracy of the DME reading. The wrong equipment was used for the DME reading and/or the results were interpreted incorrectly.
I'm willing to accept any of these possibilities. I truly don't know what caused the over rev reading. Again, I'm just reporting my results.
I appreciate your comments thus far.
You say that the rotating assy has been over 7,400 RPMs from the stock setting of 6,750 if your car has recorded type 4s. If this is true and my car has recorded type 4 over revs, then I have exceeded 7,400 RPMs. My car isn't tracked, and it isn't tuned. It's a weekend cruiser. I've hit the rev limiter once, and I've never missed a downshift or had any mechanically induced over rev. Using logic once again, we are left with the following possibilities:
1. My car actually exceeded 7,400 RPMs at some point, and the most likely point would be when I hit the rev limiter.
2. There's some kind of anomaly in my DME; it shows type 4 over revs and they didn't actually occur.
3. There's some doubt as to the accuracy of the DME reading. The wrong equipment was used for the DME reading and/or the results were interpreted incorrectly.
I'm willing to accept any of these possibilities. I truly don't know what caused the over rev reading. Again, I'm just reporting my results.
I appreciate your comments thus far.
When I mentioned previously that the Durametric could return anomalous results I'd be curious to know how many range 4 over revs were reported - if it's a low number (maybe 5 or less), I'd suspect an erroneous reading for range 4.
09-29-2015 | 07:28 PM
#35
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The first screenshot is taken from my car during my PPI. I verified it with my PIWIS 2 tester and confirmed that the info was accurate. You can see the total engine hours and the Type 1 thru Type 3's that were recorded since new.
The second screenshot was at the drag strip. I was running various tunes ALL at the stock limiter.. I was launching the car at 3600RPM's and bounced the limiter "intentionally" I also recorded a burn out/hard launch thru the water box.. My son was in the car and I recorded the Type 3 overRev.. Water equals Type 3... You can see the engine hours all getting bumped up.
Screenshot show me bouncing off the limiter (fuel cut) AND have the ECU Rev limited (tuned) to 7000 RPM's.. No water on pavement.. Recorded Type 1 and Type 2's..
I have included my computer date/time stamp. But have blurred out my Vin...
09-29-2015 | 07:38 PM
#36
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From: South Florida
Lower mass flywheel, lower chance of over revs in downshift?
Earlier in the thread it was mentioned that the unintended downshifts result in the majority of the over revs partly due to the mass of the flywheel/rotating assembly.
By this logic, would over revs be less likely when using a lighter flywheel?
By this logic, would over revs be less likely when using a lighter flywheel?
09-29-2015 | 08:03 PM
#37
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The rotating mass and inertia is to great for the engine fuel cut to slow down. There is no mechanical intervention to slow down your crankshaft. With a lightweight flywheel the RPM ramp rate is even faster.. So you need to shift sooner (6200rpm) to not hit the RPM limiter/fuel cut.
The main idea for the installation of a LWFW is to perk up the engine REV rate.. The negatives>> I have seen customer logs with higher OverRevs' ... There's information (solutions) and recommendations to minimize this.
Edit, go look at the video link that I posted.. There is no flywheel upgrade that would prevent the spike in RPM.. You downshift into a lower gear at WOT>> nothing is going to save this engine.
The main idea for the installation of a LWFW is to perk up the engine REV rate.. The negatives>> I have seen customer logs with higher OverRevs' ... There's information (solutions) and recommendations to minimize this.
Edit, go look at the video link that I posted.. There is no flywheel upgrade that would prevent the spike in RPM.. You downshift into a lower gear at WOT>> nothing is going to save this engine.
09-29-2015 | 08:40 PM
#38
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From: Florida
Background - Recently my TT 6M was in for service and major inspection. During the inspection my independent dealer found one of my two turbo actuators was stuck and I wasn't getting full boost. They fixed it and needless to say my TT performs a lot better with much quicker throttle response.
Yesterday - I over revved my TT in 3rd gear because 1) I wasn't paying attention to my tach and boost gauge, 2) I was surprised at how fast my TT accelerated after I fixed my actuator, 3) I was more concerned about the quick lane change I was making and, 4) I was (although most won't admit it) having fun and probably showing off. But, isn't that why we buy a TT?
Over Rev - Because I went to cutout (rev limiter), realized it and quickly shifted into 4th, did I set a DME code 4 or higher?
Yesterday - I over revved my TT in 3rd gear because 1) I wasn't paying attention to my tach and boost gauge, 2) I was surprised at how fast my TT accelerated after I fixed my actuator, 3) I was more concerned about the quick lane change I was making and, 4) I was (although most won't admit it) having fun and probably showing off. But, isn't that why we buy a TT?
Over Rev - Because I went to cutout (rev limiter), realized it and quickly shifted into 4th, did I set a DME code 4 or higher?
09-29-2015 | 10:14 PM
#39
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From: KC ex pat marooned in NY
I once left a new 996 with a detailer, day 10. I was very careful breaking it in etc. I took it to the dealer at 3k miles for a post break in oil change, they called me and said the ecu registered type 2 errors, multiple at the first 29hrs......the detailer had obviously taken it on a joy ride, of course they denied it but I never went back there again! The car did fine, drove it another 70k miles never missed a beat!
C
09-29-2015 | 11:50 PM
#40
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Dennis, did you leave your car with anyone for work?
I once left a new 996 with a detailer, day 10. I was very careful breaking it in etc. I took it to the dealer at 3k miles for a post break in oil change, they called me and said the ecu registered type 2 errors, multiple at the first 29hrs......the detailer had obviously taken it on a joy ride, of course they denied it but I never went back there again! The car did fine, drove it another 70k miles never missed a beat!
C
I once left a new 996 with a detailer, day 10. I was very careful breaking it in etc. I took it to the dealer at 3k miles for a post break in oil change, they called me and said the ecu registered type 2 errors, multiple at the first 29hrs......the detailer had obviously taken it on a joy ride, of course they denied it but I never went back there again! The car did fine, drove it another 70k miles never missed a beat!
C
09-30-2015 | 04:33 AM
#42
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Strato58, that's a good question. You have to realize that the counters don't stop. I banged the limiter driving on the track AFTER the water launch.... Two separate incidents... There would have been Type 1 and Type 2 and Type 3 overRevs at the 703.6 hour marker.. BUT I logged another event, banged the limiter "again" later at 703.7 It registered a Type 1 and Type 2... Similar to the 3rd screenshot.
You can see 2 years later with my progression that I have stayed away from water burn outs and my Type 3's have frozen.. My Type 1's and Type 2's have slowly increased.. I took the 3rd screenshot because bounced the limiter (raised to 7000) and wanted to see if I tripped the Type 2...
You can see 2 years later with my progression that I have stayed away from water burn outs and my Type 3's have frozen.. My Type 1's and Type 2's have slowly increased.. I took the 3rd screenshot because bounced the limiter (raised to 7000) and wanted to see if I tripped the Type 2...
09-30-2015 | 08:01 AM
#43
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Excuse my lack of DME knowledge, do these go back to the 996TT and 993TT? I had a few over revs on my 997 TT when I bought it, but the report did not scare me as the car checked out.
Some people make it seem like an over rev is a nail in the coffin for these cars. I can't imagine reports on older Porsches, I missed gears on my 930 plenty of times, never had an issue.
Some people make it seem like an over rev is a nail in the coffin for these cars. I can't imagine reports on older Porsches, I missed gears on my 930 plenty of times, never had an issue.
09-30-2015 | 08:18 AM
#44
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From: Austin
As Kevin explained what the report shows is that the last range 3 occurred at hour 703.6 and the last range 1/2 occurred more recently at hour 703.7 - not unusual at all - the last over rev event recorded a range 1/2 reading but wasn't strong enough to get into range 3.