All this talk of over revs
All this talk of over revs
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Old Trout

Original Poster:

1,705 posts

205 months

Sunday 25th March 2012
quotequote all
Reading between the lines of various posts and seeing nothing substantial I am curious as to what all this means.

Are Porsche really saying you can't hit the rev-limiter in the car? I thought, like most cars I have driven, the rev limiter is there as a safeguard.

Or are the over-revs really triggered only if you have done a dodgy downshift? Some of the figures I am seeing imply high revs beyond the normal bad downshift.

I used to run sprints in my Subaru and it was constantly bouncing off the limiter and the engine was as solid as a rock.

Aren't Porsche engines as reliable?


Bill Stein

1,595 posts

239 months

Sunday 25th March 2012
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Strikes me that Porsche/OPC have only got to produce a bit of paper saying " Computer say's NO" and all warranties are up the duffer!!yikes

Me...cynical in the extreme ??scratchchin

You better believe it!yes

mrdemon

21,146 posts

295 months

Sunday 25th March 2012
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Porsche will let you go to 7,899 in the cayman/boxster that's above the rev limiter.
Which is 7,600 on the gen 2 models. A bit higher in sports mode.

Hit 7,900 and no warranty, and also they now cannot sell them (so I was told)
But other get differant info about resale.

You can pay for a engine test if you want a warranty on your car if it,s not gone above 8,399

To two ranges above that then it,s down to luck.

Edited by mrdemon on Sunday 25th March 21:56

baz1985

3,685 posts

275 months

Sunday 25th March 2012
quotequote all
The only safe option is now a Tiptronic/PDK. But I think they can register too- it's all a bit lame....

mrdemon

21,146 posts

295 months

Sunday 25th March 2012
quotequote all
baz1985 said:
The only safe option is now a Tiptronic/PDK. But I think they can register too- it's all a bit lame....
Of course they will register in sports crono plus you will prob get hits in range 1, 2 and 3.

Porsche don,t mind that.


Old Trout

Original Poster:

1,705 posts

205 months

Sunday 25th March 2012
quotequote all
anonymous said:
[redacted]
I didn't type that sentence properly!!

I meant hitting the rev limiter through acceleration, rather than by a bad downshift.

On reflection maybe my post sounds daft - I understand mechanical over-revs and understand this may be recorded as bad over-revs.

What I mean is, does accelerating into the rev-limiter register as over-revs? That's what some of these posts would seem to imply.

Durzel

12,999 posts

198 months

Sunday 25th March 2012
quotequote all
Hmmm

Under the normal run of things bouncing off the limiter should, as I understand it, give you no higher than Rev range 1 or maybe 2 recorded. This is because the limiter isn't a brick wall, it's a software limited threshold so when you hit it under hard acceleration, and bounce off of it, you will momentarily be doing over the limit (if that makes sense). Porsche don't care about that.

To be clear Porsche don't say you can't have a warranty or that warranty is void if you record higher rev ranges, but what they will insist on is an engine boroscopy come warranty renewal (or I suspect in the event of an engine-related claim) if you record in the 4th range or above.

I think the obsession over it largely comes down to the fact that prospective owners care about it. It's one of those classic contradictions with buying cars where buyers expect to be able to buy a completely virginal car so they can then blast around in it themselves.

It also really depends on the car as well - I would expect a GT3 for example to have higher rev range values than, say, a Boxster.

mrdemon

21,146 posts

295 months

Monday 26th March 2012
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Quote
"I think the obsession over it largely comes down to the fact that prospective owners care about it"

And righty so, when you cannot renew your warranty, get a warranty, or sell your car on to the likes of RSJ and 911V
If you haves revs in range 4.

It,s the OPC,s and 3rd party dealers who have made it the issue not the punters, now as punters we have to see a read out to show range 4 clear other wise you are stuck with a car you cannot move on.

Part exed cars with range 4 revs on are punted out to auction, so buyer beware at auction time, that Porsche is cheap for a reason.

thegoose

8,077 posts

240 months

Monday 26th March 2012
quotequote all
Durzel said:
.... but what they will insist on is an engine boroscopy come warranty renewal (or I suspect in the event of an engine-related claim) if you record in the 4th range or above.
AIUI a boroscope test will inspect for scored bores but this happens over a long period and is due to high temp and/or poor lubrication, so one-off over-revs won't affect the result one way or the ohter at all.

What can happen from an over-rev is stretching of the timing chain, weakening it and potentially leading to premature failure (whihc would likely wreck the whole engine). The degree to which it's stretched can be measured though, so maybe this is the engine inspection/test that is required if ignitions in certain rev ranges are registered?

Scelto

619 posts

187 months

Monday 26th March 2012
quotequote all
mrdemon said:
Of course they will register in sports crono plus you will prob get hits in range 1, 2 and 3.

Porsche don,t mind that.
OT, but related - does anyone here actually have anything above RR1 logged on their PDK equipped car?

I have range 1 only on mine, and that's with a couple of "launches" just for the hell of it, lots of spirited driving and getting caught out by the limiter in manual mode several times in the first couple of weeks of ownership.

edit: and I've put 15,000 miles on the car in just over a year of ownership, so it's no garage queen.


Edited by Scelto on Monday 26th March 06:49

cragswinter

21,429 posts

226 months

Monday 26th March 2012
quotequote all
baz1985 said:
The only safe option is now a Tiptronic/PDK. But I think they can register too- it's all a bit lame....
Mates 997 turbo tip had rev ranges bad enough to refuse warrenty & demand an engine examination at his cost to put warrenty in place.

Slippydiff

16,468 posts

253 months

Monday 26th March 2012
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anonymous said:
[redacted]
I suspect this was more a case of the OPC/Reading/Stuuttgart using it as an excuse to not honour a warranty issue, rather than a genuine concern that the over-revs had caused a gearbox fault, but we'll never know.

I had a warranty issue with my Gen 1 GT3 last week, there seems to be little or no consistency as to how the policy is being applied. As an example, I had a front suspension top mount replaced under warranty the previous week by OPC A. The fault (a rattle) remained, but having lost confidence in OPC A, I took the car to OPC B, OPC B diagnosed the fault as the suspension top mount on the other side of the car. Initially they said it would be covered under warranty. The following day they rang me to say it wouldn't be . . . and to replace it would cost £800.

I phoned OPC A (who supplied the car) they informed me the fault would be covered by the warranty, they in turn rang OPC B, who in turn rang me to say they would "try and get the part replaced under warranty". They did, but the rattle still remains. P*ss poor service IMO.

Durzel

12,999 posts

198 months

Monday 26th March 2012
quotequote all
thegoose said:
AIUI a boroscope test will inspect for scored bores but this happens over a long period and is due to high temp and/or poor lubrication, so one-off over-revs won't affect the result one way or the ohter at all.

What can happen from an over-rev is stretching of the timing chain, weakening it and potentially leading to premature failure (whihc would likely wreck the whole engine). The degree to which it's stretched can be measured though, so maybe this is the engine inspection/test that is required if ignitions in certain rev ranges are registered?
I'm only speaking from what I've read on here and in other places. My understanding (and its only that - not first hand experience) is that they insist on a boroscopy specifically.

anonymous said:
[redacted]
Again, not speaking from personal experience. What you say may well be the case.

rigster2

126 posts

176 months

Monday 26th March 2012
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I have had the wind put up me by all this, I didn't know that this sort of thing was possible until I came on here.

I rang my OPC today and they said the first thing they do on the 111 point check is the rev range analysis and any abnormalities would mean them not being able to put the 2 year warranty on the car.

As a recent buyer of an ex demo I was particularly concerned about this, so unless the service manager is telling me porkies my mind is at rest... :-)

Durzel

12,999 posts

198 months

Monday 26th March 2012
quotequote all
Pity those people who don't even know about over-revs before buying. frown I had no idea of it or how significant it was until after I'd already bought my Cayman S, and it was just pure luck really that when it came to getting the OPC warranty applied it was revealed that it only had 81 in RR1.

Magic919

14,569 posts

231 months

Monday 26th March 2012
quotequote all
They didn't mention boroscope, but they wanted to do a leak down test when they saw overrevs on one of mine. I didn't think they had a scope in their armoury.

Wozy68

5,436 posts

200 months

Monday 26th March 2012
quotequote all
The madness of the modern (tech) world.

You can't buy a Sports car with a warranty because it's been driven fast and hard as deigned to be.

You can't buy a new sports car and enjoy it to its maximum just in case you select the wrong gear at soemtime ..... maybe only once, because you will be unable to PX it when it comes to renewal.

Just what did we all do when we bought a new/used car in times gone by?

Oh yes, we just bought and enjoyed them, and I can't ever remember a time when I had sleepless nights worrying that the high performance car I'd just bought hadn't been used in a high performance way.

mrdemon

21,146 posts

295 months

Monday 26th March 2012
quotequote all
but you can thrash the pants of it, rev range 3 is allowed and is way above the limiter !!!

the missing a gear trick (The monkey shift) normally kills your engine there and then.
My friend has just done it and it's engine rebuild time, his car dies there and then.

So before tech, you did a monkey shift, you took it you fooked up and you pay for a engine rebuild.

I don't see an issue.

yes it's pain but A: it covers buyers and sellers much better and does not stop you tracking/enjoying your car at all.

Henry-F

4,791 posts

275 months

Monday 26th March 2012
quotequote all
Wozy68 said:
The madness of the modern (tech) world.

You can't buy a Sports car with a warranty because it's been driven fast and hard as deigned to be.

You can't buy a new sports car and enjoy it to its maximum just in case you select the wrong gear at soemtime ..... maybe only once, because you will be unable to PX it when it comes to renewal.

Just what did we all do when we bought a new/used car in times gone by?

Oh yes, we just bought and enjoyed them, and I can't ever remember a time when I had sleepless nights worrying that the high performance car I'd just bought hadn't been used in a high performance way.
You can enjoy the car up to its maximum, you just need to learn to walk before you start running. Over revving a car engine has never been without catastrophic results even in the days before logging. Bent valves are bent valves regardless of what the computer says. What it would say is that there have probably been a number of folks in the past who have had their bacon saved when someone else picked up the bill for their crap driving. These days they are held accountable for their actions. Is that so wrong?

As has already been clearly stated on here no one is or has complained about cars being taken up to the rev limiter, even slightly beyond just to make sure everying is fair.

Henry smile

Wozy68

5,436 posts

200 months

Monday 26th March 2012
quotequote all
See where your coming from and understand that it is in general a good thing.

What worries me is that it seems that quite often (well at least on here) that the damn thing is giving readings that cannot be correct..... but are accepted correct by Porsche so invalidating warranties etc.

Or am I reading it wrong. Lets be honest it would'nt be the first time if I am.