Will somebody please give me a definitive solution?
Discussion
I am calling on the collective wisdom of any and all members of the Porsche firmament to help me with a continuing problem which, if not resolved soon, will undoubtedly see me, finally, committed.
The tortuous issue at hand concerns my beloved beetle, which is to say a 993tt in a high state of tune.
It has had literally tens of thousands sunk into it and has been to heaven, hell & limbo in that time.
Power is roughly circa mid-ish 500s and torque in the high 5s, so I'm reliably informed.
The engine has been stripped and rebuilt on a few occasions for reasons of preserving longevity and benefits from all the accepted bits and bobs, including cams, rods and so on.
After much f@cking around in the UK, the ecu has been temporarily fettled over the phone line by some German who will hopefully be getting the crated engine for a fully honed session in the not too distant and a good run last night indicated that as a stop-gap map it felt stronger than ever, suffering zero overboost (hurrah) and the new, aluminium boost pipes seemed to help force everything along without spillage.
However, vibrations, prdominantly via the helm, i.e. steering wheel, continue to bedevil my appreciation of what many others seem to think some kind of nirvanic proposition.
This has been a constant irritant over the years, even in the days of minimal viagra.
Before you ask - everything is new, refreshed, unworn, unperished or resolutely not otherwise out of synch with anything else - subframe this, driveshaft that and submount the other.
After 7 years I'm still not sure what I'm supposed to be comparing the sensation to: even with the newly fitted cruise control, merely hanging on to that writhing, thrumming circle can be a downright workout which on any kind of journey is borderline injurous.
But it's the nature of this vibration: it's something which seems to come and go with varying loads during both acceleration and deceleration - the smoother the road - the worse it tends to feel.
It's also noticable through high speed m-way sweepers but is often as bad during left and right negotiations.
The main speculation to-date surrounds the front diff and the possible inability of the v/c to handle the transferring slugs of grunt: I dunno, what did Ruf do on their version?
Please, can somebody give me some serious input on this: I can't find anybody in the UK with a pigging clue about this, just lots of sharp breath intake and speculation.
At the end of the day, is the car just like this? I cannot remember MOD's car at the last VMax day and anyway, that surface is meaningless.
Is the solution simply an abandonment of the 4wd? Frankly, that wouldn't be an option.
And if anyone suggests a 996tt, don't: I will implode.
In fact, I'd actually appreciate a ruddy long chat about this with anybody who feels qualified to proffer the necessaries so if you could mail me a phone number or something I promise not to lurch into a tirade against socialism.
The most frustrated beetle pilot in Christendom, DeR.
The tortuous issue at hand concerns my beloved beetle, which is to say a 993tt in a high state of tune.
It has had literally tens of thousands sunk into it and has been to heaven, hell & limbo in that time.
Power is roughly circa mid-ish 500s and torque in the high 5s, so I'm reliably informed.
The engine has been stripped and rebuilt on a few occasions for reasons of preserving longevity and benefits from all the accepted bits and bobs, including cams, rods and so on.
After much f@cking around in the UK, the ecu has been temporarily fettled over the phone line by some German who will hopefully be getting the crated engine for a fully honed session in the not too distant and a good run last night indicated that as a stop-gap map it felt stronger than ever, suffering zero overboost (hurrah) and the new, aluminium boost pipes seemed to help force everything along without spillage.
However, vibrations, prdominantly via the helm, i.e. steering wheel, continue to bedevil my appreciation of what many others seem to think some kind of nirvanic proposition.
This has been a constant irritant over the years, even in the days of minimal viagra.
Before you ask - everything is new, refreshed, unworn, unperished or resolutely not otherwise out of synch with anything else - subframe this, driveshaft that and submount the other.
After 7 years I'm still not sure what I'm supposed to be comparing the sensation to: even with the newly fitted cruise control, merely hanging on to that writhing, thrumming circle can be a downright workout which on any kind of journey is borderline injurous.
But it's the nature of this vibration: it's something which seems to come and go with varying loads during both acceleration and deceleration - the smoother the road - the worse it tends to feel.
It's also noticable through high speed m-way sweepers but is often as bad during left and right negotiations.
The main speculation to-date surrounds the front diff and the possible inability of the v/c to handle the transferring slugs of grunt: I dunno, what did Ruf do on their version?
Please, can somebody give me some serious input on this: I can't find anybody in the UK with a pigging clue about this, just lots of sharp breath intake and speculation.
At the end of the day, is the car just like this? I cannot remember MOD's car at the last VMax day and anyway, that surface is meaningless.
Is the solution simply an abandonment of the 4wd? Frankly, that wouldn't be an option.
And if anyone suggests a 996tt, don't: I will implode.
In fact, I'd actually appreciate a ruddy long chat about this with anybody who feels qualified to proffer the necessaries so if you could mail me a phone number or something I promise not to lurch into a tirade against socialism.
The most frustrated beetle pilot in Christendom, DeR.
Knowing the people u ve been using i hesitate to respond since they re pretty clued up...............while i appreciate u want it to work in 4wd have u disconnected and tried running it without to see the effect ? 959 only couple of race cars, similarly 964rsr tiny number trying to think of Porsche racers [taking this sort of bhp ] through 4 wd ???
I'm not sure what year your car is but there was a front driveshaft update (an insert between the front diff and cv joints) that is said to improve the alignment between these items in order to cure vibration. This can be checked for runout using a dial gauge. I'll try and find the page 
Failing that, what about the torque tube? Although I would have guessed that this would cause a vibration all over the car.
Failing that, what about the torque tube? Although I would have guessed that this would cause a vibration all over the car.
Herr Vic,
Your input is most appreciated: no, Sir, I have not but do you believe it will remedy the matter? There is another 993tt in the UK running even greater power but the chap likes his anonymity - he is 'known' by the cognoscenti (particularly over on Rennlist) and has indeed ditched the front coupling.
MOD500 tells me it's, er, vivid!
Having said that, obviously your eminent self, JC and the other Lords of The Sacred Order run GT2s with no paucity of ballisticism but (a) you can, so I've heard, actually drive but (b) most of your fun is at Spa and other high fallutin' gaffs?
James, I'm not sure how to take that query! Er, no, mate, it's straight! (Cheeky sod!
)
Alan, thanks very much - I'd be really graetful for any light you can shed. The torque tube is fine, btw.
My gut instinct is that it HAS to be something to do with the v/c and torque transfer loadings.
I'm more than happy to have someone definitively identify the issue then JC can knock me something up in his shed, I hear he has a lathe or something? [
]
Your input is most appreciated: no, Sir, I have not but do you believe it will remedy the matter? There is another 993tt in the UK running even greater power but the chap likes his anonymity - he is 'known' by the cognoscenti (particularly over on Rennlist) and has indeed ditched the front coupling.
MOD500 tells me it's, er, vivid!
Having said that, obviously your eminent self, JC and the other Lords of The Sacred Order run GT2s with no paucity of ballisticism but (a) you can, so I've heard, actually drive but (b) most of your fun is at Spa and other high fallutin' gaffs?
James, I'm not sure how to take that query! Er, no, mate, it's straight! (Cheeky sod!
) Alan, thanks very much - I'd be really graetful for any light you can shed. The torque tube is fine, btw.
My gut instinct is that it HAS to be something to do with the v/c and torque transfer loadings.
I'm more than happy to have someone definitively identify the issue then JC can knock me something up in his shed, I hear he has a lathe or something? [
]BliarOut said:
OK, lets think logically.
Did the car have this vibration when you got it?
Did the car have this vibration when you got it?
I can't honestly remember but in 2001 it received it's first round of fettlage - a supposed CarGraphic '493' package (which turned out to be about 455-460) - and yes, back then, I recall the effect.
BlairOut said:
Have you driven another one to see if it feels the same?
Only MOD's car: it has similar oomph but I've not driven it on smooth road surfaces. I don't think Marty has a similar issue but he is from Yorkshire.
BlairOut said:
Has the vibration increased along with the power?
I'd have to say no.
BlairOut said:
Has the diff been stripped out and had all the clearances and the balance checked?
I believe so but you never know if a certain 'critical' bit was overlooked, hmmm...
It needs AcePart Al to come along with some joyous panacea in the form of a beefed up linkage somewhere - come on, Al!
ultra violent said:
No offence intended re. straightness. I know of some one who had similar, if not exactly the same issue, and it wasn't until it went on a jig that they found it had a small bump at some stage in its life.
Wheel barings?
All wheels have correct offset?
Wheel barings?
All wheels have correct offset?
James, you're ok, sire! But you never know, I guess: again, an outfit of reasonable repute have actually said they've done this (question having being asked by myself) but as with all these things, how would I know what actually goes down, if anything and then how thorough?
Certainly, various omisions and half cocked jobs over time have sullied my faith in, well, most sources of 911 Graildom...
Bearings? Again, I doubt it but I'll ask the q.
Re offsets, etc my current techie is nothing if not fastidious on suspension setups and alignments - I was toying with the idea of a new set of some kind of blingy split rim black and/or silver BBS style wheels anyway but the nature of the beast invariably = drivetrain corruption...somehwere, somehow.
Oh God!
Deristrictor
I had exactly the same prob with my 3.2 Carrera - vibration at speed - but sometrimes not and I could feel it through the floor also - and the vibration trigger speeds varied - so
1) Be absolutely sure no stick on weight have come off - which unless you record the posns after new balancing - you won't detetmine due to the dirt.
2)Check wheels for roundness - easy when on balancing machine
3)Run your hand around the inner edge of the front tyre for ripples. The neg camber can break up the casing - did on mine without doubt
4)If you have the red painted counterweighted wheel stud, I assume you are mounting the wheels with the locking nut on the red stud - as per the manual
5)Ensure the front wheels have he identical part code stamped inside
6)If the car is left standing even a minor flat spot causes vibrations.
7) Ever locked the fronts with the ABS off - same flatspot issue?
8) Tyre directions all pointing the same way?
If all this fails - borrow a fellow club menmbers wheels that don't cause vibes. If the problem remains at least you know it's not the wheels........
I had exactly the same prob with my 3.2 Carrera - vibration at speed - but sometrimes not and I could feel it through the floor also - and the vibration trigger speeds varied - so
1) Be absolutely sure no stick on weight have come off - which unless you record the posns after new balancing - you won't detetmine due to the dirt.
2)Check wheels for roundness - easy when on balancing machine
3)Run your hand around the inner edge of the front tyre for ripples. The neg camber can break up the casing - did on mine without doubt
4)If you have the red painted counterweighted wheel stud, I assume you are mounting the wheels with the locking nut on the red stud - as per the manual
5)Ensure the front wheels have he identical part code stamped inside
6)If the car is left standing even a minor flat spot causes vibrations.
7) Ever locked the fronts with the ABS off - same flatspot issue?
8) Tyre directions all pointing the same way?
If all this fails - borrow a fellow club menmbers wheels that don't cause vibes. If the problem remains at least you know it's not the wheels........
Thanks, Mike, all points duly noted and will be treble and quadruply checked.
Thing is, as I keep saying, it seems so utterly related to some kind of (I can't believe I'm about to say this) 'shaft action,' i.e. you boot it and under certain loads there's this vibrational protest, not absolutrely wretched and to the uninitiated it probably wouldn't register relative to the ferocity of the thrust on tap but it can almost ebb away as you power on and the 'load rate' or torque build (acceptable description?) simmers down...
On a B or badly surfaced A road or m-way, you'd maybe not sense it because of the older 911's basic reversion to manic, highly damped, handling type but when you're on the billiardways it is most appreciable.
DeR.
Thing is, as I keep saying, it seems so utterly related to some kind of (I can't believe I'm about to say this) 'shaft action,' i.e. you boot it and under certain loads there's this vibrational protest, not absolutrely wretched and to the uninitiated it probably wouldn't register relative to the ferocity of the thrust on tap but it can almost ebb away as you power on and the 'load rate' or torque build (acceptable description?) simmers down...
On a B or badly surfaced A road or m-way, you'd maybe not sense it because of the older 911's basic reversion to manic, highly damped, handling type but when you're on the billiardways it is most appreciable.
DeR.
Suggestion was to try and isolate vibes to specific area or if not at least elliminate some others for starters...............only difference overall between urs and the dreaded 500bhp plus loony machines is the 4wd , the guts of ur engine pretty similar to my own [now sadly ex] twin spark , wiv rods and sexy bits etc............still thinking , i am old ......
In return, can you tell me about your over boosting issues! Was it only in higher gears (5th/6th) that it's over boosting? Do you know what levels it's hitting?
Here goes...
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[/URL] Edited by aceparts_com on Saturday 19th August 12:15
Edited by aceparts_com on Saturday 19th August 12:16
Alan, what a star! 
Just spoke to Techie No.1 who has already performed the centring procedure via the caps and confirmed (for James!) that the chassis is 100% straight [phew!]
There is a tiny flat spot on one of the rear rollers but nothing abnormal given their width and the poundage these cars take. He didn't think this was a contributory factor.
However, the front arms and serially perishing rubber mounts: these were changed a while back and now I think about it, I do recall enjoying a relatively vibe free epoch.
The rubber compound is, unfortunately, made by a company called Flora so nylon replacements may seem as the wet nosed fox, Foxy McCunning.
I hope that these, along with a set of new blingers might ameliorate the consternation.
So it's all 'true,' very what Lord VC has intimated therefore, a bit by bit elimation process requiring patience and masochism in equal, substantial measure!
Just spoke to Techie No.1 who has already performed the centring procedure via the caps and confirmed (for James!) that the chassis is 100% straight [phew!]
There is a tiny flat spot on one of the rear rollers but nothing abnormal given their width and the poundage these cars take. He didn't think this was a contributory factor.
However, the front arms and serially perishing rubber mounts: these were changed a while back and now I think about it, I do recall enjoying a relatively vibe free epoch.
The rubber compound is, unfortunately, made by a company called Flora so nylon replacements may seem as the wet nosed fox, Foxy McCunning.
I hope that these, along with a set of new blingers might ameliorate the consternation.
So it's all 'true,' very what Lord VC has intimated therefore, a bit by bit elimation process requiring patience and masochism in equal, substantial measure!
clubsport said:
DeR, I know you have had this problem for a while.....did you not disconnect said coupling and run in correct 911 2wd form for a while....or did I just imagine that?
Yes, Paul, you imagined it, conceivably whilst snorting something in celebration of the frankly immoral size of your last bonus.
Ho-ho.
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