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Discussion Starter #1
I've got a new one! Had it a few times now but HPC technician cant reproduce cos it happens at quite high speeds.

(Obviously in the UK I only experience this on private roads, plus the derestricted roads in Germany)

Comes from the offside rear. Its a loud bang/clank. Seems to occur when the suspension reaches its limits of travel either under compression or as released from compression - happens just once (until the next time).

Sounds like a bush suddenly releasing or a retaining plate/bracket flexing.

I can now reproduce it at 75mph on a surface that has a very short piece of subsidence (after an overbridge).

Any ideas what I can tell the technician to look for?

Thanks
 

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wheel hitting arch, top mounts, spring clonking about/not seated properly, something physically loose maybe..
 

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Had the car in for a wheelalignment check?? if so maybe a loose screw on the suspensionarms....they need to be very tight to hold the arms....maybe a loose underbody panel......

Alex
 

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Discussion Starter #4
Technician looked for it while doing the 6k service but couldn't find anything.

Dont think its tyre on wheel arch - too solid a noise for that

Car has got to go back for something else (awaiting parts) so now I can reproduce it I'll try and demonstrate if I can find a similar bit of road.......
 

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Discussion Starter #6
No toolkit in the boot - When I was in Germany I did think it might be my helmet rolling round the boot so took everything out.....

It doesnt seem to affect handling but I'm concerned that if it goes bang too many times whatever it is will break loose.....
 

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Discussion Starter #8
Not really - it really does sound like a substantial metal plate popping back into shape - much heavier than a body panel pop - its just one bang on each occasion.
 

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Sounds like it needs to go on a ramp with the undertrays all off for a solid check to make sure nothing is worn or loose .Have you had a Y- pipe fitted ? if the exhaust is not hanging or fitted perfectly any banging or rubbing there will sound immense .
 

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I excellerated up a steep road where i live in 2nd by then doing around 4500-5000 revs when you heard a loud bang from the rear end. It was like a heavy hammer on something solid with no before or after noise and i pulled over but couldn't see anything. Took it easy for a bit but it has never happened again.
 

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Discussion Starter #11
I excellerated up a steep road where i live in 2nd by then doing around 4500-5000 revs when you heard a loud bang from the rear end. It was like a heavy hammer on something solid with no before or after noise and i pulled over but couldn't see anything. Took it easy for a bit but it has never happened again.
That sounds similar Could you notice which side it was on, or was it rear general?

Can you reproduce it?

No Y-pipe or other mods on my car.
 

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That sounds similar Could you notice which side it was on, or was it rear general?

Can you reproduce it?

No Y-pipe or other mods on my car.
It was bloody loud but short and i felt it came from the rear in general, tried to repeat scenario a few times on the way home with no success. Done around 500 miles since, cars done 2300 in all and is totally standard.
 

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I had this the day picked it up - drove home, not quick at all and then "bang" I thought I had broken it, it was not just loud you could actually feel the clonk of whatever it was popping/jumoing back into place.

I thought it may have been a gear that had been preselected and got stuck being let go. Reminded me of the SMG gear box in M3 when you changed gear at full throttle - but with even more slam.

Only done it once.

Kp
 

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I had this the day picked it up - drove home, not quick at all and then "bang" I thought I had broken it, it was not just loud you could actually feel the clonk of whatever it was popping/jumoing back into place.

I thought it may have been a gear that had been preselected and got stuck being let go. Reminded me of the SMG gear box in M3 when you changed gear at full throttle - but with even more slam.

Only done it once.

Kp
Sounds familar KP.

Ex M3 CSL owner and the sound you are describing sounds VERY similar to one my CSL used to produce if you changed at full throttle without lifting.

It was a very noticeable BANG from the rear, turns out it was the diff "catching" up and when i was "taught" how to use the CSL gearbox properly by Thorney Motorsport it never happened again.

Could the GTR be doing the same????
 

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I've got a new one! Had it a few times now but HPC technician cant reproduce cos it happens at quite high speeds.

(Obviously in the UK I only experience this on private roads, plus the derestricted roads in Germany)

Comes from the offside rear. Its a loud bang/clank. Seems to occur when the suspension reaches its limits of travel either under compression or as released from compression - happens just once (until the next time).

Sounds like a bush suddenly releasing or a retaining plate/bracket flexing.

I can now reproduce it at 75mph on a surface that has a very short piece of subsidence (after an overbridge).

Any ideas what I can tell the technician to look for?

Thanks
I think i've got the same thing since a track day but from the nearside rear. each time i corner hard and compress the suspension it goes "clank". did you ever find out what was causing it?
 
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