GT4 strut top failure

GT4 strut top failure

Author
Discussion

edo

16,699 posts

266 months

Saturday 13th August 2016
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Interesting to see who ends up paying for that...

Slippydiff

14,851 posts

224 months

Sunday 14th August 2016
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Trev450 said:
I would imagine they would replace the complete inner wing which of course incorporates the strut tower.
^ This.

gtsralph

1,188 posts

145 months

Sunday 14th August 2016
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Further details in this rennlist thread

http://rennlist.com/forums/gt4/948382-strut-tower-...

bigmowley

Original Poster:

1,897 posts

177 months

Sunday 14th August 2016
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gtsralph said:
Further details in this rennlist thread

http://rennlist.com/forums/gt4/948382-strut-tower-...
Thanks for the link that is what I was hoping for. Clearly an issue for sustained track use.
memo to brain avoid the big kerbs idea

Porsche911R

21,146 posts

266 months

Monday 15th August 2016
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GT3 does it also on the road after hitting a curb !


v8ksn

4,711 posts

185 months

Monday 15th August 2016
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Porsche911R said:
GT3 does it also on the road after hitting a curb !

Is that a 991 GT3?

v8ksn

4,711 posts

185 months

Monday 15th August 2016
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gtsralph

1,188 posts

145 months

Monday 15th August 2016
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Curbs like these at Rockingham are best avoided....


Steve Rance

5,448 posts

232 months

Monday 15th August 2016
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A car designed for occasional track use should be easily able to handle rumble strips. I suspect that these failures were caused by substantial impacts.

ras62

1,090 posts

157 months

Monday 15th August 2016
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It's an issue that should not happen whatever the impact. I would expect wheels and suspension arms to bend or break but never the top mount. Very worrying from a longevity standpoint.

Steve Rance

5,448 posts

232 months

Monday 15th August 2016
quotequote all
Inclined to agree. I'd expect to see a wheel failure before a chasis failure. I've seen some very big accidents with 996 and 997 race cars but never seen the chasis break at a load point through an impact. Sometimes a wishbone can punch through a pick up point but if its a race car, the spherical joint normally collapses and takes energy from the impact first.

I drove for a racing car manufacturer at the start of my racing career, he was a brilliant designer and taught me a lot about chassis design and the theory behind it. The load point of the front suspension are 'the' critical points of the design. They transfer loads backwards into the space frame or monocoque where they would disperse with the minimum of flex or disortion. Obviously in these cases the load/shock has not been successfully transferred backwards into the chasis resulting in the failure of the load point.



Trev450

6,326 posts

173 months

Monday 15th August 2016
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This ^. In a previous life, I spent a good bit of time attempting to master the art of forest rallying in a MK11 Escort. I blew front struts, bent front struts, broke TCA's, etc, but never did I see this sort of failure on anything both at club and international level.

gbrown2014

220 posts

114 months

Monday 15th August 2016
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I heard the vehicle in question has been sent to Struggart for further analysis

AW111

9,674 posts

134 months

Monday 15th August 2016
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gbrown2014 said:
I heard the vehicle in question has been sent to Struggart for further analysis
Only one, or all three that have been pictured in this thread?

ETA d'oh missed the (miss-spelt) Strutgart!

Edited by AW111 on Monday 15th August 14:35

gtsralph

1,188 posts

145 months

Monday 15th August 2016
quotequote all
Steve Rance said:
A car designed for occasional track use should be easily able to handle rumble strips. I suspect that these failures were caused by substantial impacts.
Beyond the rumble strips... Is the elephant truck curb

SRT Hellcat

7,035 posts

218 months

Monday 15th August 2016
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I could be wrong but I am pretty certain that the strut top failures are because Porsche are using aluminium. Steel would not do this.

ooid

4,098 posts

101 months

Monday 15th August 2016
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According to the link above, the part labeled "11" is failing . Coming from a completely different design/engineer background, I would be curious to know why is that part failing from the racing/engineer experts? Geometry? material? both idea The white Cayman accident image also shows, there is a very strange bonding agent on the edge of the struts? (might be image accuracy or my lack of visual knowledge in the area)




Slippydiff

14,851 posts

224 months

Monday 15th August 2016
quotequote all
Trev450 said:
This ^. In a previous life, I spent a good bit of time attempting to master the art of forest rallying in a MK11 Escort. I blew front struts, bent front struts, broke TCA's, etc, but never did I see this sort of failure on anything both at club and international level.
As you'll know all too well, the rally prep boys don't p*ss about when they do shell prep, they build the cars properly to withstand massive jumps, ruts, potholes etc.

My old S5 Impreza WRC after an expensive altercation with a bridge parapet on Mull (the chassis leg was bent up nearly 3") :

|http://thumbsnap.com/1RBROmOq[/url]





Bulkhead split :




It cracked the alloy strut top mount, but it remained in it's correct position (ie didn't punch through the bonnet)

Strut seen here with new replacement top mount plate and strut casing.




Repairs underway :







Note the new turret top is formed from 10mm thick steel blank Tig'd in place ....





And the finished job :









There was some nice/clever fabbing work on those first Impreza WRC cars, but fast forward 5-6 years and the game had well and truly moved on :

















But a rally cars has to do things that racecars couldn't even contemplate, and everyone knows rallying sorts the men from the boys .... smile






Trev450

6,326 posts

173 months

Tuesday 16th August 2016
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Wow that was some impact. Superb rebuild job though.

stuttgartmetal

8,108 posts

217 months

Thursday 1st September 2016
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Porsche seem to be making road cars you can't track hard
When did this new turn around occur
Utter sh te that seems to be bad engineering, a shoddy design that they engineer out if you pay considerably more for a racing model
Awful
Used to be that you could track your road car.
It's how they sold them in the US

Edited by stuttgartmetal on Friday 2nd September 09:03