Porsche 911UK Forum

Welcome to the @Porsche911UK website. Register a free account today to become a member! Sign up is quick and easy, then you can view, participate in topics and posts across the site that covers all things Porsche.

Already registered and looking to recovery your account, select 'login in' and then the 'forget your password' option.

BBS wheels for 993RS

Sorry to spoil the speculation of all that extra effective power, but the lighter your rims are will not make that much difference I'm afraid unless you can make your tyres lighter as well...

OK it will help a bit in the rotational inertia bit, but the further away the weight is from the centre, the more effect it will have - so all you will change is the rotational inertia of the wheel itself

Personally I doubt that you would notice the difference in rotational inertia as you also seem to have overlooked the fact that the largest resistance to the wheel spinning is tyre grip - not the weight of the wheel...



Unless you're thinking of taking up ice-racing without studs of course! :wink:


Migration info. Legacy thread was 109447
 
I'm of an engineering persuasion but i left these kind of calculations behind long ago. I can understand the calculations regarding the wheel mass alone but both the std. and lighter wheels are subjected to the gross weight of the car suspended from the wheel centres. As such i'd imagine that decreasing the rotating mass will certainly have a noticable effect - just how noticible will it be.

I would still reccomend lighter wheels but reckon personally that the carbon rims are perhaps a weight saving / cost too far




Migration info. Legacy thread was 109448
 
Interesting comment for someone in PH, who obviously knows what he's talking about:

"Ive been running these on my Track/Road going GT3 RS for a year now . I originally had the 5 spoke ( mule ) wheels from Dymag, they then sent a set of 9 spokes The wheels are so light the rear wheels spin in the 1st 3 gears Dymag wanted me to try and break them ( serious - they asked me to do this )! I tried ... using all the kerbs at every cicuit I went to and used them in the Porsche Speed Championship last year The mules went back and I bought a set of 9 spokes as they looked better and I reckon 9 points of contact are better than 5 ! apparently the middle section have been beefed up a lot more When I 1st ran the car going into Paddock Hill Bend at Brands It was scary as with doing 180 + on the Autobahn but Ive done over 10,000miles now and I feel they are safe. The Koniggsegg thing has those wheels as standard Dont forget all the GP motorbike racers use them as standard ! "

That's interesting, so at least the wheels can take the punishments.


Migration info. Legacy thread was 109451
 
You are right in saying that a lot of GP bikes use carbon wheels, however generally they are for 1 time use, they get thrown after a race, not a problem with a GP teams budget. I have worked with carbon fibre for a long time and there is no way to carry out non-destructive testing on carbon fibre, unlike aluminium, magnesium or other metals. Xrays or dye penetrant methods for cracks on carbon fibre do not work. A guy died in the Isle of Man about 15 years ago flat out when his carbon front wheel let go without warning. If you kerb a carbon wheel parking it, you will have absolutely no idea whether it will later fail or not, there may well be no damage visible. I work in the aircraft industry and if we even suspect there is damage on a carbon item it gets binned as there is no way to check it. The weight saving is phenomenal, but unless you are only going to use them on supersmooth racetracks, imho give them a miss. The BBS and Cargraphic items are far more suitable as an all round wheel, still give a good weight saving, you don't get too many sleepless nights if you do kerb them(wallet permitting) and if looked after will last the life of your porker.(And they look the mutts nuts)



Max


Migration info. Legacy thread was 109460
 
Just out of interest, what will happen when the carbon wheel fails? Would it shatter into small pieces in a spectacular fashion? or will it suddenly have a large crack appearing allowing sudden total air leak?

Migration info. Legacy thread was 109461
 
Total catastrophic failure, no warning. Carbon fibre doesn't really crack as with a normal material because of the cross weave. You could drive one for years and never experience a problem, but one speed bump or pothole could be one too many., you will never know. I have looked at Dymags wheels as soon as they came out in the states, the weight saving is very tempting especially on an RS or GT, I do love their wheels and have paid a small fortune for them on bikes over the years( never carbon though) but I would always recommend your other two choices.



Max


Migration info. Legacy thread was 109477
 
That sounds rather scary! On a race car may be, as part of the risks on track, but just can't bear the thought of a sudden failure on a motorway!




Migration info. Legacy thread was 109483
 
Mick,

Let's stick to the CG's or the BBS' for our 'bulk' buy - my wallet is getting hammered at the moment :wink:

PP :p

Migration info. Legacy thread was 109945
 
BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....

my name is Dan.....

my name is Dan.....

my name is Dan.....

my name is Dan.....

my name is Dan.....

my name is Dan.....


Migration info. Legacy thread was 109972
 
Previous poster said:
Quote: Originally posted by Butzi on 16 January 2007

BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....BBS ..CG's....
scratchchin.gif

....

my name is Dan.....

my name is Dan.....

my name is Dan.....

my name is Dan.....

my name is Dan.....

my name is Dan.....
Harsh.... :eek:











but true.... :wink:


Migration info. Legacy thread was 109974
 
What's it doing painted in FERRARI yellow!!!




Migration info. Legacy thread was 109997
 
I saw that, and spoke to Paul in GTClassic who's selling it. It's not a genuine Porsche spoiler (note it says Clubsport Style spoiler), just a replica one. God knows why it's in Ferrari yellow! Paul's ordered the last set of genuine spoiler set of the current batch for me anyway. Wallet burning!

Migration info. Legacy thread was 110003
 
There was a Ferrari yellow '64RS at GT Classics so i presume the spoiler came off that.

Mick - is the clubbie spoiler you've ordered like that one or does it look like the GT2 spoiler (RSR?). Also - are you sticking in a matter cage?


Migration info. Legacy thread was 110016
 
The Clubbie spoiler looks the same as the one on for sale, and I thought they're the same as the RSR/GT2 spoiler?

No, no roll cage I'm afraid.

1) it's heavy, @50kg I think

2) after all the talk of wt reduction, I'm putting a pair of rear seat belts in for the occasional scholl runs and LeMans trip! :oops:


Migration info. Legacy thread was 110027
 

New Threads

Forum statistics

Threads
124,354
Messages
1,439,451
Members
48,709
Latest member
Silage
Back
Top