thanks guys,
i have done a few track days on my 18's with semislicks on.
i have just have just sold the 18's and now consiering semi slicks for the 16"s for track events.
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thanks guys,
i have done a few track days on my 18's with semislicks on.
i have just have just sold the 18's and now consiering semi slicks for the 16"s for track events.
This little bit of reading sheds some light on the subject:
http://www.wam.umd.edu/~greghess/sizematters.pdf
You have to also consider the unsprung weight for your vehicle, if the 18"s weigh heaps more than your 16"s then they will be heaps slower. The gearing of your car is also affected by the diameter which is a combination of the overall wheel/tyre combination.
Interestingly in this article they say that the 15"s are ultimately faster but they were able to get more consistent times from the 16"s.
Now this is for a Mk3 vehicle which is different to a Mk4 but the same principles should apply.
Cheers,
Nath
Interesting article.
From a pure physics point of view, I expected that result, that the 15's were the "fastest". The maths could have told you that.
What I found very interesting was: the sidewalls.
For the click lazy, they had 40 (profiles I'm talking here) on the 17's, 45's on the 16's and 50's on the 15's. Funnily enough, they complained about the lack of fine control and 'twitchyness' - "hop and roll" to quote them directly.
Clearly it's because they are running a 50 profile rubber. I would have liked to have seen the different a profile used. also note that the rims were different width's, but the 205 size was used on all the tyres, and as you can see, a d205-50-15 tends to bulge quite a bit on a 6.5" rim!
I would have like to have seen the dfference between 205-50-15 and say 195-40-15 (for example), basically something with alot less sidewall. This would reduced sidewall flex giving it better control and also slightly reduce the rolling diameter, for again better accel.
I think it was an unfair comparison, to compare te "handling" caracteristics of the wheel tyre/combo when the wheels weren't in proportion to each other - ie, just from the photos you can see that the 15's are bulging, and 16's are perfectly fitted and the 17's have a gentle stretch about them - all the sidewalls were different meaning they would have different handling characteristics, even if they were the same size rims!
Anyways. It's late and I'm starting to rant.
Hope you got the general gist of what I've been trying to say.
Frankly, 16's with 205-40/45 semi's or high performance tyres, will be the best combo IMO.
If I was to track my car I would be putting my stockies VR BBS wheels on it but with some really good rubber!
fixed :DQuote:
Originally Posted by DubSteve
You know you want to... I want to hear that V6 down the straight!!! j:
You'll have to take me for a spin sometime.
Interesting article but they they tested road tyres for track use.
Motor sport tyres are very different to street tyres.
Pete
Exactly right, Pete.Quote:
Originally Posted by Peter Jones
Motorsport tyres have a completely different construction and are not designed for a compromise between road noise/comfort AND handling. A taller motorsport tyre will be designed with a stiffer sidewall etc to combat the fact that they are taller.
An interesting article, but road tyres are road tyres. Unless you just want to have a bit of fun, that's all they are.