Running different sidewall heights

[Kenshin X]

Hey guys after for some advice.

i just got a set of rims (16x7) for track days. they are only bigger in width compared to my stockies (16x6). i'm looking for semis to wrap them around with.

After my tyreman informing me that Federal don't ship the RS-Rs to australia anymore i was looking for other alternatives. Now i've run into another problem that other companies don't make the 205/50r16 size or they are specail orders that i will pay an arm and a leg for. I was recommended by a forums member to try the R888s and the most suitable size thats also the cheapest is 205/55r16. The R888s do come in 195/50r16s which was a size recommended to me by another forums member but i'd be paying almost 200 bucks extra for these!

now the question i wanna ask is running a 205/55r16 profile would cause any problems (ie scrubbing and such)? My car has been raised but since i'm aware that there will be an extra 1cm diameter on the wheels, the scrubbing problem might still exist even though i raised my car 1 to 1.5cm.

i'm NOT looking into rolling my guards (offset of new wheels are +33 compared to the stock +45). i rather adjust the height of my sussy. however i have maxed out how high i can raise them.

what are also the pros and cons of running a larger sidewall? i will NOT be spinning these wheels on the public road. these are for track only.

thanks guys :)

[Buff Hamster]

Assuming the same tyre for both, the larger the sidewall the more tyre bend there is around corners but better straight line acceleration. This is "theoretic" though but you probably won't notice it much or at all.

[Kenshin X]

Assuming the same tyre for both, the larger the sidewall the more tyre bend there is around corners but better straight line acceleration. This is "theoretic" though but you probably won't notice it much or at all.

yeah i'm running a lower psi on the track anyways so maybe i wont notice a difference. but then again the sidewall on the semis would be less flexible than street tyres so might cancel out the extra flex with larger sidewall. i'm running camber on the fronts too :)

any other opinions guys/girls?

[Hiro]

the larger the sidewall ...better straight line acceleration

It's the reverse, actually. Larger sidewall means bigger rolling diameter which means taller gearing which means slower acceleration (but higher top speed). Smaller sidewall will give you better acceleration but lower top speed.

We're talking fractions here though, you'd get a much bigger effect on acceleration/top speed by changing diff/final-drive ratios.