non-ideal wheel width
 

track use/tt. 2300lb/250whp. 195/55/15 ventus td.
8" is ideal but I don't have any.
I have 7"s and 9"s. am I still losing the same amount of performance with this tire on a 9" wheel compared to a 7".

9" is too wide for that tire.

You should just run a 225 maxxis or nt01 on the 9s. The 195 TD is a really neat tire that has a lot of potential for E and F, but I don't think it's the right tire for your car.

I changed from 205 on a 7" to a 225 on a 9" and would NEVER voluntarily go back. I did once not believing the step up in performance and the difference was massive.

205's on a 7" after the 225 on a 9" was like driving on ice. I promptly sold the wheels and used tyres AND a set of new 205's on wheels the next day.

I then waited 10+ months for 9" wheels to come back in to stock for wet/spare set.

While this was frustrating, I never once regretted it, the difference was that big. I shudder to think what 195 feels like!!!

Safety, confidence AND lap times will massively improve IMO.

It needs an 8" wheel. Sell 7's, buy 8's. If not willing to do that, put them on the 7's, but I don't think it will be great. I would not try to fit in on a 9".

-Ryan

^^^

Sums it up...