Might be stating the obvious (to some) but something I didn't realise until I started trying to pick tyres for aftermarket wheels is that the profile figure - e.g. 40 - is 40% of the width.
So for a 255/40/17 tyre - diameter is 255mm, profile / side wall is 102mm (40% of 255), and radius is 17inches.
Learning this made it all make a lot more sense to me. I also have this graphic to refer to. Can't recall where I found it but it's now saved on my desktop!
I also wanted a chunky looking tyre with a solid side wall and after going 245(F) / 265 (R) , have since switched back to 235(F) / 255 (R) as I found the handling was noticeable more boggy and I use the car for fast road and track use. For ref, these tyres are on 18" BBS LMs.
By
sumshiftyguy ·
well im well chuffed with my dyno results, i came fourth of the day, getting beat (just) by an evo 6, an R32 GTR, and steve's 300zx
my mods of the day are
jwt chip
stainless scorpion exhaust with de-catt
blitz air filter
lightened and balanced flywheel with RPS clutch
im runing standard boost
not sure how to read graphs but im happy with the figures that came out, what does everyone think