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View Full Version : My Excel based wheel and tyre calculator for VR-4's


bradc
12-08-2007, 10:45 AM
made it up today, let me know what you think

It is an excel file, but I had to zip it so I could upload it.
MPBVr4
12-08-2007, 06:31 PM
Useful reference Brad. Didn't realise that width ie 215/225/235, affected the rolling diameter.:thumbsup:
richy rich
12-08-2007, 06:42 PM
Good call brad.

So long and short of it is at 100kph the normal tyres used on the vr4 are very close to stoke.
bradc
12-08-2007, 08:48 PM
stoke?

Malc - yes they do because the aspect ratio, as in the 45 in 215/45/17 is not a measurement in size, but it is 215 x 0.45 = 96.75mm
zenetti
13-08-2007, 07:15 AM
Useful reference Brad. Didn't realise that width ie 215/225/235, affected the rolling diameter.:thumbsup:

it's a common misconception that the 2nd number is a profile and so is the same across all tyres. It is actually an aspect ratio or % so a 235 is actually taller and wider than a 215.

nice work on the spreadsheet though makes it nice and easy for everyone to see the differences. My VR runs on 215/40R18's which is actually the most correct upsize from a 205/55R16.
bradc
13-08-2007, 08:08 AM
Yeah 215/40/18 is the closest to the rolling radius of the stock size, but 225/40 or even 235/40 will fill out the guards a bit better
White Lightning
13-08-2007, 08:14 AM
Looks good Brad :thumbsup:

Although you can't spell circumference :p
bradc
13-08-2007, 08:50 AM
lol Wayne, I only typed it once, ctrl-c has the rest to blame! Stupid dyslexic keyboard!

Thanks for the rep points Richy!
aaron68nz
16-08-2007, 03:17 AM
If I wanted to keep my same prefacelift wheels would it be ok to simply upgrade to 215 or 225/50/16 at my next tyre change and not suffer any adverse handling problems?
bradc
16-08-2007, 04:10 AM
215mm wide tyres might be ok, but 225/50 is too wide for the stock rim and will cause the car to wallow about quite a bit. Aaron - have you seen the ozvr4.com forums?
zentac
16-08-2007, 12:04 PM
Just one comment, where you've got Radius (mm) thats not the Radius thats the Diameter (Radius = 2 x Diameter)

I did a similar one for the FTO a few years ago to work out the different speeds/sizes of drag tyres (or should that be tires as they were american)
bradc
16-08-2007, 08:48 PM
ohh yeah thanks Richard :)
aaron68nz
17-08-2007, 02:13 AM
No I hadn't known about ozvr4 before.