View Single Post
      01-16-2013, 02:37 PM   #20
BMWWW
Private First Class
 
BMWWW's Avatar
 
Drives: BMW
Join Date: Dec 2006
Location: Toronto

Posts: 173
iTrader: (2)

Quote:
Originally Posted by CJ421 View Post
The car will turn in easier with a narrower tire up front. The 'feel' of the car is attributable to the compound/structure/tread pattern of the tire; the width (total amount of rubber) comes into play when you're using a significant amount of the available grip. There's not much of a difference in total grip between the widths you're talking about.

Personally I would keep the staggered setup and get non-directional tires so you can swap side-to-side. There's less than a 10% difference between a 235mm and a 255mm width tire. You can run a 235 on an 8" OEM wheel and a 255 on an 8.5" just fine (the latter is factory spec). For the street I run 235/265 on OEM 19" rims.
Should you go square with OEM rims, you may want to invest in some spacers to even out the appearance of using OEM rear wheels up front; it will look a little off.

RFT's work well with the standard suspension. Going to a non-RFT will improve grip (assuming the right tire) but take away some illusion of turn-in responsiveness provided by the rock-hard RFT sidewall (RFT sidewalls have very little flex so it adds to total spring rate).

Edit: Invest in some camber plates if you really want to improve the handling of the car; they aren't that expensive and running -1.5 deg. up front will noticeably improve cornering performance.
+1. There is a lot of tire-misunderstanding on this forum.
Increasing camber isn't going to increase steering response.

To be honest, most improvements that people report are due solely to the change in tire compound more than anything else. In fact, increasing your tread width actually alters your tire footprint, which can negatively affect braking/take-off a bit if you are able to isolate just this one variable--but thankfully, the change in tire compound more than compensates for this postively.

To increase grip/performance:
- better tire compound (improves every aspect of a car--actually the single most 'bang-for-buck' you can spend on a car sans ecu-tuning)
- increasing tire width will increase the ceiling for grip at the limit
- more camber = a higher ceiling at the limit
- steering response has a lot to do with weight at each corner, as well as the construction of the tire--mostly the stiffness of the sidewall. (narrower sidewalls or higher tire pressure will help improve steering response)

There's a lot more to it, but that's a very basic overview. Tires are a black-art, and there's no better example of this in action than at an autox. Where great cars with lousy tires/drivers can be beaten by $2,000 shitboxes on r-compounds + great driver.

__________________

When called an idiot sometimes is better to be quiet than to open mouth and remove all doubt.
Man who walk through airport turnstile sideways going to Bangkok.
--Confucius

BMWWW is offline  
0
Reply With Quote