McCarthy

Had a quick search to see if i could find much on this. Its on an FC.

I'm looking a a sprint style set up, for the car. its now much wider than stock. front and rear. I have 18x10 on the rear and these wheels with ET15 also fit corretly on the front.

Would 18x10 on the front wreck handling, bearing in mind i have adjustable coilovers, camber and caster, adj roll bar links too. Surely i could set the suspension to suite the wider front wheels?

driftfcbuckey

iTrader: (8)

if they fit in the wheel wells without hitting your frame rails at lock in both directions, and dont rub the coil overs you'll be fine.

the wider the front tires, the more grip you'll have up front with good tires. although with a 10j, and stock fenders depending on ride height you'll be limited to maybe a 235/40 max. maybe a 245.

BFGRX7

iTrader: (2)

McCarthy, funny, I'm asking a question on why we "shouldn't" go larger than 17x9, 255. So many have made this comment w/o providing clear proof as to why we shouldn't do it.

Red, there have been quite a few that feel otherwise with weight being the biggest issue. It my not be an issue for drifting but you not utilize the same shock motions as on a track, say, in a time attack. I'm not saying you're right or wrong. It would just be nice to get some scientific responses.

TrentO

Height is the main issue that comes to mind. With a taller rim, unless the tire is exceptionally low profile, the wheel/tire package will become taller. The taller the tire, the less gear ratio you have and the higher your car sits off the ground.
Another factor is how much you can lower the car before the suspension geometry gets quite bad. On the FC, as the tires get taller, the you have to drop the car more, which lowers the roll center quite a bit.
The more serious issue is frame rail contact.
On my FC, with 17x9.5 Enkei rims and a 260/640/17 slick up front which is a 25.2" tall tire. with the car lowered a great deal I have about 2.5" of clearance to the upper frame rail. I've upped my spring rates to keep the tires off the rail, but there is still a fair bit of rubber on there from contact over berms, etc.

With the wider tires up front you also get the issue of a positive scrub radius. ( http://en.wikipedia.org/wiki/Scrub_radius) With my 260 slicks, my hands get hammered every time I take a berm. By the end of an hour long race I have blisters in my palms from the "feedback" I get through the steering wheel.

In the rear I run an Enkei 18x10.5 and 280/650/18 slicks. They are roughly 25.6" tall. I needed to go widebody to fit the slicks in the rear and they do get close to the fender well when hitting berms, etc.
For an FC, I wouldn't go any taller. For an FD, the 18" 280's all around seems to work quite well, but you again face the issues of frame rail contact with the taller tire.

If possible, I'd suggest staying smaller diameter and running 16" rims with Hoosier or Goodyear Radial slicks. (I like the 23.5X12.0R-16 Hoosier Radial) A smaller diameter will let the car sit lower, have more travel and have more effective gearing. If I were to start over today this is likely the route I would take. Since I've gone with a big brake assembly up front, I cannot fit the 16" wheels


-Trent

McCarthy

Cheers people,

There is no issuse with clearence with a modified inner wheel arch linner. Only small adjustments to the stock one. This is on a 265/35/18. Sorry should have said Slick / race radial are not allowed.

The car has been dropped considerably but within the tolerances of the damper to not to bottom out or exceed travel on the strock of the damper. Also then using an extended Toe link at the end of the steering arms so the rods sit flat.

scot62

see that you're doing the sprint, why not go for 8"x 15" all round, as mine''s revolution RFX trim with A70A kumho soft tyre.
very good combine.
is that's for the PP car? , better with a 15" to keep the engine on the boil and with 18"will bog it down too much..

turbotoaster

im gonna be running 18x10et35 with 285/30s on the front and 18x12et20 335/30 on the rear and front what i can woprk out it should be fine.

goodfella on here runs 18x10 with 285s all around on stock arches and likes it.

with you being 20b isnt it worth getting as much tyre as you can on the car, especially for hillclimbing