Fg Offsets And Tyre Questions

[fehlbie]

Has anyone used the KPM control arms to allow the fitment of 11 inch wheels on a sedan?

I would like to run a 305 wide tyre as a minimum under the rear of my FG, which is standard height. (more like a 335 wide on a 19 inch wheel.)

[Bulletime]

bullet, people run wider wheels to increase grip by increasing the track of their wheels. combined with the right tyre size / rubber this will also add to more grip

http://www.amgaustralia.com/technical/wheels/wheel-offest-pcd

going too wide and stretching tyres affects grip negatively as it can make the tyre contact patch narrower. also because there is no sidewall to soften the impact on potholes/bumps, the wheel acts like a shock absorber as the force transfers to the wheel first before the shock which can buckle the wheel

Thanks mate didn't know about the contact patch being narrower on stretched tyres... my next question then it what constitutes an overly stretched tyre? 255 on an 8" ? 255 on 9.5/10"? 245 on 9.5"? I also can't work out what size or offset to go, I know I'll be wanting 275 on the rear and 245 on the front and assuming 8-8.5" front and 9-9.5" rear, obviously depends on diameter and sidewall.. I'm planning 18"s and want good tread contact more than a certain look.

Thanks for the linky too.

[fehlbie]

275mm is equivalent to 10.8 inches. Actual width of a rim advertised at 9.5 inches is actually 10.5 inches wide inside edge of lip to inside edge of lip. So a 275mm tyre fits perfectly on a 9.5 inch rim.

A 245mm tyre is 9.6 inches wide.

Hope that helps.

[vxr50t]

For rears you really can't beat 9.5 +30 as it sits dead flush with the guard without rolling and plenty of inner clearance. You could run fat rear tyres with that and not worry if the tyre has a bigger sidewall than rated as some are known to be bigger.

For front I'd go 9 +25 as that would be within a few mm of the guard and clear the inside suspension fine. Also no problem going full lock and no rubbing of the plastic inner guard.

An example of a stretched tyre would be a 245/35 on a 9.5 rim or anything less than that as a 9.5 should have a 265 or 275. Sure a 235 will fit but stretching reduces the effectiveness of the sidewall which is meant to cushion bumps on the road.

Most tyre calculators / tyre manufacturer websites include recommend tyre widths in their size charts which should help you work out if it's going to be stretched

Sent from my GT-I9300 using Motorculture mobile app

Edited 22/05/13 12:17 PM by vxr50t

[Bulletime]

Awesome thanks for the explanation, don't usually get that. Would 18x8.5 +30 all round work with 245 front and 275 rear? Prob bit small being 8.5... do like these though http://www.ebay.com.au/itm/18-ENKEI-RP03-SILVER-RIMS-WHEELS-18x8-5-30-5x114-3-STI-EVO-8-9-10-/110948954504?pt=AU_Car_Parts_Accessories&hash=item19d512b188 also thinking about these http://www.ebay.com.au/itm/ENKEI-RPF1-WHEELS-18-x-8-5-30-18-x-9-5-38-NISSAN-SKYLINE-R33-R34-SILVIA-S15-/190747741699?pt=AU_Car_Parts_Accessories&hash=item2c69738e03

or even these if they clear brembos

http://www.ebay.com.au/itm/ENKEI-GTC01-WHEELS-18-x-8-5-30-18-x-9-5-38-TOYOTA-SUPRA-SILVIA-SKYLINE-RX7-/190778907058?pt=AU_Car_Parts_Accessories&hash=item2c6b4f19b2

[FIXR7]

Found these on the same page bullet...Probably a bit too sticky out out at 11" +10 though. Wish they did 19's.

http://www.ebay.com.au/itm/AME-TRACER-TM-02-WHEELS-18-x-11-10-NISSAN-SKYLINE-GTR-R33-R34-EVO-X-ENKEI-/190725655430?pt=AU_Car_Parts_Accessories&hash=item2c68228b86

Oh and apparently they do...Although no real increase in dish/lip so scratch that for me I think...

http://www.ame-net.com/spec/tm02/TM-02_Print.pdf

Edited 22/05/13 01:00 PM by FIXR7

[vxr50t]

An 8.5 all round will be like the stock wheels, will look sunken esp the rears.

The 2nd and 3rd link will fit but won't be flush with the guard and you'll probably wish you'd gone a bit lower offset to fill the guard.

Its hard to find a good match of rim widths and offset as most aftermarket wheel manufacturer do them at set sizes unless you go full custom but that won't be cheap.

Sent from my GT-I9300 using Motorculture mobile app

Edited 22/05/13 01:19 PM by vxr50t

[Bellato]

I wouldn't bother with anything less than 9" on the rear otherwise kinda pointless changing wheels.

Not 100% sure with 18's because there becomes some clearance issues going too close to the inside on the rear but from what I gather in terms of best performance

18x8.5 +30 with minimum 245 tyre (Not sure what are popular 18" tyre sizes by a 255/35 or 255/40 would be good)

18x9.5 +35 with 275/35 or better. can probbaly go a 285/35 or even a 275/40 (again if that's a common size)

I'd imagine for you bullet you're looking at wheels from a practical/track perspective rather than looks and a combo such as this will mean no need for guard work, most width and profile as possible and should perform really well on the street and track

[vxr50t]

with 18s the lower trailing arm will be very close to the rim on the inside. I run 10s on mine and I was lucky enough mine cleared but only just.

to make sure they don't foul on the inside, you need to run at least +35 or lower offset but this only applies to 18s. 19s and 20s clear this with no problems

but having said that, the style of wheel barrel will also play a part as you'll see in the pics further down

the pic below is how much clearance mine has on the inside with 10 +33

it really depends on the wheel barrel and the grooves or valleys as some wheels are dead straight like the stock ford wheels and others have these valleys in the barrel which can come very close to the trailing arm bolts

eg straight

Valleys

[Bellato]

Yea your thread is what made me second guess 18's fitting. But if you go 9.5's you're gonna be 6ish mm further away from the arm so shouldn't have any issues

Edited 23/05/13 09:39 AM by Bellato