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[BodegaBay]

135i with M-Sport Suspension + M control arms + rear toe arms. Wheels are: 17x8.5 ET40

Will 245/40r17 SQUARED be ok without modification or will I need front camber plate?

[Brian_]

Originally Posted by BodegaBay

135i with M-Sport Suspension + M control arms + rear toe arms.

Will 245/40r17 SQUARED be ok without modification or will I need front camber plate?

Depends entirely on your wheels specs. What’s the width and offset?

[BodegaBay]

Originally Posted by Brian_

Depends entirely on your wheels specs. What’s the width and offset?

Sorry just added to my original post. It’s 17x8.5 ET40. Yes I’ve seen the Apex Wheel Guide notes but I don’t know if they accounted for all the variances with the 1-series: 128i base, 128i M-sport, or 135i M-sport. Additionally I’d like to know if the ///M control arms made the tolerances even tighter.

[Suprgnat]

Originally Posted by BodegaBay

Sorry just added to my original post. It’s 17x8.5 ET40. Yes I’ve seen the Apex Wheel Guide notes but I don’t know if they accounted for all the variances with the 1-series: 128i base, 128i M-sport, or 135i M-sport. Additionally I’d like to know if the ///M control arms made limits the tolerances even tighter.

The Apex fitment guide is spot on. Applies regardless of model.

The front ///M wishbone pokes the wheel out a bit, but results in more negative camber so it sort of balances out. That said, you'll still likely need more negative camber out front to prevent rubbing, just like it mentions in the fitment guide.

The rear ///M arms have no affect on suspension geometry. 245/40-17 on 17x8.5 ET 40 will likely rub in the rear. Maybe only over big bumps, but it's probably going to happen.

For reference I'm currently running square 245/40-17 PS4s on 17x8.5 ET40 on Spec-R springs with the narrow hub conversion in the rear. -2.7° in front, -2° in the rear. Fronts are tight, but zero rubbing. Rears have zero rubbing, but I'm sure they would without the narrow hub conversion.

If you're going to run very squared-shouldered tires it's going to be much worse.

[BodegaBay]

Originally Posted by Suprgnat

The Apex fitment guide is spot on. Applies regardless of model…

…For reference I'm currently running square 245/40-17 PS4s on 17x8.5 ET40 on Spec-R springs with the narrow hub conversion in the rear. -2.7° in front, -2° in the rear. Fronts are tight, but zero rubbing. Rears have zero rubbing, but I'm sure they would without the narrow hub conversion.

If you're going to run very squared-shouldered tires it's going to be much worse.

Thanks for the detailed analysis, Suprgnat. I’m looking at the Falken FK510 which are very squared shoulder vs PS4s. And I’m planning on KW Street Comfort coils which will lower same as Spec-R.

Will the Dinan fixed camber plates get me to -2.7 in the front?

Is the narrow hub conversion same as this Rear Hub Conversion Kit from ECS?

[Suprgnat]

Originally Posted by BodegaBay

Will the Dinan fixed camber plates get me to -2.7 in the front?

I'm currently using the Dinan plates, so in combination with the Swifts and the ///M wishbones, yes.

Originally Posted by BodegaBay

Is the narrow hub conversion same as this Rear Hub Conversion Kit from ECS?

Yes.

[BodegaBay]

Originally Posted by Suprgnat

Yes.

Suprgnat Thanks. If I understand it correctly, the rear conversion kit will allow 10mm more space to fit wider fitments. Does this also mean I’ll need to add a 10mm spacer to the 17x8.5 ET40 wheel?

[Suprgnat]

Originally Posted by BodegaBay

Does this also mean I’ll need to add a 10mm spacer to the 17x8.5 ET40 wheel?

That would defeat the whole purpose of the narrow hub conversion.

[BodegaBay]

Originally Posted by Suprgnat

That would defeat the whole purpose of the narrow hub conversion.

Oh I understand now. The narrow hub conversion simply gives us space to move our wheel/tire setup inwards and away from the fenders for any rubbing issues.

[ralster]

Originally Posted by Suprgnat

The Apex fitment guide is spot on. Applies regardless of model.

The front ///M wishbone pokes the wheel out a bit, but results in more negative camber so it sort of balances out. That said, you'll still likely need more negative camber out front to prevent rubbing, just like it mentions in the fitment guide.

The rear ///M arms have no affect on suspension geometry. 245/40-17 on 17x8.5 ET 40 will likely rub in the rear. Maybe only over big bumps, but it's probably going to happen.

For reference I'm currently running square 245/40-17 PS4s on 17x8.5 ET40 on Spec-R springs with the narrow hub conversion in the rear. -2.7° in front, -2° in the rear. Fronts are tight, but zero rubbing. Rears have zero rubbing, but I'm sure they would without the narrow hub conversion.

If you're going to run very squared-shouldered tires it's going to be much worse.

The guide recommends atleast -1.5 degrees with the 245/40. On the stock suspension I have just 1.5 with Bilstein PSS9. How unusable would it be to drive hard? I currently have the 18x8.5 ET45 235/40R18 square with 5 mm spacer up front and it never rubs through a corner. I have the car pretty low and i'm looking for a new wheel and tire set up for the upcoming summer. I don't exactly want to change too much from my suspension