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[Sancs]

Hi,

Greetings from Argentina

I have 4 Pirelli P Zero Slicks 235/645/18 (which is like 235/45/18 i think) that i need to put in my 12' 135i so i can use them in the tracks day. These tire is the only thing that i can find here to use in tracks.

My question is if there is any chance i can make it fit in the front? Which side and ET of wheels i need to buy?

I will be using stock suspension

Thank you!

[houtan]

On stock suspension, you should be fine with et45. But if it does rub, it will be on the fender side so you may need to roll your fenders.

[Sancs]

i forgot to mention im putting the front M3 control arms (dont know if that is relevant)

[houtan]

M3 arms will add more camber, but not give you more clearance to the fender. Adding camber plates will improves clearance to fender.

[Fume]

Originally Posted by houtan

M3 arms will add more camber, which improves clearance to fender

I'm not sure if this is true. From what I remember reading, it seemed like M3 control arms at the front adds camber by extending the bottom which doesn't really improve clearance. As a comparison, camber plates add camber by moving the top connection inwards which helps give clearance to the fender.

Maybe someone else with more experience can correct me if I'm off base here.

[John_01]

Pirelli slicks will be too wide to fit without camber plates. I expect they will rub hard on the front fenders. In general you will need camber plates if you want slicks on the car, as stock wheel alignment isn't going to work very well. If you are buying wheels, you will need to get front offset that is a bit lower when running slicks to avoid rubbing the strut (camber plates are essential). Rear offset will need to be similar to stock or higher.

For 235/645/18 sized slick tire, 645mm will be the diameter of the tyre. It means the sidewall is 94mm which is like a 235/40/18 so the height shouldn't be a major problem. You will still need camber plates to make it fit.

[Sancs]

Thanks for the answers, so i need to add camber plates. Which are the tires that the 135 use in the tracks? Now i see i dont have much space in the front part

[MightyMouseTech]

Originally Posted by houtan

M3 arms will add more camber, which improves clearance to fender

Actually, the opposite is true. The M3 arms increase camber by pushing the bottom of the tire further out, which also pushes the top of the tire out a bit. Makes fender clearance worse.

[houtan]

Originally Posted by MightyMouseTech

Actually, the opposite is true. The M3 arms increase camber by pushing the bottom of the tire further out, which also pushes the top of the tire out a bit. Makes fender clearance worse.

Not sure I follow. The top mounting point is fixed in both cases, so if I push the bottom out more, but the top mounting location is the same, how does the top of the tire end out more?

[MightyMouseTech]

Originally Posted by houtan

Not sure I follow. The top mounting point is fixed in both cases, so if I push the bottom out more, but the top mounting location is the same, how does the top of the tire end out more?

The tire is not the top, the top of the strut is. If you push out the bottom, everything gets pushed outwards.

[houtan]

Originally Posted by MightyMouseTech

The tire is not the top, the top of the strut is. If you push out the bottom, everything gets pushed outwards.

Lol. I'm tripping. Thanks for the clarification. Next time I won't try to visualize what I'm thinking haha

[John_01]

Originally Posted by Sancs

Thanks for the answers, so i need to add camber plates. Which are the tires that the 135 use in the tracks? Now i see i dont have much space in the front part

I don't have experience with full slicks. I only used R-comps. A slick seems like a softer and wider R-comp. You will need to have the right amount of camber as they will deteriorate quickly if you overheat the outside shoulder. Apart from that you will want to get all parts of the tire tread up to operating temperate evenly so the grip is consistent. Sorry if you know this already.

[Sancs]

Originally Posted by John_01

Sorry if you know this already.

John i appreciate what your are saying, im learning a lot from this forum. In my country nobody use r-comps neither what you call extreme permormance tire cause they dont sell them here, they all use full slicks in every trackday car. The only r-comp that you can get is toyo r888 and it cost $580usd each.