Extra W-I-D-E 15" alloys.

[PeterPan]

Hello,

I have been scouring the net for a couple of hours trying to find a set of alloys (at all) in either 15x11 or 15x11.5

Can anybody point me in the right direction?

At this point I'm researching wheel/tyre options for a project car and want to explore the pro/cons of fitting 305/35/15 tyres, but I am struggling to find (any) rims to accommodate that tyre size.

And body have any suggestions? Or experience what using that above wheel/tyre combo?

 

[old-git]

Rims to fit 305/35/15 is easy:

http://imagewheels.co.uk/pages/prices_billet.html

But why are you considering going so wide?

 

[PeterPan]

In short, maximum grip.

The project car will be around 370kg with around 160hp at the rear wheels, with that sort of power and tiny weight it'll need some better rubber than the present set up (175/60/13) to prevent it just spinning up the tyres in every gear.

I was pretty much set that the widest I could go would be 225/45/15 as that's the widest size I could find, and then managed to find these...

And began to wonder how much difference they would make in terms of grip and traction vs. Toyo R1-R (in 225/45/15 guise)?

Then to evaluate whether the huge price difference at £400 vs. £150 is that level of extra grip for a 'road car' worth the price jump?

Also, I would imagine there must be a point when extra width offers little or now advantage, otherwise race/sprint/drag cars would have 3ft wide tyres or more...

 

[TCJBOLDIE]

I don't think so for a road car BUT if you want to explore the outer limits of adhesion ( on the track ) then maybe you need to go that wide. OR you could invest the price difference in some advanced training BUT only if you think need it to help improve your skills.

From where I sit it seems to tally up to a considerable sum when you add the tyres and wheels up.

 

[PeterPan]

Rims to fit 305/35/15 is easy:

http://imagewheels.co.uk/pages/prices_billet.html

Thanks for that Steve, some interesting designs there. Are there any more you know of?

 

[old-git]

The width of a tyre has no bearing on the size of the contact patch. That is determined by the tyre air pressure and the weight pushing on the tyre.

Therefore the contact patch of the Toyo will be roughly the same size as the Pirelli (small variations due to tyre design).

A tyre that wide with such a low profile will result in virtually no sidewall flex making the tyre very skittish, especially in a car as light as yours.

Another point to consider is weight and wheel inertia. Big wheels and tyres will add to your overall weight and will be a fair percentage of the total weight of a car as light as yours. Also, with a bike engine with little torque I reckon these big wheels will compromise acceleration.

I am planning to run 245/255 with 520bhp/450lb/ft and 650kg.

 

[PeterPan]

Or you could invest the price difference in some advanced training...

oddly enough I made enquiries along those lines a few days ago, and found guy quite local to me who talked me through some options for training and track time. This will be the next investment after the car is finished.

 

[PeterPan]

A tyre that wide with such a low profile will result in virtually no sidewall flex making the tyre very skittish, especially in a car as light as yours.

Good point, well made.

Another point to consider is weight and wheel inertia. Big wheels and tyres will add to your overall weight and will be a fair percentage of the total weight of a car as light as yours. Also, with a bike engine with little torque I reckon these big wheels will compromise acceleration.

I guess what I'm looking for is to find the best compromise on all fronts. If those pirellis are that much better than the Toyos I could also go for a 235 in the Pirelli.

I am planning to run 245/255 with 520bhp/450lb/ft and 650kg.

what are you building?

 

[old-git]

http://www.splitrims.com/pages/prices.html

http://www.superlite-wheels.com/index.html

I don't think the 305 Pirelli will be any better than a Toyo 245 888 on your car, especially taking into account the extra weight. Most cars I look at up at Santa Pod use the Toyo 888 so that must tell you something Having said that, I have heard good things about the P7Corsa.

It boils down to what tyre works best with your car and this can only be discovered by trial and error, especially as you are entering uncharted waters

I am buildng this:

http://www.torquecars.com/forums/f8/last-i-have-started-my-car-part-2-a-7440/index2.html

1967 Lotus Elan powered by a Cosworth YB turbo.

 

[old-git]

This P7 Corsa Classis tyre is interesting me

The reasons being it comes in more sizes in 15" than Toyo R888s as well as more compound options. I need to do some investigation. The 15/265/40 looks a possible alternative to the Toyo 16/245/45 or 16/255/50 I have been considering. It is also 20mm less in diameter than the 245 which also helps re clearance issues. Sidewall is a little shallower, though.