15" tire sizes

[jbcollier]

Interested in hearing what you are running in the way of 15” tires with stock wheel arches and hubs.  Anyone running 195/50R15s for example? Too stiff a sidewall?

[Clifton]

Not stock wheel arches, a little flare but I'm running a 205 50/15 on the front with stock hubs.

[BDA]

I don't fit your criteria but maybe I can give you some insights from what I may have done correctly and what mistakes I may have made.

I run 195/50-15 on the front and 205/50-15 on the rear.

The rear wheels are 7" (stock +1.5"). I have "flares" I got from Dave Bean. After I glassed them in, they didn't seem to provide much flaring. But because I have Richard's twin link, I can choose my rear track. I haven't measured it, but I suspect my hubs are not really wider than stock. I have 3-piece wheels and chose the offset to wheel width to be the same as or similar to stock alloy wheels.

In the front, I have Richard's vented disc kit which includes GT-6 hubs. I'm not as sure about the width of my front wheels because I think I reduced the width an inch to fit under the unflaired fenders. They started out as 7" wide IIRC. They are ok but I might at some point move the offset in a bit so they would fit better under the fenders.

I converted to 12mm studs.

I am running 120#/130# springs. I run SPAX shocks. At the moment, they are as delivered which I believe is their softest setting. The ride quality is fine. The handling in higher speeds is a bit "loose" so I will be experimenting with stiffening the shocks and it's not out of the realm of possibility that I revert to a more stock setup. I obviously can't separate the effect of the shorter sidewalls and the stiffer springs. I suspect they would be a bit stiffer than the stock tires, but I'm not sure it's significant.

I am running 15 - 18 psi in the front and 24 - 26 psi in the rear. I usually try to hit near th middle of the range but I expect I'll be experimenting with tire pressures too.

I hope that helps someone!

[EuropaTC]

Hi John,

I'm running 195/50x15 front, 205/50x15 rear with no body mods. But my car is the TC and although the suspension is lowered I doubt it will be as low as you have with your S1. 

I also suspect the wheel arch clearances may be slightly different because a guy on the Yahoo List (Richard) runs the same front tyres on his S2 but has clearance problems at full lock. This is at the rear of the wheel as it turns outward and the rubber contacts the back of the wheel arch. It's tight on mine but there's still clearance throughout the range of vertical movement - photo attached.

There's plenty of clearance at the rear on the arm & body. The only snag is to replace the wheel I need to let the suspension go to full droop so that the wider tyre clears the bodywork when you're tilting it out. I've not tried 195 there, assuming you'll be keeping the same ratios all round you might be ok there, certainly better than me anyway.

Wheels are 15x6" all round,  offset is 30mm I think. Not sure, I'd need to check that.

Pressure wise I run 18-20psi front, 28-30 rear. (that means I pump them to 20psi and top up when I find they're 18psi or lower    ) 

Stiffness;  I'm not sure I'm the guy to comment because my suspension has higher rates, from OEM 1.25F, 1.36R to 1.81F/1.96R and the wheels came along around the same time as the suspension, it was a package deal.   

I calc'd the S2 as 1.1F, 1.4R so if you're the same as the S2 then I'd guess you'd notice the difference in sidewall.

Brian