Ok, I've heard people saying that 18" wheels affect the cars handling negatively. Is this true? I'd like a nice set of 18's but I'm more worried about performance than looks so I'm keen to hear peoples thoughts on this???

Ed

 

Ed,

Went from 17" on my MY01 to 18"s thinking that I was going to screw around with the ride quality. Things actually got better and the handling was great.

I put this down to the fact that the original Bridgestones appear to be made out of bakelite and the Toyos that went on had a much softer compound.

I'd also point out that the ride will be whole lot harsher if you are running 18" on a classic shape. This is cause you will be dropping to a 35 section tyre whereas I had a 40 section on the MY01.

Still, lots of peeps running 18" with no probs, just make sure you get a reasonable offset otherwise you may well bugger up the handling.

Hope that this helps.
Cheers,

S/

 

I have a MY01 / 02 so thats ok. What ideal offset / tyre should I run then on 18"s?

 

Ed,

Personally I think the Toyos are very nice, and as for offsets, 52-54 seems to be a pretty good range (if memory serves me right)

I had a set of Technomagnesio Detroit F1's on and the offset was in that range although slightly off what the standards are and it added a bit of extra weight to the steering which was good, without messing up the handling. Pete Croney at ScoobySport seems to know what he is on about here.

Cheers,

Simon

 

It's not just as simple as saying the size messes up the handling or not.

Typically the lower the profile of tyre the less forgiving it is. The reasons are that the ideal slip angles are smaller and the range at which the tyre produces grip is narrower. In addition, the tyre does not flex around imperfections in the road surface as well so on bumpy / uneaven surfaces the tyre will be more "skitty" (for want of a better word)

BUT...

often, a larger wheel (if it's a good one) can mean that the overall weight of the tyre and wheel combination (remember there is less tyre weight and some wheels are incredibly light) means that your unsprung weight is reduced. This is a surefire way of improving handling (when isolated from everything else).

So.. in essence, reducing unsprung weight is one of the only things that (if done without changing anything else) is ONLY a benefit.

So you need to weight (excuse the pun) up the benefits of the reduction in weight and the increase in the challenge of the tyres.

My advice, would be to go for the wheels if you really want them, but only if they are lighter than the ones you have on, then MAKE SURE you fit REALLY good tyres.

All the best

Simon

 

good points...thanks. need to check the literature tonight and see if there is anything about the weight of the standard MY01 17" wheels. Unless anyone knows off the top of their heads?

 

ed, look at the touring cars - biggest, widest, lowest profile possible for smooth tarmac. on the other hand thew rough rally stages use thinner taller tyres on smaller diameter wheels. horses for courses.

 

Can't give you exact wheel weight but I have weighed my wheelsets.

Std P1 17" wheel (Oz) with Toyo T1-S tyre = 15.5Kg
Speedline 17" wheel with Bridgestone SO3 tyre = 18.0Kg
And a "standard" tyre in this size is about 8Kg I think.

The Toyo is said to be a lighter tyre than usual so the wheel weight is about 9-10Kg for a 17x7J.

Perhaps someone from the trade on here will weigh one for you to get an exact figure.

Marc
http://www.impreza-p1.org.uk

 

My UK300 came standard with 18" OZ's. I would have thought Prodrive new what they were doing.

My car handles ok with them