Downsizing 981 wheels

[Beknown]

I have 20" wheels on my 981 and although they look great I can't help but wonder how much nicer/better it would drive with smaller wheels.

I don't really have any complaints about the current wheels other than the knowledge that the car should drive better on smaller ones, and the fact that it may reduce the offensiveness of the tyre skipping when a lot of steering angle is applied.

Has anyone dropped down a size, if so what were the differences? Just to add, I don't have PASM.

[nbetts]

The tyre skipping goes away on full lock with my 19" Winter wheels and tyre combo.

The ride I cannot say is massively different. My car was also a non PASM car with 20" Carrera alloys.

[Beknown]

I drove a 718 on 19"s recently and it didn't skip at all which is nice, although I appreciate they may have different suspension setups.

My 987 on 19"s or 18"s never did any skipping.

[981Greg]

981 base models had 18" and 981S had 19" as standard, so you could go to either of those sizes quite happily. Higher profile tyres will certainly give more compliance in the ride, but it's impossible to quantify how much.
I have 18" cold weather tyres/wheels and 19" summer wheels/tyres. There's no tyre scrub at all on the winter set, and the ride is certainly softer.

[bcr5784]

Having tried my car on 18 " Goodyear s 19" pirelli s - both N0 and N1 - I'm happiest with N1 pirelli s. The ride on 18s is a bit better - but it's so good with PASM that wasn't a factor for me. N1 pirelli s are much better than N0s - much more throttle adjustable than 0s, no significant scrubbing at reasonable temperatures but less understeer and more precision than the Goodyear s.
If you do go 18" I have a set of practically new F1s which might be of interest.

[bcr5784]

ATM said:

So you're now on 19 pirelli n1?

Do you think there is not much between
18 and 19?

I can definitely feel the difference between awful pirelli 20 and soft winter 19.

YES N1 Pirelli now. There is definitely a difference between 18" Goodyear and 19" pirelli in favour of handling to 19"pirelli and ride to 18" Imo.

In my case the ride on my 18" winter Dunlops is definitely Worse than my summer pirelli s. The handling on the winter tyres is entertainingly loose, but the lack of precision irritates over time.

[bcr5784]

I'm not sure that oversize tyres are the fundamental problem - and after going to N1 Pirellis I'm perfectly happy with both the balance of the car and the level of grip (which certainly seems less than N0s)

Look at it this way almost all Caterhams have 185 or greater section tyres which are FAR wider than a 981s relative to the vehicle weight (which is well over double that of a Caterham) . Even the 160 with its 80 bhp has 155 section tyres which are STILL wider than a 981s relative to it's weight.

Actually if you do the sums then relative to its weight a 981's tyres are no bigger than an early Elan, and a lot smaller than an Elise.

And no-one complains that any of the above are over-tyred.

[ATM]

Surely the caterhams run very soft and sticky compounds?

[bcr5784]

ATM said:

Surely the caterhams run very soft and sticky compounds?

They've run all sorts on compounds over the years, some relatively sticky some not. It's only with (relatively) VAST sticky rear tyres that excess grip is commonly discussed.

[bcr5784]

On Pirelli N1s the rear of the car moves around at sensible speeds and is responsive to the the throttle. Seems a much simpler way of achieving that than changing wheels and tyres, which, as far as I am aware, no-one has tried on a 981. N1s are one of the reasons (extra torque is the other) why the handling of the 718 is generally preferred to the 981.

Edited by bcr5784 on Tuesday 23 May 08:13

Edited by bcr5784 on Tuesday 23 May 08:17

Edited by bcr5784 on Tuesday 23 May 08:57

[So]

Beknown said:

I have 20" wheels on my 981 and although they look great I can't help but wonder how much nicer/better it would drive with smaller wheels.

I don't really have any complaints about the current wheels other than the knowledge that the car should drive better on smaller ones, and the fact that it may reduce the offensiveness of the tyre skipping when a lot of steering angle is applied.

Has anyone dropped down a size, if so what were the differences? Just to add, I don't have PASM.

Well done for doing this. It will drive better on smaller wheels, almost certainly. I personally also think they look better on smaller ones.

[bcr5784]

ATM said:

I'm willing to try it but the problem is they are so big to start with that finding anything with a similar circumference which is thinner is almost impossible - unless you stray into SUV tyres.

50 profile tyres are about the right size - but you'll probably find Y speed rated ones thin on the ground. So you will not only lose any possibilty of a Porsche warranty, but will be on dodgy ground regarding the law (academic as that might be in a country with a 70 limit)

Edited by bcr5784 on Tuesday 23 May 17:03

[bcr5784]

ATM said:

What about instead of thinner tyres I just try tyres with less grip like a gt86. Surely there are some grandma type tyres available which are not ditch finders but also not high performance blah blah.

It's already a bit vague and understeery for my taste with 18" F1 Eagles of the standard size - and even more vague (if not understeery) with 18" winter Dunlops. Can't help feeling grandma tyres will make things worse.