964 tyres advice

[Bosh 964]

My first posting on here

I have had my April 1992 964 for 10 years and had the original 16" Design 90 wheels /Pirelli tyes (skinny 205/55 & 225/40) replaced several years ago by Strasse with cup2 wheels fitted with Fulda Carats (came on 215/45 & 255/40). The car handled well but always wondered what a "proper" set of tyres could do to the handling

So I decided to bite the bullet when I had my £12K service done last week at Millbrooke in Sheffield (Highly recommended). They had fitted a set of Continental Sports Contact 2 N2 but I had to drop down to 205/50s on the front as 215/45s dont come in Porsche N spec. Brand new, the front end grip was much worse and it doesnt seem to be getting much better with about 150 miles on them with early onset of understeer in the dry. Grip is much worse than my 2004 BMW 3 series which runs on the same non-N tyre albeit in a 225/45 width which I am totally happy with

Question is,
1. Should I stick with them a bit longer to see if they get better with bedding in
2. Go back up to 215/45s in a non-N rating
3. Try going up to N rated 225/45s - will they fit?
4. Ditch the fronts and try a different tyre - can they be "mixed and matched" front to back

Advice appreciated

Bosh

[warmfuzzies]

Well, if it's a C2, the 205 255 is the correct setup, if a C4 then 225 is a preferred option on the front for correcting under steer, tyre pressures also make a difference, 36psi all round on 17" so check these first, I'm on S02's all round, on both my 17 and 18" setup. I for one would not mix brands.

Kevin.

[Bosh 964]

Not checked pressures will do that first, I had hoped Millbrooke's tyrefitter had sorted that so not checked them

Interesting to hear that 225s are fitted to C4s, does this mean that 225s would fit my C2s arches. I would have though that going up 2 sizes on the front when going 16" to 17" (ie 205-225) would make for a better handling balance than sticking with 205s when the rears have gone up 3 sizes from 225 to 255

Thanks

Bosh

[warmfuzzies]

225's are only really use on C4's to adjust the understeer, the normal tyres are 205's.

That is 205F and 255R are the norm for both C2 and C4.

I have 225's on my C2, but only because I have 265's on the rear and didn't want to have it too mismatched front to rear.

The 215 thing only comes into play if you look at the rolling radius issue, changing tyre ratios allows a bit of tweaking for dialling out understeer etc, http://www.carbibles.com/tyre_bible.html will give info about keeping the rolling radius the same whilst allowing a range of tyre/wheel sizes to be played with.

Edited by warmfuzzies on Saturday 26th May 08:29

[LeoSayer]

Bosh 964 said:

Question is,
1. Should I stick with them a bit longer to see if they get better with bedding in
2. Go back up to 215/45s in a non-N rating
3. Try going up to N rated 225/45s - will they fit?
4. Ditch the fronts and try a different tyre - can they be "mixed and matched" front to back

5. Get the suspension and alignment checked/adjusted/replaced.