Tyre help - anyone running 275 rears?

[Dougle_turbo]

As above really. I want a set of Pilot sport 4 S but no rears are available until 10th May and Bedford totally smoked the current ones. 

 

I can get 275/35/19 has anyone run these successfully?

[Mavrik]

14 minutes ago, Dougle_turbo said:

As above really. I want a set of Pilot sport 4 S but no rears are available until 10th May and Bedford totally smoked the current ones. 

 

I can get 275/35/19 has anyone run these successfully?

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I run a 35 profile on the rear of my 350z with a 40 on the front... No issues for me...

[Dougle_turbo]

3 hours ago, Mavrik said:

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I run a 35 profile on the rear of my 350z with a 40 on the front... No issues for me...

It’s the width I’ll be changing. The standard tyre is a 265/35/19.

[crafty1]

Is your car on 'R' / Spyder wheels ?

 

If so they are 1/2 inch wider than most other wheels on the Gen 2 CS. I would not put 275 on my car but on yours if I might, only thing is more rear grip may mean more understeer ? 

 

http://www.944racing.de/wheelweights.php

[Craiglm68]

I have overwidth (245/40 fronts, 275/40 rears, on 18" rims (both the standard Cayman S wheels (performed without issue at Silverstone), and the current Fuchs)

[Dougle_turbo]

1 hour ago, crafty1 said:

Is your car on 'R' / Spyder wheels ?

 

If so they are 1/2 inch wider than most other wheels on the Gen 2 CS. I would not put 275 on my car but on yours if I might, only thing is more rear grip may mean more understeer ? 

 

http://www.944racing.de/wheelweights.php

Yes I'm on the Spyder wheels, so sounds like it could work. More grip is good, but I get your point, it'll be easier to 'over drive' and therefore understeer in the corner.

[Dougle_turbo]

14 minutes ago, Craiglm68 said:

I have overwidth (245/40 fronts, 275/40 rears, on 18" rims (both the standard Cayman S wheels (performed without issue at Silverstone), and the current Fuchs)

So no problems running the oversize tyres? What made you go oversize?

[Andrea]

15 hours ago, crafty1 said:

Is your car on 'R' / Spyder wheels ?

 

If so they are 1/2 inch wider than most other wheels on the Gen 2 CS. I would not put 275 on my car but on yours if I might, only thing is more rear grip may mean more understeer ? 

 

http://www.944racing.de/wheelweights.php

 

First of all R and Spyder don't have wider tyres. If anything they have wider rims. 8.5J at the front and 10J at the rear but even the 2.7 or the S comes with same specs rims anyway. 

 

15 hours ago, Dougle_turbo said:

So no problems running the oversize tyres? What made you go oversize?

 

A lot of people run 265 at the front and 295 at the rear. the problem is not the width. it's the overall diameter.  If you use 275/35/19 you will have a bit more grip, but your gearing will be longer and you'll just lose time.  Other thing to check is the difference in % between front and rear tyre overall diameter since this can mess up with your ABS and traction control. 

 

So, if you go 245/35/19 and 275/35/19 that's fine, but I would't use this set up at the track.  Best option is a set of 18" wheels....

[Andrea]

P.S. without adequate  negative camber you'll just eat your tyres in few laps. You are better off investing in some 996 GT3 lower control arms than buying a new set of tyres over and over again. 

[Craiglm68]

20 hours ago, Dougle_turbo said:

So no problems running the oversize tyres? What made you go oversize?

Sorry, a bit slow getting back to you. Why did I go overwidth? Something I've done previously with other road cars, in my opinion I picked up a little in the handling department, and aesthetically I like the look (I'm a bit of a Princess like that 🙂 ).

I ran this setup on the original Cayman S 18"'s at Silverstone with no problem, and now I have Fuch's on, spacers were used front and rear (rear wheels are 10" wide, offsets a bit different etc), so the look is even better now. Again, in terms of handling, this has only improved on the road at least, turn in definitely sharper (hence comments above re potential for oversteer etc). I'm off to the PEC at Silverstone in a week or so, will see how things fare on their handling tracks.

[crafty1]

Ref 'R' / Spyder wheels I never said they had wider tyres I was making the point they are in fact wider than most of the factory 19 inch rims on Caymans by 0.5 inch hence they could perhaps get away with a wider tyre than on my wheels for example.

 

The problem with 18 inch wheels are the lack of tyre options if you want a 'do it all' type of tyre like the PS4S which only come in 19 upwards or did. If you want a 18 inch track focused/only tyre sure there are options but the spyder wheel is nice and light so personally I'd keep using them.

 

Also I agree wider is better aesthetically but wider rear track does nothing for the cars overall handling unless you up the front track too, without doing that turn in is worse, oversteer less likely and understeer more likely. Imo these cars drive best with a small increase to front track only, but they don't look great with this set up, horses for courses and all that.

[jcm987]

I can't comment on road driving, but on the track I run both 235/40 and 245/40 fronts and 275/40 rears and it works well. No issues with understeer going oversize at the rear with spacers. However with more than 3 degrees negative camber at the rear that is definitely a contributing factor. 

[Dougle_turbo]

Thanks for all the replies guys, I'll have a think about my next move.

[Bushman]

I'm just pricing up 2 new rears, P zero's again. its cheaper on Oponeo tyres to buy 275/35/19's than 265/35/19's. both 93 or 94y carcasses. I imagine that I shall have to drop the pressures down to 27 or 28 to suit a stiffer carcass.