Non-XL tyres. Have I made a terrible mistake?

[Hooner]

i reckon ive nailed it with 225/4018 n rated michelin cups on the front, ps4 zr 265/35/18 rear car drives really nice. all tyres dot 22

 

[ndg]

I have Asymmetric 5s on my 86, and a good friend of mine put PS5s on his. Both stock size & suspension. After spending a few hours as a passenger in his car, the PS5s sure ride comfier and quieter than the Goodyears. Even though I made sure to get the Goodyears in non-XL rating.

Michelin are well known for being quieter/better riding in each segment. This does come at the expense of turn in response due to a softer sidewall.

As ever with engineering it's a compromise, and my preferred compromise is not yours!

 

[jerzybondov]

I feel like I can wrap up this thread by saying: no, fitting modern non XL tyres is not a terrible mistake.

Have got 245/45/17 Goodyear Eagle F1 Asymetric 6 on the back, and 205/50/17 Asymetric 5 on the front.

Both are non XL rated (so 93/94 load rating ish).

And the car rides beautifully and steers beautifully. I am aware that this is just about the ‘least tyre’ that you can fit to a 996, but I actually think the car drives better as a result. 911s are not exactly short of grip after all! Highly recommended.

 

[gizlaroc]

911s are not exactly short of grip after all!

Well that depends on the geo.

You can make one with 295's on the back feel very tail happy if that is what you want from your car.

 

[IUI675]

Well that depends on the geo.

You can make one with 295's on the back feel very tail happy if that is what you want from your car.

Recommendations for who can tune the handling with the geo?

 

[TurboSandGT4]

all round tyres -Pirelli PZero or Good year F1

You only live once -Cup 2s

 

[gizlaroc]

Recommendations for who can tune the handling with the geo?

Center Gravity seems to be the go to.

I have started doing mine myself using fishing wire.
I have no idea what my actual settings are, need to get it on an alignment machine to get them read as right now it is the best it has ever been.

It depends what you want, so many ask for a "fast road/track set up" without really understanding what that means. What you tend to end up with is loads of negative camber, that makes the car tramline and constantly feels fidgety on the road, and very little toe in on the rear and even some toe out on the front, which will make the car turn very quickly, but be a real handful and have the back end wanting to kick out far too easily.


I run mine with fairly aggressive rear camber, quite a lot of toe in on the rear too, then very little camber at all on the front and no toe in or out on the front.

This gives a very, very planted feel, the steering can feel a bit heavy but it goes where you point it without the back end coming round, in fact you almost have slightly dialed in understeer but you can really feel when the back is going to let go, although you have to really provoke it to make it let go.

The car feels planted, secure and the steering is just how I like it, the steering wheel doesn't constantly move around following every single rut in the road but you can feel what is going on still through it.

I'm sure this will scrub the inside edge of my rear tyres after 5-6k miles, but so what, I would rather a car I really enjoy and is exactly how I want it and swap rear tyres every year than have it feel less planted.

This means I can carry far more speed on the road than I would with more standard setting. It would not be the best for a track with tight turns, but I'm not using it on a track, so I don't need to compromise in that regard, mine is set up for being a very fast backroad blaster, and more importantly set up to give me confidence.

 

[jerzybondov]

Centre Gravity definitely know their way around a 911!

I can also put a shout out for the team at Top Cats Racing near Aylesbury - they did a cracking job setting up my Elise and DeLorean.

 

[corneg1]

DeLorean - nice!

Centre Gravity are great - really know their stuff.

 

[jerzybondov]

DeLorean - nice!

Centre Gravity are great - really know their stuff.

Yes it's another rear engined six cylinder car - there's not that many of them!

 

[Xstyle]

Why are "OE' tyres more expensive from the same brand, same size?
Michellin PS4 on a 997,
235/35/19 - 91Y - £179 ... the OE equivalent is £203!
the non-OE is also a C rated fuel efficiency, and the OE is D rated.
Why pay more?? I don't understand.

 

[Xstyle]

Why are "OE' tyres more expensive from the same brand, same size?
Michellin PS4 on a 997,
235/35/19 - 91Y - £179 ... the OE equivalent is £203!
the non-OE is also a C rated fuel efficiency, and the OE is D rated.
Why pay more?? I don't understand.

I think I answered my own question...!
...BMW M related, but OE for Michellin PS4S
on 12min 30 seconds mentions PORSCHE, that the OE for rear is recommended due to engine placement and weight. More reinforcement in tyre.

 

[gizlaroc]

If you add more reinforcement on the rear tyres you will also get a sharper, more precise turn in/steering feel too. Same as when you put a firmer damper on the rear of your car.

 

[911UK]

Yes it's another rear engined six cylinder car - there's not that many of them!

View attachment 100768

memo to @jerzybondov we still need a seperate and new thread on the Delorean !!

 

[jerzybondov]

memo to @jerzybondov we still need a seperate and new thread on the Delorean !!

Very happy to oblige! What kind of things would you like to know?