Sorry tyres again

[Zener]

LucyP said:

PhilF329 said:

^^ I think Zener made a good point about avoiding extra load tyres on TVR's. They are so common now that if you omit them, the choice of tyre drops massively off the shelf. If you are running XL tyres then in theory you need to drop the pressure to compensate for the stiffer side wall

I don't think that is correct.

They are not fitted to performance cars because the car is heavy. They are fitted because they provide better grip, especially during hard braking and fast cornering, because they are stiffer. This is especially important now, given the use of 40 and 35 section tyres, where the side wall is about as thick as a rubber band.

You do not run them at a lower pressure either, because that just wears the shoulders out more quickly.

Yes I should of made that clearer they just tend to be on the same cars that are all obese overweight too with rubber bands fitted

[Classic Chim]

LucyP said:

I don't think that is correct.

They are not fitted to performance cars because the car is heavy. They are fitted because they provide better grip, especially during hard braking and fast cornering, because they are stiffer. This is especially important now, given the use of 40 and 35 section tyres, where the side wall is about as thick as a rubber band.

You do not run them at a lower pressure either, because that just wears the shoulders out more quickly.

The poster mentioned XL fitted to TVR as being a bad idea which it is given TVR are often many hundreds of kg’s lighter than most modern heavy sportscars of which such tyres may be fitted too which is why RS work so well as an all round year tyre on TVR. They offer compliance.

[LucyP]

But again......

They don't fit XL tyres now to sports cars because they are suddenly much heavier than they used to be. They fit them because of the benefits that they provide in braking and cornering, and that applies just as much to a TVR.

[QBee]

I always thought XL stood for eXtra Load - so they were fitted to cars that wore out standard tyres too quickly because they were either heavy or often laden with stuff.
Please correct me if i am wrong - I do like a bit of correction (but that's another story)

[PhilF329]

Lucy P is referring that in theory a stiffer side wall controls the tyre contact patch more effectively, BUT if you run that tyre at the same pressure you increase the effective spring rate. That’s why in theory you should lower the pressure. I’m not talking about doing that to stupid degree and I suspect most TVR tyres get changed now because of age rather than being worn out on the shoulders, which I really doubt would be a problem.

We need to remember that Porsche’s etc running on XL tyres had suspension etc designed to compliment the factory spec tyres. A few square inches on each corner that keep us on the road!

[Classic Chim]

Maybe on Porsche cars.
On Tvr in a corner loaded up and without tyre compliance an already light footprint you will lose lateral traction and in the hedge. I went for W rating, I’m way faster if I wish too and safer in almost all road going situations, it’s not made up
As for braking,,,,, hmmm

[PhilF329]

^^ I get that. The point here is that changing the tyres, mixing brands and using XL’s can change the handling characteristics in real life and we should be aware of that

[Zener]

Regardless of opinions just avoid XL rated rubber on TVR cars

[geordiepingu]

Update on the geometry adjustment:

-1 camber feels like the on-spec I had on the T1Rs previously. I have a non-PAS car, and it feels equally as heavy as it did before, but the understeer problem has been eliminated, it certainly darts around much more nicely now. I haven't tried flinging it around any roundabouts at stupid speed since it's been a bit damp since picking it up from the specialist, but the grip is much better. I still feel like I'd prefer a dry tyre for the dry, but the RS5s are now definitely a recommended all-rounder. Still on 24F 26R psi. Still a stiffer ride than the T1Rs so I think I might admit defeat and soften the dampers a click or two.

Now the next problem is eliminating a click at low speed from the rear nearside the car has suddenly developed on the way back from said specialist.....

[Classic Chim]

geordiepingu said:

Update on the geometry adjustment:

-1 camber feels like the on-spec I had on the T1Rs previously. I have a non-PAS car, and it feels equally as heavy as it did before, but the understeer problem has been eliminated, it certainly darts around much more nicely now. I haven't tried flinging it around any roundabouts at stupid speed since it's been a bit damp since picking it up from the specialist, but the grip is much better. I still feel like I'd prefer a dry tyre for the dry, but the RS5s are now definitely a recommended all-rounder. Still on 24F 26R psi. Still a stiffer ride than the T1Rs so I think I might admit defeat and soften the dampers a click or two.

Now the next problem is eliminating a click at low speed from the rear nearside the car has suddenly developed on the way back from said specialist.....

Take it straight back if that’s practical so they can check the work.

I understand your sentiment re preferring something different for a dry tyre but once the roads warm up the tyres stick really well. Heat = extra pressure so 24 can easily become 27 when pushing on so keep experimenting but I find the lower I go cold the better they are when hot.
They feel stiffer through this pressure increase when hot which is nice yet are super soft over man hole covers when cold doing local journeys. I hit them for fun just to remind myself how much better it all is. Non pas its a good idea to soften shocks to achieve a similar thing. I hate steering wheel shake over bumps, it’s gone because I have tyres that give me 2 inches of soft suspension when it’s needed most which is uneven roads. 90% of roads are uneven in a TVR. My old CRASHY RIDE has gone.
They might not be the optimum tyre but for 90% of real time driving they are a fabulous compromise
I prefer a nice ride to just pure cornering ability so as Tvr are basically very stiff if set up right RS tyres give you that bit of suspension the shocks and wishbones can’t deliver, they just shake the vibration right through the lot on stiff tyres, these tyres absorb those frequencies extremely well. A transformation it has to be said. Modern almost, I’ve now been in modern cars with low profile tyres that crash about more. It takes a bit of getting used to but your driving brain will pick up on this extra tyre action, they feel like they move about but it’s just the extra grip digging in. Get them warm and bedded in. They will wear badly quickly if you run too much camber so keep an eye on them for awhile. You should find they display a good heat spread right across the tyre. If to soft outside edges will be hotter, too hard centre will get hot so just monitor your pressures as they are soft tyres and sensitive to pressure and geo changes. I think they are good for 20,000 miles on a Tvr if looked after and used regularly easily.

[QBee]

Soften the dampers off a bit.
On occasions I have finished a track day on track tyres and with the suspension really hard, and have decided just to head home without adjusting the dampers. Cadwell Park is my favourite track for doing this, as I only live about 40 miles away. Trouble is the first 20 miles is Lincolnshire's finest......and I have on more than one occasion pulled over and softened the dampers off at the road side, in the interests of saving my teeth.