Racing soft tires

[Duvorynn]

Hi to all!

Today I've raced with VW 1200 '66 and notice that the car isn't turning with RS tires like it did. Tried SS tires and they were pretty similar like RS so wtf...I've changed setups and change different settings but still car wouldn't turn like it did before.
I've inspected a lot of stuff a notice that ALL racing tires on VW 1200 abd VW Type-2 have grooves...how can that be?
Changed vehicles from different manufacturers and those DON'T have grooves on racing tyres but do on sport and comfort which is how it should be.

I'm clueless.

Thanks for any info.
Davorin

 

[Theufcveteran]

Hi to all!

Today I've raced with VW 1200 '66 and notice that the car isn't turning with RS tires like it did. Tried SS tires and they were pretty similar like RS so wtf...I've changed setups and change different settings but still car wouldn't turn like it did before.
I've inspected a lot of stuff a notice that ALL racing tires on VW 1200 abd VW Type-2 have grooves...how can that be?
Changed vehicles from different manufacturers and those DON'T have grooves on racing tyres but do on sport and comfort which is how it should be.

I'm clueless.

Thanks for any info.
Davorin

Old cars have grooved racing tyres if the Honda RA272 is anything to go by. Are you sure the front tyres aren’t rubbing against the wheel well on racing softs when turning? That can limit rotation.

 

[SoulSilvera]

Hi to all!

Today I've raced with VW 1200 '66 and notice that the car isn't turning with RS tires like it did. Tried SS tires and they were pretty similar like RS so wtf...I've changed setups and change different settings but still car wouldn't turn like it did before.
I've inspected a lot of stuff a notice that ALL racing tires on VW 1200 abd VW Type-2 have grooves...how can that be?
Changed vehicles from different manufacturers and those DON'T have grooves on racing tyres but do on sport and comfort which is how it should be.

I'm clueless.

Thanks for any info.
Davorin

Racing tires don't necessarily have to be slicks to be racing tires.

Either way, the appearance of the tires doesn't matter to your problem. Haven't touched that VW in a while, but I remember it being a pain, especially with the engine swap. Increase the natural frequency (above 3.00 Hz for Racing tires) and increase the values for the roll bars as well. If the problem persists, raise the ride height. Usually 20mm above the lowest possible value is the bare minimum.

 

[lbpomg95]

Hi to all!

Today I've raced with VW 1200 '66 and notice that the car isn't turning with RS tires like it did. Tried SS tires and they were pretty similar like RS so wtf...I've changed setups and change different settings but still car wouldn't turn like it did before.
I've inspected a lot of stuff a notice that ALL racing tires on VW 1200 abd VW Type-2 have grooves...how can that be?
Changed vehicles from different manufacturers and those DON'T have grooves on racing tyres but do on sport and comfort which is how it should be.

I'm clueless.

Thanks for any info.
Davorin

As above, it's most likely arch-rubbing. Increase body height, and natural frequency until the problem stops.

 

[Duvorynn]

Racing tires don't necessarily have to be slicks to be racing tires.

Either way, the appearance of the tires doesn't matter to your problem. Haven't touched that VW in a while, but I remember it being a pain, especially with the engine swap. Increase the natural frequency (above 3.00 Hz for Racing tires) and increase the values for the roll bars as well. If the problem persists, raise the ride height. Usually 20mm above the lowest possible value is the bare minimum.

I have tried all of that but the car just don't handle corners like it did...didn't swap engine so it's 124hp. It should and did corner better

Old cars have grooved racing tyres if the Honda RA272 is anything to go by. Are you sure the front tyres aren’t rubbing against the wheel well on racing softs when turning? That can limit rotation.

Switched to Unimog and RS on it ARE slicks and the car is as old as ut could be 😂

 

[CalumAstro]

When you say it doesn’t handle right, is it juddering or does it just lack the kind of front-end grip you’re expecting? If it’s the latter you’ve got some set-up options to try: if SS and RS are delivering the same amount of grip then your race tyres aren’t in contact with the tarmac enough to make use of the available grip. With the beetle being RR the weight is already towards the rear, so it might be a simple as adding some ballast over the front axle to keep it down when you’re accelerating. Similarly you can adjust the dampers to make it harder for the nose to rise: harden front expansion and rear compression. You should also check your front camber and rear downforce levels. If you’ve put the big wing on the back it may be lifting the front tyres too much in medium speed corners, and try lowering front camber, i’ve found around 2.0 is a decent sweet-spot rather than the default 3.0.

Hope this helps!

 

[Duvorynn]

When you say it doesn’t handle right, is it juddering or does it just lack the kind of front-end grip you’re expecting? If it’s the latter you’ve got some set-up options to try: if SS and RS are delivering the same amount of grip then your race tyres aren’t in contact with the tarmac enough to make use of the available grip. With the beetle being RR the weight is already towards the rear, so it might be a simple as adding some ballast over the front axle to keep it down when you’re accelerating. Similarly you can adjust the dampers to make it harder for the nose to rise: harden front expansion and rear compression. You should also check your front camber and rear downforce levels. If you’ve put the big wing on the back it may be lifting the front tyres too much in medium speed corners, and try lowering front camber, i’ve found around 2.0 is a decent sweet-spot rather than the default 3.0.

Hope this helps!

Yes, it's the latter, but my point was that last month I've drove it and it was way better...used my default setup for tarmac and drove the same circuit as before and now my lap times are 2s lower cause I need to slow more...the feel is that it goes into the corner well and suddenly like I've returned the wheel into straight position not cornering at all

EDIT: Like the grip has a faulty switch and goes on/off on/off in corners...weird and it wasn't like this before...when it lost grip it lost it and now is like I described

 

[CalumAstro]

Yes, it's the latter, but my point was that last month I've drove it and it was way better...used my default setup for tarmac and drove the same circuit as before and now my lap times are 2s lower cause I need to slow more...the feel is that it goes into the corner well and suddenly like I've returned the wheel into straight position not cornering at all

EDIT: Like the grip has a faulty switch and goes on/off on/off in corners...weird and it wasn't like this before...when it lost grip it lost it and now is like I described

Yep, that’ll be the arches then. There’s not been any physics changes in a while (until next week looks like…), so there must have been a change in either the track, your line or maybe some part of the set-up that you forgot about after (it happens). Fix is simple: 1) raise the ride height by 10 at the front, match on the rear if you want. 2) stiffen the ARBs and the dampers by 1 or 2 notches, this will stop the body rolling or diving onto the tyre. 3) in GT auto take the wide wheels (the middle option) off if you have them equipped, this is often one of the bigger issues. Hope this fixes it for you! This problem impacts quite a few cars, I first encountered it on the DB11 I think. I do wish PD would bring back the feature from GT5 or 6 which changed the font colour to red in the setup screen if the car was going to clip the tyres…

 

[Highlandor]

This is going to be a bit of a Picard 4 lights thing, or I've somehow got a different version of GT from everyone else

These cars are all the same, minimum ride height, biggest (and widest wheels), no widebody conversion but can run on comfort, sport and racing softs, without changing anything, other than the tyres.

They can all be chucked round the ring, kerb hopping wherever you want. Supra, M4 and Alfa are for hypercar events, so 6/700bhp and 200mph, so we're not exactly driving miss daisy.

EDIT: Correction, Alfa has stock wheels that have been given a bit of a polish

 

[lbpomg95]

This is going to be a bit of a Picard 4 lights thing, or I've somehow got a different version of GT from everyone else

These cars are all the same, minimum ride height, biggest (and widest wheels), no widebody conversion but can run on comfort, sport and racing softs, without changing anything, other than the tyres.

They can all be chucked round the ring, kerb hopping wherever you want. Supra, M4 and Alfa are for hypercar events, so 6/700bhp and 200mph, so we're not exactly driving miss daisy.

EDIT: Correction, Alfa has stock wheels that have been given a bit of a polish

Now try the same on the E36 M3, '65 GT350, Toyota RAV4 and the Beetle with the widebody fitted. Some cars suffer with it, some don't.

 

[Highlandor]

Now try the same on the E36 M3, '65 GT350, Toyota RAV4 and the Beetle with the widebody fitted. Some cars suffer with it, some don't.

As I said in my other post about ride height this isn't possible on all cars, but a rough guess of about 2/3rds - 3/4s of cars can do this out of the box, with about 1/10 just not being possible. Most people can't even get 1 single car doing this, let alone hundreds in all different kinds of specs.

If the problem or solution was a single variable as people, especially people like you, keep saying (wheel arch rub / need to make springs stiffer), then that variable would be applicable to all cars, it absolutely isn't. The fact that this (minimum ride height, biggest widest wheels, no widebody) is possible on so many cars, and variations of these cars, shows that it can't be a single variable.

This is one of the reasons I've feel there's no wheel arch rub, I've been consistent with that and will stick by that 100%. But there's also another reason for this too, which I think is far more valid - has no-one else thought it's strange how cars are able to drive over kerbs that are far higher than the car's ride height(?).

Spoiler

Yes, there is something amiss and it's probably PD's attempt at recreating certain problems associated with running cars at minimum ride height, but PD being PD, they haven't done a great job of this. Even that garbage Beyond the Apex guide (correct for real life, a joke for GT tuning) says there's more than one reason why lowering cars to minimum isn't a good idea, but the other reason is hardly ever mentioned.

Oh, btw, nice mis-matched tyres on your Superbird setup 👍