GT Class

[Mirek]

That doesn't mean there is any problem. Do You really believe that on dry asphalt You need 4WD to cope with 400 Hp?

[Ucci]

That doesn't mean there is any problem. Do You really believe that on dry asphalt You need 4WD to cope with 400 Hp?

One thing what you forget: when the 911 starts to slide, you have a very tricky situation. Where is all the weight? Behind the rear wheels.
And if this happenes at the speed above 100 km/h, you need space to save the situation. In such kind of moment the 4WD computer rally designed cars are easier to save. Amen!

[Lundefaret]

One thing what you forget: when the 911 starts to slide, you have a very tricky situation. Where is all the weight? Behind the rear wheels.
And if this happenes at the speed above 100 km/h, you need space to save the situation. In such kind of moment the 4WD computer rally designed cars are easier to save. Amen!

Driven a lot of 911s have you?

[stefanvv]

That doesn't mean there is any problem. Do You really believe that on dry asphalt You need 4WD to cope with 400 Hp?

Well, if 4wds have 375hp I'm sure the will cope better.

[Mirek]

Well, if 4wds have 375hp I'm sure the will cope better.

That's quite a bold statement. As I said 4WD doesn't automatically mean better. 4WD especially very simple one (better to say primitive) which we know from current R5/WRC cars brings a lot of disadvantages for use on dry asphalt with a high level of grip - namely a lot more understeering, higher power loss in the drivetrain and much worse turning radius without handbrake. Please also don't ignore the wide tyres Porsche has. It's huge difference if You have 235 or 325 mm tyre on asphalt.

Rallycars are 4WD not because of dry asphalt but because of loose and dirty surface. If the championship was all held on dry asphalt only, there would be winning 2WD machines such as F2 cars once were.

[stefanvv]

That's quite a bold statement. As I said 4WD doesn't automatically mean better. 4WD especially very simple one (better to say primitive) which we know from current R5/WRC cars brings a lot of disadvantages for use on dry asphalt with a high level of grip - namely a lot more understeering, higher power loss in the drivetrain and much worse turning radius without handbrake. Please also don't ignore the wide tyres Porsche has. It's huge difference if You have 235 or 325 mm tyre on asphalt.

Rallycars are 4WD not because of dry asphalt but because of loose and dirty surface. If the championship was all held on dry asphalt only, there would be winning 2WD machines such as F2 cars once were.

Yes, I agree 4wd cars are made for loose surfaces, but they can also have advantages on dry asphalt at the same power, AUDI has proved that in IMSA series in late 80's when they abandoned rally for good. Tyre width makes difference too and current 4wd car differential system is not perfect I know. Even more, rdw cars with rear/center engine mount have some advantage on the grip.
But what is strange is that huge power can also cause this lack of traction on corner exits, that's why the driver need to react, while with 4wd he is much more eased with the front wheels biting the asphalt.

So part of my statement is Porsche drivers need to handle more "moments" than 4wd drivers - this huge power slide, respect for that.

[GravelBen]

Think about why there are nearly no 4WD cars on circuits.

In a number of cases its because they got banned for having too much of an advantage over their 2wd opposition

[Ucci]

Driven a lot of 911s have you?

Yes, I had this privilege....or on circuits as on open roads, highways, even on Nordschleife....as a driver and as a codriver.....from basic 997 & 991 to Turbo & GT3.....

[Mirek]

So part of my statement is Porsche drivers need to handle more "moments" than 4wd drivers - this huge power slide, respect for that.

I have never said I don't have respect for them. I said that unrestricted 911 is faster on dry abrasive tarmac than R5. That's fact. The drivers choose it because it's faster not because it's some kind of challenge or some special bravery.

[janvanvurpa]

T

Rallycars are 4WD not because of dry asphalt but because of loose and dirty surface. .

From an historical perspective I can't agree and have read old magazines which were then current when first Saab and then Audi began using turbochargers---and Saab, where I am friend with and stay on visits with rally engine development guy---admittedly were going to turbochargers to make huge amounts of torque---that the main problem was putting down the massive amounts of torque with just 2 tires of a limited specific size...

The engine torque in turbo car regardless of surface drove the need for dividing the power up to 4 tires instead of just 2...Old group 4 --which the Saab 99 Turbo and Audi Quattro we homologated in---it had wheel and tire max size limits based on engine size x turbo factor (1.4 in early days if I recall correctly..Later 1,7 times engine cc later)

Who can forget the scenes of Vatanen in his Escort at Ilse of Man going thru a 90 degree corner so hard and leaving 2 very wide black marks all the way thru the corner? It still sends a shiver up the spine to see that..

In those days BDG Escort (2,0 liter) made 262 hp (10,000 rpm) and the first Quattros in Group 4 made 265hp...but the quattro made maybe 3x the torque and was spread over a big broad band.
THAT drove the need for 4wd---even on asphalt IN RALLY 9with the width restrictions and available tires in those days)

Different perspective but that's the talk from when this crazy trend was just beginning..and some of it I got directly from at least one person directly and intimately involved (and frustrated too! Saab was so small and the gearbox they could make was very delicate even for good n.a. power, and there was no "9 minutes gearbox swaps" for a Saab)