Why is AWD Banned in Most Touring Car Series?Touring Cars 

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GT3, GTE, GTLM, and GT4 all ban AWD. Why is it so? I know that various race cars that had AWD were so dominant that the respective series they raced in banned the drivetrain configuation, but why is the rule still carried over to this day, when BoP can make adjustments to balance the AWD advantage these cars get?
 
GT3, GTE, GTLM, and GT4 all ban AWD. Why is it so? I know that various race cars that had AWD were so dominant that the respective series they raced in banned the drivetrain configuation, but why is the rule still carried over to this day, when BoP can make adjustments to balance the AWD advantage these cars get?

Last series I saw trying to performance balance AWD was Italian/European V8 Superstars with the RS5 against the likes of M3's and C63's. It wasn't that successful, and the restrictions got pretty silly in the end, IIRC ballast penalties of 100kg, tiny air restrictors, and ride height set at something like 100mm were used, which made the car a road block in most circumstances but still too quick in others.

Fun series though, it's a shame it folded.
 
Where is the RS5 competitive and where does it become a roadblock? The BoP to that thing seems like overkill :ill:

The problem is, it had a significant traction advantage, so giving it more weight and less power didn't address the real issue at all - it slowed them down across a lap by slowing them down on the straights (where they didn't have an inherent advantage), but it didn't properly address their advantage through the corners. It's not like it made the series uncompetitive or anything, the RS5 still won and though it wasn't utter domination, it did seem like the rules weren't thought out very well.

There's a few races on YouTube, worth checking out, though I can't remember now which seasons to look out for, probably 2012 and 2013.

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The closest to GT4 I can think of, is Super Taikyu, Production Car racing and Speedvision WC&TC.
In S-Tai, Impreza and Evo duke it out in a separate class. In the past Speed WC/TC, Audi(RS6 & A4) and Impreza, ran in the same class as their competitors. Shannon's National PC have awd cars versus RWD(the RWD cars are actually quicker).

Moving up to GT3 cars and stepping down from LMP, can it be a cost thing? Audi, Lamborghini, Bentley(?), Nissan, maybe Jag, have awd systems for the road cars represented in GT3. I feel if those cars were able to develop their awd systems, it'd be too much cost involved.
 
The problem is, it had a significant traction advantage, so giving it more weight and less power didn't address the real issue at all - it slowed them down across a lap by slowing them down on the straights (where they didn't have an inherent advantage), but it didn't properly address their advantage through the corners. It's not like it made the series uncompetitive or anything, the RS5 still won and though it wasn't utter domination, it did seem like the rules weren't thought out very well.

There's a few races on YouTube, worth checking out, though I can't remember now which seasons to look out for, probably 2012 and 2013.

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So in a way, they went the GTS route of doing BoP and had the car specialize to specific tracks? I'll check out youtube later, sounds lika a good series in general :)
Shannon's National PC have awd cars versus RWD(the RWD cars are actually quicker).
How does this competition achieve the RWD advantage? Do they BoP or do they give AWD competitors handicaps?
Moving up to GT3 cars and stepping down from LMP, can it be a cost thing? Audi, Lamborghini, Bentley(?), Nissan, maybe Jag, have awd systems for the road cars represented in GT3. I feel if those cars were able to develop their awd systems, it'd be too much cost involved.
What I thought is that should GT3 allow AWD, the system should be derived from the production car, just like the engine to keep costs down. Or go the Ford GT route and make a road car to meet homologation requirements for the race car :lol:
 
In any series where development is open and there is no BoP, sky’s the limit on how much money you want to spend on R&D for an AWD system, so banning it becomes a cost saving excercise.

In series with BoP, it’s really difficult to BoP RWD cars against AWD cars. BoP is difficult and controversial enough as it is, adding AWD to the mix complicates it immensely.
 
In any series where development is open and there is no BoP, sky’s the limit on how much money you want to spend on R&D for an AWD system, so banning it becomes a cost saving excercise.

In series with BoP, it’s really difficult to BoP RWD cars against AWD cars. BoP is difficult and controversial enough as it is, adding AWD to the mix complicates it immensely.
Ohhhh I can see that. My initial train of thought is that if AWD cars are given enough of a weight ballast, the RWDs can compensate on apex speed, while the AWDs will probably dominate the exit. Now that I look at it that's a really simple train of thought :lol: thanks for the explanation :D
 
IIRC, the Continental Tire Sports Car Challenge series used to have Subaru's with AWD. They weren't dominant at all, I'm assuming from some form of BoP. That was several years ago though so I don't know if they still run these days.
 
IIRC, the Continental Tire Sports Car Challenge series used to have Subaru's with AWD. They weren't dominant at all, I'm assuming from some form of BoP. That was several years ago though so I don't know if they still run these days.
CTSCC had AWD Audi A4s in the ST class as recently as last year. They were moderately successful, the team kind of struggled with general setup for most of the 2 seasons they ran the cars. They did have one or two good races, but if I’m remembering correctly, only did well when it was wet or raining.

Ohhhh I can see that. My initial train of thought is that if AWD cars are given enough of a weight ballast, the RWDs can compensate on apex speed, while the AWDs will probably dominate the exit. Now that I look at it that's a really simple train of thought :lol: thanks for the explanation :D
I don’t think it’s as simple as “rwd can have faster apex speed”

How much fiddling around would you need to do to make a Lexus RCF or Merc AMG (rwd boats) have higher apex speeds than a Lambo Hurricane or Audi R8?

If you stick to the rule of “AWD in big heavy cars, rwd in lightweight nimble cars”, then maybe....but the system breaks down if you put an AWD system on a nimble, lightweight car.

Furthermore, corner exit speed is king in racing. If you look at just overall lap time, then yes, there’s lots of different ways for different chassis to make similar lap times around a given circuit. However, racing wheel to wheel, corner exit speed will trump any other performance advantage, be it straight line speed, braking, or mid corner speed. A driver who knows how to take advantage of their exit speed advantage while defending in braking zones is nearly impossible to overtake, especially if you’re in a car who’s performance advantage is mid corner speed. Mid corner speed is no good if there’s a brick 🤬 house parked on the road at the apex.
 
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So in a way, they went the GTS route of doing BoP and had the car specialize to specific tracks? I'll check out youtube later, sounds lika a good series in general :)

How does this competition achieve the RWD advantage? Do they BoP or do they give AWD competitors handicaps?

What I thought is that should GT3 allow AWD, the system should be derived from the production car, just like the engine to keep costs down. Or go the Ford GT route and make a road car to meet homologation requirements for the race car :lol:
I believe, in Shannon's Nationals. I believe it's just about a better performing car. The M4 & M3 and the 1-Series hatch, have just been way faster in a straightline over the Evo, STI and Focus RS. However, the AMG A45s can nearly match the BMW's in top speed.

South Africa's Sasol Production Car series had the S4 vs 335i. Don't know the BOP there, but they seemed evenly matched.

With DTM and Group A having done awd about 25 years ago, it didn't last long. Even in IMSA GTO. It's just the clear advantages evidenced by the Quattro and R32. I have no idea how BOP rules could govern about 10 different manufacturers in one series.
 
What about series where everyone has AWD so it's even? Any cup series like that?

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For BoP, why not limit tire width over putting in ballast and restricting power? Less width allowed for AWD, more for RWD. Wouldn't that balance out a tad better?
So the AWD teams would need to bring different wheel packages every time they had the BoP adjusted? And the tire supplier would need to make special width tires just to accommodate the AWD BoP. Sounds extremely impractical.
 
So the AWD teams would need to bring different wheel packages every time they had the BoP adjusted? And the tire supplier would need to make special width tires just to accommodate the AWD BoP. Sounds extremely impractical.
How about have the tire width not balanced, but rather required by the rulebooks to be a set width thinner than RWD? This would standardize AWD tire width so tire manufacturers wouldn'tbe so strained. But like all other new rules, it couldn't be perfected in a year, so I'm guessing they'll change the tire wodth regulation every year or so. At least it gives the tire manufacturer time to research and prepare for these tires?
 
How about have the tire width not balanced, but rather required by the rulebooks to be a set width thinner than RWD? This would standardize AWD tire width so tire manufacturers wouldn'tbe so strained. But like all other new rules, it couldn't be perfected in a year, so I'm guessing they'll change the tire wodth regulation every year or so. At least it gives the tire manufacturer time to research and prepare for these tires?
Some series run multiple branded tyres. There may be advantages to certain brands, even with a narrower width.
Could be an aero advantage as it's narrower, maybe a wear advantage because it weighs lesser than a wider tyre. Maybe costs significantly less or could cost more if it's the minority size over the field.
What if one manufacturer are the only supplier to those awd teams and also have to supply tyres to a portion of RWD teams? That's a lot of R&D.

Again, probably a good reference is Super Taikyu. Mainly Yokohama supplied tyres, but Pirelli have take over.
 
I’m just remembering that Formula Drift uses tire width as a form of BoP. I haven’t followed the series closely for a couple years now, so not sure if they’re still doing this, but they used to use a formula that used the weight of the car to determine the max width of the tires. Heavier cars got to use wider tires.

The problem was that people quickly figured out that a heavy car with wide tires could put the power down really well, so lightweight cars disappeared and the cars became more and more like 1000hp dragsters.

In my opinion FD has never been good at writing a rule that works, this tire width one didn’t seem to have the desired effect, and like I said, I’m not sure if it’s still in use. I’ve only mentioned it as an example of a series using tire width to balance performance across various chassis.
 
I’m just remembering that Formula Drift uses tire width as a form of BoP. I haven’t followed the series closely for a couple years now, so not sure if they’re still doing this, but they used to use a formula that used the weight of the car to determine the max width of the tires. Heavier cars got to use wider tires.

The problem was that people quickly figured out that a heavy car with wide tires could put the power down really well, so lightweight cars disappeared and the cars became more and more like 1000hp dragsters.

In my opinion FD has never been good at writing a rule that works, this tire width one didn’t seem to have the desired effect, and like I said, I’m not sure if it’s still in use. I’ve only mentioned it as an example of a series using tire width to balance performance across various chassis.
Hmm, considering that AWD will be inherently heavier than RWD, be it by actual construction of the car or by balancing regulations that history has reflected many times over, would it compensate for their thinner tires that some of us suggested?
 
The elephant in the room here is that we're all trying to suggest ways of taking away AWD's advantage to even things out... and if you take away its advantage, then there's no point having AWD in the first place. When it's "even" with everything else you just have a car that's more complicated and BOP'd into oblivion for no benefit to those competing in it and no benefit to those watching.
 
I would have thought smaller/lesser brake discs would be a good and interesting solution. You can keep your 4WD corner exit advantage, because now you're having to make up the time you lost approaching the corner.

I'd think the pros and cons would create more on track battles.
 
I would have thought smaller/lesser brake discs would be a good and interesting solution. You can keep your 4WD corner exit advantage, because now you're having to make up the time you lost approaching the corner.

I'd think the pros and cons would create more on track battles.
It's a good idea, as was the narrower tyres thing, but it does come back to hobbling AWDs in such a way that they can't use any of their inherent advantages.

I recently spent some time talking to some of the people involved in the BTCC when the Audi A4 was racing. That car was good pretty much everywhere aside from top-end power. It had better traction than other cars, it had less tyre wear because it had better traction, it had more stability because it didn't need to be set up in a natural oversteer stance like the FWD cars (which are very twitchy just to help them turn), and it was better on the brakes because of all the above. Oh, and unrelated to it being AWD but a factor anyway, it was mega-reliable. And Biela was a machine.

They did run weight penalties from the start, and then increased them further after the car dominated the first half of the season, but its advantages were inherent to it being all-wheel drive. You could potentially even it out by taking away brakes or grip or whatever, but that goes back to what I said above - you take away the incentive for a car being AWD if you remove the benefits of that AWD, when fielding a FWD or RWD car would be simpler.

Now to be fair, Audi's decision was marketing as much as anything (I bet they sold a few A4 quattros on the back of it thrashing everyone in the BTCC), and once AWD was banned and Audi ran FWD it was no longer competitive anyway (because it wasn't quick in a straight line and the longitudinal engine gave it poor weight distribution), but those are only really problems for a production-based formula, which Super Touring (very loosely) was. If you're building an AWD race car from scratch for a GT series or something and then the governing body gives you crap brakes and skinny tyres, you may as well just save the effort and run two-wheel drive.
 
The easiest way is to help the non-AWD than making AWD suffer. Give the two wheel drive cars better grip, more power, less weight or better aero, make them competitive against AWD. A limit can be imposed on the AWD, tire width, weight, power, aero limit. Limiting the amount of torque that can be split in AWD also may be useful or disallow the dynamic torque distribution like ATTESA or Haldex.
 
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