Fwd Inferior In Motorsport?

[warps]

No, not another FWD vs RWD debate. I know that this topic polarises most opinions, so I really am not interested in hearing uninformed "I drove my cousins Vtec CRX and it felt like a bus compared to my 350hp GTSt" discussion.

I know there are some educated / experienced people here who have very strong views (with engineering knowledge and hard facts to back up their claims) about the benefits / otherwise of FWD. I was reading the regulations for the new ARC G2 class (basically reads like round 2 of the old group G formula). Essentially it's 2WD only, and wither 2L N/A or 1.6L forced induction. It sounds like it's geared for the small shopping trolleys (Jazz / Fiesta / Polo etc) with engine transplants, and a lot more freedoms than the boring old Gp N (and even PRC) used to allow.

Anyway, to my point. I note that the FWD cars get hit with a 40-50kg weight penalty (depending on engine size). If FWD is so inferior, why do the RWD's get lower weight limits? I know that it has been said that FWD is beneficial in very specialised cases (motorkhana - low speed on slippery surfaces) but the ARC these days is much more high speed than the tight twisty stuff where FWD is supposed to have a benefit. My own experience with FWD vs RWD tends to support the beneifts of FWD on dirt. Interested to hear some (educated) views.

The full regs can be found here http://www.camsmanual.com.au/pdf/04_rally_road/RR17_Group_G2_2012-1.pdf

Regardless of whether you prefer FWD or RWD, I think that a bunch of light weight 250hp 2WD rockets in the forest (with manufacturer support at some level) can only be a good thing.

[JAS-25T]

Only sensible answer I can give in regards to the weight penalty is that the RWD drive train is heavier, and therefore FWD is given a penalty to even it out.

[MBS206]

If it's a minimum weight, then that wouldn't make sense. Which I think this is what OP is referring to.

[hrd-hr30]

strange regs - a NA 2l would have no hope compared to a decent 1.6turbo! Are they seperate classes or all lumped in together?

[Marlin]

^^^ that's what I was wondering?

The new model BMW 120i would be the go, grunty little 1.6 with a Borg Warner snail on it

[warps]

Yeh, Harry - I think it's a draft at this stage - there's still a few copy and paste errors in there. eg how they quote minimum weights for cars with an engine capacity of 5 litres (what multiplier are they using for that?)

1.6 turbo would put it into the over 2L category in all other CAMS rally regs, so I can't see how they would lump the 2 together - which makes your point even more significant.

I don't know how much a 30mm restrictor would...errr....restrict a 1.6 turbo engine, but that may be what they're trying to achieve. I think that would limit power to the vicinity of 250hp, which is easily achievable with NA 2L (obviously massive difference in torque curves)

[Marlin]

Yeah, the torque is what talks, never mind the HP figure.

[Dale FZ1]

Having trouble getting the regs to download so can only go off comments posted above.

The 1.7 multiplication factor would always see a turbo 1.6 running in a different equivalent engine capacity class.

Torque hauls cars out of turns, but getting a FWD with massive midrange to pull, steer, and not eat its front tyres in a single stage might be a challenge.

I'd be all for ballasting the turbo cars if that meant hearing a b.it of N/A bark in the forest. But I don't think weighting up FWD cars is the way to encourage broader participation. How many small/medium RWD platforms are out there these days? Not many .

[Duncan]

Interesting. This is dirt rally right?

The only thing I know for sure is that none of the existing dirt formulas are being won by rwd cars over fwd cars. I have seen very few rwd in the forests since the 1600s all (mostly) died off, and all the new cheap cars are fwd. There are a handful of rwd around (I remember speaking to a guy in NSW having some success with a Silvia na) but very few.

But it is very hard to do a fair comparison just based on the driven wheels, because so much else is different. Especially in production based cars because manufacturers dont generally make a big FWD, or a small RWD to compare. In NSW prod circuit racing it is AWD > RWD > FWD, but then again the fastest FWD makes about half the power of the RWD cars. Certainly BTC and WTC prove the FWD and RWD can be very close under tight enough regs.

[Dale FZ1]

AWD cars are very efficient point-to-point cars through the forest. No doubting that. But if all I want to see is something fast I can go to the nearest airport and view the takeoffs. The 2wd regs are an overdue step in the right direction from the viewpoint of spectator interest. And I think that a sensible approach to regulating for equity/ parity between N/A and turbo via weight and/or inlet restrictors would work. Might also be a workaround for cost savings so people don't feel obliged to have to build a new car each year or 2 just to stay competitive? The economic climate doesn't look like getting any healthier anytime soon so any competitor interest is better than dwindling numbers.

I think the Poms have got it right with their touring car formula. They are prepared to play with it to ensure it continues to work rather than let things go and then wonder what went wrong.

Edited January 25, 2012 by Dale FZ1

[hrd-hr30]

I know there's a 1.7 multiplication factor for turbos, but that means very little when the ARC is for 2WD vehicles this year. The turbos and NA's will be going head to head for outright regardless of maths.

[Dale FZ1]

Agreed, but the maths is (for me) where it's at to ensure the different configurations ARE going head to head. I don't want to see a one/two make championship, and I would like to see a Drivers championship. Where's Jack Monkhouse?

[Nee-san]

Interesting. This is dirt rally right?

The only thing I know for sure is that none of the existing dirt formulas are being won by rwd cars over fwd cars. I have seen very few rwd in the forests since the 1600s all (mostly) died off, and all the new cheap cars are fwd. There are a handful of rwd around (I remember speaking to a guy in NSW having some success with a Silvia na) but very few.

But it is very hard to do a fair comparison just based on the driven wheels, because so much else is different. Especially in production based cars because manufacturers dont generally make a big FWD, or a small RWD to compare. In NSW prod circuit racing it is AWD > RWD > FWD, but then again the fastest FWD makes about half the power of the RWD cars. Certainly BTC and WTC prove the FWD and RWD can be very close under tight enough regs.

This is more or less on the money, it seems the entire automotive market is making a shift towards smaller FWD vehicles, even into the sports car theatre.

Racing, especially in production based categories always reflects the general state of the domestic market with trends etc.

I know in BTC and WTC that RWD cars are penalised with weight over the FWD models and of course AWD has the harshest penalties of all.

It comes down to the fact that there are far less RWD cars that are small and lightweight enough to compete with some of the FWD vehicles being run.

Most FWD vehicles are small and very lightweight, which is more of a differentiator then the performance deficit fundamental in FWD layouts.

Generally when I make an argument about the various pros and cons of a drivetrain layout, I use a like for like comparison. weight, COG etc etc.

anyway this is more about rally and does not IMHO accurately reflect the consensus of motorsport(S) in general.

[warps]

anyway this is more about rally and does not IMHO accurately reflect the consensus of motorsport(S) in general.

Dem's fighting words, fella.

Agree though - FWD's don't seem to have the same "advantages" in other forms of motorsport as they do in gravel rally. (apart from some very quick Civics in U2l IPRA) Even the rally communities are divided on the FWD vs RWD debate. I've seen some basic spec FWD's carve up much faster and more powerful RWD's (turbo RX7's, Silvias) - even taking driver talent into consideration. Even my own stock engined EG civic, which gets hosed at LAkeside to the tune of 10 sec a lap can hold its own against the RWD's on dirt (I have always managed to finish ahead of all but 1 RWD car in dirt sprints so far)

Will be interested to see how this pans out though. I hope it isn't one sided, or doesn't turn into a "one make series". Whether you love RWD or not, you can't deny that the sight and sound of a well driven NA RWD in the forests is poetry in motion indeed

[mad082]

This is more or less on the money, it seems the entire automotive market is making a shift towards smaller FWD vehicles, even into the sports car theatre.

Racing, especially in production based categories always reflects the general state of the domestic market with trends etc.

I know in BTC and WTC that RWD cars are penalised with weight over the FWD models and of course AWD has the harshest penalties of all.

It comes down to the fact that there are far less RWD cars that are small and lightweight enough to compete with some of the FWD vehicles being run.

Most FWD vehicles are small and very lightweight, which is more of a differentiator then the performance deficit fundamental in FWD layouts.

Generally when I make an argument about the various pros and cons of a drivetrain layout, I use a like for like comparison. weight, COG etc etc.

anyway this is more about rally and does not IMHO accurately reflect the consensus of motorsport(S) in general.

getting slightly off topic for a second (partly to stir a few people up), had the weight penalties been more accurately/evenly done then the GTR wouldn't have had the success it did.

back on topic, i think that where fwd gets its advantage in rally is from the fact that, as it was said in the first post (i think), it can pull itself out of the corners, where as rwd has to balance oversteer and understeer. both rwd and fwd will understeer into a corner (pretty easily) when pushed too hard. but if oversteer occurs then the fwd can pull itself out while the rwd has to try and accelerate and control the slide with the wheels that have lost traction. also when running a bit wide (and losing a bit of rear traction) and fwd cars are putting their power down on a 'cleaner' part of the track. all the loose gravel gets pushed to the outside of the track, where the rwd cars are trying to get their drive from.

[Duncan]

well on tarmac, the btcc fwd cars certainly show the advantage of being able to keep their foot down when the car starts to oversteer....those guys catch the biggest angle slides I've ever seen. If you were in a rwd you would give up and hit the anchors, going along for the ride, waaaay sooner.

[Duncan]

Will be interested to see how this pans out though. I hope it isn't one sided, or doesn't turn into a "one make series". Whether you love RWD or not, you can't deny that the sight and sound of a well driven NA RWD in the forests is poetry in motion indeed

BTW I totally agree with this. no doubt rwd is the most fun to drive.

it's just when you are chosing a formula/set of rules, it may not be the cheapest, fastest, or most competitive.