4 wheel drive & the real world
Discussion
GravelBen said:
I'm trying to think of a race series people have entered 4wd vehicles in that hasn't ended up banning or at least restricting/ballasting them to equalise performance. 
I'm trying to think of a wet b-road where you would be anywhere even close to that kind of performance without risking every other road user.cologne2792 said:
300bhp/ton said:
Maybe power plays a part in it too. My 4.0 litre Cherokee could be rwd (open diff) or AWD with an open centre diff.
On the road it drove a lot better in AWD and would just wheelspin far too easy in RWD and make it unruly on tight turns. In the dry 2wd was fine, or if you drove more gentle. But in AWD mode you really could abuse it and hussle it along at a fair old rate.
Unfortunately Ranger drivers don't have that option. No centre diff means rear wheel drive + lsd or 4wd on loose or slippy surfaces only - when we did have some snow last year then in rwd it was going nowhere but once in 4wd it was quite brilliant and felt like normal tarmac.On the road it drove a lot better in AWD and would just wheelspin far too easy in RWD and make it unruly on tight turns. In the dry 2wd was fine, or if you drove more gentle. But in AWD mode you really could abuse it and hussle it along at a fair old rate.
GravelBen said:
doogz said:
WRC?
You can enter a 2WD car if you like, there's no penalty for having 4WD.
You can enter a 2WD car if you like, there's no penalty for having 4WD.
Fair point, I guess you could still enter a 2wd if you didn't mind being slower than everyone else. Some of the slower classes do exlude 4wd though.
WRC cars when dealing with gravel/ice/snow are not really relevant to this debate.
Edited by nickfrog on Tuesday 28th January 12:11
doogz said:
Scuffers said:
No?
There were 2wd audis running, as well as Peugeot.
There were? in LMP1?There were 2wd audis running, as well as Peugeot.
They don't appear anywhere on the entry list or the results.
That said, the quatto Audi would seem to be faster than the non quattro?
Scuffers said:
Shambler said:
I think if you are being honest, a good spec four wheel drive car such as the sti or evo in the wet on a country road will be extremely hard to beat. Did Chris Harris not say something similar in his review of the A45. The limiting factor for the P1 is it's size, width of tyres and road clearance.
blearyeyedboy said:
I think choice of tyres makes almost as much difference as drivetrain for the majority of people.
Mave said:
Doubt it. 2g at speed means stiff suspension- hardly optimised for potholed B roads...
Good to see some here have actually thought about it and come up with the pertinent points....as an example of what I am getting at, if anybody has been to Bedford Autodrome for a trackday when it's wet, you will know that it get's somewhat slippery.
try driving an Elise on Pzero's round there and it's just comically slow, basically zero grip and even less traction - basically, too light a car on the wrong tyres, (I actually managed to out-corner them easily in a 2+ tonne Jeep)
in the dry, completely different story.
We were in an old Sierra XR4x4.
deltashad said:
The people who really need AWD in this country won't buy an X-drive 5 series, they'll buy a RWD 5 series and something a bit more useful as a work horse for when they really need it.
I'd disagree with that remark as I know half a dozen people who have either collected or have ordered a 3 or 5 series X-Drive in the past twelve months. Not everyone lives in London and not everyone feels the need to have an SUV just because they live in the middle of nowhere and commute 70+ miles a day over broken moorland roads which frequently have potentially problematic driving conditions in winter.scherzkeks said:
300bhp/ton said:
Also depends how the car is setup, oversteer and power oversteer aren't quite the same thing.
When I first got my Impreza I wondered how it'd handle on the limit, as TG and the mass media will tell you they understeer massively.
Which is precisely the problem with certain ego-driven reviews. And a lot of modern mags suffer from it. Understeer isn't in and of itself inherently any "worse" than oversteer. So long as the car allows the driver to keep things neutral on limit and get the rear rotating enough to follow the front end, all is well. Mild understeer is almost always preferrable to a car that is prone to persistent oversteer -- which is fatigue inducing to drive at the limit over time. When I first got my Impreza I wondered how it'd handle on the limit, as TG and the mass media will tell you they understeer massively.
Oversteering due to losing rear lat grip has little to do with which wheels are driven. It has to do with how the car is set up.
Power oversteer is a function of the driver's ability to modulate the throttle as opposed to rely on 4wd. Each to their own though.
But at least when you oversteer you can still steer, unlike when you understeer.
Again, watch the Monte Carlo rally last week on wet asphalt and tell me that drivers prefer understeer, even with 4wd.
Edited by nickfrog on Tuesday 28th January 12:15
GravelBen said:
I'm trying to think of a race series people have entered 4wd vehicles in that hasn't ended up banning or at least restricting/ballasting them to equalise performance.
Race series aren't really a level playing field for technology, though, once you've put technical regulations in place. The 4wd cars might have a higher minimum weight, for instance, but if otherwise they would run at the same weight as the 2wd cars while carrying less ballast (because they are inherently heavier, and the 2wd cars aren't allowed to run as light as they could do) you're into a highly artificial situation. otolith said:
GravelBen said:
I'm trying to think of a race series people have entered 4wd vehicles in that hasn't ended up banning or at least restricting/ballasting them to equalise performance.
Race series aren't really a level playing field for technology, though, once you've put technical regulations in place. The 4wd cars might have a higher minimum weight, for instance, but if otherwise they would run at the same weight as the 2wd cars while carrying less ballast (because they are inherently heavier, and the 2wd cars aren't allowed to run as light as they could do) you're into a highly artificial situation. deltashad said:
A FWD car on winter tyres is probably just as effective as AWD in snow conditions running summer tyres.
Under those circumstances and trying to negotiate narrow lanes on steep hills where I live - no. Without a front lsd all that occurs is the power is spun away by one wheel.On more level ground under those conditions - I'm sure you're right.
Neither my fwd XM or rear wheel drive Ranger will cope - but with the drive spread out more in 4wd the Ranger will.
nickfrog said:
You clearly still don't understand the difference between power oversteer and lat grip oversteer, which was 300BHP/ton was referring too.
Oversteering due to losing rear lat grip has little to do with which wheels are driven. It has to do with how the car is set up.
Power oversteer is a function of the driver's ability to modulate the throttle as opposed to rely on 4wd. Each to their own though.
But at least when you oversteer you can still steer, unlike when you understeer.
Again, watch the Monte Carlo rally last week on wet asphalt and tell me that drivers prefer understeer, even with 4wd.
I wasn't discussing power oversteer. I was discussing the fact that many of the mags today pan AWD cars as being understeery, yet said understeer is typically mild and progressive in onset and almost entirely avoidable when the chassis is driven with sympathy for its AWD nature. Further, power oversteer is not fast, it is slow; and an "understeery" AWD that allows neutrality via trailing throttle allows a driver to almost entirely eliminate understeer. Oversteering due to losing rear lat grip has little to do with which wheels are driven. It has to do with how the car is set up.
Power oversteer is a function of the driver's ability to modulate the throttle as opposed to rely on 4wd. Each to their own though.
But at least when you oversteer you can still steer, unlike when you understeer.
Again, watch the Monte Carlo rally last week on wet asphalt and tell me that drivers prefer understeer, even with 4wd.
Slow-in, fast out. No pinning the throttle on corner exit. Driven this way, any AWD car that distributes torque in a balanced manner will be stable, fast, and for those of us that enjoy performance driving in the classical sense, fun.
In most of the technical threads on AWD you tend to just hurl endless abuse, but keep quiet on issues related to how the systems function and the driver's role in the process -- I can see why.
Scuffers said:
otolith said:
GravelBen said:
I'm trying to think of a race series people have entered 4wd vehicles in that hasn't ended up banning or at least restricting/ballasting them to equalise performance.
Race series aren't really a level playing field for technology, though, once you've put technical regulations in place. The 4wd cars might have a higher minimum weight, for instance, but if otherwise they would run at the same weight as the 2wd cars while carrying less ballast (because they are inherently heavier, and the 2wd cars aren't allowed to run as light as they could do) you're into a highly artificial situation. Having onced/driven all 3. The only real benefit is getting moving quickly is easier in 4x4s.
Fwd and rwd can scrabble for grip if you want to get away quickly.
I've found it helpful in standing water but then again, having a weight advantage will help along with good tyres with loads of tread.
My limited experience on tracks with fwd and rwd is that rwd was more fun to drive. I have only done 2 track days so not a very good example though.
Fwd and rwd can scrabble for grip if you want to get away quickly.
I've found it helpful in standing water but then again, having a weight advantage will help along with good tyres with loads of tread.
My limited experience on tracks with fwd and rwd is that rwd was more fun to drive. I have only done 2 track days so not a very good example though.
otolith said:
What is the minimum weight for a fwd car? How much lighter would the fwd cars be than the 4wd cars if you removed all weight limits and penalties?
Not sure for BTCC cars, but the couple of series that aren't regulated for weight between 2wd and 4wd, the 2wd cars are about 10-20% lighter depending on power outputs.deltashad said:
cologne2792 said:
300bhp/ton said:
Maybe power plays a part in it too. My 4.0 litre Cherokee could be rwd (open diff) or AWD with an open centre diff.
On the road it drove a lot better in AWD and would just wheelspin far too easy in RWD and make it unruly on tight turns. In the dry 2wd was fine, or if you drove more gentle. But in AWD mode you really could abuse it and hussle it along at a fair old rate.
Unfortunately Ranger drivers don't have that option. No centre diff means rear wheel drive + lsd or 4wd on loose or slippy surfaces only - when we did have some snow last year then in rwd it was going nowhere but once in 4wd it was quite brilliant and felt like normal tarmac.On the road it drove a lot better in AWD and would just wheelspin far too easy in RWD and make it unruly on tight turns. In the dry 2wd was fine, or if you drove more gentle. But in AWD mode you really could abuse it and hussle it along at a fair old rate.
However on deeper snow, fresh snow or very powdery snow, then less so. Also if the snow is laying on wet tarmac or mud or grass. In such situations AWD can be a lot more useful.
Especially if you need to go up and down curbs, or onto the verge or into a field to get around obstacles (other stranded vehicles). Or indeed snow deep enough to beach a car.
Personally I'd take 4wd most times as it offers a wider degree of abilities in the snow, even if you end up driving a little slower than a 2wd on snow tyres.
It's also worth remembering many 4x4's are fitted with M&S rated tyres, so can be quite capable with no changes.
My Impreza worked very well in the snow last winter, but tbh a Jeep or Land Rover is way better in such conditions.
Gassing Station | Advanced Driving | Top of Page | What's New | My Stuff