Mr_TonyC

Carl said:
JGTC is an interesting case. The fastest cars are Supras (front-engined, RWD), then Skylines (front-engined, AWD) then NSXs (mid-engined, RWD). Theoretically the NSXs should be fastest

Ah... but whos got the fastest driver ?

Sorry Theo. yuk yuk. But I've got an AWD as well. so I'm kinda dumbed down. Dumb me down any more and I'd be a mushroom.

Claudius

For the same reason they banned
active suspension
traction control
ABS
bigger wheels
and made the cars narrower

uxg

Just my 2p's worth from a non-technical point-of-view

AWD might be called dumbing down to some. I'd call it good sense. How many people can actually drive a RWD drive car properly in variable weather and raod conditons. Not many. Out of all the people I know I could probably only say 1 or 2 people have that kind of skill.

For the rest of us mortals who can't afford to buy a new set of rear tyres every month and who don't have access to our own private test track or are unwlling to try powersliding on normal roads I'd say it's definately a no no. If I had the opportunity I would love to be able to learn to drive rwd car properly but unfortunatley I can't so in the real world where I live, AWD is the best solution for me as it allows me to go quickly in the reasonably safe knowledge that I am not going to end up in the nearest tree and I think this would apply to 95% of people.

That's why I sm pissed off when people spout on with a holier than thou attitude about "Oh but rwd gives the purer driving experience" and "a true sports car has to be rwd". Says who? I have owned a BMW for nearly 4 years previous to my Scooby and although I did get to learn some of it's nuances by the end of that I can still tell stories of countless instances of ending up looking back the wrong way down the road coz it was slightly wet and the car span at 30mph. I would take the so called boring handling of my Scooby anyday of the week. The stabilty and the speed of exit it can give coming out of a corner far surpasses anything I could do in a rwd car by a long chalk.

carl

All of which offered a performance advantage before they were banned.

Mr_TonyC

Only 1 or 2 people have the sort of skill to drive RWD in variable weather. Crikey.
It wasn;t that long ago that all cars were RWD.
Sorry but what a daft statement.
Its not hard to drive RWD, AWD or FWD without crashing. Know your limits and understand the cars messages.
If you are daft enough to not understand the messages given to you or be wary of road conditions then the only wheel drive that you'll be safe in is ZWD.

ABS, and anything else banned in F1 was more for other reasons than simply that they made cars faster. Spiraling costs, team/manufacturing lobbying/safety.
The williams woudlhave run all manner of active diffs and suspension to make it as fast as it was (enabling the extra traction to be employed). One of these systems goes worng and you are in the boondocks at highspeed. Not to mention, who's driving the car - the driver or the elecy systems ?

carl

Much as you are if you have a rear wing failure. Or a blowout. If the FIA were interested in 'driver skill' they wouldn't have reintroduced traction control. The fact is that the devices quoted have all been banned to keep speeds under control. Stuff like safety/spiralling costs (ban one thing and teams will just spend the money on something else) are just a smokescreen.

ex-webby

carl

neural net = don't know parameters thing... absolutely... the subject is WAY too complex to be able to just come up with a set of parameters that work in all circumstances. So software can be built to monitor what the driver had to do to deal with an output the software made, then learn from that and use further outputs to counter the work he had to do, or try a different output next time based on the newly refined input parameters. Spooky stuff. In the end you take the parameters and compete with them, loggin everything and run the whole lot through the net again, and tweek it with human intervention through testing.

theo... unfortunately, that diff cannot take enough inputs to make it truly useful. It may well have some good uses like opening the diff when the handbrake is pulled, etc. But there is not enough data available to the software to make it do the job really properly (unfortunately).

uxg
Nothin holier than though about it. Just because it didn't suit you, you can't say that it doesn't actually provide a purer sports car experience. If you don't like something it doesn't make it bad.

carl.. I think Claudius was agreeing with you.. but ..

Claudius, is that yet another blanket statement with no evidence to back it up? How can you be so sure? You will note I say things like "maybe it was this" , "i would think it might be that".. you say "this is fact".

Come on Claudius, let's discuss this with some sort of supporting evidence to back it up.. Not just make broad statements based on assumption.

All the best

Simon

Mr_TonyC

Traction control was re-introduced as they could nto think of a way to ban it. Rear wing brakeages, suspension breakages etc are the saem deal. But these are physical things and such can eb stress tested etc and made as safe as possible. Active diffs+suspension are software controlled and there-in lies the safety problem.
Lots of things besides AWD has been baned in F1 - not lal becuase the cars were faster.

I would love to hear of a AWD race car that has been succesful in both wet and dry races that uses mechanical diffs, and not active diffs. I'd love to now how they did it.

ex-webby

in fairness, we are getting off topic here a bit.

I think we would all agree that with high power (meaning, not very low power) AWD with state of the art active diffs is going to be quicker in almost all circumstances ("almost" because of weight disadvantage).

But the discussion was whether standard AWD is "better" than RWD.

As a side note.. I have a new 3 series BM as my hire car out here on the rally and it has this poxy stability control thing. The system is truly remarkable... you can throw it into any bend (at your own risk, etc, etc) at anything but ridiculous speeds and it just sorts it out and drives round.

Unfortunately, after the day's travelling I'd had, I really wanted to switch it off and get at least 1 hours pleasure out of the day, but switching it off only reduced the effect, not removed it (god knows why??)... in fact.. if anyone knows how to turn it off properly I'd be VERY grateful! LOL

carl

Audi A4 BTCC car

BTW Simon -- the problem with neural nets is always providing enough training sets. Do you really have to run the car hundreds/thousands of times to train the net, or can you simulate some of it?

ex-webby

oh.. to be honest, the majority of the big outputs are done manually, then it's just fine tuning. I guess everyone will do it differently, but the neural net is mainly for exception cases...

take the example situation of the lift and steer...

let's say in some situations a driver might do that to gracefully slide the back end out approaching a scandinavian flick... the sudden lock up in the rear would point him in to the scenery in a split second, so the neural net will process that when that happened, the drive had to put in HUGE inputs to hang on to it (and the inertia packs know what actually happened to the car in space) and then the test driver says "holy ****, that was scary" and they analyse what was different about the signature of that input and see if a) they can make a progressive program for it based on the orriginal agressive one, or b) they remove the program altogether and the driver still has to do all the work for the original situation, or c) the driver learns to use that characteristic meaning he needs way less of an input to cope with the second scenario.

A lot of it is way over my head. But the principles at a high level are pretty much the same as chassis development, in that any "improvement" you make in one area, can (and almost certainly WILL) adversely effect another. So you then look at doing something else that handles that as well, which then effects further areas, etc, etc, etc.

The main difference is that you can have a lot more technology working on the calculations, and can set it up to actually "create" partial programs based on it's "experience". And of course, you can change something by plugging a lap top in to it, rather than jacking the car up and changing components.

Cheers

Simon

barry_white69

Well here's my tuppence worth. RWD is faster out of a bend until the power overcomes the rear grip and the wheels start to spin, at which point you are wasting power and threatening to have the end come around. At the moment the rears start to slip you don't want any more power going to them, that's why we have traction control. However rather than just stopping the power it can be beneficial to send it to the front tyres, that way you can use more of the power more of the time.

The benefit of AWD only comes in to play once a RWD car would lose grip at the rear. That is why it is best to have a car that usually has 100% rear drive, but can transfer some of that power to the front at the moment the rear tyres are overcome. So, RWD cars are better because with the weight transfer more grip is available to the driven tyres, however once they spin you are wasting power. So AWD cars are best when you have far more power than grip in slow corners.

Claudius

That's what I said a few pages back, Simon!

And you told me that it surely wasnt only because of the lower weight.

Is there some obscure reason that makes you HAVE TO contradict me or something?

Claudius

Well, YOU are the one who knows better (according to yourself), so why dont you prove me wrong in saying that they did not ban all these things because it was making the car faster?

The whole damn motoring press in the whole wide world, Jacques Lafitte on French TV, Niki Lauda on German TV, Michael Schumacher in interviews etc. ALL agreed that these things were banned to reduce speed to reduce accident damage. Appearently YOU know better. So , please, tell us.

jeremy

TO everyone...

It would seem that there are no magazines or other outside testers that have ever really put any through analisis to any of the road car handling differences about which many speak- based upon their real-life experiences. While of course real-life experiences are great, they do not really allow for comparison with other cars or with a particular car modified!

It would just seem obvious that someone could actually do comparisons of so may of the cars and systems mentioned back to back on real roads or those that mimic real conditions- and use many important parameters to judge how cars react to different road irregularities/conditions, and/or driving techniques. It really could be done. Just pick the aspects of handling/driving technique you wish to test.

However, it would cost money, hence why it has not yet been done, hence, someone with deep pockets would have to fund such a effort. Maybe if my software project comes through I'll fund it?

Comments?

EvilBevel

So Claudius you have active diffs ????

Try a reading course.

Theo

stephen30

Should not have gone to the pub before reading this.
It is very interesting (mostly) and I am learning something. Enjoy the rally Simon.

Steve

ex-webby

Claudius... I'm finding it really difficult to communicate with you.

That is NOT what you said a few pages back. AND I did not just say "AWD cars are slower because of the added weight". I said that AWD with active diffs will be QUICKER in almost all circumstances.. and then clarified that the reason I use the word "ALMOST" (in other words. Not ABSOLUTELY ALL circumstances) and didn't just say ALL is that there are some points where RWD will be quicker than EVEN an active diff car due to the extra weight.

The only reason I would HAVE TO contradict you would be if you are wrong. Do you think I am making this stuff up for fun or something?

Why don't you try to learn something, or at least discuss it, rather than just trying to shoot down anything I say, and take my wording and twist it.

This is SUCH a valuable thread, and this kind of thing is just cluttering it up.

I have never stated that they DIDN'T ban them because it made the cars faster, although I strongly dissagree that this is the case. I merely said that there could / would have been other reasons. I suggested reasons, and gave insight into the reasons why I thought this was the case. I didn't just say "THEY BANNED THEM BECAUSE THEY WERE TOO FAST". Blanket statements!

This is becoming REALLY tiring. They would have been talking about ACTIVE diffs. Read my replies... Read the replies of other people. ACTIVE diff AWD is the ultimate as it gives you everything (along with a slight weight penalty) so it will almost always be quicker.

Regards

Simon

jeremy

Nat,
the only problem with that Evo test was that it was at Mira. No bumps, surface changes obstacles, blind corners etc. Much better to do an Autocar style test (the one where they compared the different drivetrain configurations) on real roads or tracks that mimic them.

In fact I'm not even sure that Mira's wet track is even similar in its surface to any road at all?

ex-webby

The MIRA wet hanlding circuit is something like .8 mu which is the industry standard (as I understand it) for the average road... motorways are higher, something like 1 mu, and really dodgy back roads can be about .6 mu. The delugrip (sp?) stuff they stick in front of roundabouts are about 1.2 MU. (SERIOUSLY grippy)

Mr_TonyC

MIRA's wet handling surface is a normal surface, only the concentric circles are in the multi-layered, multi grip surface (I believe), They also have a small handling circuit near the control tower tht has some very grippy (Dunlop developed ?) surface that is not like a normal road at all.

It was a valid test i think, as most of the elements you describe have nothing to do with the drive train config. Blind corners ? FWD, AWD, RWD - deal with them the same way.
Obstacles - same again unless you mean accident avoidance and so much of that comes down to the driver having the abaility to recover and maintain control of the car - the drive train is irrelevane as its possible to crash any car.
Bumps will upset any car if you go into too hard and the suspension isn't compliant enought - more to do with dampers/springs than drive train. I've seen AWD bounced off a road as easily as a RWD or FWD on a bumpy.

jeremy

Tony,
Actually I would say that public roads would test the chassis of both the 911's more than Mira did, provided you wish to test, uneven surface poise, various forms of stability, self-centering/correcting ability from loss of grip, predicability, progressiveness, and yes accident aviodance and recovery would be good to test for too. And I do believe that drivetrain config would be tested by the above also, because the weight dist of the cars is different, as would be the traction on differing surfaces or losses of grip/recoveries. There really is quite a bit more to the handling equation than first meets the eye, I think that Simon could agree with this.

ex-webby

agreed with jeremy... i think the point however is that nobody (as I understand it) is arguing that on uneven / low grip surfaces, the AWD configuration is superior in the majority of situations.

The "argument" is whether this is also true on smooth clean tarmac.

Cheers

Simon

jeremy

Simon,
Thanks for the reply.
Any thoughts concerning creating handling tests as I mentioned a few posts up? Doesn't it stink that no car rags really put the effort in to truly measure the full compliment of handling dynamics? Couldn't someone do a better job?

Mr_TonyC

There is a lot to it Jeremy, my only point was that the Mira test would be about the best we coudl accept. A test as you describe would be enormouse and probably beyond most mags.
Accident avoidance tests (elk test?) woudl be interesting but like many things a particular drivetrains abilities may not be exploited by everydriver, so the results from a professional driver could be different to a less capable driver.

For an ultimate opinion on a car you really need opinions in the various conditions and states from prefesional, enthusiast, novice and make a judegment based on that and your own abilites.
Mags can only be a rough barometer as to a particulars cars abilities.
The ultimate test is to try it yourself and see what suits you. For me, I'm happy to use RWD in any conditions and I'm able to keep up a good pace if I want to. Others are happy with AWD and that is down to their tastes.

jeremy

Tony,
I agree with you that there is only so much that magazines can do. My problem is that magazines do almost nothing at all!

IanWatson

I thought the recent Evo tests (TED, lateral G, slalom, wet and dry braking etc)looked pretty comprehensive, slightly better than 0 - 60 certainly. Unfortunately they haven't used the format very often.