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Old 01-29-2010, 12:24 AM   #16
BimmerDriver
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Great explanations John. And Dave, just to sum it up, if it makes it easier to understand just think of this. You know how when you send too much torque to the wheels they break loose and spin? Like when you build up revs and dump the clutch?

You can actually try this on a tight corner like a 360 highway ramp as somebody said with an AWD and a FWD. Just slowly increase the speed while cornering until you find the point where the wheels start to slide a little bit.

On an RWD when that happens the rear wheels lose grip, that is good from a handling standpoint because the tail slides outside and basically slingshots around like a pendulum pointing the nose towards the inside of the corner (where you want it to go).

On an FWD the front wheels would be the ones to lose grip, that's bad cause now the nose of the car would slide towards the outside of the corner where you don't wanna go, so you have that feeling you're going too fast for the corner and you won't make it, in order words, understeer. AWD are similar in that way cause they also have so much grip going to the fronts

Of course there are AWD cars that have exceptional handling even on tarmac like the R8 and the Nissan GTR but those send only about 20% traction to the front wheels and the rest to the rear to avoid this kind of situation. Most of these cars also have an automatic system that adjusts the traction balance sending more or less power to the fronts or rears depending on the situation. These systems solve the understeer problem but they are still way heavier than a simple RWD, that's why those are used in high end racing like F1

For tarmac racing then, RWD is the perfect combination because the front wheels do the steering and the rears do the propulsion instead of using the fronts for both. If you watch Top Gear at all, pay attention when you see Jeremy and his buddies testing those FWD hot hatches like those powerful VW Golf concepts and stuff, they have so much power on the front wheels that it just overwhelms the tires while cornering, you hear that understeer tire squeal, and the car struggling to make the corner hopelessly... When you see them testing RWDs though all you see is spectacular oversteers, that's cause they push it too much on purpose but overall that makes the car more maneuverable

As for Heel-and-toe and throttle blips for the turbo, Ayrton Senna was a master on that. Back when F1 used to have manual transmissions and turbos no-one knew how he was so fast until after they released the telemetry which showed that he used to blip the throttle really really fast during the corners and other drivers would just coast along the apex until it was time to get on the power again. Schumacher did something similar, but with automatics which was easier hahaha. Check Senna's foot work on this video, pretty sick stuff:
http://www.youtube.com/watch?v=yAwJsOECGBU

This other video about Schummi's technique is pretty interesting as well:
http://www.youtube.com/watch?v=Uk2p2nRK-p4

Last edited by BimmerDriver; 01-29-2010 at 12:51 AM.
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Old 01-29-2010, 03:31 PM   #17
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Good videos, thanks.
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Old 01-29-2010, 05:00 PM   #18
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Senna was nuts, I just realized he was wearing no helmets, dress shoes and going flat out on Suzuka lol

Too bad he's gone :/
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Old 01-29-2010, 07:54 PM   #19
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sorry but explain how the ix is more revolutionary then the quattro system? I am a bimmer guy, but no other awd car i've driven was anywhere near as great as the quattro systme on my 20year old audi 90 20v Quattro! And the awd cars im comparing it to, are a subaru wrx, forester, ix, and mazda gtx.

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Old 01-29-2010, 11:34 PM   #20
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could it be argued though that with the latest technological enhancements to awd systems found in cars like the audi r8 and nissan gtr that they are superior to rwd systems because they make it a much easier car to drive at the limit?
No it can't. I'll try and explain in as little space as possible. These systems ARE vastly more advanced than Quattro from Audi, but still not as good as RWD on dry tarmac.

I'll use the Porsche 911 as an example because they make both a awd and rwd versions. The 911 turbo is awd and vastly powerful, but weighs approx 3500 lbs, the GT3 is non turbo and makes way less hp and torque, is rwd and weighs approx 3100 lbs. (I don't remember exact figures and am too lazy to look them up right now - this is just for example) The GT3 is almost as quick in a drag race, but lap for lap is considerable quicker than a 911 turbo. A test was done at Willow springs in Cali, and the GT3 was a staggering 3.5 seconds a lap quicker than the Turbo.

Why? Weight and drivetrain. The awd in the turbo coupled with the added weight creates a very poor understeer condition, where the GT3 is much more balanced and can carry way more speed through the corner. Yes the Turbo can get on the power a little sooner, but too little too late.

The R8 and GTR do not as of yet have a sibling with rwd only to do back to back comparisons, but these cars would shed somewhere in the vicinity of 300 lbs if they lost the awd systems and would therefore increase the grip through the corners and accelerate quicker from 2nd gear onwards as the power to weight ratio is more favourable, and traction no longer a concern. AWD is good to the layman, who is intimidated by high powered rwd cars, but for REAL performance and or anyone interested in track days/lapping/racing, definitely RWD is the only option.
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Old 01-29-2010, 11:41 PM   #21
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^ Good point. In mid to late-2000s, Raeder Motorsport ran a Lamborghini Gallardo in the VLN Endurance series at the Nurburgring. It too was converted from AWD to RWD.
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Old 01-30-2010, 12:26 PM   #22
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AWD is good to the layman, who is intimidated by high powered rwd cars, but for REAL performance and or anyone interested in track days/lapping/racing, definitely RWD is the only option.
was waiting for someone to chime in, maybe there is some hope for this forum.

Lets go theoretical. Simply put lets say two cars weight exactly the same and the weight is distributed exactly the same, and their geometry and engineering is exactly the same, however, magically one is awd and one is rwd. obviously, the awd will launch quicker because it has power at 4 wheels. the awd one will be easier to drive faster by the novice driver simply due to lack of skill. put both these cars in the hands of an experienced driver and the awd will be put to shame.

It really comes down to if you want to think you know how to drive fast with driving aids and no skill in a very forgiving car, or learn to drive properly in a rwd by spinning every other corner.

I am surprised to see so many people think awd is superior to rwd in terms of cornering performance on dry pavement.
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Old 02-01-2010, 08:48 PM   #23
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To answer OP"s question: Drive your IX like a FWD, that's how most AWD cars handle anyway.

1. Quatros were superior to IX's.
2. If you throw enough money and technology (that already exists), like torque shifting, as in sending most or all of the power to the front, rear or even side wheels, apples to apples, AWD will kick RWD ass every time. It just costs a huge amount of money to do.

3. F1 is limited by a very tight rules package. If the rules were free, ALL F1 cars would be AWD... but, astronomical budgets of today would seem like pocket change in comparasing... not because of AWD, mostly because of aero, but sophisticated AWD systems would account for a good part of that budget.
Few months ago I threw away about 200 pounds of car magazines, so unfortunately, I can't show you the article, but one of the ten or so year old F1 Racing mags, had asked Frank Williams what kind of car would he build if the rules were free.
Guess what? Among other changes like a flat wedge-shaped body, with closed wheels, he would have a SIX wheeled AWD car.

On the track, in the dry, I would take RWD.
In the wet, AWD is way better.
I agree that, weight makes a big difference in handling. Extra 200-300 lbs of AWD technology doesn't help.
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Old 02-01-2010, 08:59 PM   #24
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Oh, and by the way, left foot braking has nothing to do with AWD, RWD, FWD or fifth wheel drive

it's very useful with sequential or automatic gear boxes, OR, weight transfer mid turn, OR to save time, when a shift is not required, OR, to pump up the brakes, before braking hard at the end of a long straight, OR, if you have a turbo-charged engine.
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