[pawan]

Originally Posted by elf

pawan, let's not get into tuner modified cars in this discussion. It's out of place.

i am sorry the only reason i put up that was to show that rwd launch with no traction loss.

[mclaren1885]

Originally Posted by pawan

a awd has a loss of 20% loss because its being transfered to two differentials and a rwd has about 10% loss. a awd has no such effect on a launch at a drag talking about high power cars this is because when the car starts to move suddenly the front end lifts increasing traction at rear wheels its only when the front end lands down its gives front wheel power thats why you dont see any awd dragsters any most of thw world record holders have rwd cars.

Well theory is one thing, but having been in some pretty high-powered FWD, RWD and AWD cars, I would say if you were to bring a manual without traction control, I'd place my bets on an AWD. The sort of launch you can get with 4 wheels is just unbelievable.

The reason you don't see many dragsters do so is because they RELY on wheelspin to get off the line. If you look at any pro-dragster video, their wheels have hit 100mph at the start line, before they even start moving. They only gain traction after the initial layer of rubber has been shredded. Also, dragsters normally run centrifugal clutches and Mickey Thompson type drag slicks, which take traction to a whole new level.

Originally Posted by pawan

see this video its a 6 sec car it is street legal as no emission tests on older cars its s 84 vette with 106 mm Precision turbo iput this video to show about traction loss:
YouTube - Street legal Corvette 400ci SBC fed via 106mm turbo Wheelie

Pawan, PLEASE stop bringing modded cars into this discussion, man. We get it, you love American muscle and big and small block V8s. Really, we do!

[Rtech]

well, it seems this has turned into a discussion of a different sort. So why not add my 2 bits!

In drag races, the theoretical advantage gained from AWD at the launch is soon lost due to frictional losses and the weight penalty that AWD comes with.

If you look at any pro-dragster video, their wheels have hit 100mph at the start line, before they even start moving.

Take a look at this video!

youtube.com: slow motion drag launch

[mclaren1885]

Originally Posted by Rtech

In drag races, the theoretical advantage gained from AWD at the launch is soon lost due to frictional losses and the weight penalty that AWD comes with.

True, but this is assuming the RWD being compared to is driven by a very good driver. Seeing how things are going here, almost no one can pull off an RWD launch to beat an AWD.

Rtech, given 2 equal cars with equal power and weight -- say a WRX STi with and without AWD -- who do you think would win, given average drivers?

EDIT: That vid has such incredible slo-mo that the green start light is actually strobing!

[Rtech]

Rtech, given 2 equal cars with equal power and weight -- say a WRX STi with and without AWD -- who do you think would win, given average drivers?

aaah young grasshopper! If the weights are the same, you are taking away a key advantage of the RWD setup! In the above case, it would be the AWD car that would be quicker ofcourse (provided he doesn't bog down on the start with too much traction!).

However, for anyone who sets out to build a pure, strip only dragster, I do not see them going in for AWD. A RWD setup with the correct tyres and suspension and a good driver will be quicker and lighter.

[mclaren1885]

Originally Posted by Rtech

aaah young grasshopper! If the weights are the same, you are taking away a key advantage of the RWD setup! In the above case, it would be the AWD car that would be quicker ofcourse (provided he doesn't bog down on the start with too much traction!).

5000 rpm, dump clutch, collect trophy. Isn't that how it works?

Originally Posted by Rtech

However, for anyone who sets out to build a pure, strip only dragster, I do not see them going in for AWD. A RWD setup with the correct tyres and suspension and a good driver will be quicker and lighter.

Yes, provided you have a good driver!

[The Wolf]

Originally Posted by mclaren1885

The reason you don't see many dragsters do so is because they RELY on wheelspin to get off the line. !

Incorrect, the wheelspins are inevitable. Infact the back slap of the tyres when they are trying to straighten themselves after flexing in opposite direction supposedly isnt intended coz an opposite force to the direction on of the movement is always undesired but in this case its inevitable!!!

Speaking about why dragsters dont have AWD, well, transmission losses, front wheel drag coefficient and loads of additional weight!!! Morover, when there are tyre manufacturers who give you tyres which stick to the tarmac like glue why take all the pain thats involved with an AWD?? The negligible wheelspin and tyre flex is still a viable option in comparison to the AWD disadvantages(but remember this is only when you have a dragstar and not a street car)!!!

[sAP]

I guess the discussion is already off topic, so here's my 2 cents. The classic Porsche C2 (Carrera 2 RWD) vs C4 (Carrera 4, AWD) comparison is all over the Internet and most motoring video magazines.

So in effect I would agree with someone who says that an RWD is what you would choose for track, drag or any kind of serious competition over an AWD version of the same vehicle.

sAP

[Shan2nu]

why do people always say if its a american car its build for straight and if its euro its build for the track there are euro cars that are good in the strip and american cars that are good in the track

Then why not show us videos of the SSC being driven on tracks like the Nurburgring, where most of the present-day supercars (Veyron included) have been extensively tested.

Shan2nu

[pawan]

well i did a search but coudnt find any videos of a ssc being tested at Nurburgring but did find this info:

veyron:7.40(1001 bhp)
carrera gt:7.28(605bhp)rwd
c6 z06:7.43(512 bhp)rwd 3 sec off
ford gt:7.42(550 ps) rwd 2sec off
they are pretty good compared to the veyon

also found this at this point i wish i had awd-
Z06 gets huge air in Nurburgring*MUST SEE* - Z06Vette.com

at this point about a day over did they really hope they beat it the site say from 21st they are going to try and beat it.so have to wait and see.

[veyron1]

RWD is what you would choose for track, drag or any kind of serious competition over an AWD version of the same vehicle.

Beg to differ. In a drag, yes. RWD has a distinct advantage. On a track, no. Torsional forces over the chassis (depending upon vertical loads over each of the four tyres) and suspension setup ensures that an AWD has more traction over a RWD to accelerate faster out of corners.

The next obvious question would be- then why aren't F1 cars AWD? It's not like they have money or weight issues?

The answer- F1 cars have been restricted over the years, to a great extent. So much so, that F1 regs. are demanding lesser power nowadays.
An AWD F1 car would be, theoretically, faster over ANY circuit. But the gains would be marginal, since the modern viscous LSD's at the rear coupled with TC, LC etc. make the RWD's pretty close.

As for the Veyron. Just a pointer. The quad-turbo W16 makes 3000 shaft horsepower. 1000 bhp is lost in cooling. Another 1000 in transmission and exhaust. And the engine is restricted. Drastically.

[BUSA]

I would only say driving a 600-700bhp car at full throttle is easier then driving a 1000bhp car at full pelt and hence the Veyron's time is slower then a few other cars.

[ananthkamath]

Originally Posted by veyron1

As for the Veyron. Just a pointer. The quad-turbo W16 makes 3000 shaft horsepower. 1000 bhp is lost in cooling. Another 1000 in transmission and exhaust. And the engine is restricted. Drastically.

Thats definitely interesting. 67% loss due to transmission & cooling? Did you mean that the indicated power is 3000 hp? Something doesnt sound right about this.

[ananthkamath]

pawan, you're most definitely biased towards american cars (everyone's entitled to their own opinion), and nothing that anyone says or does is gonna change that. Which means that you're gonna keep thinking that the SSC is better than the Veyron and therefore all of this discussion is moot anyway. I'd prefer not to get into this.

[Vid6639]

I dont think it means that the engine makes 3000bhp at the crank. It means that the engine is capable of that but has been restricted since the transmission couldnt handle the power and the cooling wouldnt have been sufficient.

Something like for india you detune the engine to account for poor fuel. The engine in the Civic makes 140bhp internationally but in india only 130bhp.