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You guys are over exagerating the drivetrian loss of awd. It does take some power, but not nearly as much as some of you are saying

I prefer allwheel drive. I have owned an mr and an ff, but I never have driven and fr

That's like saying "if awd was better from a roll, why doesn't everyone in NASCAR drive AWD cars?" Of course RR/MR top fuel dragsters launch better, they're also a completly different class of specialized racing cars. Concerning regular cars, unless you have slicks or something, an AWD can usually outlaunch a FR (considering that they are similar hp cars on street tires). Well at least that's what I've seen, and that's what everyone on every auto forum has always said, but hey we could all be wrong. So, you're basically saying:

1. AWD is slow off the line. (due to its weight and drivetrain loss)
"Very, im just syaign from a dead stop awd dont have the advantage in comparison, they tend to lose more hp through their drive train, and they have more weight to get moving off the line."

2. AWD is fastest from a roll. (suddenly no more weight and suddenly drivetrain loss isn't an issue)
You stated in regards to FF, but about drivetrain loss in general: "True they dont lose as much power through the drivetrain, but were talking a few % difference. thats just a -few- horsepower. A few horsepower wont make the difference, its all about traction."

If its all about traction, doesn't that give AWD a very big advantage right off the line? But once moving, straight line traction isn't as much of an issue making their drivetrain less effective.

"as for this awd accelerating slow thing, well.. theres a reason the porsche 911 turbo awd accelerates faster in comparison to the rr porshes, despite the loss of power through the drivetrain."

'99 Porsche 911 Carrera 4
Rear Engine/4WD
3263 lbs.
296 bhp@6800
258 ft.lbs.@4600
1/4mile: 13.5
0-60: 5.0
0-100: 12.6

'99 Porsche 911 Carrera
Rear Engine/Rear Wheel Drive
2919 lbs.
296 bhp@6800
258 ft.lbs.@4600
1/4mile: 13.2
0-60: 4.6
0-100: 11.6

Granted they aren't 911 Turbos, but they have the exact same engine output.

However, I'll say that your points make much more sense if you're looking at it from a HIGH horsepower point of view. If a FF is making say 400+hp, it's probably going to be spinning tires all the way up to 3rd gear, and even a FR will start having trouble getting the power down without LSD and/or slicks. And in that power range, of course the AWD will have a traction advantage from a roll. So maybe everyone is looking at this in different ways. . .

(not trying to start an arguement flame war)

AWD is faster off the line.

I agree with 1slow honestly. First off the porchses' are very good off the line becasue of the rear engine layout, that car just tkaes off. ALso the thing is I have seen AWD vehicles always jump ahead off the line against FF FR, I have seen this first hand while riding along w/ people are even watching the old Speed touring series with the audis, they always were on pole and then they would just jump way ahead right off the line, then tire wear would slow them down allowing the other to catch up. Anyways the only reason the AWD porsche is slower is becasue the other porsche is lighter, its basically the same car with more weight.

Zero, you effictively have proven my point, and for that i thank you.

You compared 2 cars, of the same specs, one bing rear wheel drive, the other being awd.

If youll notice from a stop, talking the 0-60, and the 0-100, the rear wheel drive version BEATS the awd version, which is what i said would happen, isnt it?

Now something funny happens; compare the times.. do some math in your head. 60-100 on the rear wheel drive it 7 seconds. 60-100 on the awd is 7.6, thats a .6 second difference.

Now compare their 1/4 mile times, theres only a .3 second difference. That can only mean one thing; the awd is starting to accelerate faster then the rear wheel drive once in motion.

Added: Oh and one more thing, thats from a "rolling" point of view.. keep in mind from a dead stop it takes the awd a full second longer to reach 100, and then it shaves the difference in the 1/4 mile down to .3

Thanks for the information.

This post has been edited by sidewaysgts on Oct 26 2004, 03:16 PM

"your as cold as ice!" Foreigner

Sideways, if I sounded like an ass earlier, I truly apologize. Having said that, I don't appreciate your attitude in your response, we can be civil about this. You're obviously one of the most knowledgable people on this forum and if you are indeed right, hats off to you sir. I'll help you spread the truth.
But, I believe that the math you used and the comparisons that you made are wrong. There are fundamental differences between:

0-60 and 60-100 times (measures of mph acceleration)
and the quarter mile (measure of time over a straight distance being 1320 feet)

They're different aspects of acceleration and velocity, but they're NOT equivalent scales and can't be used together like you did. It just doesn't make sense physics and math-wise. Apples and oranges basically. Besides, you have know that 0.3 seconds is an ETERNITY in drag racing.
Alright, so you say that "the awd is starting to accelerate faster then the rear wheel drive once in motion".
So, I did some math in my head and this is what I got:

AWD 0-60 = 5.0
RWD 0-60 = 4.6
The difference is 0.4 here.

AWD 60-100 = 7.0
RWD 60-100 = 7.6
The difference is 0.6 here as you stated.

The acceleration difference is INCREASING, favoring the RWD. So at what point does the AWD suddenly pass the RWD? It definitly isn't going to do it before top speed.

I don't want to get off on the wrong foot, but perhaps I didn't understand your original point and maybe you misread mine. You said the AWD is faster. Okay. Well if you're looking at numbers, the AWD is behind the RWD in every comparison. So you're saying that even though the AWD lost EVERY time, it's still somehow accelerating faster?

agreed. it has nearly a 350lb weight dissadvantage, which, when comparing only the drivetrain layout, throws another variable into the mix. if you want to accurately use those times to compare awd and rwd, then all other elements must be the same, IE, two cars with the same power output and same weight. then and only then will you have meaningfull comparissons.

ur right sideways. it makes perfect sense. people dont like to be wrong thats all..........porsches are cool

This post has been edited by gt3turbocharged9 on Oct 26 2004, 03:45 PM

I never said the awd would beat it in the 1/4 mile, just that it was starting to accelerate faster.

The 2wd porsche gets to 100 in 11.6 seconds, and finishes the 1/4 mile at 13.2; meaning it crosses the line 1.6 seconds after it reaches 100.

The awd porsche reaches 100 in 12.6 seconds, and crosses the 1/4 mile line .9 seconds later.

If the 2wd porsche is always accelerating faster the entire time, why is its 100mph-1/4 mile line time so much higher then the awd porsches 100mph-1/4 line time? Doesnt this mean the awd is accelerating faster somewhere, considering its time is shorter? In all hoensty you may be right, and i may have done my math wrong, in which case i fully apologize and take back what ive said.
___

I was doing some digging of my own, and most the sources ive used have given me slightly different numbers (though very close to yours in all respects) but i found something interesting.

The 2wd usually beatst he awd in 0-60, and 0-100 by quit a bit. However in the 1/4 mile the 2wd barely manages to beat the 4wd, BUT i have noticed the 4wd has had a slightly higher 1/4 mile speed. Considering the 4wd reaches 100 mph later, and exits with a higher 1/4 mile speed.

Sourves were like msn autos, motor trend, super cars, and a few various sites i didnt recognize (some even had the exact same info and review though word for word which i found funny)

the thing is 1/4 mile is measured like that becasue of distance covered and tq. this is the reason why you may see somone running a 1/4 mile with a certain MPH then somone else may have the same MPH but a slower or faster time. The AWD has no wheelspin even though a RWD car may beat it in the 0-60 or 0-100 it doesnt mean its neccassarily quicker over a certain distance just to that MPH. would somone like to add/correct me if I have said somthing wrong?

This post has been edited by AETRAN86 on Oct 26 2004, 04:32 PM

The awd reaches 100 mph after the 2wd

the awd goes from 100mph- 1/4 line faster then the 2wd, and leaves at a higher speed. It accelerates to a higher mph in a shorter amount of time.

Once again i never said the awd should beat the rear wheel drive in the 1/4 mile, i said it would be slower at the start, and start to accelerate faster towards the end. which according to the numbers shown is pretty much what is happening.

This thread is very confusing to read, so i'll just add what I know without referencing anything above:

In theory, an awd car will accelerate better from a dead stop since it can transfer more power to the ground. So an awd car should go faster 0-60, all other things equal. This is theory, in the real world this might not be the case if the awd drivetrain adds so much weight it negates this, if the drivetrain saps enough power to negate this, or if the car is so underpowered that it can use most of its power on launch. (A good example would be the FF eclipse vs the AWD eclipse, stock for stock, the AWD is faster 0-60 but the FF is faster in the quarter mile)

In theory, a 2wd car should be slower to launch. But this is not always the case. Especially if all the weight is over the rear axle. Or if the rear geometry of the car is setup like a live axle drag car, to actually use the axle's rotational inertia to plant the tires into the ground. (Alot of muscle cars still have live axles for drag racing)

In theory, an awd car is slower to accelerate from a roll than its 2wd counterpart. Since there are more parts involved in sending power to 4 wheels as oppose to 2, it makes sense that more drivetrain loss will occur. Also since awd hardware is almost always heavier, it makes sense that the 2wd car will be faster from a roll because it is lighter. Technology however is the great equalizer, when it comes to drivetrain loss, a modern system will lose less compared to something designed 4 decades ago. (I'll bet that the EVO loses alot less through the drivetrain than a 1970 Nova)

So what does that all mean? Nothing!

This post has been edited by Jabberwocky on Oct 26 2004, 05:14 PM

no kidding, everyone just needs to do some reasearch and make theyre own desicion.

As i said from the start, it -really- depends on the system

Er, from the way you posted I thought you were speaking in absolutes.

I understand your points, and I think we probably got caught up in the details and limits of magazine specs (1/4 miles, etc.). I was really looking for trap speeds, but couldn't find any. The porsche thing was just the only example I could find of the same engine in AWD and RWD. Which in itself was a bad example cause it's RR and not FR, and RR is a very small niche of the auto market. Hmm, maybe I should've looked at the Skyline or something. . .

Well I'm done, until sidewaysgts gets an AWD 911 and I get a RWD one. Then it's on!

but i dont like awd you take the awd.. ill take the rwd...

ha, sideways911. . .

yah it's all about the rwd.

agreed the ability to create and maintain oversteer for an unlimited amount of time is what makes them fun, im not into driving to be the best (maybe close to it ), but its an event ive enjoyed 100% so far.

I don't wanna sound like an ass or anything... but your logic is a bit off on your example.... This is becuase it took a longer distance for the AWD porche to reach 100mph. And when you take a longer distance to reach a certain mph, the distance is shorter to the goal. Its pretty simple math...

For example... I could accelerate up till 99 mph... stay at 99mph... and wait till i was 50 feet from 1320feet, and hit the accelerator and do the 1/4 mile .05 secs or so after I hit 100mph. Or better.... if you had a car that trapped the 1/4 mile at 101mph, this would mean that the time interval from 100mph-1/4mile is probably around .1 seconds.

If you compared distance to distance your numbers might work... but you are comparing distance to velocity...


Anyways... yeah... both AWD and RWD rule

This post has been edited by awddrifter on Oct 26 2004, 07:46 PM

I dont see how i was off in my logic.

According to what ive been reading the awd has a higher 1/4 mile speed then the rwd.

The awd once it reaches 100 mph has .9 seconds until it crosses the line. The rwd has 1.6 seconds until it crosses the line. Awd is ending up with a higher speed, in a fraction of the time.
__

Im comparing the speed they was at (100 mph), the time they had left until it finishded the 1/4 mile (1.6 in the rwd, .9 in the awd), and their speeds at the 1/4 mile line.

The awd near the end of the 1/4 mile accelerated to a highger speed in a shorter frame of time.


Added: In a 1/4 mile, slow starting speeds and a higher top speed at the end mean better acceleration -down- the line.

(pointing this out would have saved much time and argument...)

This post has been edited by sidewaysgts on Oct 26 2004, 08:01 PM

Ah. If the AWD does in fact have a higher 1/4 mile trap speed then I suppose you are right. I didn't see any 1/4 mile trap speeds in the numbers zero gave, so I just assumed that the RWD would have a higher trap speed since it got to 100 mph way before the awd did. I would like to see these numbers if you have them though... not to prove you wrong, but to just see them for myself since im amazed the AWD car gained so much speed in the last second

This post has been edited by awddrifter on Oct 26 2004, 08:03 PM

From the soces i found the awd has a higher 1/4 speed, as low as .7 mph faster (thats right) up to nearly 4 mph faster (different tests give different resutls, no drag launch will get the same time every time due to drive and weather conditions)

And btw

Acceleration is = Change of velocity over time... which is what i pointing out

the rwd was going from about 100 to 103+ in about 1.6 seconds, where the awd was going from about 100 to 104+ (as i said these speeds differe depending where u get the info from, this is just one example) in about .9 seconds.

This post has been edited by sidewaysgts on Oct 26 2004, 08:08 PM

If I am reading this right, you are saying that the AWD carrera accelerates faster from a roll.

I think you've got it backwards. Think of it in terms of simple physics. If both cars put out the same power but one car is heavier, shouldn't the lighter one go faster?

This post has been edited by Jabberwocky on Oct 26 2004, 09:05 PM

Things that are heavy and are moving have more momentum, than light things that are moving.