Aspera's thoughts on AWD/RWD...

[White Comet]

Originally Posted by NESW20

AWD is like training wheels.

the Porsche GT2 is faster than a Turbo, and it's RWD only.

That's because of the weight reduction in removing the AWD system, amongst other things.

AWD = quicker off the line than a similarly weighted RWD car. And it can also be a lot of fun (4 wheel drifts).

[NESW20]

Originally Posted by White Comet

That's because of the weight reduction in removing the AWD system, amongst other things.

AWD = quicker off the line than a similarly weighted RWD car. And it can also be a lot of fun (4 wheel drifts).

okay, and as we're all well aware, weight is the enemy. i don't need this car to be capable in inclement weather or dirt, so i have no need for AWD. give me something lighter.

quicker off the line doesn't (to me, i'm not a drag racing fan) make a car "faster." briefly in a straight line, yes, the car will be moving faster. after that, there's increased drivetrain loss resulting in a lower top speed, and generally more understeer around a corner. to me, that says slower.

i've had my MR2 in a 4 wheel drift, sliding slightly sideways with zero countersteer coming out of a couple corners at Streets of Willow Springs. that was plenty of fun.

sorry guys, no one here will convince me that AWD is better for anything in dry conditions.

-Mike

[White Comet]

Originally Posted by NESW20

okay, and as we're all well aware, weight is the enemy. i don't need this car to be capable in inclement weather or dirt, so i have no need for AWD. give me something lighter.

quicker off the line doesn't (to me, i'm not a drag racing fan) make a car "faster." briefly in a straight line, yes, the car will be moving faster. after that, there's increased drivetrain loss resulting in a lower top speed, and generally more understeer around a corner. to me, that says slower.

i've had my MR2 in a 4 wheel drift, sliding slightly sideways with zero countersteer coming out of a couple corners at Streets of Willow Springs. that was plenty of fun.

sorry guys, no one here will convince me that AWD is better for anything in dry conditions.

Never said it was better. Just said it could also be fun. I don't see the need for drivetrain snobbery. Whatever gets you through the 1/4 mile, track, drift course, etc. etc. faster than the other guy, then more power to you.

[NeXuS-GT]

As for the 0-60mph. You can't compare an AWD to a FWD or RWD.. You can launch an AWD car at about 6000rpm and you'll get just a little wheel spin if you have anought power. What that mean? better 0-60mph.

But I can assure you that on a longer race on a ¼ mile for exemple, AWD vs FWD/RWD with same power? the AWD will be behind.

[White Comet]

Originally Posted by NeXuS-GT

But I can assure you that on a longer race on a ¼ mile for exemple, AWD vs FWD/RWD with same power? the AWD will be behind.

Similar power, perhaps, but what about similar weight (and therefore, similar power-to-weight)?

[aspera]

Originally Posted by NESW20

i sincerely doubt anyone will be rallying their FT86.

Why? Don't you think it would be competitive in Group 2 rally? From the way you're talking about RWD being superior, I'd expect you to say that it would not only win Group 2, but blow the doors off of all the AWD cars and take the overall win. LOL

Most guys will admit that AWD has an advantage just off the line in a drag race (given the same tires, torque, and vehicle mass). But they don't go the next step. Every corner is just the starting line to the drag race down the straightaway. A race track is essential a set of drag strips of different length connected by curves. In that case, AWD has the advantage on every slow speed corner exit. As the car approaches the limits of adhesion (due to increased torque, higher speeds, or slippery road conditions)...the AWD advantage claws its way towards medium and high speed corners.

RWD is nice for underpowered cars without racing tires, tho. LOL

[aspera]

Originally Posted by NESW20

after that, there's increased drivetrain loss resulting in a lower top speed, and generally more understeer around a corner. to me, that says slower.

sorry guys, no one here will convince me that AWD is better for anything in dry conditions.

Drivetrain loss: How much? 0.5hp? 100hp? I remember seeing an Audi study on frictional drivetrain loss and the results are not what you'd expect. There are more gears, but less torque going through those gears on average.

Understeer: Do rear mid-engined cars understeer? What kinds of differentials are you talking about? The Impreza would still understeer if it was RWD because the engine is in the nose and the factory rear swaybars are tiny. You might also be dealing with driver error. I wonder if the drivers were trail braking when they complained that the cars were understeering pigs.

AWD better in dry: Audi raced against RWD cars on pavement back in the 1980's in IMSA and Trans Am. They won so much that they were banned for having an unfair advantage. When Audi Quattros get to race on paved tracks, they usually are forced to take heavy weight penalties or even tire penalties.

"Audi came into the series in '88 and surprised many with their Quattro scoring eight wins out of 13. To top it off, one of their three drivers walked away with the drivers' title. Hurley Haywood took the good while teammates Walter Rohrl and Hans Stuck gave aid for the 4-wheel drive cause. Audi left for IMSA and SCCA made rule changes: two wheel drive only cars and to the shock of many, they placed a ban on non-American manufacturer cars."

[aspera]

Watch the end of the video and hear it from the drivers' own mouths. AWD has a 'hidden' advantage in dry conditions. During a road race, all cars start on cold tires and a fresh track. The RWD works the rear tires very hard. The AWD works them more evenly. The RWD car is more likely to have the rear tires "go off". The track itself becomes covered in tire rubber and debris (marbles). That's then the AWD cars attack.

[scape]

not sure where i stand, but...

[aspera]

Originally Posted by scape

not sure where i stand, but...

...at 14:00 "Four wheel drives are fast at the corner exits."

Hrmmm, now where did I see that?

The contest compares 4 door cars that are nose heavy, high Cg, with AWD traction to 2 door coupes that are only 2WD, but are lower and lighter due to packaging. The best car would be AWD but with better packaging. That's why I'm in favor of a FM AWD car.

[scape]

i wonder what kind of chassis stiffening is required for an AWD system vs a RWD

[aspera]

Look to the Cusco/Advan Super GT cars for a comparison of RWD and advanced AWD. Early Cusco Imprezas were RWD. Then they got clever and built a new AWD system. This is NOT like a production Subaru AT ALL.

[scape]

Originally Posted by aspera

Look to the Cusco/Advan Super GT cars for a comparison of RWD and advanced AWD. Early Cusco Imprezas were RWD. Then they got clever and built a new AWD system. This is NOT like a production Subaru AT ALL.

now that makes sense for road use, the engine is WAY down on the bottom. i couldn't possibly see this for rally use tho. how much weight did their system add?

[NESW20]

Originally Posted by aspera

Why? Don't you think it would be competitive in Group 2 rally? From the way you're talking about RWD being superior, I'd expect you to say that it would not only win Group 2, but blow the doors off of all the AWD cars and take the overall win. LOL

now you're just being silly. that'd be great to see a rally-prepped FT, but i'm not gonna hold my breath...

Most guys will admit that AWD has an advantage just off the line in a drag race (given the same tires, torque, and vehicle mass). But they don't go the next step. Every corner is just the starting line to the drag race down the straightaway. A race track is essential a set of drag strips of different length connected by curves. In that case, AWD has the advantage on every slow speed corner exit. As the car approaches the limits of adhesion (due to increased torque, higher speeds, or slippery road conditions)...the AWD advantage claws its way towards medium and high speed corners.

like i said, AWD is more of a "point-and-shoot" type car. if you think that style of driving is fun, more power to you. i prefer something that will help sharpen my skills instead of doing the driving for me.

RWD is nice for underpowered cars without racing tires, tho. LOL

nah, maybe if you like drifting. i don't care much for it.

Originally Posted by aspera

Drivetrain loss: How much? 0.5hp? 100hp? some. more than without it. I remember seeing an Audi study on frictional drivetrain loss and the results are not what you'd expect. There are more gears, but less torque going through those gears on average.

right, but you still have bearings, additional rotating mass, etc... it adds up.

Understeer: Do rear mid-engined cars understeer? What kinds of differentials are you talking about? The Impreza would still understeer if it was RWD because the engine is in the nose and the factory rear swaybars are tiny. You might also be dealing with driver error. I wonder if the drivers were trail braking when they complained that the cars were understeering pigs.

anything will understeer if you drive it wrong, duh. how much do you understand about weight transfer? in many cases, trail braking REDUCES understeer by shifting weight up onto the front wheels, increasing their grip and reducing the rear's grip, helping the car to rotate. sure, if you do it wrong, it'll just understeer more because you exceed the grip threshold by too great a margin.

AWD better in dry: Audi raced against RWD cars on pavement back in the 1980's in IMSA and Trans Am. They won so much that they were banned for having an unfair advantage. When Audi Quattros get to race on paved tracks, they usually are forced to take heavy weight penalties or even tire penalties.

"Audi came into the series in '88 and surprised many with their Quattro scoring eight wins out of 13. To top it off, one of their three drivers walked away with the drivers' title. Hurley Haywood took the good while teammates Walter Rohrl and Hans Stuck gave aid for the 4-wheel drive cause. Audi left for IMSA and SCCA made rule changes: two wheel drive only cars and to the shock of many, they placed a ban on non-American manufacturer cars."

i just saw a few great names in sports car racing. there are many factors that contribute to a winning racing team.

here's an article for you: http://speedhunters.com/archive/2009...rmula-one.aspx

notice what it says about understeer, the cars being heavier, and their overall lack of pace.

Originally Posted by aspera

Watch the end of the video and hear it from the drivers' own mouths. AWD has a 'hidden' advantage in dry conditions. During a road race, all cars start on cold tires and a fresh track. The RWD works the rear tires very hard. The AWD works them more evenly. The RWD car is more likely to have the rear tires "go off". The track itself becomes covered in tire rubber and debris (marbles). That's then the AWD cars attack.

and an AWD car is more likely to have the front tires off. putting torque through the front tires will wear them out faster.

Originally Posted by aspera

...at 14:00 "Four wheel drives are fast at the corner exits."

Hrmmm, now where did I see that?

The contest compares 4 door cars that are nose heavy, high Cg, with AWD traction to 2 door coupes that are only 2WD, but are lower and lighter due to packaging. The best car would be AWD but with better packaging. That's why I'm in favor of a FM AWD car.

how much cost do you think it will add to do what you're saying? if they were going to use AWD, it's likely they're not going to completely redesign the system on this entry level car. if they do, expect it to drive a lot like a Subaru. did you see the understeer in the video? also notice that the AWD were CONSIDERABLY more powerful in each challenge. of course it's gonna be fast at corner exits, it has way more torque.

feel free to try and bring me some more convincing arguments, but until then... :happy0180: don't misunderstand, i quite like AWD for certain things, just not in the FT86. i'm enjoying the discussion though, and i hope you are too.

-Mike