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Maybe GM gets it?

May 30th, 2006, 9:32 pm

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Mr-914
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Hot after GM figures out that selling the stylish and dynamic cars from Opel/Vauxhall as Saturns might be a good idea to differentiate a dead brand, GM shows a glimmer of intelligence with regards to Pontiac. Stealing a page from the John DeLorean play book (the guy turned Pontiac from the senior citizen brand to GM's sports brand in the '60's), GM is considering going all rear wheel drive and sporty with Pontiac again.
"They really want to narrow the range of products and narrow the sales objective," Scott [an industry analyst] says. It means sacrificing sales volume at dealerships for profit at corporate level.
Duh!

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June 1st, 2006, 11:03 am

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It's interesting that RWD is making such a comeback now, after comsumers have been told by manufacturers for so long that FWD is so much safer. Maybe the new stability/traction controls have something to do with it; they can be as safe as FWD, with the fun balance of a RWD car, and without the added weight of an AWD system.

For that matter, I think that 4-wheel drive, on a street car, is heavily overrated. If you need power to all 4 wheels to stay in control, you're driving way too dangerously for public roads and/or don't have the skill to be driving such a car.

Good news about Pontiac, though. The Solstice is an interesting car, but it's not really my cup of tea (I like the Sky much better). If they could use the Solstice as a template for their next lineup, like what Cadillac did with the Cien/Evoq/CTS, they could have a winning, distinctive lineup that would sell like wildfire.

It would be interesting to see what the Grand Prix would look like in this case. What would be the offspring of these two?

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June 5th, 2006, 9:39 am

Kung Fu Jesus
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i would like to see more RWD vehicles. i have owned FWD, AWD and RWD vehicles with the RWD and AWD being the most memorable and sporting. however, most of my driving experience and 90% of my racing experience has been FWD.

yes, RWD cars do cost more to manufacture, lose more power to parasitic losses in the drivetrain, and require more skill to drive in inclement weather than the other types. i feel they have more "soul" in theri characteristics.

my fear is that with more RWD vehicles, people will rely on electronics to make up for a lack of skill. stability control, yaw, pitch and independent wheel speed sensors with traction control and anti-lock braking can only help you _so_much.

handling and safety aside, the most comfortable cars i have ridden in and driven have been RWD.

the best "CARS" i have had for utility purposes have been FWD.

i currently own FWD and RWD vehicles. it's a race to the garage in the morning between the wife and i to get to the RWD car first.

nostalgically speaking, my first car was a RWD general motors sedan i shared with my sister. it was indestructible. :twisted:
"Furniture that is too obviously designed is very interesting, but too often belongs only in museums." - MBJ

June 8th, 2006, 10:18 am

golden
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Dearest Jesus,
I'm wondering where you learned your automobile knowledge from, or what your "racing experience" is exactly? Regardless, I'd like to clear some myths...
The disadvantages of FWD are mainly the decrease in vehicle handling ability. With more weight over the front of the automobile, the back end tends to become very light. Rear tire traction is decreased and the car may swap ends on icy roads easier. This has been overcome by designers somewhat by placing as much weight as possible further back in the vehicle. Ideal weight distribution is often described as 50/50 front to rear, but FWD cars seldom get near this.
Unfortunately for the front tires, they must transfer all acceleration, steering, cornering, and braking forces to the road. The tires have only a finite amount of grip, so using some of it for acceleration must decrease it in other areas. The rear tires have very little load on them and are basically only along for the ride, hence the tendency to understeer. Though, in wintery conditions having all this weight on the tires powering the vehicle aids in preventing the tires from slipping.
With some of the mechanical parts removed from the front and installed at the rear, vehicle balance and handling are much improved. Using the rear tires for acceleration traction takes the load off the front, so drivers accelerating out of a corner have much more lateral grip. With FWD, you experiance torque steer. RWD is used on all the world's fastest road course race cars and many performance production vehicles for this reason.
Additionally, AWD is what you were thinking of when you mentioned parasitic loss through the drive train, not RWD. :)

June 8th, 2006, 11:02 am

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A-Line
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The main factors in the proliferation of FWD for passenger vehicles is A) cost, and B) safety for the inexperienced and/or ham-fisted (footed?) driver.

Packaging and assembling FWD is cheaper than RWD, with fewer parts. As a bonus, FWD is lighter, too, all things being equal.

Go through a corner with FWD, give it too much gas, and the front end goes wide of the intended path (understeer). Lift off the gas (as a frightend inexperienced driver would), and the front end regains traction and goes back on the intended line.

Go through a corner with RWD, give it too much gas, and the rear end goes wide of the intended path (oversteer, or worse, a spin). Lift off the gas (as a frightened inexperienced driver would), and the rear end regains traction, shooting the car into the inside of the turn, still off the intended path.

For good drivers, and for performance-minded drivers, there is absolutely no doubt that RWD is better. But for the average schmoe commuter, FWD makes the most sense.

June 12th, 2006, 8:48 am

Kung Fu Jesus
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golden, former SCCA club driver, no longer have the time, nor the car. i competed in ita in a '90 protege in the midwest division, detroit and west michigan regions, 92-95, scca spec-miata, 02 and 03, same regions. solo1 and 2, HPDE, rallycross, ice racing etc. what is yours?

you are very well-read in simple chasis dynamics, but your application not so much. what is your point? your post reads like a bwm/mercedes/lexus advertisement.

typically, on a fwd vehical you will lose about 10-12% of the engine's measured bhp through the drive line. on a RWD car is about 18-20%. AWD lose even more, but it depends on the system. RWD cars must move more mass to get the power to the wheels, hence the higher loss. simple physics.
"Furniture that is too obviously designed is very interesting, but too often belongs only in museums." - MBJ

June 12th, 2006, 1:48 pm

golden
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I race hillclimbs. Can you provide me with a source where RWD has more loss through the drive train? I've never heard of anything like this before. Sorry that you got upset, though there’s no need to be arrogant.

June 12th, 2006, 3:34 pm

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A-Line wrote:Lift off the gas (as a frightened inexperienced driver would), and the rear end regains traction, shooting the car into the inside of the turn, still off the intended path.
The second half of your sentence is right, but lifting mid-corner on a RWD car causes a pitch that transfers weight to the front wheels, resulting in oversteer if you were on or near the limit due to lateral acceleration. If you're a crap driver it's more likely that you're nowhere near the lateral limit, and you're just giving it too much gas and causing power-induced oversteer. In that case, lifting will bring it back in.

I've never seen an 8%-10% power loss due to a propshaft, but you do get a bit (more like 2%) from vibration and windup and friction in the u-joints (all this is assuming a front engine of course). The added rotational inertia from a propshaft affects the transient response of the engine a lot more than it does the static power, and even then it's not that much.

One of the biggest performance advantages of a RWD car that I haven't seen mentioned is that squat from acceleration transfers weight to the rear, which gives the rear tires more grip, enabling more power to be put down. The exact opposite happens in a FWD car. You also have to do some weird stuff to the suspension geometry on a FWD car to maximize the traction and keep the inside front tire planted (really stiff rear ARB for example).

[Before you ask: B.Eng. Automotive Engineering, designed Indy 500 winner, Baja 1000 Trophy Truck, etc.]

June 13th, 2006, 10:47 am

Kung Fu Jesus
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golden wrote:I race hillclimbs. Can you provide me with a source where RWD has more loss through the drive train? I've never heard of anything like this before. Sorry that you got upset, though there’s no need to be arrogant.
sorry for the misinterpretation. on a chasis dyno, parasitic losses are measured greater on RWD vehicles than FWD.
"Furniture that is too obviously designed is very interesting, but too often belongs only in museums." - MBJ
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