Why build 'powerful' FWD cars?

Crackity Jones

MCMLXXV wrote: »

FWD cars are fine in small engined light cars but don't suit cars with larger more powerful engines. I just don't understand why manufacturers do this - In fact I would go as far as to say that I don't find these cars safe to drive. Take a regular Audi A8, Volvo T5, etc - these are large cars with powerful engines and are better suited to RWD IMO. Even worse are the 1.8T VAG engines that return all sorts of judder through the steering wheel when you plant it. Is it just me or does anyone else find the delivery of power more smooth from larger RWD cars?

Agree. Have had a relatively powerful german FWD previously and now have relatively powerful RWD for last yr and a bit and I'm not going back! Quattro would be only other choice.
OP all A8's have quattro as far as I'm aware.

high horse

PaintDoctor wrote: »

FWD, RWD, AWD, doesn't matter a damn unless the pilot knows what they're doing.

And for the record, just like Stealthy Speeder, my 220Bhp FWD car has a heck of a lot of fun out performing all the RWD cars it comes across, and did pretty well (2nd) at Silverstone 3 weeks ago too.

Check this out, FWD chevrolet Lacetti BTCC

http://www.youtube.com/watch?v=gPCGnkApnDU

Very impressive piece of driving there. For the record, I love the feel of RWD. I've had a BMW E30 318is for 3 years now. Most drivers on the road would not even notice the difference between FWD/RWD/AWD. Even those who can afford large luxury cars don't care for the most part.

Mycroft H

Did SAAB engineers not say 220hp was the absolute limit for FWD??

If so, why do we have cars that are more???

Johnboy Mac

What do you think?

Audi's original UR Quattro only came into existance because all their cars were FWD and an easy way to get decent traction with far more powerful engines than their current products at the time was to convert to 4WD, handy as Audi mounted their engines north/south. I suspect if Audi had a RWD car in their stable prior to the Quattro, the Quattro would never have seen light of day.

I'm not knocking the Quattro, just making a comment as it's a great car by all accounts and has the competition history to prove it.

Johnboy Mac

landyman wrote: »

Did SAAB engineers not say 220hp was the absolute limit for FWD??

If so, why do we have cars that are more???

Indeed they did and not too many years ago either.

*Kol*

Johnboy Mac wrote: »

What do you think?

Audi's original UR Quattro only came into existance because all their cars were FWD and an easy way to get decent traction with far more powerful engines than their current products at the time was to convert to 4WD, handy as Audi mounted their engines north/south. I suspect if Audi had a RWD car in their stable prior to the Quattro, the Quattro would never have seen light of day.

I'm not knocking the Quattro, just making a comment as it's a great car by all accounts and has the competition history to prove it.

As it spawned the birth of the bgroup B rally car it's a good enough reason for it to exist in my book!! And all the subsequent great 4WD road cars too.

galwaytt

Johnboy Mac wrote: »

......I suspect if Audi had a RWD car in their stable prior to the Quattro, the Quattro would never have seen light of day.

....why they would want to have a car that is worse than their 80/100 line, since 1969, is beyond comprehension. They make all their peer RWD cars look, and feel, like carts. Which of course, they were. Don't forget, Audi's have been fwd since 1931 iirc......

Quattro was to add to the fwd dynamic, not a sap backward to the rwd one.

What's wrong with the A5 is not the 1.8t engine - it's the 500kg too much weight it's carrying around..........with 1100kg in a coupe it wouldn't torquesteer half as much, as it'd spent more time gripping rather than spinning.

JHMEG

MCMLXXV wrote: »

Massive feedback / judder through the steering wheel from both cars.

That's a combination of bad road surface, hard/unsuitable tyres and the lack of an LSD.

Less jabbing, and more progressive movements of the throttle to give the tyres a chance to grip will overcome the above to a large extent.

You can't get into a powerful FWD car, floor it, and expect it all to work. That's naive!

Lord Nikon

high horse wrote: »

http://www.youtube.com/watch?v=gPCGnkApnDU

FWD power slide, good stuff. Wow, Plato driving a Lacetti???

Lord Nikon

I think you have more control in a RWD car, not when trying to powerslide or anything, but you get less wheelspin cause you have more weight on the rear, and that's where the power is.

Cornering in FWD aims you into the corner, and the front wheels have enough to do with steering and breaking too. RWD pushes you out of a corner, and gets you more grip on the back, with TC on of course.

Big Nasty

Crackity Jones wrote: »

Agree. Have had a relatively powerful german FWD previously and now have relatively powerful RWD for last yr and a bit and I'm not going back! Quattro would be only other choice.
OP all A8's have quattro as far as I'm aware.

Regular A8 is FWD, Quattro and S8 models are 4WD.

galwaytt

neuromancer wrote: »

I think you have more control in a RWD car, not when trying to powerslide or anything, but you get less wheelspin cause you have more weight on the rear, and that's where the power is.

Cornering in FWD aims you into the corner, and the front wheels have enough to do with steering and breaking too. RWD pushes you out of a corner, and gets you more grip on the back, with TC on of course.

Sorry, but no.

FWD is predominant also because it's inherently more stable for the-man-in-the-street. And you're incorrect about the weight distribution,too. A fwd car is heavier at the front, where the traction is.

And, if you're steering and braking into a corner............you're doing it wrong. Even in a rwd car, you don't brake AND steer. A quick lap of Mondello will show you that. Brake first, then steer.

RWD is inherently always unstable, trying to swap ends - it's the old throwing the hammer handle-first scenario. The head will always...'arrive'......first

Big Nasty

JHMEG wrote: »

That's a combination of bad road surface, hard/unsuitable tyres and the lack of an LSD.

Less jabbing, and more progressive movements of the throttle to give the tyres a chance to grip will overcome the above to a large extent.

You can't get into a powerful FWD car, floor it, and expect it all to work. That's naive!

Fair enough point but I would expect more from a recently engineered FWD. 1.8T isn't *that* powerful after all!

Biro

landyman wrote: »

Did SAAB engineers not say 220hp was the absolute limit for FWD??

If so, why do we have cars that are more???

What have Saab done in the last 15 years that makes you think they're the best engineers in the world?

Biro

galwaytt wrote: »

Sorry, but no.

FWD is predominant also because it's inherently more stable for the-man-in-the-street. And you're incorrect about the weight distribution,too. A fwd car is heavier at the front, where the traction is.

And, if you're steering and braking into a corner............you're doing it wrong. Even in a rwd car, you don't brake AND steer. A quick lap of Mondello will show you that. Brake first, then steer.

RWD is inherently always unstable, trying to swap ends - it's the old throwing the hammer handle-first scenario. The head will always...'arrive'......first

That's a more accurate analogy for rear engined cars. Doesn't translate equally with RWD.

Zube

galwaytt wrote: »

FWD is predominant also because it's inherently more stable for the-man-in-the-street.

I don't believe that for a second. FWD is predominant in small cars because of the packaging advantages. Full stop. Look at the space in a Golf compared to a BMW 1 series.

No designer ever set out with a clean sheet and said "let's make this car FWD because it's safer if Joe Soap's car understeers rather than oversteers." In fact the likes of Peugeot have done the opposite: taken a car like the 205 which is FWD for packaging reasons, and then engineered lift-off oversteer back in.

Mr.David

galwaytt wrote: »

Sorry, but no.

And you're incorrect about the weight distribution,too. A fwd car is heavier at the front, where the traction is.

RWD is inherently always unstable, trying to swap ends - it's the old throwing the hammer handle-first scenario. The head will always...'arrive'......first

1) Under acceleration the "weight" of the vehicle is transferred from the front of the car to the rear - favouring RWD not FWD as you state. If you work out a force diagram for FWD and RWD you will see that physics mean that a RWD can always accelerate faster than FWD (for same power, weight etc obviously)

2) RWD is not unstable. Which wheels are driven in an F1 car again?

mickdw

JHMEG wrote: »

Less jabbing, and more progressive movements of the throttle to give the tyres a chance to grip will overcome the above to a large extent.

You can't get into a powerful FWD car, floor it, and expect it all to work. That's naive!

Im finding it hard to put across to people how bad it is in my car. It doesnt need aggressive throttle really. If my A5 had for examle the 1.6 crap petrol engine from the old A4, that would easily have enough power to cause this tramping even in second gear. Even on a smooth wet road, it jumps. I would expect it to just spin up but no, it does this terrible tramping. Actually, a person in the passenger seat helps with this problem (as silly as it sounds) as well as making the whole left front feel alot better in general as there appeared to be a barely perceptible looseness in that area which is harder to feel with a passenger on board. Its just crap to be honest and will be gone come 2010.
No Audi technician/engineer can find a fault although Ive had everything from: They are all like that, Its in them, If it was mine I wouldnt be happy.

Mr.David

Zube wrote: »

I don't believe that for a second. FWD is predominant in small cars because of the packaging advantages. Full stop. Look at the space in a Golf compared to a BMW 1 series.

Exactly. Packaging and cost drive FWD decisions.

FWD chassis tech has come a long way in the last 5 years (mainly due to Renault and Ford) but RWD is still king, and unless the laws of physics are completely rewritten, it always will be.

galwaytt

Mr.David wrote: »

1) Under acceleration the "weight" of the vehicle is transferred from the front of the car to the rear - favouring RWD not FWD as you state. If you work out a force diagram for FWD and RWD you will see that physics mean that a RWD can always accelerate faster than FWD (for same power, weight etc obviously)

2) RWD is not unstable. Which wheels are driven in an F1 car again?

2)Which F1 car is front-engined again ?
And RWD is inherently less stable than fwd, as it's a naturally oversteering condition. FWD is popular because it is a naturally understeering condition. This suits the majority of driving, and mfrs, even Audi and Quattro's, and even Porsche and their 911's, are engineered to understeer under 'normal' conditions, for this reason.

1) if force diagrams were the arbiter, we'd all still be driving Beetles. Or 911's. Or Tatra's. Or Skoda 130LE's. All of those work even better, by dint of their engines increasing traction. That we don't, tells you that that measure of performance isn't the clincher.....;)

Zube

galwaytt wrote: »

And RWD is inherently less stable than fwd, as it's a naturally oversteering condition.

A FWD car will lose traction while cornering before a RWD car of the same weight, since the front tyres are driving and steering: they will exceed their static coefficient of friction before the tyres on a RWD car, where fronts steer and the rears drive.

Mr.David

The traction limit for rear wheel drive cars is higher than front wheel cars, its phyiscs and its not open for debate. It just is. As the weight shifts to the rear of a car during acceleration, FWD will never match RWD on straight line performance.

Why buy a car with 4 wheels and then put the power, majority of braking and steering through only 2 of them?

As regards stability, stability is inversely related to agility i.e. unstable = agile.

Biro

*Kol* wrote: »

As it spawned the birth of the bgroup B rally car it's a good enough reason for it to exist in my book!! And all the subsequent great 4WD road cars too.

Not so! Group B was there, the Quattro just changed the game dramatically!
Group B essentially allowed the Quattro to exist.

Johnboy Mac

galwaytt wrote: »

....why they would want to have a car that is worse than their 80/100 line, since 1969, is beyond comprehension. They make all their peer RWD cars look, and feel, like carts. Which of course, they were. Don't forget, Audi's have been fwd since 1931 iirc......

Quattro was to add to the fwd dynamic, not a sap backward to the rwd one.

What's wrong with the A5 is not the 1.8t engine - it's the 500kg too much weight it's carrying around..........with 1100kg in a coupe it wouldn't torquesteer half as much, as it'd spent more time gripping rather than spinning.

I don't agree.

Bear in mind I'm not knocking their 80/100 models and can't comment on the A5.

The simple fact is a good RWD set up is far better than FWD or else BMW,Merc,Porsche,Ferrari etc are all wrong . Audi engineers of course were well aware of this thus the Quattro with the advantage of 4WD (poss. it's real advantages came to light in rallying only) as they already had a FWD vehicles excluding some commerical/military model. So I contend that the Quattro came about only due to Audi wanting a 'hot' product with the advantages of RWD.

I'm not attempting to state fact just as in my original post 55 on this subject, I was asking for views.

Vegeta

I think this video from about 3 minutes 50 seconds on shows that light FWD cars are quite capable

https://www.youtube.com/watch?v=W2scgC-QXlg

stealthyspeeder

With regard to mass production, FWD is cheaper, FWD gives more space and FWD tends to produce understeer for the normal driver who has accidently pushed the car to hard, making it less panic inducinng and safer as a side effect of that.

With regard to straight line performace, RWD only has the acceleration advantage when the traction can be exceeded in the low gears. so this would give an advantage on initial acceleration from dead but would not really apply from a rolling start.

With regard to cornering performance, FWD's need lower entrance speeds but are able to achieve higher exit speeds, once the apex is just about to be reached power can be fed into the front wheels wheras RWD require the power to be fed in after the apex. (RWD can drift round the corner but this wont be as quick, and FWD can left foot brake or lift off oversteer before the corner but again this wont be as quick)

RWD and AWD are obviously faster in the big boys leagues (pretty obvoius from the lack of FWD supercars!) but up until the price and physics involved kick in, can anybody think of a faster (new) RWD car than the Mark II Focus RS for its (new) price of £28,000 Sterling?

metzengerstein

ive a honda inspire ,powerfull engine fwd great fun too drive and i find it safe ,when i drove an altezza it was boring to sturdy and you dont seem to feel the power that its giving,whereas you feel it in mine the front lifts up when ya give it some wellie ,everyone has there diffrences and likes i supose

Lord Nikon

metzengerstein wrote: »

whereas you feel it in mine the front lifts up when ya give it some wellie

All cars will lift at the front when you give it some wellie, it's the laws of physics.

When take weight off the front on FWD cars. Why not use the weight shift to your advantage, and bed the back of the car down. Applying weight to the rear gives better traction.

Weight on the front is only good when steering. Your hardly going to be red-lining into a corner, you red-line out of it.

stealthyspeeder

Vegeta wrote: »

I think this video from about 3 minutes 50 seconds on shows that light FWD cars are quite capable

That is class I thought you were taking the piss when the R32 looks like its whipping past it, and then the cheeky fellow pops out of nowhere on the inside!!.....he didnt like having somone faster than him out there so he went to pit stop! (wonder if he considered how much the less the Civic cost!)

Vegeta

stealthyspeeder wrote: »

That is class I thought you were taking the piss when the R32 looks like its whipping past it, and then the cheeky fellow pops out of nowhere on the inside!!.....he didnt like having somone faster than him out there so he went to pit stop! (wonder if he considered how much the less the Civic cost!)

That CRX is mental it handles superbly and has about 1/3 the power of that skyline.

Also if you go to mylaps.com and look at some of the lap times its interesting to see just how well these lowly FWD cars can perform

Here are the lap times for a race on the 7th of June for some Porsche and similar. Fair enough the car in first is way faster but that's because its a space frame car with fibreglass body.

But compare say the Porsche 997 GT3 race car, which is on slicks, to times in the 59 second region for this CRX which is on road legal tyres.

I personally don't really care what wheels supply the drive, there are plenty of great FF and FR cars out there. Ruling out a car because the front wheels are the driven wheels is pretty sad to be honest as it may just be a much better drive than your current rear wheel drive.

Stephen

This is the most interesting motors thread I've seen in ages

SV

I really can't see any advantage to a RWD car over my own.. Sure there's some mean understeer sometimes but so what? It still handles a hell of a lot better than the majority of RWD cars.. That said it's not exactly powerful though.

Vegeta

SV wrote: »

I really can't see any advantage to a RWD car over my own.. Sure mean understeers sometimes but so what? It still handles a hell of a lot better than the majority of RWD cars.. That said it's not exactly powerful though.

That's it exactly really, I'd much rather drive a great handling FWD car than a crap handling RWD car and vice versa.

Big Nasty

Vegeta wrote: »

Ruling out a car because the front wheels are the driven wheels is pretty sad to be honest as it may just be a much better drive than your current rear wheel drive.

It's not sad at all! I like cars with a bit of power and I don't like the feedback through the wheel I get from the vast majority of FWD cars. I haven't driven every car in the world so I can only comment from my own experience. For me it's RWD / 4WD all the way! Maybe someday I'll be pleasantly surprised by a FWD car, but I doubt it!

Vegeta

MCMLXXV wrote: »

It's not sad at all! I like cars with a bit of power and I don't like the feedback through the wheel I get from the vast majority of FWD cars. I haven't driven every car in the world so I can only comment from my own experience. For me it's RWD / 4WD all the way! Maybe someday I'll be pleasantly surprised by a FWD car, but I doubt it!

Ignorance is bliss I suppose

Me I like good cars, I don't discriminate.

Big Nasty

Vegeta wrote: »

Ignorance is bliss I suppose

Me I like good cars, I don't discriminate.

I believe in looking reality straight in the eye and denying it!