Ok, I'll start of by saying I'm playing devils advocate a bit here but why do kit cars generally have to be rwd or no one will consider
them?
After all no one complains about mini/205/etc etc handling and we all pretty much drive fwd cars nowadays anyway....... I know there are various
'packaging' problems but all the rwd cars available nowadays (with the exception of the MX-5) are big old heavy things which don't
really lend themselves to lightweight kit cars.... so why not? is it because everyone just wants to follow the crowd and have a 7 alike because
they're comfortable with the shape as it's different but not too different? It can't be because parts are easier to find and/or cheaper
because they're not.... so go on why not?
its a massive hassle designing a sporty looking car but with the engine sitting transversely over the FWD drivetrain was the conclusion of a similar thread that was posted some time ago.
because you cant get sideways in a fwd like you can in rwd, rwd is more fun!
Ask McClaren, Ferrari and a whole host of other sports car manufacturers!!!
At a guess when a FWD car spins wheels it gives uncontrollable (without backing off) understeer whereas a RWD car can have the over/understeer
"dialed" out to suit a particular drivers needs. And if a RWD does spin the wheels it can be controlled more easily by the driver without
having to back off too much.
My question (sorry for the hijack) is why 4WD kits?
Andy
quote:
Originally posted by dan__wright
because you cant get sideways in a fwd like you can in rwd, rwd is more fun!
quote:
Originally posted by cd.thomson
quote:
Originally posted by dan__wright
because you cant get sideways in a fwd like you can in rwd, rwd is more fun!
i beg to differ, ive been sideways - sideways - backwards - sideways and upside-down in my fwd
because its much harder to put the power down in a front wheel drive car - for exaple, have you ever hear of a front wheel drive car do 0-60 in 3
seconds??? nope
with to much power you start to create torque steer aswell
rear wheel drive cars are just alot better imho
As above, if it was best. Then why arent all the top manufacturers running fwd?
As for 4wd, i think the cost element stops any 4wd kit cars...
Have you ever tried doing a donut in a FWD ?
How else are you supposed to impress the girls in Tesco's car park ?
if you mean 4wd performance cars then you can get one from Dax. The issue with them is the weight outweighs the traction advantage as it uses the heavy sierra gear.
Its easier to build a RWD car. The components are separate and laid out better. Your diff is separate from the gearbox. Your steering is separate from the drive shafts. Its just simpler! Weight distribution is more favourable in a RWD format as well.
because apparently front wheel drive cars aren't real drivers cars!!
..................so that means that the majority of cars that we drive and have fun it are all crap!
.........Who has driven a Leon Cupra/Civic etc?
We've done this one before and it seemed to come down to pub talk and that only real men drive rear wheel drive cars!
My GTM Rossa was wicked fun - the whole front of a Mtro GTI bolted onto the rear of a monocoque.
I also have a Minari - which is FWD - front end of an Alfasud/33 bolted to the front of a monocoque - Alfa handling 700kg
I think it's about breaking away from the norm - some could stop moaning about packaging problems and make it work.
Originally posted by eddie99
As above, if it was best. Then why arent all the top manufacturers running fwd?
Most manafacturers produce vehicles built with the sole purpose of carrying around 2.5 people and half a dog. Fun doesn't come into it!!
<controversial> because car enthusiasts are sheep just like all other people, the few FWD kitcars manufacturers have trried have all been
pilloried by the herd (who haven't actually driven one) so no one buys them, so no one makes them </controversial>
It's also harder to make a sleek looking sportscar with a tall FWD engine in the front.
Edit: It's quite possible to make a mini oversteer instead of understeer, but those that set up the suspension make it neutral because they want
to go fast.
[Edited on 2/3/10 by iank]
quote:
Originally posted by cd.thomson
quote:
Originally posted by dan__wright
because you cant get sideways in a fwd like you can in rwd, rwd is more fun!
i beg to differ, ive been sideways - sideways - backwards - sideways and upside-down in my fwd
lol, I have to admit I'm a little past wanting to impress 17 year old chav girls outside the chip shop or Tescos but then why do people lust
after 'Z' cars minis every time they're mentioned? fwd as I recall....... and what is a 'sporty' looking car? people say
Civic Type R's are 'sporty' looking after all!
Edited to say:
Lol IanK - that's what I suspect is going on too but shhhhhhh
[Edited on 2/3/10 by D Beddows]
quote:
Originally posted by cd.thomson
quote:
Originally posted by dan__wright
because you cant get sideways in a fwd like you can in rwd, rwd is more fun!
i beg to differ, ive been sideways - sideways - backwards - sideways and upside-down in my fwd
link
onyx sports cars.
Supposedly quite quick. Looks might be an acquired taste.
Matt
there seems to be a leg/engine interface in that car!
quote:
Originally posted by BenB
Originally posted by eddie99
As above, if it was best. Then why arent all the top manufacturers running fwd?
Most manafacturers produce vehicles built with the sole purpose of carrying around 2.5 people and half a dog. Fun doesn't come into it!!
quote:
Originally posted by se7en
quote:
Originally posted by cd.thomson
quote:
Originally posted by dan__wright
because you cant get sideways in a fwd like you can in rwd, rwd is more fun!
i beg to differ, ive been sideways - sideways - backwards - sideways and upside-down in my fwd
Is this you then?
Or maybe this one?
RWD is the only way a man can enjoy himself, the car becomes part of his body and makes him more masculine (why do you think sports cars have so much body out front) FWD is for women drivers
[Edited on 2/3/10 by se7en]
quote:
Originally posted by fesycresy
Have you ever tried doing a donut in a FWD ?
How else are you supposed to impress the girls in Tesco's car park ?
Also, there are a few kits (and home designs) that use FWD engine and transmission to give mid-rear layout with RWD. Maybe that's the way to go? The result just doesn't look much like a seven.
quote:
Originally posted by deezee
Its easier to build a RWD car. The components are separate and laid out better. Your diff is separate from the gearbox. Your steering is separate from the drive shafts. Its just simpler! Weight distribution is more favourable in a RWD format as well.
I thought part of the driver appeal was that when you put the power through a separate set of tyres to those you're using to steer, you get a
better feel of the road?
Hugh
quote:
But if you use a FWD donor, all that work is done for you. Simply take your FWD engine / box / diff etc and bolt it to your new chassis in the same position. Take your hot hatch of choice, fit the oily bits to a nice space frame. Add a light weigh body and instantly your power to weight ratio goes up by 50% to 100%. I'd have thought this would be the easiest type of kit conversion.
quote:
Originally posted by Humbug
Also, there are a few kits (and home designs) that use FWD engine and transmission to give mid-rear layout with RWD. Maybe that's the way to go? The result just doesn't look much like a seven.
I think the main reson is its hard to make them look good (its not easy for the mid engined ones either mind)
quote:
Originally posted by smart51
Take your hot hatch of choice, fit the oily bits to a nice space frame. Add a light weigh body and instantly your power to weight ratio goes up by 50% to 100%. I'd have thought this would be the easiest type of kit conversion.
This is one of the best: Minari, based on Alfa 33. They go pretty well with a 1.7 16v motor in them.
Description
Not many of these about though.
Stu
The bottom line is that FWD cars are the result of compromise. They are cheaper to build, and they allow the most space for occupants, luggage etc.
for the price. FWD cars give you compromised control over the front as you are putting both power and steering inputs through the same set of wheels,
and control over the rear is compromised as you have no input other than the handbrake (and lift off oversteer)
RWD (or 4WD) is the layout of choice for performance and space/layout is compromised to achieve it. RWD gives you good control over both ends of the
car, the front via steering and the rear via throttle.
Kit car builders tend to be performance car enthusiasts and so go for RWD (or 4WD)
Ok then, devils advocate again - how many people who insist a rwd car is 'better' have ever actually driven a rwd car with a seriously high power to weight ratio before building a 'kit' to actually know? or is it because everyone says it is?
have driven a 470hp rx7 and a 400+hp subaru and a 300hp escort rs turbo...
the rx7 was scarey but fun and good off the line...but terrifieing in the wet.....traction controll was a godsend!!!
the subaru was good all round and allways felt safe even up to 175....
the rs turbo was only any good over 60mph in 3rd gear....way to much torque stear and wheelspin......
quote:
Originally posted by D Beddows
but then why do people lust after 'Z' cars minis every time they're mentioned? fwd as I recall.......
quote:
Originally posted by fesycresy
How else are you supposed to impress the girls in Tesco's car park ?
quote:
Ok then, devils advocate again - how many people who insist a rwd car is 'better' have ever actually driven a rwd car with a seriously high power to weight ratio before building a 'kit' to actually know? or is it because everyone says it is
I think that which one is 'better' is difficult to say, but for an average driver, catching a slide and maybe holding it for a bit, however
small the slide, is a million times more exhilarating than waiting to get on the accelerator, trying to stop understeering towards the nearest
hedge!
[Edited on 2/3/10 by GRRR]
[Edited on 2/3/10 by GRRR]
quote:
Originally posted by dan__wright
ok let me rephrase that, you cant get as sideways in a controlable manner in a fwd.
I asked this question a while back too, I think there's definitely a market for a pretty looking 'sporty' convertible or small coupe
with fwd setup from a saxo, or fiesta, to hopefully tempt more people into kit cars.
But!!! at the price it would end up at, there's too many other options like mk3 MR2, 206cc that already fit that brief
RWD because contact patch at front steers, rears take the power. On a FWD the front wheels take the power and steer, rears just follow. Go figure
what will lose traction first..
Dan
quote:
Originally posted by GRRR
I asked this question a while back too, I think there's definitely a market for a pretty looking 'sporty' convertible or small coupe with fwd setup from a saxo, or fiesta, to hopefully tempt more people into kit cars.
But!!! at the price it would end up at, there's too many other options like mk3 MR2, 206cc that already fit that brief
Hi
Now i admit i haven't read all the replies so bare with me if this has already been mentioned.
Take a serious look at all these so called Midi Kits where they have just taken the FWD drive train and mounted it in the back. There is not a single
one of them that realy has any handing to challenge a seven type layout. They are appalling. The trouble is that the overall weight of the kit when
finished is still quite light. But you have now moved the whole drive train to one end. Now whether that happens to be the front or the rear you have
just created a rather significant problem. It just doesn't work. Now if you take say a hot hatch which has a better weight distribution due to
it's over all higher weight it dose not become such an issue but the lighter you go the worse the problem.
So the end result is if you want a good FWD kit it will need to be as heavy as a hot hatch with a few bits of interior removed. Mmm Might aswell go
buy a decent hot-hatch and have some fun. Strikes me thats what many on here are already doing doing with Clio's etc.
Cheers Matt
Nice FWD car
[Edited on 3/3/10 by MikeRJ]
I'm no expert but I was under the impression that its possible to put more power out through the back, not just because of things like torque stear but because you can get gear boxes built to take high powers for longitudinal engines. There are FWD cars with longitdinal engines but it means the weight distribution is centre even further forward which is bad for handling.
quote:
Take a serious look at all these so called Midi Kits where they have just taken the FWD drive train and mounted it in the back. There is not a single one of them that realy has any handing to challenge a seven type layout. They are appalling. The trouble is that the overall weight of the kit when finished is still quite light. But you have now moved the whole drive train to one end. Now whether that happens to be the front or the rear you have just created a rather significant problem. It just doesn't work. Now if you take say a hot hatch which has a better weight distribution due to it's over all higher weight it dose not become such an issue but the lighter you go the worse the problem. So the end result is if you want a good FWD kit it will need to be as heavy as a hot hatch with a few bits of interior removed. Mmm Might aswell go buy a decent hot-hatch and have some fun. Strikes me thats what many on here are already doing doing with Clio's etc.
Is there a front mid engined FWD car that could be used as a donor? That would improve the weight balance a bit. As for more power through RWD, I believe that 200 BHP through a FWD set up is fine and that most people on here build cars with less than that.
the mitsubishi evo has the engine in the same way as a fwd car but runs through a transfer box......
Ah just figured out what you mean (engage brain) FWD with the gearbox at the front.
Renault 5
VW Beetle
Porsche 911
The R5 was used in the Hudson Free/Kindred Spirit trikes
Beetle and 911 might be considered cheating, but if moved to the front of the car would work as you suggest.
[Edited on 3/3/10 by iank]
using a beetle / 911 RWD donor to make a FWD kit would seem a bit bloody minded. Renault 5s are probably not modern or powerful enough for most. The
Toyota IQ has its diff at the front but the bigest engine is a 1.33 88 BHP lump that is probably not enough. And they're too new. They're
short enough front to back to make a good donor for a 2 seater in the future though.
Is there a way of turning a FWD engine round without it having 5 reverse gears and 1 forwards?
quote:
Originally posted by smart51
Is there a way of turning a FWD engine round without it having 5 reverse gears and 1 forwards?
quote:
Ah just figured out what you mean (engage brain) FWD with the gearbox at the front.
Thinking further what would the locostbuilders hive mind suggest as the best possible donor, though it's bound to be a compromise.
Things to consider
IMHO ford focus surely? before you say its too big, MEV package it into a go-kartesque body so its not too big a deal!
quote:
Originally posted by cd.thomson
IMHO ford focus surely? before you say its too big, MEV package it into a go-kartesque body so its not too big a deal!
My considerations were that the focus is abundant, cheap, it has a record for being fairly well engineered and also has a history of being a kit
donor.
They are simple to work with and come fitted with a range of zetec engines which is a plus. There are sport/rally versions for easy kit upgrades
too.
Size is an issue, but I just cant help thinking that the MEV rocket deals with it well, and thats a small kit??
quote:
Originally posted by cd.thomson
My considerations were that the focus is abundant, cheap, it has a record for being fairly well engineered and also has a history of being a kit donor.
They are simple to work with and come fitted with a range of zetec engines which is a plus. There are sport/rally versions for easy kit upgrades too.
Size is an issue, but I just cant help thinking that the MEV rocket deals with it well, and thats a small kit??
quote:
Originally posted by whitestu
quote:
Ok then, devils advocate again - how many people who insist a rwd car is 'better' have ever actually driven a rwd car with a seriously high power to weight ratio before building a 'kit' to actually know? or is it because everyone says it is
I disagree with all the RWD advocates. FWD is better, but not with too much power.
Drive an early Alfasud - Not sure it ispossible to have more fun in a car!
Stu
quote:
Originally posted by sucksqueezebangblow
quote:
Originally posted by whitestu
quote:
Ok then, devils advocate again - how many people who insist a rwd car is 'better' have ever actually driven a rwd car with a seriously high power to weight ratio before building a 'kit' to actually know? or is it because everyone says it is
I disagree with all the RWD advocates. FWD is better, but not with too much power.
Drive an early Alfasud - Not sure it ispossible to have more fun in a car!
Stu
There is no "agree" or "disagree" here, it is science and physics RWD outperforms FWD every time. How many FWD cars are there in top level motorsport? none.
...
quote:
Originally posted by cd.thomson
My considerations were that the focus is abundant, cheap, it has a record for being fairly well engineered and also has a history of being a kit donor.
I've just done a few calcs assuming a 500kg finished car with a 2000mm wheelbase. If you put the fuel tank and the battery behind the rear axle and you put the seats right in against the rear axle like a seven then you get a front weight distribution of 60% with a driver along and 55% with a passenger. That's not too bad. Find some other way of moving weight to the rear and you could perhaps nudge 50/50, which BMW tell us is ideal Perhaps its not such a bad idea. Wasn't the lotus elan FWD?
quote:
Originally posted by iank
quote:
Originally posted by sucksqueezebangblow
quote:
Originally posted by whitestu
quote:
Ok then, devils advocate again - how many people who insist a rwd car is 'better' have ever actually driven a rwd car with a seriously high power to weight ratio before building a 'kit' to actually know? or is it because everyone says it is
I disagree with all the RWD advocates. FWD is better, but not with too much power.
Drive an early Alfasud - Not sure it ispossible to have more fun in a car!
Stu
There is no "agree" or "disagree" here, it is science and physics RWD outperforms FWD every time. How many FWD cars are there in top level motorsport? none.
...
Touring cars and rally cars are just two examples of successful FWD sports cars.
quote:
Originally posted by sucksqueezebangblow
Touring cars are only FWD because the manufacturers only make FWD cars so have no RWD cars to compete.
quote:
Originally posted by MikeRJ
quote:
Originally posted by sucksqueezebangblow
Touring cars are only FWD because the manufacturers only make FWD cars so have no RWD cars to compete.
No so, the BMWs are RWD.
They may be fwd out of necessity but they do bloody well though! - especially when the Seat's were diesel as well.
Steve
[Edited on 4/3/10 by gottabedone]
quote:
That is exactly my point, the other manufacturers would use RWD, if they produced them, but they don't so they have to use FWD.
quote:
Originally posted by whitestu
for road use there are many more examples of superb handling FWD cars than RWD, though they generally tend to be lower powered. Despite this they are usually quicker on anything other than a perfect road than their RWD counterparts as it is easier to avoid ending up in a ditch!
Discuss.
FWDs main plus points are (In my opinion) the more practical things like more interior space and making the cars cheaper. I don't think you can
really say there is a right or wrong set up as all have ups and downs.
Just going back to the idea of putting the engine and box out of a 911 or Beetle into the front of the car, would it not give you problems when it
came to sorting out the stearing?
quote:
Originally posted on Wikipedia
The choice of front wheel drive is unusual for a sports car, but according to Lotus sales literature, "for a given vehicle weight, power and tyre size, a front wheel drive car was always faster over a given section of road. There were definite advantages in traction and controllability, and drawbacks such as torque steer, bump steer and steering kickback were not insurmountable."[3] This was the only front wheel drive vehicle made by Lotus. Every model made since the M100 Elan, such as the Lotus Elise, has been rear wheel drive.
The M100 Elan's cornering performance was undeniable (on release the Elan was described by Autocar magazine as "the quickest point to point car available". Press reaction was not uniformly positive, as some reviewers found the handling too secure and predictable compared to a rear wheel drive car. However, the Elan's rigid chassis minimised roll through the corners and has led to its description as 'the finest front wheel drive [car] bar none'
A little bump.
I dont think a FWD should have a 50/50 weight distribution. 60/40 will be good enough. You need the extra weight at the front for traction.
Don't forget the Quantums and the Midas Bronze/ Gold. Both brands produce very competent kitcars with all year useabilty too.
Onyx wasn't too bad either with the Firefly and Firecat.
The problem is that there are a lot of OEM small coupes (Tigra, Puma, 206CC), which would be secondhand cheaper then a kit.
On the other end of the scale are the GTI versions of the small hatch which perform very similiar to a base model wich kitcar chassis + body.
So a FWD kit should be:
A) very stylish 2+2 coupe (a la Quantum 2+2)
B) an ultralight trackday rocket (Onyx Firefox)
The other big difficulty with making decent handling fwd cars is the moment of inertia. Because of the need for interior space the engines tend to be ahead of the fron axle line, so while you can achieve 60:40 weight distribution, its still all out in the ends where you dont want it!
I get the feeling that it would be easier to set up good handling in a rwd car, thus the weekend mechanic (us) can do it.
With weight distribution being at either end, what about a dry sump and tilting the engine slightly? It might add to the height but I'm thinking
of moving some of the weight behind the front wheels.
Also if you're throwing said engine in the back surely you could put other parts in the front? Radiator, battery, fuel tank (possibly?) and so
on.
I think the main problem in no-one doing the kits though is that yeah you can buy a Puma or a Tigra etc for the same kind of price..
My view (FWIW) is that people don't sell them because the 'RWD is best' camp form the major market for kits these days so it's not
commercially viable anymore. Even lotus couldn't break that mindset with the Elan which by any stretch handles extremely well.
Whether RWD is better is debatable, as said ^^ all layouts are a compromise and it really does depend on what you are doing with the car.
For example the firefox was beating big money 7's in the sprints at seven sisters while it was being developed. All it had was a bog standard
'as it was fitted in the Rover 200' 1600 K series under the bonnet.
Why? Well I suspect the weight advantage over a front engined RWD and having the weight over the driven wheels giving better grip meant it was simply
more suitable for that particular discipline.
My next kit, which is a locost, because that's what its going to be, will have FWD, and RWD, in fact AWD.
Longitudinal front mounted engine with a transfer box to split the drive.. much the same as any 4x4 Dax actually but in more mud plugging vein...
LG,
Steve
quote:
Originally posted by Bluemoon
RWD because contact patch at front steers, rears take the power. On a FWD the front wheels take the power and steer, rears just follow. Go figure what will lose traction first..
Dan