SWB rwd performance cars
Discussion
There was a thread a few eons ago where people commented on how snappy something like an Aygo would be if converted to RWD (I believe there is one, maybe seen at FOS and other places) and how rubbish it would be due to its short wheelbase. During the same thread it was also mentioned that a Pug 106 if RWD would be nigh on impossible to control. Not sure I fully agree with those views though.
So what do people think is a suitable wheel base for a short vehicle in relation to it's front and rear track?
Some examples:
Think in terms of handling, how nimble it is and speed. Ignoring the stock performance figures of the above cars as some are slower than others. How do you think each wheelbase would respond with say 170bhp/tonne?
So what do people think is a suitable wheel base for a short vehicle in relation to it's front and rear track?
Some examples:
| smart Roadster | smart fortwo | Mini (classic) | Caterham Roadsport 1.6 (2001) | Peugeot 106 Rallye | Toyota Aygo | |
|---|---|---|---|---|---|---|
| Width | 63.3 | 61.4 | 61 | 62 | 63.2 | 63.6 |
| Length | 134.9 | 106.1 | 120 | 133.1 | 140.3 | 134 |
| Wheelbase | 92.9 | 73.5 | 80.1 | 87 | 93.9 | 92.1 |
| Weight | 790kg | 750kg | 615-640kg | 550kg | 810kg | 790kg |
| Height | 47.5 | 60.7 | 53 | 43.9 | 52.4 | 57.5 |
| Track (Front) | 53.4 | 50.5 | 48.5 | 50 | 54.3 | 55.9 |
| Track (Rear) | 54.8 | 54.5 | 46 | 52.6 | 51.2 | 55.5 |
Think in terms of handling, how nimble it is and speed. Ignoring the stock performance figures of the above cars as some are slower than others. How do you think each wheelbase would respond with say 170bhp/tonne?
300bhp/ton said:
There was a thread a few eons ago where people commented on how snappy something like an Aygo would be if converted to RWD (I believe there is one, maybe seen at FOS and other places) and how rubbish it would be due to its short wheelbase. During the same thread it was also mentioned that a Pug 106 if RWD would be nigh on impossible to control. Not sure I fully agree with those views though.
So what do people think is a suitable wheel base for a short vehicle in relation to it's front and rear track?
Some examples:
Think in terms of handling, how nimble it is and speed. Ignoring the stock performance figures of the above cars as some are slower than others. How do you think each wheelbase would respond with say 170bhp/tonne?
The elise has 90inch wheelbase, and it seems to do ok in RWD form So what do people think is a suitable wheel base for a short vehicle in relation to it's front and rear track?
Some examples:
| smart Roadster | smart fortwo | Mini (classic) | Caterham Roadsport 1.6 (2001) | Peugeot 106 Rallye | Toyota Aygo | |
|---|---|---|---|---|---|---|
| Width | 63.3 | 61.4 | 61 | 62 | 63.2 | 63.6 |
| Length | 134.9 | 106.1 | 120 | 133.1 | 140.3 | 134 |
| Wheelbase | 92.9 | 73.5 | 80.1 | 87 | 93.9 | 92.1 |
| Weight | 790kg | 750kg | 615-640kg | 550kg | 810kg | 790kg |
| Height | 47.5 | 60.7 | 53 | 43.9 | 52.4 | 57.5 |
| Track (Front) | 53.4 | 50.5 | 48.5 | 50 | 54.3 | 55.9 |
| Track (Rear) | 54.8 | 54.5 | 46 | 52.6 | 51.2 | 55.5 |
Think in terms of handling, how nimble it is and speed. Ignoring the stock performance figures of the above cars as some are slower than others. How do you think each wheelbase would respond with say 170bhp/tonne?
200-300Bhp is normal for engine conversions, but there some in the 500-600Bhp mark
Interesting chart. The dimensions have a big impact on the handling but it would also be down to suspension set-up, wheels and tyres.
A Talbot Sunbeam Lotus dimensions which was renowned for being a twitchy and hard to control RWD:
WB - 95
Track - 52.8 F, 52.3 R
Length - 150.8
Width - 63.1
Height - 55.3
Weight - 960kg
Was it down to the dimensions or the suspension/tyres? A bit of both I think.
P.S. I have the rear track of the Rallye as 52.6in
A Talbot Sunbeam Lotus dimensions which was renowned for being a twitchy and hard to control RWD:
WB - 95
Track - 52.8 F, 52.3 R
Length - 150.8
Width - 63.1
Height - 55.3
Weight - 960kg
Was it down to the dimensions or the suspension/tyres? A bit of both I think.
P.S. I have the rear track of the Rallye as 52.6in
Edited by thiscocks on Wednesday 18th May 13:43
thiscocks said:
Interesting chart. The dimensions have a big impact on the handling but it would also be down to suspension set-up, wheels and tyres.
A Talbot Sunbeam Lotus dimensions which was renowned for being a twitchy and hard to control RWD:
WB - 95
Track - 52.8 F, 52.3 R
Length - 150.8
Width - 63.1
Height - 55.3
Weight - 960kg
Was it down to the dimensions or the suspension/tyres? A bit of both I think.
P.S. I have the rear track of the Rallye as 52.6in
Thanks for the correction. A Talbot Sunbeam Lotus dimensions which was renowned for being a twitchy and hard to control RWD:
WB - 95
Track - 52.8 F, 52.3 R
Length - 150.8
Width - 63.1
Height - 55.3
Weight - 960kg
Was it down to the dimensions or the suspension/tyres? A bit of both I think.
P.S. I have the rear track of the Rallye as 52.6in
Edited by thiscocks on Wednesday 18th May 13:43
I agree about tyres and suspension. I was just curious to what people would make of it.
In my view a shorter wheelbase is usually less prone to slide, will grip longer, but when it does let go is more severe. A narrower track will make it less snappy, but also less stable at speed. And the complete opposite for a wider track.
I know these are generalisations though.
I think, as mentioned, it's the wheelbase to track ratio that determines how snappy the car is going to feel. My GTV was RWD with, if memory is right, a 93in wheelbase, and about 130bhp, so it's similar in those respects to the 106 (but weighs a fair bit more) and it was benign enough.
Going on reputation I'd suggest that the GTV is probably less snappy than the 106, but then the GTV may have had narrower tracks, and it had a transaxle so the weight was spread around the car a bit like a dumbbell, which, I believe, would give it more resistance to spinning than a car with similar weight distribution but all the weight near the middle?
However, the GTV can be compared with the Alfetta / Giulietta / 75 sedans, which were mechanically all close to identical, but the 4 door cars had a longer wheelbase than the coupes, with a longer propshaft to accomodate this. If I recall, the difference was 3 to 4 inches.
Compared to the sedans, the coupes were definitely a bit more snappy when they let go, i.e. you'd have to wind the opposite lock on a little bit quicker.
I'd say there's a lot more to it than just the wheelbase then, but, if this makes any sense, I'd think that a RWD pug 106 with a 93in wheelbase would swap ends a bit more enthusiastically than a RWD pug 106 with a 100in wheelbase, if that makes sense. I can see no reason why a RWD 106 would be any twitchier than a FWD 106 with the same wheelbase if all else was equal though.
Going on reputation I'd suggest that the GTV is probably less snappy than the 106, but then the GTV may have had narrower tracks, and it had a transaxle so the weight was spread around the car a bit like a dumbbell, which, I believe, would give it more resistance to spinning than a car with similar weight distribution but all the weight near the middle?
However, the GTV can be compared with the Alfetta / Giulietta / 75 sedans, which were mechanically all close to identical, but the 4 door cars had a longer wheelbase than the coupes, with a longer propshaft to accomodate this. If I recall, the difference was 3 to 4 inches.
Compared to the sedans, the coupes were definitely a bit more snappy when they let go, i.e. you'd have to wind the opposite lock on a little bit quicker.
I'd say there's a lot more to it than just the wheelbase then, but, if this makes any sense, I'd think that a RWD pug 106 with a 93in wheelbase would swap ends a bit more enthusiastically than a RWD pug 106 with a 100in wheelbase, if that makes sense. I can see no reason why a RWD 106 would be any twitchier than a FWD 106 with the same wheelbase if all else was equal though.
k-ink said:
I think you need to consider the ratio achieved in each case of: wheelbase v track v height.
I suspect something like a 106 would be great due to very low height to avoid the roll.
Of course you could go 4x4. There are Cosworth powered 106 out there!
The reason behind this question/thinking was I stumbled across a video of ForTwo with a GSXR engine in it. 160hp and 700kg in a car that'd make a great Q car and has a degree of practicality about it. Lets just say it puckered my interests to find out a bit more. I suspect something like a 106 would be great due to very low height to avoid the roll.
Of course you could go 4x4. There are Cosworth powered 106 out there!
But it's the handling that I'm not so sure about. I know Z-cars sell RWD classic Mini's with similar motors. They weigh similar and I suspect have a similar track too with chunkier alloys on. So it leaves a difference in wheelbase between them of about 6-7"
The vids I've seen the little ForTwo doesn't seem too bad at all. But having not been in one and certainly not in a BEC version I have no point of reference.
I have seen the videos, the one where it comes screaming down the straight and the guy nearly drops his video camera when he realised it is s Smart car overtaking everything .... hilarious. The only others I have seen are donuts.
The ForTwo is pretty snappy...but actually it isn't 99% of the time, it just understeers (see the Top Gear ForTwo lap !). The tall chassis means that even on the stiffer Brabus suspension it can't control the body roll and the front will wash out. You can't power oversteer because the ESP will cut power as soon as it starts to go. But...lift off or brake mid fast sweeping corner and the resultant weight transfer will snap oversteer without warning. The ESP will sort it out by applying bits of brake, but it isn't all that much fun. Been there, changed the trousers. You also get the ESP light flickering down a bumpy B-Road. I know people do disconnect it.
I assume the BEC conversion looses the ESP, so you may gain a little feel there. But this still leaves a stiff chassis and short wheel base = rather bumpy. And that big weight transfer due to high CoG won't go away.
Will the obvious fun of smoking things away from traffic lights make up from what are going to be obvious handling quirks ?
The ForTwo is pretty snappy...but actually it isn't 99% of the time, it just understeers (see the Top Gear ForTwo lap !). The tall chassis means that even on the stiffer Brabus suspension it can't control the body roll and the front will wash out. You can't power oversteer because the ESP will cut power as soon as it starts to go. But...lift off or brake mid fast sweeping corner and the resultant weight transfer will snap oversteer without warning. The ESP will sort it out by applying bits of brake, but it isn't all that much fun. Been there, changed the trousers. You also get the ESP light flickering down a bumpy B-Road. I know people do disconnect it.
I assume the BEC conversion looses the ESP, so you may gain a little feel there. But this still leaves a stiff chassis and short wheel base = rather bumpy. And that big weight transfer due to high CoG won't go away.
Will the obvious fun of smoking things away from traffic lights make up from what are going to be obvious handling quirks ?
Noger said:
I have seen the videos, the one where it comes screaming down the straight and the guy nearly drops his video camera when he realised it is s Smart car overtaking everything .... hilarious. The only others I have seen are donuts.
The ForTwo is pretty snappy...but actually it isn't 99% of the time, it just understeers (see the Top Gear ForTwo lap !). The tall chassis means that even on the stiffer Brabus suspension it can't control the body roll and the front will wash out. You can't power oversteer because the ESP will cut power as soon as it starts to go. But...lift off or brake mid fast sweeping corner and the resultant weight transfer will snap oversteer without warning. The ESP will sort it out by applying bits of brake, but it isn't all that much fun. Been there, changed the trousers. You also get the ESP light flickering down a bumpy B-Road. I know people do disconnect it.
I assume the BEC conversion looses the ESP, so you may gain a little feel there. But this still leaves a stiff chassis and short wheel base = rather bumpy. And that big weight transfer due to high CoG won't go away.
Will the obvious fun of smoking things away from traffic lights make up from what are going to be obvious handling quirks ?
That's sort of my point or question really.The ForTwo is pretty snappy...but actually it isn't 99% of the time, it just understeers (see the Top Gear ForTwo lap !). The tall chassis means that even on the stiffer Brabus suspension it can't control the body roll and the front will wash out. You can't power oversteer because the ESP will cut power as soon as it starts to go. But...lift off or brake mid fast sweeping corner and the resultant weight transfer will snap oversteer without warning. The ESP will sort it out by applying bits of brake, but it isn't all that much fun. Been there, changed the trousers. You also get the ESP light flickering down a bumpy B-Road. I know people do disconnect it.
I assume the BEC conversion looses the ESP, so you may gain a little feel there. But this still leaves a stiff chassis and short wheel base = rather bumpy. And that big weight transfer due to high CoG won't go away.
Will the obvious fun of smoking things away from traffic lights make up from what are going to be obvious handling quirks ?
I very much like the idea of a nimble little car that is darty and can change direction quickly. It's height might be an issue I agree, although I don't have any data on it's roll center or CoG, so I don't know if it actually is as bad as its visual height might suggest or not.
I've seen a couple of vids, one is a drift car on a circuit. It seems fairly controllable. Another vid has the car powersliding all over the show. Again it doesn't look hugely snappy. But I've no idea what they are like at higher speed and when you involve bumps.
Yes you lose the ESP completely, although £500-600 and you can fit Racelogic.
Another hugely important factor is where the engine weight is.
Even cars which are properly designed such as the elise tend to want to snap around in wet corners given half a chance. All that mass hanging out the back is like throwing an axe - all it wants to do is spin. Great for a sharp turn in on a dry road. Not so great in poor weather.
If the engine was upfront and the power was delivered to the rear via a prop shaft, then it would make a much more chuckable and safe car.
A bit predictable, but to be honest I'd just buy an MX5 or similar and tune it up. Great balance out of the box.
Even cars which are properly designed such as the elise tend to want to snap around in wet corners given half a chance. All that mass hanging out the back is like throwing an axe - all it wants to do is spin. Great for a sharp turn in on a dry road. Not so great in poor weather.
If the engine was upfront and the power was delivered to the rear via a prop shaft, then it would make a much more chuckable and safe car.
A bit predictable, but to be honest I'd just buy an MX5 or similar and tune it up. Great balance out of the box.
andy43 said:
An over-powered Smart with the ESP completely off would be lethal IMHO. There's a reason it's set-up to understeer horrendously. Snap oversteer in a Smart car would not be pretty.
But is it as bad as Internet folklore proclaims? That's the question really. As for it's standard setup, well it is a city car typically aimed at non enthusiasts. So I'm not sure it's stock setup is all that important as it'd be a heavily modifed vehicle anyway. 300bhp/ton said:
andy43 said:
An over-powered Smart with the ESP completely off would be lethal IMHO. There's a reason it's set-up to understeer horrendously. Snap oversteer in a Smart car would not be pretty.
But is it as bad as Internet folklore proclaims? That's the question really. As for it's standard setup, well it is a city car typically aimed at non enthusiasts. So I'm not sure it's stock setup is all that important as it'd be a heavily modifed vehicle anyway. andy43 said:
We've had two, both standard suspension, one was mapped with a heady 20 bhp over standard with wider roadster wheels. I honestly think that whaever you do to a Smart, suspension-wise, with the short wheelbase and the engine in the back, it'll try and kill you if you put too much power through it. Or just fall over, elk-dodging-style.
You might well be right. This looks rather a laugh though: http://www.youtube.com/watch?v=PuVc1OdVDyIGassing Station | General Gassing | Top of Page | What's New | My Stuff