Snow questions

[Anonymous]

So... a bit of snow, first time trying with an MR2... anyone any idea what's going on:

1) Why is it so hard for a RWD car?  Is it the lack of steering?

2) Does the LSD make things easier or harder, or have no effect?

3) Surely it'd do a better job with the engine over the rear wheels than a normal FR car?

Anyone any idea about the above?

[Anonymous]

I was quite surprised at how badly the 2 coped with the conditions.

I was expecting reasonable traction with a rear engined, rear drive car, with an LSD to do quite well.......

The LSD should certainly help in such conditions....

Our rear tyres are not that wide to cause undue problems....

Although it was quite fun having the car sideways, even when travelling in a straight line, it did not inspire confidence!

Neither did having idiots in 'Transit White Vans' travelling 2 feet off my back bumper, when I was slithering all over the road....bloody idiots!!!

No explanations from me.....equally baffled.

Andrew

[markiii]

firstly this is a very light car so traction will be interesting anyway.

Secondly your on stock tyres? neither teh RE040 or Yokos have a tread pattern thats very good in snow.

thirdly, in a front wheel drive the front wheels will try to pull you in teh direction they are pointing. If they manage it great. If they don't they don't.

with rear wheel drive you have two variables, can the rear grip, i.e will you move anywhere?

and which direction are you going in? this is dependant on whether you have any front end grip?

So in scenario one, if the front wheels can'r grip you won't move. in scenario two if the rears grip but the fronts don't you'll move, but have sod all control of where.

All RWD cars have this problem to some degree. The GF old 320 merc was dire in the snow and ice. But at least with front engined you have some weight over teh front to give you a better chance of steering.

[Anonymous]

I'm guessing a bit here;

1) Why is it so hard for a RWD car?  Is it the lack of steering?

Pendulum effect I think. Once things start to go wrong, the moment around the pivot (ie the front wheels) is significant.

2) Does the LSD make things easier or harder, or have no effect?

Harder I think; that's why the rear "kicks" to the left when you lose traction.

3) Surely it'd do a better job with the engine over the rear wheels than a normal FR car?

Pass.

Of course, I could be wrong on all the above. All I do know is that it's a PITA   s:wink: :wink: s:wink:

[Tem]

Here's my thoughts...

"1) Why is it so hard for a RWD car?  Is it the lack of steering?"

Because FWD cars are for dummys. Just point and go, the ass will always follow. You need to know more with RWD car, but once you get it, you'll keep wondering why anyone wants a FWD car. IMHO RWD is easier to drive on snow, but that's just cause I never learned to drive a FWD car.


"2) Does the LSD make things easier or harder, or have no effect?"

Depends on your drivestyle, it makes things easier when you know what it does. It prevents a situation where other wheel would spin freely while other had traction. LSD helps you accelerate, cause you won't be just spinning the other wheel. But if you step on gas in a corner a bit too much, you'll just spin the other wheel without LSD and keep traction. But with LSD, the ass is loose right away (in theory it helps to keep traction in a corner, but that can be pretty much ignored on ice/snow).


"3) Surely it'd do a better job with the engine over the rear wheels than a normal FR car?"

Yes. But if you had winter/all around tires on that FWD and the stock tires on MR2, the FWD would do a better job. Tires are everything on snow.

[aaronjb]

"1) Why is it so hard for a RWD car?  Is it the lack of steering?"

Because FWD cars are for dummys. Just point and go, the ass will always follow. You need to know more with RWD car, but once you get it, you'll keep wondering why anyone wants a FWD car. IMHO RWD is easier to drive on snow, but that's just cause I never learned to drive a FWD car

I agree with you mostly there Tem - FWD are 'safer' in conditions like these for 'most' people..

If (like you did) you learn to drive in a RWD car, then you can have some fun in the snow, and it's not too bad (helps if you have decent winter tyres of course, but over here we don't have any laws about that - so nobody does)..

If you learnt in a FWD car then you'll find that much easier in snow - if you c*ck it all up and apply too much throttle, the front end will either a) go nowhere, or b) go nowhere (assuming a standing start). In a RWD car you'll do lots of nice pirouettes  s:) s:)

In a corner it's debatable - in a FWD car if you're going too fast, you'll just carry on in a straight line (usually..), RWD car you'll either carry on in a straight line, or more usually end up doing more pirouettes..

Carrying on in a straight line is usually less frightening  s:) s:)

You can still end up doing pirouettes in FWD cars of course (trust me, I've done it more than once  s:oops: :oops: s:oops:  ), but you usually have to provoke them much much more.

Anyway, I'm with Tem, RWD + snow = fun and/or more controllable than a FWD car, if you're good at it  s;) s;)  (I'm not, really..  s:D s:D  )

Oh yes, and regards the rear engine effect - as Phil said, it's down to moments about pivots. There's more weight at the rear, which means when there's zero grip - if things start swinging, they swing hard.. with a FR car more of the weight is over the pivots (and therefore has neutral effect).

Aaron

IMHO, E&OE etc  s;) s;)

[Anonymous]

I'm with Tem, RWD + snow = fun and/or more controllable than a FWD car, if you're good at it

I couldn't get my car out of the carpark.. or for that matter move it round the carpark.  That's sort of what I'm on about.

I appreciate what yourself and Tem are saying, but that seems to me applies equally to wet roads, as snow slush.

I can't even get onto the road because of the snow, hence my questions.

[aaronjb]

I couldn't get my car out of the carpark.. or for that matter move it round the carpark.  That's sort of what I'm on about.

Blimey..

My road was mostly sheet ice the other day (the first morning after the snow half melted and then froze), and I could still get out with no real difficulties - which includes; getting down off my front grass, going over a sleeping policeman, left at a T, left at another T then out onto the road..

The first two T's were ok as I didn't have to stop, just trundled round them in 1st at idle.. Getting out onto the main road wasn't too bad, although I did exit my road distinctly sideways   s:twisted: :twisted: s:twisted:  

If you live on a hill though or something along those lines, there can be times when you just can't get anywhere.. I came across a woman once who was stranded half way up a railway bridge - her driveway actually came out onto the bridge half way up.. She was just sat there spinning the wheels in first, but even using everything I'd learned (driving around the Yorkshire moors in winter teaches you a lot  s:D s:D  ), I still couldn't get her car up the slope.. Not without taking a runup - sadly there were about 15 cars behind us at the time who weren't moving anyplace for her..

[Anonymous]

I think the carpark problem is a made harder by it not being snow on tarmac or snow on gravel, but snow on large pebbels.  And that the exit/enxtrance for the carpark is quite a short steep slope on the same surface.

That coupled with the stuff discussed above made it very hard to move around, let alone get out.  I'm hoping to drive home for the first time tonight.

[aaronjb]

I think the carpark problem is a made harder by it not being snow on tarmac or snow on gravel, but snow on large pebbels.  And that the exit/enxtrance for the carpark is quite a short steep slope on the same surface.

Yeah - that'd probably do it.. pebbles = lots of round surfaces = miniscule contact patches under the tyres..

Not a lot of grip as it is, but when your tyres are trying to grip the snow/ice via probably two thumb-sized blobs.. you've got problems  s:) s:)  Especially when some bright spark adds a hill at the end  s:D s:D

There is one thing you can try, and that's dropping your rear tyre pressures right down (15psi or so perhaps), just to get out of the carpark (don't drive home like that, obviously!)..

[Anonymous]

Cheers... may try that  s:) s:)

[Tem]

And if you get really stuck, put carpets in front of the rear wheels and pull of SLOWLY...that should get you going. And by slowly I mean slowly. Slower than your normal walking pace. Slower than your granny walking. Once you spin the wheels, nothing happens anymore. Keep your foot off the gas and feather the clutch so that you barely move. The slower the better.

Just remember that if you have no grip to accelerate, you won't have any grip to brake either. With a little downhill, you might accelerate even if you floor the brake pedal...


Quoting myself...

Tires are everything on snow.

I know things are different in UK, if we had snow for a day or two, I wouldn't nother changing them either though. But I wouldn't drive the car either. Ask a friend to help you out, use a taxi, rent a car, call in sick.

Even if you don't mess up, chances are that someone else hits you  s:? :? s:?

[aaronjb]

It'd be better if we either a) didn't have snow at all, or b) had lots of it (like you guys), so that we had decent laws concerning winter tyres (not to mention being able to buy a specific winter tyre)..

Maybe I should just move to Finland or Norway  s:D s:D
Or Florida.. Maybe not - I hate really hot weather  s:) s:)

I'm just glad I wasn't driving the 300ZX - 300bhp to the rear wheels on very wide tyres would have proved.. interesting!

[Tem]

(not to mention being able to buy a specific winter tyre)

I'm sure you can buy winter tyres in UK...cause Colway is semipopular winter tyre over here and they are made in UK  s8) s8)

[Anonymous]

I'm sure you can get winter tyres over here, but probably not in your average Kwik-Fit, given the average intelligence level.

[Anonymous]

I'm with Tem, RWD + snow = fun and/or more controllable than a FWD car, if you're good at it

I couldn't get my car out of the carpark.. or for that matter move it round the carpark.  That's sort of what I'm on about.

I appreciate what yourself and Tem are saying, but that seems to me applies equally to wet roads, as snow slush.

I can't even get onto the road because of the snow, hence my questions.

As FWD have it easier, pulling and weight over driving wheels, did you think of trying to reverse out???

[Anonymous]

I did think about it, but never tried it  s:) s:)