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Driving in the Rain
Nick Davison - 4/8/11 at 08:27 AM

Hi everyone I have been away for a while but thought it was about time I joined in again.

I had to drive home in the rain last night, well following a realy heavy storm so there was a lot of water about. It was particularly scary as what are normally fairly sticky roads turned to an ice rink. I was wheel spinning changing into 2nd and if pushing it into 3rd as well. As for going round corners I value my life too much to push them when wet!

Nick


franky - 4/8/11 at 08:45 AM

Maybe your set-up is too hard or its your tires?

I was in the rain we had last night, I set the traction control to 'wet' and it was amazing how much progress you could make


adithorp - 4/8/11 at 08:58 AM

quote:
Originally posted by Nick Davison
Hi everyone I have been away for a while but thought it was about time I joined in again.

I had to drive home in the rain last night, well following a realy heavy storm so there was a lot of water about. It was particularly scary as what are normally fairly sticky roads turned to an ice rink. I was wheel spinning changing into 2nd and if pushing it into 3rd as well. As for going round corners I value my life too much to push them when wet!

Nick


Driving in the wet in a light weight car i about being smooth and short shifting (keeping the revs down) and avoiding standing waterwhere possible. Light on the throttle,light on the steering and light on the brakes. Terms like "pushing it" aren't what you want. The difference between wet and dry handling is magnified by the low weight.

What tyres are you on?


Richard Quinn - 4/8/11 at 09:39 AM

Something that has niggled me for a little while now - Why do we have such an issue with wet/damp roads when bikes don't seem to struggle to the same extent? I was following a 'blade in my tin top this morning. It was raining quite heavily but although he was riding smoothly he didn't appear to be holding back too much.


David Jenkins - 4/8/11 at 09:43 AM

I always found wet roads "exciting" when I used to ride a motorbike... including coming off once.

There's very little margin for error on a bike - one patch of oil lifted by rain and you're toast, if you're unlucky.

My Locost is still exciting in heavy rain - but with the fundamental advantage of not falling over when it looses grip (although it may lose direction!)

[Edited on 4/8/11 by David Jenkins]


paulf - 4/8/11 at 10:02 AM

Tyres make a lot of difference, the original tyres I had on were like driving on ice when it rained but the A021s the car is fitted with now allow it to be driven at normal road speeds even in heavy rain.The only downside is due to being very soft compound the wear out rather quickly.
Paul


Nick Davison - 4/8/11 at 10:06 AM

Tyres are 215/40/17 can’t remember the make but a decent one.

I wasn’t pushing it to be honest, just a quick acceleration in a straight line which resulted in a lot of spinning, the rest of it was quite gentle, as I had less grip I couldn’t nip past the traffic and was very wary of slippery bends.

This was the first time out in the 7 in lots of standing water and I don’t know the limits of the handling yet, combine this with very different characteristics to a road car and I have a bit of a learning curve on my hands. I could do with some nice open space after rain to have a play and see where the limits are, until then it’s gently does it – or just keep dry (after all it is Italian electrics!!!!)

Nick


adithorp - 4/8/11 at 10:48 AM

The tyres won't be helping matters. Anything in that size/profile will be designed for a much heavier car. Low profile, wide tyre aren't very flexible.


scootz - 4/8/11 at 11:06 AM

I know how you feel. I had to drive my Exige home from the Balkans in November to meet a VAT saving deadline. Everything was fine until I hit Austria and then it started snowing and didn't stop until I was past Germany! Negotiating a couple of inches of snow in a lightweight RWD car on A048's whilst being passed by heavies was bloody terrifying!


bi22le - 4/8/11 at 11:09 AM

Do a couple of wet track days in this coming winter. Thats what I want to do to increase my car control.

One of my mad biker friends does track days all year round since passing his direct access 2 years ago and getting an Aprilliz RSVR for a first bike (I said he was mad!). He said that the winter track days taught him more about control and handling on the limits than any other track day. It also means you can practice with out having to do silly speeds.

Just a thought


Norfolkluegojnr - 4/8/11 at 11:12 AM

quote:
Originally posted by Richard Quinn
Something that has niggled me for a little while now - Why do we have such an issue with wet/damp roads when bikes don't seem to struggle to the same extent? I was following a 'blade in my tin top this morning. It was raining quite heavily but although he was riding smoothly he didn't appear to be holding back too much.


i'd regularly poo myself riding in the wet. its scary, and bikes are noticeably slower in the wet generally.

But, on a bike you can shift weight more easily, allowing you to keep the bike more upright in the corners. this isn't something that can't be replicated in a car.

Also, modern all weather bike tyres are amazing. I used to ride on Michelin Pilot Road 2's and the wet grip was incredible. They use dual compound so the centres are 'harder' to aid mileage, whereas the shoulders are 'softer' to aid corner grip.

clever stuff.


hughpinder - 4/8/11 at 12:24 PM

The coefficient of friction for a tyre (avon track tyres data here):

wet data - u=0.87-(0.0064*weight on tyre-kg) e.g about 0.75 for a 7 type
dry data - u=2-(0.002*weight on tyre-kg) e.g about 1.6

assuming the tyres are at working temperature you have 2.2 time the grip in the dry. It is obviously easier to get a tyre hot in the dry than in the wet.

Also, the ability of a tyre to clear the water away to get the rubber on the ground depends on the tread and the (weight/contact area), so a tintop is much heavier, and on a similar sized tyre, so it can squeeze the water away much easier

Regards
Hugh


greenwood03 - 4/8/11 at 02:05 PM

as has already been said smooth is the order of the day in the wet, but smooth doesn't necessarily have to mean slow - just tempering when to feed the power back in and short shifting if it is really that wet and horrible. I find a good way 9 for me at least ) to get smooth is to aim to drive without braking, letting the engine help slow the car for corners and reading teh road further ahead to make sure that you're at the right speed when you get to a corner/bend etc. Gradually you find that you're more confident with what the car car do and naturally your speed increases whilst still being consistently smooth - obviously that doesnt make you smooth on the throttle - thats another story!

bottom line with these types of cars we all know they can bite, its not like its an unknown - so just a question of getting used to it. If you drive it all year round - rain/sun/ice you'll soon find your comfort zone.

and yes tyres 9 and tyre pressures ) are def key...


beaver34 - 4/8/11 at 04:15 PM

only drove mine once in the wet, its was quite scary, i think that main issue is tyre and having no temp in them, i was on normal road tyres and it was like driving on glass, although i think that the 7 type cars are that fast it feel slike your going slow but your not actully

either way ive softer tyres now


DIY Si - 7/8/11 at 09:08 AM

When I first got mine, it was awful in the wet. But then I realised the tyres were 5 or more years old and getting quite hard. As soon as I got a new set of decent tyres fitted the difference was like night and day. I didn't go silly with the tyres, just as set of Marangoni Zeta Linea's, but I could still get most of the power down in the wet and still drive in a spirited fashion.

I always used my car regardless of the weather, as if you car manage ok in the wet I think you get a much better feel for the car and how it moves about. I've been out in the snow in mine and the only problem I had was that my visor kept freezing up!


Oh, also on 17" tyres, you're never going to have much joy in the wet in a 7. There's no way they were designed for a car as light as a 7, so they won't clear the water very well.

[Edited on 7/8/11 by DIY Si]


Volvorsport - 7/8/11 at 10:29 AM

a set of intermediates would be ideal in super soft compound .