Has Anyone Ever Spoke About This?

[zebidi]

how would you improve wet road stability on the MR2? driving in the wet seems to be a big problem to me, its in the workshop now and im getting racelogic traction control fitted, my tein superstreets and my alloys and some Toyo T1-Rs.

tyres and traction control are obviously one way to escape the rain, what else could?

how can aquaplaning be avoided also? well not avoid but at least make the affects of it less, anyone tried any new tyres recently?

[Bibbs]

TC won't assist as much as you think .. as soon as the rear breaks traction, it's lost. And in the wet it'll not get it back.

The only thing is to slow down .. Studies by the RAF have shown that the only thing to stop aquaplaning is to pump up your tyres (36psi) and drive below 50mph. Aquaplaning is totally different to wet grip.

Aquaplaning : Simplified its 9 x square root of your tyre pressure.

Theory Link

Based on 32 psi it gives you an aquaplane speed of 51 mph.

With regards to wet grip, you need a set of tyres that will remover the water from the road. I found Toyo's to be rubbish, F1's were a lot better in the wet.

To quote a guy "aldfort" on the S2000 forum

Aquaplaning is a very serious issue, leading to many road accidents and deaths each year, yet it is relatively easily avoided: slow down and change your tires when the treads get too shallow.

First, there is a lot of confusion among motorists about the difference between wet grip and aquaplaning.

Wet grip is the grip between the tire and the road when the road surface is wetted, but the tyre remains in contact with the road, and the two can react against each other. Wet grip remains more or less constant at all speeds.

Aquaplaning performance is the ability of the tyre to clear standing water from beneath the tyre, so that the rubber is in direct contact with the (wetted) road surface. Aquaplaning performance declines markedly at higher speeds

The wet grip of a tyre is defined only by the rubber compound, and has nothing to do with the tread pattern, or depth of tread, except insofar as there is a different type of rubber underneath the main tread. So that when the entire tread is worn away, the compound in the sub-tread offers limited grip in the wet.

Aquaplaning performance of a tyre is defined almost entirely by the tread pattern and the depth of the tread grooves. It has nothing to do with the rubber from which the tyre is made.

Explanation

Aquaplaning is the condition in which the weight acting on the tyre (or half-shaft) is borne entirely on a film of water, with no direct contact between the tyre and the road surface. In this condition, the tyre is not in contact with the road surface and there is no exchange of lateral forces between tyre and road. Thus the tyre offers no grip at all in either the lateral (steering) or longitudinal (braking/accelerating) direction.

Once a tyre is aquaplaning, there is nothing to be done, except wait for the vehicle to slow down and for the tyre to regain contact with the road surface. It is essential for effective control of the vehicle that when the tyre does settle back onto the road surface, it is aligned with the direction of motion. If the tyre is pointing in a different direction from the motion of the vehicle, then any driver (even an expert) will have great difficulty in controlling the vehicle. When grip returns (usually very suddenly), the tyres will immediately force the vehicle to change direction, and this will frequently cause either the front or rear tyres into a lateral skid.

Aquaplaning happens because the ability of the tyre tread to pump water away from the contact patch is less than the amount of water it encounters during its forward motion.

A tyre tread pattern is designed to pump as much water as possible away from the contact patch. The deeper the tread grooves, the more water the tyre can cope with. However, if the grooves are shallower than the depth of water on the road, then it becomes increasingly likely that a film of water will build up underneath a tyre, eventually lifting the tyre entirely off the road surface, in much the same way that a hydrofoil can skim across the water on only a tiny bearing surface.

Tyre companies design the tread pattern using computers to model the flow of water under the tyre contact patch, and test them with high speed photography. They use a laboratory built underneath a test track. A camera is positioned under a glass plate built into in the road surface. The plate and surrounding road are covered in a defined depth of water. The car then drives through the puddle and over the plate at a pre-determined speed. The photographic apparatus is designed to trigger the flash and shutter at the instant the tyre is above the lens, producing an image of the tyre as it passes through the puddle. Fluorescein dye is mixed with the water to highlight the areas of rubber, air and liquid.

Using this technique, the researchers look at the amount of rubber actually in contact with the glass at various speeds and water depths.

At any given tread depth, the onset of aquaplaning depends on the forward speed and the water depth. It happens across a relatively narrow speed range. Up to a certain speed, the tyre is in good contact with the road, but as the speed increases, the tyre cannot cope with the inrushing water and the front part of the tyre starts to lift off the road surface. Eventually, as speed increases still further, the tyre lifts completely off the road surface and all control is lost.

[JustJJ]

wot Ben said... lol :P

the 'little answer' (below:P )

basically Aquaplaning is one of those things... and comes from the tyres not being able to push away the water from underneath them... hence they begin skating over the top... either tyres with serious tread on them.. would help... or basically dont drive so fast that they cant bail away the water quick enuff lol..

Basically 'good driving skills befitting the circumstances' is the way forward on this one... you can do whatever you like to your car.. but when it comes down to it.. you cant turn the laws of physics on their head hehehe :P

[Bibbs]

All the exact details are in the theory link.

[1bloke1dog1mr2]

I agree with JJ, it goes on driving techniques. I used to have a Civic Type R with Avons all round and found them really good wet or dry. My Roadster has P6000 and I do find them a little skitty in the wet and the dry if my right foot's a little heavy, but then what else would you expect from a rear wheel mid engine car!

If it's wet, slow down, you never know what nutters you're gonna meet!!!!

[zebidi]

thanks for all the info guys, yeah the p6000 are the continentals? or are they the dunlops? anyhow i've had trouble with both before lol.

so T1Rs arent so good in the wet then after all? my cousin has T1Rs on hiss scooby P1 and he literally CARVES his way through water, but end of the day the best thing is to just slow down.

anymore eagle F1 vouches?

choices are T1Rs, parada 2s or eagle F1s

got untill afternoon tomorrow to tell them.

[kenny.c2828]

are p6000's not made by pirrelli ??

[Jesus]

The MR2 even in the wet will be stable as long as you drive according to the conditions of the road. No need to drive quickly in the wet.

If you want to improve your chances in the wet, get yourself onto a wet skid-pan for lessons in your own car.

The MR2 will only swing out if you give it the opportunity to... just use common sense when driving in different conditions.

Adding stiffer suspension is not going to improve wet handling. Nor will wider, low profile tyres. Fatter tyres don't cut through the water so well. Low profiles have less give in the sidewalls.

Basically 'good driving skills befitting the circumstances' is the way forward on this one... you can do whatever you like to your car.. but when it comes down to it.. you cant turn the laws of physics on their head hehehe tongue.gif

I agree.

[GiJoe90]

Had Eagle F1's on mine and drove in some trecherous weather, one which springs to mind was on the way to the first biker cafe meet in Sherburn. It felt absolutely fine, no problems at all. Tyres seemed to like wet weather.

Just the damp stuff that caught me out

Joe

[zebidi]

Had Eagle F1's on mine and drove in some trecherous weather, one which springs to mind was on the way to the first biker cafe meet in Sherburn. It felt absolutely fine, no problems at all. Tyres seemed to like wet weather.

Just the damp stuff that caught me out

Joe

the damp stuff? you mean when it looks like the road is greasy?

P.S i'd like to thank bibbs again for the info, it's a great read.

[Bibbs]

NP .. Glad I could help (or cut and paste info ;) )

Toyo T1-S's were on the MR2 .. and I've got the R's on the back of the S2000 (the fronts are S's, but will be swapped to R's when bald).

They are good, but RWD "pushing" through water will always be trickier than FWD "pulling" through water .. It's a nightmare when you get toasted by Saxo's on the motorway, with pram wheels, in the wet. But I just kick back and think, yeah, but you are still in a Saxo.

[GiJoe90]

Had Eagle F1's on mine and drove in some trecherous weather, one which springs to mind was on the way to the first biker cafe meet in Sherburn. It felt absolutely fine, no problems at all. Tyres seemed to like wet weather.

Just the damp stuff that caught me out

Joe

the damp stuff? you mean when it looks like the road is greasy?

P.S i'd like to thank bibbs again for the info, it's a great read.

Yeah, no tyre seems to be of any use when it gets greasy as I found out in a big way. Maybe it's my driving! Definitely the best road tyres I've had on any car so far though.

Joe

[zebidi]

Yeah, no tyre seems to be of any use when it gets greasy as I found out in a big way. Maybe it's my driving! Definitely the best road tyres I've had on any car so far though.

Joe

somethign to do with the "MU" rating of the road (grip level)

rain can give it a mu of 45 while a recently drying one i.e just been showered on can result in a mu of 2 or 3,

petrol mixing with the rain and emission crap.