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Snowball
21-09-05, 06:28 PM
Me again... last one for the night :p

This might be a stupid question:angry: , I am sure you will tell me if it is :D

Obviously Cobras are famous for lack of rear end control in the rain...

If I want to use the car every day, and in the Uk this means the wet, is there anything I can do to make the rear end stick to the floor more?

I drive a beemer at the momment, (traction control defaults to being on... Grrr) dont shout at me, I know its sacrilege, but could you fit traction control to aCobra to use in the rain?

Ok now you really know how little I know about cars, if this is totally stupid, please be nice and educate me! :D

Cheers all

Snow

TINKA
21-09-05, 06:34 PM
There are several possibility's to make them more friendly in the wet, If you fit traction control this will as you say help also fit narrower rear tyres to help you cut through the water and thirdly make sure you fit an open diff as when you do ( and you will ) put too much power down only one rear wheel will spin up normally the one which has less weight on and so as the other wheel will not spin it should maintain some grip. With a limited slip or power lock BOTH wheels will light up and before you know it you will be completely out of control. IMHO :D

Grease Monkey
21-09-05, 06:34 PM
How about a variable rev limiter ?

Set to 3k in the wet, 7k in the dry, might save your ar5e.

dave
21-09-05, 06:48 PM
How about a variable rev limiter ?

Set to 3k in the wet, 7k in the dry, might save your ar5e.




:D :D :D Just for a moment then Adrian i thought you'd written "Variable rev COUNTER"!!!!!:D :D :D

TheUnixKid
21-09-05, 06:51 PM
There's a rather simple and short solution to the problem...don't drive it in the rain? Actually if you drive correctly it's impossible to lose control of any car, regardless of safety features etc.

TheUnixKid
21-09-05, 06:53 PM
I've only driven my rolling chassis on gravel and the slightest push of the throttle makes the back end fly out, I guess it'd be the same sort of thing in the rain (that's with a Rover 3.5l V8 in a Sumo). I've had skid training before but wouldn't like to try it on a road with other cars.

Grease Monkey
21-09-05, 07:10 PM
I've driven mine in the pouring rain 2 weeks ago tomorrow, and other than getting a wet left arm (water ran off the tonneau onto the centre tunnel), and a wet right leg (water came in through the door join?!) it behaved perfectly.

Admittedly i was being somewhat respectful of the right foot on the way home!

Moral of the story: Easy on the right foot and pack a full set of Musto HPX Offshore oilies in the boot.

Ricky
21-09-05, 07:12 PM
www.racelogic.co.uk (http://www.racelogic.co.uk) :thumb: :thumb:

regards

dingocooke
21-09-05, 07:19 PM
If you're gonna use it every day, I'd be more worried about how I was gonna pay for the fuel and tyres!!

If I did my 40,000 a year in my cob, it would cost me getting on for 13,000 in juice!

Maybe you're loaded, or your girlfriend works at the Shell garage!!! (Either way, lucky man!)

Seriously, my cob gets more wayward in the damp than the soaking wet, damps much greasier, I think Tinka is right about open diffs in the slippy conditions.

Have fun,

Regards,

Steve:thumb: :thumb:

Grease Monkey
21-09-05, 07:24 PM
www.racelogic.co.uk (http://www.racelogic.co.uk) :thumb: :thumb:

regards

Fancy paying 800 to have the fun removed?! The cobra, as an adrenalin rush, would be reduced by thinking it's not going to flip you into a hedge. :thumb:

You want safe fun, go to Alton Towers. :rolleyes:

Ricky
21-09-05, 08:10 PM
Fancy paying 800 to have the fun removed?! The cobra, as an adrenalin rush, would be reduced by thinking it's not going to flip you into a hedge. :thumb:

You want safe fun, go to Alton Towers. :rolleyes:

can always turn it off;) plus you can dail the oversteer. e.g set to 10 degrees slip and the back end will only come out 10 degrees. just a thought:thumb:

regards

Robin427
21-09-05, 08:54 PM
I know Steve was going to fit traction control to his GD. As GD, TVR and others say, if you drive it properly then you don't need all the driver aids. Then again, few of us are trained racing drivers so perhaps a tuneable system like the Racelogic one would be a good idea. The problem I have with it is that it cuts out the spark to individual cylinders, and so surely you are passing unburnt fuel through the cats?

robert
21-09-05, 09:20 PM
There are several possibility's to make them more friendly in the wet, If you fit traction control this will as you say help also fit narrower rear tyres to help you cut through the water and thirdly make sure you fit an open diff as when you do ( and you will ) put too much power down only one rear wheel will spin up normally the one which has less weight on and so as the other wheel will not spin it should maintain some grip. With a limited slip or power lock BOTH wheels will light up and before you know it you will be completely out of control. IMHO :D

Martin

Narrower tyres will have the effect of LESS grip, it is the tread of the tyres that disperse water, not the overall tread width, more tyre contact equals more grip, by narrowing the tyre contact, you are reducing the overall contact area, hence less grip.

WRT a limited slip diff, the problem is that you get NO traction with an open diff.

The problem is an open diff always tries to balance the torque. That's a hard statement to get a grasp on, but it means that if the spider gears are pushing on both drive gears and one of them offers lots of resistance (tire sitting on pavement) and the other side offers no resistance (up in the air, or sitting on a patch of ice), then it will find a happy balance where both sides are receiving almost no torque at all. All the rotational energy is guided to the side with the least resistance. In the end, that side spins very fast and the pressure on each drive gear is the same.. Almost no torque is needed to spin one wheel, and therefore almost no torque is going to the other side as well. Anyone who's driven on snow or ice knows this trick.

The only way to drive safely in the wet is to treat the loud pedal very nicely, and get something that handles.

Steve
21-09-05, 09:38 PM
the racelogic system I use (will use when i get round to fitting it) cuts injector pulses, not spark, therefore it is fine for cat cars, and is regularly used on modern cat cars.

I figure that we often drive out of bends at 80% throttle, because you want to leave a margin for error, whereas with traction, you can drive harder, letting the traction accomodate. I see it as a HP addition tool as much as anything else, it prmits me to use all the hp more often, and is definately quicker (as proven over and over on F1 etc)

I drove a car with racelogic fitted, and it is very easy to dial in and set, the racelogic system also has a WET setting, which dials slip to zero.

add to that full throttle gear shifts, launch control, it becomes more fun to use.

Snowball
21-09-05, 10:08 PM
LOL... cheers guys... made me laugh :)

Thanks for the advice, in an ideal world I would like a switch that you flick when you get into wet weather that says "control this beast"...

but I get this wouldnt get through the SVA, so i will have a button instead ;) LMAO

Thx all :)

Snow

TheUnixKid
21-09-05, 10:44 PM
Statistically you are more likely to crash with traction control than without it (same goes with air bags, seat belts, ABS etc). Psychologically we see such things not as safety measures but as performance tools that allow us to go faster in a lot safer a fashion so we push limits more.

If you respect the thing you are driving and don't push the limits you will be fine. I don't recommend a technological fix but an advanced driving course. Check out www.rospa.org or www.iam.org.

John

smash
21-09-05, 11:10 PM
Martin

Narrower tyres will have the effect of LESS grip, it is the tread of the tyres that disperse water, not the overall tread width, more tyre contact equals more grip, by narrowing the tyre contact, you are reducing the overall contact area, hence less grip.

Eh? always thought wider tyres, even now, are more prone to aqua planing. You don't really want contact area, you want tread to deal with the water wedge that occurs - the bloody great stripes down the middle of most performance tyres are supposed to act as a pump to disperse water through the tread aren't they? Or is that what you just said?!

tarmacscratcher
21-09-05, 11:24 PM
wet or dry...smoothness is always the way to drive..remember your old driving instructor?....3 causes of skidding......braking,steering and acceleration :)..and I think I'm right in saying acceleration is the easiest to control :)

clive a brown
22-09-05, 09:22 AM
allways be in a higher gear - pull away in third and down't use the throttle!

Have driven in the rain with both Comp TA & Toyos - at least Toyos get rid of the water - where as Comp TA are mud and snow tyres and completely useless in the wet.

with a very gentle right foot - it is possible to stay safe - no fun though - I really enjoy the buzz of the cobra after a spell in the dog (306 XTDT)

robert
22-09-05, 10:46 AM
Eh? always thought wider tyres, even now, are more prone to aqua planing. You don't really want contact area, you want tread to deal with the water wedge that occurs - the bloody great stripes down the middle of most performance tyres are supposed to act as a pump to disperse water through the tread aren't they? Or is that what you just said?!

Yep, thats what I said.

All tyres will have tread to disperse water, however a narrower tyre will have less contact area, ie a 225mm width tyre has erm, 225mm where as a 275 has 275mm width. Some tyres have better wet characteristics than others, however comparing like for like, ie Pilot Sports, the 275 will have a larger contact area, therefore better traction.:thumb:

Pim.Cobra
22-09-05, 11:25 AM
Narrower tires will give you more grip on slippery surfaces. Look at rally cars, or iceracers...
Wider tires wil give more grip on dry surfaces, as long as there is enough downforce.
It all comes down to weight per square inch of tire sitting on the road surface...
Take an advanced driving course with your Cob. Lots of fun and very useful, as it reacts differently than your average day to day transport.....
I'm not bothered about driving in the wet, but having to break.... You need a very sensitive foot.
Pim

robert
22-09-05, 11:39 AM
Narrower tires will give you more grip on slippery surfaces. Look at rally cars, or iceracers...
Pim

Rally cars have to run narrow tyres due to the regulations, not by choice.


Asphalt rallies and Colin McRae have often been dramatically contradictory. The crash in Corsica in 2000, which could have been life threatening, led to most unpleasant surgery, then the accident in 2002 which ended with a broken finger which could have seriously upset his championship chances.

"Yes, bad things have happened to me on asphalt rallies, but I do not have a problem with driving on asphalt. For me the one problem with asphalt rallies is that I do not think the regulations enable the car to work to best advantage, because the rules mean the cars are under-tyred. The tyres the regulations make us use are far too narrow in relation to the weight of the car in rally trim.

http://www.rallysportmag.com/cms/A_30382/article.html

Neil O
22-09-05, 11:57 AM
The guys I know in Germany who change their tyres/wheels from summer to winter, nearly always put narrower tyres on for the winter, never wider. They have a different tread pattern, but they are still narrower.

I reckon you could be wrong on this one Rob...........;)

On open diffs, I think that you are safe with either in the wet as you shouldn't really be pushing hard enough for it to make a difference.

When driving in the wet, I use much less right foot and take corners steady etc. but above all leave much more room/time for braking. The Dax brakes are a bit too sharp for the wet in my opinion, very good in the dry though! :D
First thing I do when leaving my house in the wet is brake quite hard till I lock up briefly, it gives me a reminder of how slippery it is and also reminds me I've left the antilock brakes in the Honda! :D

Cheers,
Neil.

kenf
22-09-05, 01:46 PM
somebody mentioned Alton Towers earlier on in the thread...I say Bollocks to Alton Towers - available from Amazon http://www.amazon.co.uk/exec/obidos/ASIN/071814791X/qid=1127396691/sr=8-1/ref=sr_8_xs_ap_i1_xgl/026-2268371-5282863

:-}

tarmacscratcher
22-09-05, 01:49 PM
"The guys I know in Germany who change their tyres/wheels from summer to winter, nearly always put narrower tyres on for the winter, never wider. They have a different tread pattern, but they are still narrower"

Snow and wet are totally different........wider tyres equal more grip but for snow this would mean more weight distribution, the car would sit on top of the snow rather than compacting it for grip.

Neil O
22-09-05, 02:09 PM
"The guys I know in Germany who change their tyres/wheels from summer to winter, nearly always put narrower tyres on for the winter, never wider. They have a different tread pattern, but they are still narrower"

Snow and wet are totally different........wider tyres equal more grip but for snow this would mean more weight distribution, the car would sit on top of the snow rather than compacting it for grip.

I agree, however, driving through standing water with wider tyres will result in an increased risk of aquaplaning. Standing water doesn't have to be very deep before you can end up sailing over the top of it, especially in a Cobra.
I think it's correct that the weight of the vehicle is relevant to the width of the tyre (someone said this earlier).

Cheers,
Neil:D

Snowball
22-09-05, 02:10 PM
LOL... you guys make me laugh..

Well I am glad I got a decent thread going, even if it did turn into a debate over the thinkness of tires... lol :)

To behonest, I dont care if they do make me slide all over or not, I would love nice fat ones LOL :P

Thanks for all the pointers, everything has been noted :)

Snow (no pun intended)

robert
22-09-05, 02:36 PM
Unfortunately, its not just a case of sticking narrower tyres on the car, yes, narrower tyres will give you more weight on the given contact area, but if you have a tyre with good water dispersal then its a moot point. Aquaplaning is a different matter, but who would drive through a dirty great big puddle in a Cob anyway. :thumb:

The best option is to have compliant suspension, which stops tramping and excessive wheel movement over undulatios in the road. The best option is to wind the damping to a soft setting, thereby ensuring whatever tyre patch is available is being used to full effect.

Tyre pressures also have a large bearing, too hard and you only get the centre contact, too low and the center becomes in effect a water trap.

Sorry, but I have to disagree with Tinka, its not enough to just stick narrower tyres on.

queeniee
22-09-05, 04:30 PM
Since I have the Michelin Sport Pilot tyres, (285 in the rear)the behavior of my Cobra has greatly improved in the rain; adapt the driving style when it rains, use a feather right foot for the throttle and use smoothness when it is wet even if it tnen reduces the fun of driving the Cobra
Yep, thats what I said.

All tyres will have tread to disperse water, however a narrower tyre will have less contact area, ie a 225mm width tyre has erm, 225mm where as a 275 has 275mm width. Some tyres have better wet characteristics than others, however comparing like for like, ie Pilot Sports, the 275 will have a larger contact area, therefore better traction.:thumb:

robinj66
22-09-05, 06:30 PM
I used Granada wheels & tyres for the SVA and drove back down the M2 in the pouring rain. I slid sideways every time I hit a pool of water.

Once the road wheels were on (225 on the rear) I have never had the same problem.The suspension set up has not been changed and the car has been used in the wet ( despite no wet weather gear whatsoever (except a baseball cap and a pair of gloves).

To answer the original question - BE CAREFUL WITH YOUR RIGHT FOOT IN THE WET!

Purple AK
22-09-05, 07:19 PM
From a Tyre Mans point of view ;) Winter tyres are normally narrower to cut through SNOW and obtain some sort of grip from below. The same applies to Rally tyres which are predominantly used on loose surfaces, They need to cut through the surface to find grip. Both are a totally different ball game to wet and dry on tarmac! :( The best WET tyre is one that pumps the contact patch dry. The larger the contact patch the better. Ask yourself, Do F1's Superbikes or GP Bikes use smaller tyres in the wet? No. They reply on water clearing grooves and a different compound (something not available in road tyres) Tyre manufacturers spend millions perfecting tread patterns/compounds for general ALL ROUND wet/dry road use.
As for Traction Control, It may be of some use with a higher spec engine where the power comes in with a bang higher up the rev range. But with a milder camed motor, Care with the loud pedal should be all that is required ;)

Just my tuppenth :thumb:

wilf
22-09-05, 07:42 PM
Let's face it. For the vast majority of us, a Cobra is a bl**dy nightmare in the wet.

It is not so much having to keep the right foot light, as the huge reduction in braking power that is the problem. You cannot control what jumps out in front of you.

Let me be the first to come out and say it: "Cobra as all weather daily drive for the average driver?" - You must be joking.

mylesdw
22-09-05, 07:56 PM
The larger the contact patch the better. Ask yourself, Do F1's Superbikes or GP Bikes use smaller tyres in the wet? No.


Surely the answer is yes! A grooved tyre of the same width as a slick has maybe 20% less rubber on the road so they are effectively running a narrow tyre and raising the effective weight of the car. If your first premise was true, why do they not run a wider rain tyre to compensate for the grooves and keep the amount of rubber on the road constant?

Purple AK
22-09-05, 08:06 PM
Surely the answer is yes! A grooved tyre of the same width as a slick has maybe 20% less rubber on the road so they are effectively running a narrow tyre and raising the effective weight of the car. If your first premise was true, why do they not run a wider rain tyre to compensate for the grooves and keep the amount of rubber on the road constant?
Because Regulations specify a maximum tyre size. The point I was trying to get across is that a narrower tyre is not the answer. Any tyre is going to give less performance in the wet. So it's down to tempering the right foot ;)

snakebite
22-09-05, 09:18 PM
Poodling along in traffic in in a French town in the pouring rain, went to overtake (this was done ever so gently - so I thought) the car in front to catch up with rest of the cobs, ended up with the rear of the cob at 180 degrees to the traffic. Ted Drew driving behind thought "Oh S****". The boss beside me, who does not use bad language said F****, I let everthing go except turning into the skid - luckily the car straightened up. The only good thing about it was that I survived without any damage with a valuble lesson learnt plus the Boss was so frightened she didn't utter a word for the next hour (must have been shock) :thumb: . BE CAREFUL! Cobs do bite!!

smash
22-09-05, 10:31 PM
Let's face it. For the vast majority of us, a Cobra is a bl**dy nightmare in the wet.

It is not so much having to keep the right foot light, as the huge reduction in braking power that is the problem. You cannot control what jumps out in front of you.

Let me be the first to come out and say it: "Cobra as all weather daily drive for the average driver?" - You must be joking.

Nail.........hammer...............direct hit! :thumb:

tony c
23-09-05, 08:15 AM
There is a very important point you may have missed when considering using a Cobra as an every day car. Most insurance companies quote a very low rate with restricted mileage because they know that the car will only be used for pleasure driving and normally that means in dry conditions. My insurance cover prohibits me from using it for travel to and from my place of work (check the small print) hence the low price. If you apply for an insurance quote for every day driving I think you will find the premium will be prohibitive. Best you check this first.