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Negative Camber and wet tracks.

With a bit of hindsight reviewing my horrendous lack of grip and inability to drive out of corners at Lakeside during the wet track day on Monday, it has occurred to me that running too much negative camber maybe quite detrimental in the wet. I figure there is a lot less tyre on the road surface. Anybody with any insights?

It's not as if I would be having settings changed on the off chance of rain but I'd be interested to learn a bit more about it.

My settings are:
Car NA8 with 141 RWKW

Rear Camber -2.1
Toe in 1.5

Front caster 4.5
Camber left -2.8, right -2
Toe in 1.1

Take it your car has turbo?

What tyres?

What tyre pressures?

What springs, shockers, roll bars etc?

-2 is hardly a lot of camber. I'd be looking elsewhere, starting with tyres...

davekmoore wrote:Take it your car has turbo?

What tyres?

What tyre pressures?

What springs, shockers, roll bars etc?

Supercharged NA Dave - I'm not sure what tyres he is running but he was eyeing my KU36's [36psi cold] off Monday, damp/wet track at Lakeside. I suffered no understeer/oversteer and it seemed the turbo/supercharged cars had just a little too much power - Natsoft lists lap times and 3rd fastest from 35 was a standard NC3!!

I run similar set up with camber/castor etc with TEIN and whitelines, 15x7.3 6UL's and Winmax W3 pads all round on non venyed rotors

another vote for tyres.

I agree the alignment is not aggressive, especially considering the amount of toe in.

In the post with similar title, I suggested to increase your tire pressure to get to your normal hot temp. The wet will not allow the tire to reach your normal condition so your contact patch will not be the same, hence adding more air pressure will seek to match the contact patch size. However the tire will still not be at its optimum heat so grip will be reduced, however the heat does not effect contact patch size.

Thanks everybody for their input, that was an interesting read on tirerack regarding tyre pressure and contact patch. A little counter-intuitive.

I reckon that my Dunlop direzza Z2's (which came with the car) at about 50% are well past their usefulness as a wet tyre. I sure was having to tip-toe around and focus on smooooooth.

I was running 35psi in the wet, pretty much the same starting point for dry track which I've found produces 39-40 psi hot and seems to be the sweet spot for these particular tyres as far as I can tell.

Hmmm...decisions KU36's next or NT01's

Hornibrook Motorsport - Geebung. I got my KU36's when others were quoting 6 week wait - they specialise in Motorsport tyres

$175 a corner plus fitting and balancing so about $375/pair - got mine fitted 31 March and manufacture is stamped '0315'

Out of interest, have you had any experience driving on a wet track prior to your alignment being set to its current form? With the car at this or other power figures?

I've not had much experience (dry or wet tracks) but with the same tyres (re002s) the difference between wet and dry grip was substantially more than I had expected, given what otherwise was only experience in the wet on the road.

That is, are you sure that the lack of grip is not simply down the the fact that the surface was wet?

In response to the question re. less rubber on the road at any given time, that logic would apply whether wet or dry, no? Although I suppose less grip = less corner speed = less body roll = less use of camber = less grip?

My guess would be the camber is not the first culprit but the wet?

If you've had lots of time in the wet or on the track, please disregard the above

StuwieP wrote:Out of interest, have you had any experience driving on a wet track prior to your alignment being set to its current form? With the car at this or other power figures?

I've not had much experience (dry or wet tracks) but with the same tyres (re002s) the difference between wet and dry grip was substantially more than I had expected, given what otherwise was only experience in the wet on the road.

That is, are you sure that the lack of grip is not simply down the the fact that the surface was wet?

In response to the question re. less rubber on the road at any given time, that logic would apply whether wet or dry, no? Although I suppose less grip = less corner speed = less body roll = less use of camber = less grip?

My guess would be the camber is not the first culprit but the wet?

If you've had lots of time in the wet or on the track, please disregard the above

I'm not very experienced, I've done about 8 or 9 track days so far and this was the first time in the wet. Similarly to you the difference between wet and dry was far more than I had expected. Basically I was 18 seconds slower in the wet than dry. 18 seconds is a LOT. That is why I asked the original question regarding camber as you put it "less grip = less corner speed = less body roll = less use of camber = less grip?"

Anyway I'm quite happy to accept that I'm a sh*t driver at he best of times and even more sh*t in the wet.

I suspect that the 50% tyres may have quite a lot to do with it though, not many people were as sh*t as me! Reviews of the particular tyres I'm running (Dunlop Direzza Z2's) indicate there are supposedly ok for wet conditions. That doesn't line up with my experience at all. I guess the only proof will be running something else next time it's wet, maybe KU36's or NT01's. Then I'll know for sure.

zero00 wrote:Hornibrook Motorsport - Geebung. I got my KU36's when others were quoting 6 week wait - they specialise in Motorsport tyres

$175 a corner plus fitting and balancing so about $375/pair - got mine fitted 31 March and manufacture is stamped '0315'

Thanks Roger.

davekmoore wrote:Take it your car has turbo?

What tyres?

What tyre pressures?

What springs, shockers, roll bars etc?

Hi Dave.

It's supercharged with a rotrex SC.
Tyres: Dunlop Direzza Z2's
Tyre pressure was 35 psi.
Tein SuperStreet, set around half way, fairly soft on the day. Springs what ever are on the Teins. I don't know spring rates but they are not ridiculously hard. Roll bars are the standard 20mm front, rear =? ( I think) 1994 Clubman standard originals.

Not a fan of KU36s in the wet. Reason I on sold my set years ago.

Red_Bullet wrote:I'm not very experienced, I've done about 8 or 9 track days so far and this was the first time in the wet. Similarly to you the difference between wet and dry was far more than I had expected. Basically I was 18 seconds slower in the wet than dry. 18 seconds is a LOT. That is why I asked the original question regarding camber as you put it "less grip = less corner speed = less body roll = less use of camber = less grip?"

Anyway I'm quite happy to accept that I'm a sh*t driver at he best of times and even more sh*t in the wet.

I suspect that the 50% tyres may have quite a lot to do with it though, not many people were as sh*t as me! Reviews of the particular tyres I'm running (Dunlop Direzza Z2's) indicate there are supposedly ok for wet conditions. That doesn't line up with my experience at all. I guess the only proof will be running something else next time it's wet, maybe KU36's or NT01's. Then I'll know for sure.

You've done more than me, but I wouldn't have been surprised to hear I was 20s slower at Sandown in the wet than in the dry. I do know at LeMans Kart's 700m track I went from 38s to 55s in the wet... that's 17 seconds over far shorter distance at far lower speeds.

Compounding factors:
Less traction due to water requires more skill to get good times.
Less experience usually equates to less skill, or at least less practice.
Psychological elements like, oh, damn, slippery and a few understeer moments (or, as I experienced, no-steer moments) plus locking up brakes easily takes confidence out.
Add to the mix potentially unsuitable tyres, especially if they're not displacing water as efficiently as they should?

Good luck next time! I suppose you'll get your answer if you're still 18s down on your dry times in the wet with new tyres? Or maybe be able to discount one thing.

Driving fast is hard at the best of times. I imagine driving well in the rain is a matter of yet more practice.

Cheers
Stu