Racing In The Rain

[GTS4WD]

Hi people

I’m going down to Phillip Island in a couple of weeks for Island Magic and am preparing for the worst.

I have found it quite difficult setting up cars to race in the rain as it’s quite difficult to plan test days in the rain. But I have come across a couple of interesting theories and devised my own curiosities about how to get a quick car in the wet. As far as I understand, the idea is to move as much water off he surface of the track so as the tyres contact patch is on as dry a track as possible.

We do not have dedicated wets and will be running Yoko Advan’s AD050.

Aside from softening up dampers, the two ideas I have concern running extra static camber in the wet and increasing tyres pressures in the wet.

Extra camber:

After looking at some old Improved Production photos recently I noticed that the water which has settled on the track seems to be “ploughed” out of the way (similar to a bow wave) due to the angle of the camber.

Now I see a couple of big cons with this. One being less contact patch which means less grip, less braking performance as less of the tyre is in contact with the road (and as the wheel moves into bump more dynamic camber occurs due to unequal length arms) and decreased mid corner grip.

BUT!.. and this is where I need help. Because the contact patch is smaller, there is more weight on a smaller area so more water is moved to the outside of the tyre and ploughed away by the camber. But a decreased contct patch translate to decreased grip!!! So I’m not sure which is fact, which is fantasy. Do the benefits of moving water outweigh the decreased contact patch?

Increasing tyre pressures:

Secondly, by increasing tyre pressure to above normal you again have less contact patch but more weight on a smaller area so water is moved more easily. I’m not concerned about tyre blistering etc. from overheating as the water on the track will keep tyre temps down.

So who has had any experience or insight to this would be greatly appreciated.

If anyone has any other tips for racing in the rain, it would help greatly too.

Cheers,

Cris

[Roy]

If its raining at PI and you are driving, I think the most important setup change you have to make is with the driver between the ears...and make sure that at all times the brain remains talking to the right foot

I dont buy into all this dry and wet setup talk. If it is a road car running semi slick tyres then you are generally not running anything radical in the way of susp. Perhaps you could do with a degree of camber taken out of the front and 0.5 a degree from the rear...

I actually think its best to just rock up and drive the thing...you will find any issues with your handling that grippy tyres normally hide in the dry. So wait until you get there....if its wet you could learn a thing or two about the character of the car to the point that when you play with swaybars etc it could actually correlate to a quick and nicer car to drive in the wet.

But, if its wet at PI....just pot around and take it easy and drive the thing straight...even in the wet you see some pretty high speeds and a lot can go wrong on wet grass at those speeds

If you are at the PIARC day on the 13-14th then come say hello. I will be there in a silver R32 with black TE37s

Edited October 31, 2010 by Roy

[warps]

True on higher tyre pressures in the wet, as they will heat up less, so your "hot" pressures will be down compared to a dry track. The otehr thing is that there will be less grip, so less weight transfer and body roll, so you'd tend to run slightly softer springs, part etc.

This is in theory, and I agree with Roy that you'll gain a hell of a lot more by adjusting your attitude to driving. No good being fastest on the day only to spin off on the last lap. I guess that's the beauty of track days though. You can do one fast lap and 20 crappy ones, and still take home the trophy.

Edited October 31, 2010 by warps

[Snowman]

I won't talk about set-up changes or anything but the one thing I will say is the A050's are an incredibly good wet tyre. BUT - you have to have the courage to get some heat into them in order for them to work properly in the wet.

But if you do you will be amazed at just how much grip they have in the wet.

[toddlls]

I agree with Roy, Mindset is the biggest gain you will achieve other than having a spare Million to experiment with every option to develop a street car wet race setup.

Good tyres, plenty of Skidpan training may just be the only way we as weekend warriors may learn the finer points of fast wet weather driving whilst staying in control of our vehicles & putting down some respectable times.

Keep us posted

[Beer Baron]

I would not be winding in more neg camber for a wet set-up. you want to take out a bit of camber to get more of the tyre on the road. the car will not be moving around on it's tyres and suspension nearly as much as it does in the dry so you don't need as much neg. and I agree with pressures. hot pressures will be down so you need a higher starting (cold) pressure.

[Neil]

Here's a link from my good Radical friends in yanky land. Radical or not,,,most of it still applys. Oh and a "Nic Link" is a basically a sway bar.

http://socalpeeps.yuku.com/topic/1013/t/EZ-rain-setup.html

Cheers

Neil.

[Risking]

An aggressive dry circuit setup will suck arse in the rain no matter how you drive it.

You want to take camber out.

Toe in not toe out on a wet circuit.

For a a roadie I'd suggest toe in and less camber, stuff around with sway bars to try and balance it all out.

Most important go have fun. Wet weather driving is the best

If you go searching for speed on a wet circuit you won't find it, go looking for balance in the vehicle and the speed will come very easily.

There is a massive amount of changes that can be made but most of it is outside the scope of a road going car with basic suspension mods

[Duncan]

lol I've got 1 whole day's experience with wet racing....so here's my tips (very wet, not just damp)

run no camber at all....you will never get the car to roll up onto a tyre anyway. toe in would be nice too.

run heaps of pressure in the tyres. I was running 2 psi more cold than my usual hot target for those tyres before they starting working at all.

didn't get to soften the springs or shocks because they aren't adjustable on my car.

don't bother with a racing line, you won't go any faster no matter which part of the track you run on. just hug the inside, about 1 foot in to miss any puddles at the edge of the ripple strip.

and have good tyres. the guys on dunlop softs were 11sec a lap quicker.

[Roy]

I have only ever done one Supersprint in the rain and truthfully I didnt even bother about the times. Its great fun and learning experience to jsut circulate. I was at a day the other week where it was slick/wet and drying out...I was driving around and learning and thought I was going ok....the give away was the 8-10 cars per lap overtaking me...lol I didnt care. It was still fun and interesting to learn how to drive the car in those conditions....just had to use the mirrors and be sure i was timing my lifts on the straights so as not to hold up the maniacs who were flying in the wet conditions

Edited November 1, 2010 by Roy

[GTS4WD]

Interesting points you guys raise.

The driver I work work is vey good in the respect he is very calm when he drives and plays smart. Never seen the red mist decend.. yet. So im not tooworied about that..

Im just looking for something thats going to give a little more edge in the rain..

I will deffinately do so Roy if we get the funds to make it there!!

So best thing is to get as much heat into the A050's as possible and they aren't too bad then hey?

[GTS4WD]

don't bother with a racing line, you won't go any faster no matter which part of the track you run on. just hug the inside, about 1 foot in to miss any puddles at the edge of the ripple strip.

and have good tyres. the guys on dunlop softs were 11sec a lap quicker.

Which dunlops? what Track? What were you running? In our category we are allowed to run Michelin Wets.. but shoestring budget team

The only advice I say is to keep to the dry race line

[UWAM]

http://buddyfey.blogspot.com/

Some interesting reading.

[Roy]

Ok, so you are spannering for a person racing that weekend? Sorry , i have confused Island Majic with the last PIARC Supersprint.

SO what car and category?

[Beer Baron]

I have only ever done one Supersprint in the rain and truthfully I didnt even bother about the times. Its great fun and learning experience to jsut circulate. I was at a day the other week where it was slick/wet and drying out...I was driving around and learning and thought I was going ok....the give away was the 8-10 cars per lap overtaking me...lol I didnt care. It was still fun and interesting to learn how to drive the car in those conditions....just had to use the mirrors and be sure i was timing my lifts on the straights so as not to hold up the maniacs who were flying in the wet conditions

don't sell yourself short brisby.

troy and I did some wet sessions at the green hell aka nurburgring nordschleife a few weeks back. with 2 cars (alfa 75 3 litre, caged with semis and a VW scirocco turbo DSG with cage and good road tyres) we had a good play in the wet. it was white knuckle stuff to be sure. in underpowered alfa we were getting swamped in the dry but in the wet I think there were session where barely a single car passed us and we passed plenty... it needed a smooth touch but you had to drive it positively. it responded well when you got some heat in the tyres and drove it through corners on the throttle. that car did have some 'interesting' handling quirks though... anyway bris was pretty handy in the wet. I think just doing the laps we did without ending up in the fence was an achievement in its self. consider that at 24km a single nordschleife lap is the same as a 10 lap session at wakefield and you can understand why you feel knackered at the end of a white knuckle wet lap...

[GTS4WD]

Ok, so you are spannering for a person racing that weekend? Sorry , i have confused Island Majic with the last PIARC Supersprint.

SO what car and category?

RX7 S8 Production Sports

Great Link UWAM!

Thanks!

[Duncan]

ahh OK, we are in production touring, have to run tyres from the production car list. Bob Pearson's emo X was running dunlop soft DZ03G.....killed me by miles.

production sports allows slicks right...so hand cut soft slicks are the go. expensive and they will probably go off before you use them. If you are allowed to run semi slicks buy a set of the dunlops, about $2400 for a set 235/45/17

check my youtube for footage from the race, it was terrible!

[Kinks]

I actually think its best to just rock up and drive the thing...you will find any issues with your handling that grippy tyres normally hide in the dry. So wait until you get there....if its wet you could learn a thing or two about the character of the car to the point that when you play with swaybars etc it could actually correlate to a quick and nicer car to drive in the wet.

I second this, did an open day at Wakefield and the lowered grip levels gave me a real sense for whether the grip was at the front or the rear of the car at a given point on the track. I felt like I learned a lot, whether it actually helped is another matter but I had an absolute ball.

Regardless of setup, you will learn a LOT from the first day. Hence I think it's even more important that you forget about camber and pressures and so on during the day and just learn to drive what you've got. Once you've got a baseline then the next wet track day you can start fiddling.

[Jetwreck]

progressive throttle application at PI me thinks....but I did find that PI was way better for grip in the wet than some of the other track's in OZ!......as Duncan mentioned driving on line is not alway's the best way to do things(I might add..."especially at EC!").....I find that if I drive around the preferred dry line in heavy rain I find heap's more grip!

[boxheadmr]

the point raised about extra camber and acting like a wedge to push more water out probally won't work as in order for them to push water out they need to grooves on the tyres and once these are full and they can't push out more water you start to aquaplane as the water can't go anywahere.