Ive been autocrossing for 4+ years and have run in the rain a few times. However this year I made the jump from a strut and spring combo to adjustable coilovers. While the car has been amazing Im noticing the tail end likes to come around much easier than it use to when its wet out and Im not quite sure what to do with it. Here is my set up

10k F 8K R
- 2.5 F - 1.5 R
22mm FSB 24mm RSB
0 Toe all around
4 deg caster
Running RE070s at 37 PSI all around

It looks like the first autocross of the year will be in the wet and I am looking for some advice on some technique. And before anyone says anything about the sway bars I have an RS so sizing is restricted. Only the rear is adjustable from 22 to 24mm. Im doing the best with what I have. Im sure I will be flamed and if need be just point me to the right thread to read because I havent found it on my own.

Thanks Jake

Soften or disconnect the rear sway bar to make it less tail happy in the rain. Or increased front/decrease rear tire pressure. You'll have to play with it to see how those kinds of changes interact with your driving preference. When I was road racing SCCA, if we knew the race/practice/qualifying was gonna be in the rain, I'd disconnect one side of my rear sway bar (rear drive car). That made it much less tail happy in the wet. Problem is, about half the time, the rain came while we were on the track. All you can do then is clean your shorts afterwards. ;)

I'd say dial back the rear shocks a click (if it's a 5 clicker) and change the bar to the softest position and then lower air pressure. I did this at an NT before my co-driver took his last run and he won the class because of it.

let some air out of the rear tires should also keep it more planted and have less of a rotation to it.

let some air out of the rear tires should also keep it more planted and have less of a rotation to it.

Unless you're already running on the low end of your pressure zone, at which point it will still roll over and cause slide easier... :D


There is setup stuff you can do to help the car in the rain, and all of the above can work, it might not though.


First thing in the rain: Slow down. Realize that your braking distances increase, cornering abilities decrease and acceleration ability decreases.

So..
brake a little sooner and smoother
dont try to carry the same speed through the corners you would in the dry, and recognize that the same "seat of the pants" feel will not be there.
Accelerate smoother. I have heard people describe the rain as "doubling your horsepower" and it's probably a decent general rule. So.. act like you are driving a car with 2xHP, and squeeze the throttle more gently.

As far as setup, the most likely thing that will happen is the rain will exaggerate the current handling characteristics. So:

If your car is already loose in the dry, then consider a rear shock adjustment, or dissconnecting the sway bar, or a tire pressure adjustment.

If your car pushes.. chances are in most corners the rain will just make it push worse - you might not have to do anything. In my G-Stock CRX I ran stupidsuperstiff rear shocks and 55+ psi of rear air pressure. I felt like it was still always understeering, so when it rained I didn't change a thing. I killed people in the rain with it as they chased "rain setups". In the DSP 2.5 RS this year.. unless it's normally loose or perfectly ballanced toward a good slip angle, I won't change a thing with it either. I will just adjust my driving.



Jon K

For rainy events, I drop my pressures about 5-8psi all around and soften the rear shocks if needed. I will brake alot earlier to keep the corner speeds down, but also get on the power sooner and take full advantage of the AWD.

Looking at your setup (what tires and class?) I would try adjusting your driving first. It's less stuff to futz around with (on the car) and easily reversible.

Jay

Unless you're already running on the low end of your pressure zone, at which point it will still roll over and cause slide easier... :D


There is setup stuff you can do to help the car in the rain, and all of the above can work, it might not though.


First thing in the rain: Slow down. Realize that your braking distances increase, cornering abilities decrease and acceleration ability decreases.

So..
brake a little sooner and smoother
dont try to carry the same speed through the corners you would in the dry, and recognize that the same "seat of the pants" feel will not be there.
Accelerate smoother. I have heard people describe the rain as "doubling your horsepower" and it's probably a decent general rule. So.. act like you are driving a car with 2xHP, and squeeze the throttle more gently.

As far as setup, the most likely thing that will happen is the rain will exaggerate the current handling characteristics. So:

If your car is already loose in the dry, then consider a rear shock adjustment, or dissconnecting the sway bar, or a tire pressure adjustment.

If your car pushes.. chances are in most corners the rain will just make it push worse - you might not have to do anything. In my G-Stock CRX I ran stupidsuperstiff rear shocks and 55+ psi of rear air pressure. I felt like it was still always understeering, so when it rained I didn't change a thing. I killed people in the rain with it as they chased "rain setups". In the DSP 2.5 RS this year.. unless it's normally loose or perfectly ballanced toward a good slip angle, I won't change a thing with it either. I will just adjust my driving.



Jon K

The car in the dry is perfect for me. At the limit it still has the Subaru push but when you get everything right the car rotates perfectly. It seems to be only in the wet that the car begins to get squirrelly. In previous seasons I would literally not change a thing and just drive slightly more cautiously. Now I feel like I have lost that confidence.

For rainy events, I drop my pressures about 5-8psi all around and soften the rear shocks if needed. I will brake alot earlier to keep the corner speeds down, but also get on the power sooner and take full advantage of the AWD.

Looking at your setup (what tires and class?) I would try adjusting your driving first. It's less stuff to futz around with (on the car) and easily reversible.

Jay

I am running RE070s at a pretty low pressure right now (37psi) so I could probably go only about 2 or 3 psi lower. I am in DP (stupid ALK, different classing normally) because the local club lost their lot and I am running SCCA for the first time. Otherwise I would be DSP.

I am just looking for any tips on rain driving. So if its a matter of changing technique whatever you guys got, I want to hear. Thanks again everyone.

First thing in the rain: Slow down. Realize that your braking distances increase, cornering abilities decrease and acceleration ability decreases.



Agreed. I have found that the biggest adjustments are required to me, not the car. If your car is pretty balanced in the dry, I wouldn't usually make changes for the wet except maybe slightly softening the rear rebound.

I have never had a lot of luck chasing a wet setup. Mostly because you just don't spend that much time practicing in the wet and there are too many degrees of wetness. If there is a chance it will dry out some before your runs are over I would regret having made swaybar or alignment changes.

James

The car in the dry is perfect for me. At the limit it still has the Subaru push but when you get everything right the car rotates perfectly. It seems to be only in the wet that the car begins to get squirrelly. In previous seasons I would literally not change a thing and just drive slightly more cautiously. Now I feel like I have lost that confidence.


Sounds like it's snapping at weight transfer then - dissconnect or soften the rear bar. Watch your tire pressures like you would with the dry - ie: with shoe polish to see rollover and such - adjust pressure as needed.

If you have lost the confidence the sway bar will be the best change, it might create more push than you want on corner-exit, but it will help get the confidence back.



Jon

D Prepared?

Your answer is Avon wets..... :)

Jay

First thing in the rain: Slow down. Realize that your braking distances increase, cornering abilities decrease and acceleration ability decreases.

Jon K

Agreed. I have found that the biggest adjustments are required to me, not the car. If your car is pretty balanced in the dry, I wouldn't usually make changes for the wet except maybe slightly softening the rear rebound.

I have never had a lot of luck chasing a wet setup. Mostly because you just don't spend that much time practicing in the wet and there are too many degrees of wetness. If there is a chance it will dry out some before your runs are over I would regret having made swaybar or alignment changes.

James

I agree with both of these posts. I've also never really changed my set up for rain. I would prefer to be on good tires of course.

I think you'd have a hard enough time rotating in the dry with that much rear camber and you should be good to go in the rain.

I tend to focus on slowing everything I do in the rain down. As stated brake earlier and try to be aware of what the tires and car are telling you. I also try to be smoother (read slower) with inputs, mainly steering. I don't want to be jerky on the wheel, brakes, or gas.

Above all enjoy it. You have a great car for it. I like driving in the rain, I'm not particularly great at it, I hate working in it though. Realize that some people are just fish and will out drive you on bald tires with no changes to the car.

Just like the dry...practice, practice, practice. I take every opportunity I get to drive in the wet. You may learn more by focusing on what your doing in the car then by futzing with adjustments.

Try to anticipate and get to know when/how and what makes the back end of your car step out. If you can figure out how to induce it and become comfortable with catching it (read appy gas) it can be fast and fun. Auto-x is an extremely safe arena to explore the limits, I say find them..........just watch out for your fellow course workers.

Just my.02
Greg

In year's past, I've dropped the rear sway bar down a notch (I've got the same one as you) if time allows and I drop 2-4 clicks from my rear suspension (Megan Racing coilovers). For tire pressures I generally aim for the same operating pressure, but I start them lower because a little less pressure tends to let them heat up quicker, get grippier quicker, then get up to my normal operating temps quicker.
-N

Sounds like it's snapping at weight transfer then - dissconnect or soften the rear bar. Watch your tire pressures like you would with the dry - ie: with shoe polish to see rollover and such - adjust pressure as needed.

If you have lost the confidence the sway bar will be the best change, it might create more push than you want on corner-exit, but it will help get the confidence back.



Jon

I think if anything Im going to start with tire pressures and work my way back. Id hate to start changing the set up to drastically and have to be constantly relearning the car.

D Prepared?

Your answer is Avon wets..... :)

Jay

Care to send me some :D My local club does car classing completely differently than SCCA so I kinda wasnt prepared this season for DP. Oh well its all in good fun.

I agree with both of these posts. I've also never really changed my set up for rain. I would prefer to be on good tires of course.

I think you'd have a hard enough time rotating in the dry with that much rear camber and you should be good to go in the rain.

I tend to focus on slowing everything I do in the rain down. As stated brake earlier and try to be aware of what the tires and car are telling you. I also try to be smoother (read slower) with inputs, mainly steering. I don't want to be jerky on the wheel, brakes, or gas.

Above all enjoy it. You have a great car for it. I like driving in the rain, I'm not particularly great at it, I hate working in it though. Realize that some people are just fish and will out drive you on bald tires with no changes to the car.

Just like the dry...practice, practice, practice. I take every opportunity I get to drive in the wet. You may learn more by focusing on what your doing in the car then by futzing with adjustments.

Try to anticipate and get to know when/how and what makes the back end of your car step out. If you can figure out how to induce it and become comfortable with catching it (read appy gas) it can be fast and fun. Auto-x is an extremely safe arena to explore the limits, I say find them..........just watch out for your fellow course workers.

Just my.02
Greg

Im going to trying to get as much seat time as possible since my suspension has changed so much since last year. As for the set up, with the heavier rear sway the car rotates very nicely (at least for me) even with the rear camber. I have had some seat time in the rain in previous seasons which I thoroughly enjoyed. Driving in wetter conditions is a ton of fun on almost any tire Ive run. Its just the new set up seems to have thrown me off which is why I asked for the help. The advice that has been given so far has given me a lot of insight into what I should be looking to do. Only 1 week before the first event, I cant wait.

Greg and James are absolutely correct. The only changes I make in the wet is to bring tire pressures down and that's really it. To Greg's point, figure out under what conditions the car will step out and learn to use that to your advantage. You have to learn to adapt what you do so that the car will act how you want it to.

i didnt know nasioc had so many race car drivers

Me too, just a tire pressure change. I feel that I actually drive more aggressively in the rain, because I know my competition will be slowing down and being "careful". You'd be surprised what a Subaru can do in the rain :) Rather than a defensive approach to preventing a condition (snap oversteer, gross understeer), I tend to be more proactive and force the car to do what I want it to do, wet or dry, rather than react to what the car may be doing on its own. Won a lot of Tours, ProSolos, and a Super Challenge with that mindset (usually holding a knife, in a machine gun fight). Works for me, but YMMV. I suggest not staying home during the next wet weekend and focus on really experimenting on your wet driving....not necessarily car changes (because they will also be varying and course-dependent, what worked in January may not work in June...too many variables), but changing the driver. But I'm on the far left field side.....change/develop/sharpen the driver, the car is last...but that's more of a budget thing hahaha