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View Full Version : Tomorrow's BMW CCA Auto-x in SD could be interesting


Jeff_DML
09-06-2002, 01:29 PM
raining right now and supposed to be rain tomorrow.

Anybody with experience of driving a auto-x in the rain?

Any tips?

Should I just expect a lot of understeer/oversteer and a lot of cones being run over?

Can adjusting tire pressure help with traction in the rain?

TIA
Jeff

·clyde·
09-06-2002, 01:38 PM
Originally posted by Jeff_DML
raining right now and supposed to be a rain tomorrow.

Anybody with experience of driving a auto-x in the rain?

Any tips?

Should I just expect a lot of understeer/oversteer and a lot of cones being run over?

Can adjusting tire pressure help with traction in the rain?

TIA
Jeff

If the course is wet, you might want to drop a couple PSI below what you would run in the dry. The wetter the lower PSI

You'll have less grip, but that will affect front and rear pretty evenly perhaps leading to more initial understeer and power oversteer. Steady state tendencies should be pretty much the same as in the dry, with the limits just being a bit lower.

Have someone take pics and post them here!
http://www.lawair.com/bmw/sigT2.jpg

chukiechz
09-06-2002, 01:42 PM
Im hoping to go tomorrow too. My front tires are near bald. Should be interesting

Jeff_DML
09-06-2002, 01:44 PM
Originally posted by Clyde@work


If the course is wet, you might want to drop a couple PSI below what you would run in the dry. The wetter the lower PSI

You'll have less grip, but that will affect front and rear pretty evenly perhaps leading to more initial understeer and power oversteer. Steady state tendencies should be pretty much the same as in the dry, with the limits just being a bit lower.

Have someone take pics and post them here!
http://www.lawair.com/bmw/sigT2.jpg

thanks for the suggestion.

Last time I went SHinobi took pictures, hopefully he will be there again. I plan on borrowing a digital camera and snapping a few.

SOT, Do see a difference in your ranking when it rains compared to the RWD cars?

Jeff

·clyde·
09-06-2002, 01:46 PM
Oh, forgot...

At the last autocross in the rain here, there was no consenus regarding traction control. The D Stock winner left DSC enabled in his Cooper S, but he probably would have won with it off. I turned it off and did better than I usually do.

Jeff_DML
09-06-2002, 01:47 PM
Originally posted by chukiechz
Im hoping to go tomorrow too. My front tires are near bald. Should be interesting

Rotate them and have some fun with oversteer:D :D

·clyde·
09-06-2002, 01:49 PM
Originally posted by Jeff_DML
SOT, Do see a difference in your ranking when it rains compared to the RWD cars?

I've only done the one in the rain and I did better than usual vs the rest of DS, but I don't think that the AWD had anything to do with it. The fact that everyone else was running on street tires like me probably had more to do with it.

chukiechz
09-06-2002, 01:50 PM
Originally posted by Jeff_DML


Rotate them and have some fun with oversteer:D :D

225/40 18's in the back?? No way!!! Cant get any dry traction with 235 in the rear!! I still gotta bolt an amp rack down, dunno if I'll make it yet. Plus the drive to SD that early is not appealing to me

Jeff_DML
09-06-2002, 02:11 PM
Originally posted by chukiechz


225/40 18's in the back?? No way!!! Cant get any dry traction with 235 in the rear!! I still gotta bolt an amp rack down, dunno if I'll make it yet. Plus the drive to SD that early is not appealing to me

I was thinking you might have different offset tires for front/rear, oh well.

Going early to SD is better then late. Late you will sit in the usual LA going to SD for the weekend traffic.

DougDogs
09-06-2002, 02:27 PM
Originally posted by Clyde@work


If the course is wet, you might want to drop a couple PSI below what you would run in the dry. The wetter the lower PSI

You'll have less grip, but that will affect front and rear pretty evenly perhaps leading to more initial understeer and power oversteer. Steady state tendencies should be pretty much the same as in the dry, with the limits just being a bit lower.

Have someone take pics and post them here!
http://www.lawair.com/bmw/sigT2.jpg

I would make one comment to this, for the driver to beware of lowered psi. If you have large puddles (unlikely at the course) lowering the psi makes you more susceptable to hydroplaning. Becareful when leaving the track, if you can't adjust your tire pressure back up right away. Street or highway standing water could give you problems.

On the track you will have 110 percent attention to the car, on the road afterward you won't be as careful

Just my .02 cents

·clyde·
09-06-2002, 05:42 PM
Originally posted by DougDogs


I would make one comment to this, for the driver to beware of lowered psi. If you have large puddles (unlikely at the course) lowering the psi makes you more susceptable to hydroplaning. Becareful when leaving the track, if you can't adjust your tire pressure back up right away. Street or highway standing water could give you problems.

On the track you will have 110 percent attention to the car, on the road afterward you won't be as careful

Just my .02 cents

Thanks for mentioning this...I don't think that I was specific enough. I was talking about running less than would be used in the dry, but probably still higher (or within a couple psi) of what would normally be used for the street. I wasn't recommending running at 15psi or anything :D

Raffi
09-06-2002, 05:49 PM
Qualcomm should be fun in the rain! :D expect to run over a lot of cones and get wet when you work the course! As others said, drop the tire pressures. I would turn DSC off, as it will tend to kick in too much otherwise. I've attended the LA autocrosses in the rain several times, and I have always turned off DSC - rain or shine.

Be gentle with the throttle and it will be fun - your car will just be disgusting by the end of the day...:yikes: :yikes:

Shinobi
09-06-2002, 06:09 PM
I'll be there for sure. However, I just swapped wheels and now have my R-Compounds on. Earlier this year during a rainy event, drivers with R-Compounds were going so much slower than guys with streets on. I think I'll lug my other set of wheels so if things are bad, then I'll switch when I'm there.

Jeff_DML
09-06-2002, 06:13 PM
Originally posted by Shinobi
I'll be there for sure. However, I just swapped wheels and now have my R-Compounds on. Earlier this year during a rainy event, drivers with R-Compounds were going so much slower than guys with streets on. I think I'll lug my other set of wheels so if things are bad, then I'll switch when I'm there.

Looks like there are still some showers out there so it might be worth dragging them along.