Calling all FWD autocrossers

"GRIVLET - Proud of Cobalt" (Gr1vleT-ProudOfCOBALT) 09/21/2013 at 16:52 • Filed to: autocross

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My third event is coming up and now that everyone in the local club has seen my #lolferrari post I feel like I really need to step up my game.

I ran 34 psi in the fronts last time and 30 in the rear on a friends advice. I keep seeing that raising the pressure is beneficial, but according to my chalk marks I wasn't using much of the shoulder even at above pressures. The tires do have an xl sidewall.

My goal is more rotation and earlier on the power as these are things I felt I could have improved on significantly from my previous event. Any other fwd tips/ tricks are welcome. Car has stock camber which is already fairly agressive.

Car is a 2009 Cobalt SS/TC

Thanks!

DailyTurismo > GRIVLET - Proud of Cobalt 09/21/2013 at 17:30

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Are you trying to stay in stock class? If so, put the biggest front sway bar on it you can find - sure it'll introduce some understeer, but the added total grip will make you faster. If you don't care about classing, put the largest rear bar you can find and then it'll have turn-in oversteer and mid-corner grip. If you only want some car settings - then I suggest first bumping the front pressure up to 40psi (this is if you have crappy tires -if you are running something good with a stiff sidewall (Azenis RT-615k) you don't need to go that high, but if you've got some all-season street tire, I'd add some pressure. Next bump the rear pressure up to 45-50psi - I know it sounds insane, because you will lose some rear end grip, but it will help it turn. Last - and most important - adjust the loose nut behind the wheel. Seriously, show up and ask the fast guys (you'll know who they are, they won't be in Ferraris or Cobra Kit cars - they will be in ugly S2ks and SE-R sentras and Civics) to ride with them - and ask if they will ride with you. If they think you are going to steal their championship points they won't tell you anything, but if you tell them you are new and just want to have fun and learn they will give you all kinds of advice on your driving. There is an old autocross saying - it goes like this - "The perfect late apex still is too early." Enjoy!

GRIVLET - Proud of Cobalt > DailyTurismo 09/21/2013 at 17:48

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Good info! I'm running in STU on some cheap but grippy uhp tires.

http://www.cobaltss.net/forums/wheels-…

While they do stick they exhibit some odd chacteristics, they do seem to have a very stiff sidewall. My friend who races pro in a 04 caviler has been helping me out and riding along but i plan on seeking a second opinion.

The car really puts the power down thru the lsd but it is an odd sensation and I think its causing some hesitation on my part.

Axel-Ripper > GRIVLET - Proud of Cobalt 09/21/2013 at 18:32

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Hit your line, stay tight on the slaloms, and left foot brake. Last part is critical in a FWD car. Brake not only before the corner but into the corner. Light amounts of brake will help your turn in. This will also allow you to get on the gas quicker coming out of the corner. Once you get used to the delay (if any) of your engine, you can start rolling in earlier than you think you should so that the engine comes in when you want it to. I have had to do that in my Sonic, as there is a significant lag coming out of tight corners. It basically comes down to brake-turn-throttle-keep turning- go.

-Amateur > GRIVLET - Proud of Cobalt 09/21/2013 at 18:47

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I run the STF class and have a 1" sway up front with a 1.25" in back with stiffer springs and Direzza DZ101's all around. I usually run more PSI up front than the rears. All I can say is you really have to feather the throttle/ or get off it completely in turns so you don't break traction under acceleration and understeer. and definitely use braking to your advantage in cornering to shift the load to the front for more bite when you feel understeer taking over. I haven't even got this down pat yet, but I'm working on it. At the end of the day, just keep racing and you'll eventually find out what works and what doesn't for you and your car and have your own rhythm going.

DocWalt > GRIVLET - Proud of Cobalt 09/21/2013 at 23:33

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Those pressures seem a bit low, but I'm running all seasons that are a bit soft on the sidewalls. The biggest thing is to trail brake cleanly to get turned in, and then as much power as possible as early as possible. Pick a line that means you can put power down earlier while still keeping on line. Understeer kills speed.

ThatCrazyGu > GRIVLET - Proud of Cobalt 09/22/2013 at 20:09

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STU? The Cobalt SS/TC should be an STX car unless you're running a wheel wider than 9", or a tire wider than 265. My best advice would be to get a massive rear bar. A new sway bar rule was instated a couple years back allowing any car to change 1 sway bar, front or rear. Generally people get a thicker front for RWD cars, and a thicker rear for FWD cars. I know it made a world of a difference on my old Cooper S Mini. Much sharper turn-in, less body roll, less inside wheelspin (peg-leg diff) and sharper in the transitions. If you don't feel like buying parts, then just work on your driving. Autocrossing a FWD car requires a good deal of patience in my opinion, because power application out of corners can be difficult unless you're already pointed where you need to go. I always went with higher pressure in the rear to help aid rotation, you're going to want as much of it as you can get.