Yesterday I ran against the guy who placed first at the SCCA Vail National Tour event and the guys who were 5th and 6th at Vail -- the first 6 finishers were all within 2 seconds. I ran Vail with ProKit springs, Konis, Progress rear swaybar, and old Kumho 285/35 x18s -- and I was 6 seconds slower than 1st place.

Yesterday, I have the new 550 lb front Ground Control coilovers, new 650 lb rear springs, still on Konis, the Progress bar removed entirely, and new Hoosier 285/35 x 18 tires -- 1st time out with the complete new setup. Wow! Huge difference, car handles like a completely different vehicle. No under-steer, no over-steer, very neutral, everything seemed slower than it used to feel -- but I was faster every run. I was 2.5 seconds slower than 1st place and about 1 second slower than 2nd/3rd places -- a huge improvement.

Overall best times times for DSP (a relatively short, tight course -- I do better faster):
(VW R32) 1st -- 36.211
(BMW 325) 2nd -- 37.803
(BMW 325) 3rd -- 37.969
(me - SS) 4th -- 38.849

1-3 are driving very sorted-out cars that they've owned and run for several years. This is my first year with the Cobalt and the 1st run with a decent setup. I'm no longer as worried about finishing last at the Nationals in Lincoln.

Scott

 

Thats great! I have yet to autox my balt, but thats great placement considering you were behind two Bimmers, and an AWD R32.

 

glad you finaly got your suspension figured out. Now just some fine tuning the allignment, maybe some more power

 

I have camber plates so I'm able to adjust camber easily. I was conservative on the camber Saturday and I was over on the outer edges of the front tires. Next time, more camber. I'm going to keep the toe at zero for now.

I've already bought a Stage 1 so I'm just waiting on GM to get the flash ready -- then more HP and more important, more torque.

Scott

 

Excellent story! Good details.

I'm thinking about doing my 1st one this weekend. 09 SS Sedan..
It's completely stock etc... Does this mean my tires with 11k miles on them are going to be useless?

I see so many going with Hoosiers... Do you use a separate set of rims for these?

 

Hoosiers and other race-compound tires require a separate set of rims because they wear out in just a few miles of hard use.

Your street tires are fine. You'll know when they're holding you back, and that will be several events or even seasons from now.

Once your streets wear out, consider a set of grippier street tires rather than full R compounds.

 

Any recommendations for tire pressures on the stock tires/suspension?

It should be 80-90 degrees air temp.

Thanks again for the info.

 

You'll want the maximize grip in the front by keeping the tire patch flat. Too much air and you get tires worn in the middle and too much wheel spin. Too little and the tire will roll over on its sidewall and give mushy response. 42 would be a good place to start.

At the same time, you want the rear tires to give up grip before the fronts do. That means shrinking the contact patch by under inflating or over inflating the tires. Most people choose to over inflate the rears; it tends to make the back of the car livelier. I like to remove pressure, though; oversteer tends to be more progressive and controllable. Try 5 pounds above or below your front pressures to start.

You can set your pressures, but you need to adjust them, more importantly. You'll probably gain three or four pounds on just your first run. Hot sun and back-to-back runs can drastically raise pressures so that

Your first investment for autocross should be a good tire gauge.

But if this your first event, you'll really just be learning how autocrosses work and deciding whether or not you want to come back. Concentrate on the course and learning a set of skills you can build on. It's very much like skiing, and your first event is the bunny hill.

If it's not fun, you're not doing it right. Have a blast!

 

Wow Des, thanks tons for the good advice...

I'll post here on how far I was in last place by...

 

A number of clubs host "driving schools" for road courses and auto-crosses. Generally it's a non-competitive day with an instructor riding shotgun. I did this my first time out on an auto-cross and learned a lot doing so. I still had a helluva good time and learned a lot so that I didn't feel like a complete noob when I went to my first competitive auto-cross.

Have Fun!!!!!!!!!!

 

Well I didn't get last.
I was 2nd in NV1-D Stock (Novice 1, stock cars)

Here are links to the 3 vids I took

1st Run http://www.youtube.com/watch?v=Ssji_jFNk4s

(forgot to record 2nd run)

3rd Run http://www.youtube.com/watch?v=jf3t05m-hxs

4th Run http://www.youtube.com/watch?v=lBT4bo4l71Y

 

your times were right there with the guy in the z06 corvette, good runs

 

Wow, great runs! That looked like a really fun course too! I'm jealous, I can't wait to go again myself What'd you use to record with and what kind of mount?

 

sounds like a lot of understeers from the video...
i would get a good alignment.... if you plan on running in stock class.. you can get another
degree of negative camber in the front by modifying the front strut a bit...

 

the word modify would take me out of stock class though...

Yes, lots of understeer....but probably mostly due to my driving aggressively.

I know caster/camber.....what type of 'modifying' do you mean?

 

modify according to GM's service manual..so you stay within stock class..
like this.. http://www.pbase.com/jt_kgy/image/11...0/original.jpg

 

I guess that'd definately still be within the rules!

 

yup.. oh ya, i saw your sig said about stage #1.. i guess you dont plan on staying in DS for
long..

 

looked agressive yet smooth, great job. Don't forget when you hear the tires screaming like that just unwind the wheel just a little bit. Usually when you do that the car won't turn any less you'll just reduce the slip angle.

 

How did you fit 285 wide tires without rubbing? I thought that 235 to 245 was almost pushing it. I heard there are issues with rubbing on the front brake lines and the rear shocks. I watched the videos. Good job by the way!

 

I'm running American Racing Rogue wheels that are 18x8.5" wide with a 35mm positive offset. I mount these on custom 20mm wheel adapters (a net offset of 15mm positive). I spent hours carefully pounding over (beating with a small sledge) the inner wheelwell lip at the back of the wheelwell until it lays flat againt the wheelwell. I've beaten the bottem rear edge of the wheelwell back (sledge again) and used a dremel to cut away both some of the body moundling in the rear wheelwell are and cut away some of the rear fender liner. The tires do occasionally rub against the inner liner, but they'll just wear away until there's no more problems.

Since these tires/wheels protrude slightly outside the body line, I needed significantly striffer suspension to avoid rubbing the tires with the body -- besides it's a better autocross setup. I'm running Ground Control coilovers with (the racing suspension) 6" 550 lb front springs and 7" 650 lb rear springs -- over Koni adjustable strut cartridges up front and Koni adjustable shocks in the rear (Koni yellows). I run the stock front and rear sways.

Last suspension item: I use a set of modified B&G camber plates (that I modified - these cost about $200 from Gravana/B&G), on the stuts to let me mod the camber as much and as often as I want. They work well.

No problems with the front calipers, brake lines at either end, and shocks in the rear. I clear the front struts by about 1/2".

I met my goal at the SCCA Nationals, I've had only run the car once with the above setup before the Nationals, my goal was to not finish last -- I didn't. But I was darned close -- I finished 28th out of 31 DSP cars. The competition was truly impressive!

I just finished the last local SCCA event today and I beat the next DSP competitor by about a full second (I ran a totally different camber and tire pressure setup than I used at the Nationals, plus hit tires -- it's much better). This means I'm first in points in DSP for the Rocky Mountain Region this year.

I'm looking forward to next year's Nationals -- they'll be in Lincoln, NE again. I'm taking a co-driver this time so I can run with hot tires (my Hoosiers never got above 85 degrees after the 2rd run - today my tires were about 130-145, with a co-driver). I'm still going to hope I don't finish last, but I'm shooting for at least mid-field next year. Finally, getting the Stage 1 -- whenever it finially shows up, I've been waiting since June! -- with the extra torque/HP will be very nice!

Scott

 

scottherbert,

In your opinion... would there be that much work to get 265 street tires to fit?
I'm wondering about the work needed to run in STX...

I assume your 285 is v710... which should be much wider than a 265 street tire.

 

Here in lies the dilemma! To me, it's a lot more rewarding to go run the car through its paces on the autocross track than take a chance of losing my license on the street...

So..I might just hold on to the stage1 kit for a while...(it's not even fully released yet anyway..so it might not even be a matter of choice!)

I think I was to stay in DS as long as possible. Cheaper class to run in.

 

What does the stage #1 do??
Does it modify boost?

If not, you can save it for STX class

 

It modifies the ECU... That's where the problem lies I think.