V4kerker

The car 2007 A6 base coupe with non-runflat street tires and Johnny O Connell stage 1 swaybar shock setup with OEM springs. Rear bar is set in the middle. The car has under steer at turn in and a little less under steer going though the turn.

Would like to know if I tighting the rear sway bar will it help with the under steer or just make the rear want to snap around easier?
I have a street alignment DD.

I'm into my 2nd year of HPDE's +15 events with this setup and only played with tire pressures. Now I think I might try adjusting the sway bar and see what happens. I run VIR, SPM and NJMP-T and I'm doing NJMP-L for my first time this June 22,23 with TrackDaze.

Thanks v4kerker

mountainbiker2

I would stiffen the sway bar. It's not going to make a huge difference. If it's not enough, you might want to raise the back up some. Plus, you might want to trail brake more.
Steve A.

froggy47

I think your "street alignment" is causing the issue more than the rear bar setting.

You can try getting a little more front grip by stiffening up the rear bar, but I don't know if you'll be satisfied with the result.

For myself bigger front rims / tires and more negative have been the answer.

Soften the rear bar has then pulled off a nice balanced car.

V4kerker

Thanks for the reply mountainbiker2. I'm going to tighten the rear swaybar for my next HPDE and see what happens. I'm still working on my trial braking but I think my Hawk HP+ pads release to quickly/abrutly when coming off the brake. It might just be me releasing to quickly not 100% sure.
I'm not going to adjust the ride height the car has 60K+ and I'm afraid the adjusters might be frozen in place. One adjust at a time for me. Trying to keep it simple and fun and learn how adjustments effect my car.

I do know going thur a long turn with decreasing radius at the end I need to let up/come off throttle to get the car to turn.

V4kerker

I agree froggy47 on the street alignment, but I'm not going to play with the camber unless I get a after market kit to make adjustments easier. I do most of my own work when I've got the time and the swaybar should be easy to adjust right now. Tires are wearing pretty even right now for a DD.
I'm on the fense about getting bigger tires. I've priced a new set of tires and it's going to cost me the price of a used C6Z06 or 2013 GS or 2014 C7 Z51

I think my car would be a little more balanced if I put a Z06 front spring on the front.

Crepitus

+1 for trail braking. Apply the brakes hard quickly and late, trail brake. It will lift the rear a little more and transfer weight foreword. Try the bar as well but a little extra driving technique is always a good tool to have.

SouthernSon

To increase INITIAL turn-in you might increase front camber, increase front toe out or lower the front some. If too much toe out you might get understeer THROUGH the corner after suspension takes a set. You can also monkey with the tire pressures as well as the rear bar settings.

el es tu

I run a front z06 spring and base rear - it reduces the brake dive significantly and the car has a really nice balance.

As far as alignment goes, you can get the pfadt camber kit for right around 300 shipped from rpi. With the joc bars (and a z06 front spring) Id suggest -1.8 front camber and -1.4 to -1.6 rear camber
0.0 front toe and -0.05 rear toe

good luck!

argonaut

I'll be there on Saturday only. I'm in a black 99 FRC (that looks like a Z06 on a count of the brake cooling ducts). I'll be in the black group. Look for me if you get the chance, name is Brad.

I've changed the rear sway setting many times adjusting for a particular track - it only takes about 20 min. I've found the car's balance to greatly depending on temp, track surface and tires and the sway adjustment has been a helpful, quick tool to bring the balance back in line.

V4kerker

el es tu if I keep this car I'm going to get a Z06 front spring and camber kit. Looking at some of my HPDE track event photos it looks like the front of the car dives down and the back end gets high and light.

V4kerker

Good to here argonaut. I'll look for you and catch a ride along. Beleive it or not I've only had 3 or 4 ride alongs in over 15+ HPDE events. My instructors either have 2 students or broken car or they want to run solo. I'm to the point I just act like a hitch hiker in pit row or the paddock.

SouthernSon

Check out 10/10ths, it is a very important part of each HPDE event. Seeing is believing. Many instructors available with passenger seats for demonstration.

redtopz

I would have to agree that driving style is the cause of your understeer at turn-in. Rear sway bar settings should have little affect if any at turn-in since very little weight is on the rear tires at that point. My hunch is that you are asking too much from your front tires applying hard brakes and turning the steering wheel and expecting the car to turn in while the tires are beyond their grip potential. Try to keep the car balanced and within the grip potential of the tires and it should turn in just fine. This will require lifting off the brakes slightly while turning in to provide more lateral grip to your front tires. With that in mind, I would still adjust the rear sway bar to the stiffer setting and go with a more aggressive track/street alignment with your upcoming track days.

Adam@Amp'dAutosport.com

You should try a set of Carbotech XP10 and 8. Hawk pads act like an on off switch, which upsets the car. where is our pads are built for modulation which give you more control and better trail braking.

Carbotech Performance Brakes™, the world leader in Ceramic friction materials™. It was over eight years ago that Carbotech started building brake pads out of Ceramic, Kevlar, and Carbon for street, autocross and racing applications. Carbotech is the only brake pad manufacturer in the world with a complete line of Ceramic compounds for street, autocross, and track use. Carbotech-Ceramic™ compounds are known for their unsurpassed release & modulation, while maintaining very consistent torque control characteristics. Carbotech brake pads are extremely rotor friendly and contain 100% non-corrosive brake dust, that’s something that has been unmatched by any other brake pad in the industry.

Our competitor’s brake pads perform like an “on/off” switch. Brake pads that perform like an "on/off" switch are upsetting the balance of the car by violently throwing all that weight forward (not to mention that you don't get any modulation with an "on/off" type of brake pad). You don't realize how much it upsets your car until you have tried Carbotech Performance Brake pads. Carbotech has almost a seven year head start on the competition when it comes to our great philosophy on release & modulation, rotor friendliness, non-corrosive dust, and an unmatched consistent bite.

Crepitus

Adam and Redtop lead to a good point. too much front brake bias will probly cause more push going in if you try to lift the back of the car with the brakes and use heavy trail brake going in. Bars and springs will have most effect in the center. brakes shocks and cross weight goin in, shocks and x weight comming out.

TorontoC6

I ran a 2006 C6 A6 for a few years before I got my Z06 racecar. I preferred the softest setting on the rear sway bar but mine had the LG G2 (Bilstein) coilovers and their G1 bars. You can run 265 front 305 rear on stock rims for more front grip. I liked RE-11's and RS-3's. With that setup, car was very well balanced. I agree with the alignment suggestions. Get at least 1.8 front negative camber and no toe.

V4kerker

Thanks for all the tips and tricks guys. This weekend I'll try my best at trail braking.
Redtopz you might be right about me asking to much from my street tires. I just want to make sure I'm doing everything I can as a driver before making to many changes. If things stay about the same I'm going to try camber next. I'd like to see if I can get any more grip and turn in with this this tire setup.

V4kerker

Results from last weekends HPDE at NJMP-L.
I went tighter on rear swaybar (tightest setting on JOC 1). The front felt like it had less to no under steer. This was my first time at NJMP-L. I only felt bad under steer once going into T7.
I had a hard time modulating the gas pedal coming out of T4 and T7.

Overall the car was better handling even if my padel modulation sucks. Work in progress.
A big thanks to my instructor Tom. He got me running 1:22's.

sleeperstyle

glad to hear the issue is resolved. both of the turns you mentioned are tough to power out of- i looped it on t4 with too much throttle/ not opening the wheel enough... kept it on track thankfully..

as i am sure you know, always be ready for these things to step out on you.. i had to catch it coming out of the lightbulb turn, probably going 90-100mph.. telling myself "DONT LIFT!" lol

i was the white c5 with blue/red stripes.. yellow group..

V4kerker

sleeperstyle you had your c5 hauling tail around that track. I had 2 tires off coming out of 5 a couple of times and 4 tires off coming out of lightbulb due to early apex and staying in the throttle during session 3.
I missed most of the 2nd classroom session on Saturday and missed all the crying.
Dam 2 liter go-carts had me driving my mirrors. First time running in a pass away group and first time at that track.

I'll be posting some Youtube sessions from the weekend. Youtube user name is v8kerker.