Quote:
Originally Posted by tanukifit
Thanks Brad, 3 events so close together means I can only stay for a short while. I don't want to stay away from the family to long on my only day off. 
I am stomped, ever since test and tune at the end of last season. I can't get any kind of speed into or out of the hair pins without big time understeer. Going into that event I changed springs and tires (RE 01Rs). Since then I went through my old Federal 595 rs, Kumho Ecsta XC and now the Dunlop Z specs. I added a fatter sway bar thinking I might be bottoming the suspension into the turn and it helped a lot but still not there. I've been going over and over understeer corrections and I'm seriously thinking of throwing my old springs in.
1. Old springs are 1" higher in front and 1/2" higher in back. This would give me more travel in front and a better roll center.
2. The back wheels will move from -2 degrees to -1.5 camber. I remember I could kinda get a drift going out of the hairpins like Randy was doing at the end of the round about.
3. scratch 1 and 2 and run full tank of gas and leave the spare in to get more movement in the rear so the front can dig in.
4. retire and keep my sanity.... (just joking)
5. seriously frustrated.........
6. and yes I know I got to study the track more and absorb what you've been teaching us. Thank you so much for all the help......
This is what I've been working with....
Roger Kraus Racing Enterprises | Castro Valley, CA | Testimonials |
I think the idea of changing equiptment to make a difference is attractive. The truth is the biggest difference comes from your level of driving skill. There is nothing really wrong or lacking with your current setup since you have gotten the Dunlop Direzza Z1 Star spec tires. Your other tires were not up to the same level as the Dunlop Star Specs. The biggest suspension difference between you and Randy is he has coilovers which can be adjusted for ride height and are stiffer for the shocks. You are working with the less costly lowered spring option but it's a softer suspension so you have to be smoother on weight transfer to make up for it.
Test and tune is a great time to work on technique. One test is to have Randy drive your Fit and you drive his. First do some runs to know the course. Then swap and compare your fastest times in both cars and see the difference. Sometimes a setup may favor your particular driving style.
More rear camber increases understeer. -2 degrees in the rear is not helping you but changing to stock springs is not always a good compromise as it raises your ride height and softens the rear suspension which increases understeer.
First thing would be to focus on driving. Work on skill. If you are understeering at any time you are going too fast entering the turn. Even 1 mph too fast will cause you to understeer. It's always better to enter 1 mph too slow and exit fast than to enter 1 mph too fast and exit slow.
On the long curve going out headed to the far turn around you want to enter that section going as fast as possible. If you make the sharp left too fast you will understeer- watch Randy's videos, the second run he understeered and went wider and took longer to pick up speed. The last run was cleaner and smoother. A small difference in speed in a crucial slow turn can make a huge difference. Once you are in the long straight headed out you have to stay on the gas and not be afraid.
Anytime you are coasting you are loosing time. If you get a chance try to ride along with Ken in the BMW or Barry in the white Miata. They don't coast, full gas or full brake and a lot of balancing the weight of the car just right. The other person that does well is Chris in the Honda S2000 CR. When you go for a ride see how they make the car handle for them.
While coilovers seem like a good autocross solution they do cost more and can make ride stiffness more harsh and less friendly for daily driving.
I still run stock suspension, the other cars in my class have better suspension for performance but I have to live with driving my car on the street plus I have the stock warranty for 3 years. I have much more roll and weight transfer to deal with and I could easily change to lowering springs or full coilovers. Besides tires, suspension is a huge part of making your car handle better but there are always compromises.
As for the tire pyrometer. Since you both are in Street Touring and I am in ASP we never drive at the same time and you are welcome to borrow my pyrometer. The probe tip is fragile so just be careful when using it. Insert perpendicular to the tire surface and it will be fine. The temperatures should run as even as possible inside to outside front and rear but in reality they vary with the course and your level of driving skill. Too much negative camber and the inside edges will be too warm, too little negative camber and the outside edges will be hot. Too much tire pressure and the middle will be hot, etc. The faster you drive the hotter the temperatures.
You can also attach the scangauge II during your run and set to trip, look at max rpm or max speed. This tells you how fast did you get up to, I think you might see as much as a 5 mph difference between runs.
Things to work on, being smoother with:
Braking early enough but not excessively
Throttle up sooner
Throttle up and stay on it longer and stronger
Keep balance of car better not being abrupt
Hands on wheel and steering a straighter line
How do you know how fast you should be going on a sharp turn?
The best speed for your car is different than another car. You have to speed sense how you are doing and adjust as you go. There isn't enough time to look at the speedometer. Most drivers will go by feel and just know that they have to take it a bit slower on entry then get on the gas hard on exit. The natural tendency when trying to go fast is to enter the sharp turn too fast, then the only thing that can happen is understeer. While it is possible to rotate the back end (oversteer) you have to be careful because that is sometime more difficult to control and too much oversteer will result in a full spin out.
What heat do you run in for this week? I am in heat 1.
Oh well, hope to do better next week.
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