First SCCA Autocross of 2009
This past weekend featured the first SCCA Autocross event of the new season at FEDEX field. It was a chance to test out my new suspension and tires. During the winter, I picked up some Hankook Ventus Z214 competition tires from Frisby Race Tires. For a while, they had a special on the C50 (medium) compound in 205/50R16 for about the same price as a regular street tire. So I grabbed a set, repainted the white Kosei rims, and had them mounted up. (The new rim color is as close to “brake dust” as I could find, thus saving time from cleaning.)
Sunday turned out to be in the ’90s — very unseasonably warm for April around here. I was worried about overheating the new tires on their first use. They were not heat-cycled so I knew they would be a bit slippery anyway, but I’m very happy with them. I ran with 38-40 lbs in the front and 35-37 lbs in the rear. I can probably drop it down a pound and start off with 35/33 cold instead of 36/34 which I had. The new springs are also a bit softer than the old ones, but once I got used to them I could make them work for me. I dropped 2 seconds over the four runs, with the last two runs being exactly the same down to the thousandth of a second. Odd.
I came away from the event thinking I hadn’t done that well, but ended up placing 6th out of 16 in my class (street mod). I always compare myself to G Stock, which is where I probably should be running, where I would have placed second. One day, maybe I’ll bite the bullet and make my car eligible for that class again.
H&R Sport Springs for the MINI
I’ve been having some problems with the MINI’s suspension lately. First was a thumping sound in the right rear, and the left front seemed to bottom out on even the slightest bump in the road. That and the fact that my family won’t ride in the car anymore because of the harshness of the ride, finally got me to thinking of changing the suspension again.
The photos above show the old TSW springs compared to the new green H&R springs. The new springs look to be quite a bit taller, but that’s somewhat deceptive. The H&R springs are progressive and have extra coils at a lower rate so they do not slip when the strut is fully extended such as when the car is on jack stands. Shorter springs will slip when not in compression and then you have to reseat them before lowering the car.
One of the added benefits of having shorter springs and shorter struts is that you can remove the entire strut assembly without having to separate the ball joint at the hub. With the standard strut height, there isn’t enough movement in the lower control arm and axle to get the strut out of the housing. With the shorter strut, you can just drop it out.
The front H&R springs appear to be a bit wider than the TSW springs they replaced. That means I’m going to loose a bit of negative camber once I get it realigned. We took a quick trip once I had it all back together and the harshness is gone. Seams in the road no longer bottom out the suspension.
Once installed, the rear has the same ride height as before. I cut down the bump stop by a half inch so I’ll have a bit more suspension travel now. It turns out the retaining nut on the right rear strut was almost completely loose. That may have accounted for the noise I was hearing. I reassembled the strut and tightened everything. If there’s still a sound there, then it’s either in the swaybar or in the subframe.
I measured the ride height before and after the change. The rear ride height is the same, but the front is about an inch taller. That splits the difference given the two inches it was lowered previously from stock. I also found the source of the “whump” in the front. There was no bump stop installed on the front left strut. The strut was bottoming out against the camber plate.
First Autocross of 2009
The autocross season got off to a soggy start on the Triple Skid Pad at Summit Point. The NCC had their first points event of the season on Saturday. I’m running a street-tire class in the BMW this year. The rain meant I had a good chance of scoring well.
I was fastest most of the morning session and ended up fourth in my class. The three ahead of me all ran in the afternoon when it was dryer. The course was partially under water. The surface is new and slick. The run off areas are muddy and deep.
NCC BMW CCA HPDE Summit Point 3.17.09
No, that’s not a vintage photo from 20 years ago. That’s from this past weekend at Summit Point. It was time for the annual Spring HPDE on the main circuit. It was a weekend of a number of firsts for me. First time out on R-comps; first time for this car; and first time on the track driving a rear-wheel drive car.
[The sound quality is poor. If you have a fast connection, click the HD button to get better picture quality once it starts playing.] The video doesn’t convey the sense of speed down the front straight. I was just touching on 120 before the braking zone. There may have been a bit more in the car, but since it’s more than 20 years old and has over 215,000 miles on it, I didn’t want to have to buy a new engine, so I didn’t push it. Since it’s so much quieter than the MINI, I often ran it out to 7,000 RPMs on the straight from turn 9 to 10 before I got my rhythm down.
The car was much more like the MINI than I thought it would be. They are similar in weight and braking characteristics, thought the MINI brakes have more bite. It is very neutral in handling like the MINI, but no where near the amount of torque. You have to get on the power much sooner in corners and are rewarded with trailing throttle oversteer. Toward the end of Sunday, I felt as comfortable diving it into an apex as I did the MINI.
Here are a couple of things to remember for next time on the main circuit in this car.
- Between 2 and 3 don’t follow the edge of the track. Line up in the middle toward the gap in the tire wall, wait for the dip after the access road to turn in and use the camber on the inside.
- Tap the brakes right after the crest before 4 to settle the car, turn in, and full gas through the apex. Brake straight into 5.
- As soon as possible, get back on the gas in 5 to counteract the understeer. Go wide to keep up speed into 6. Position in 6 isn’t as important as a good set up to apex 7.
- Between 7 and 8 starts steady throttle to max gas at apex of 9. Try to get the shift into 4th gear before 9. Don’t early apex 9. (See M3 photo below.)
- Move the brake point for 10 back a bit. Key off of power lines. Brake less, carry more speed into corner, full gas through the apex. There is plenty of room to track out. An extra 3 MPH at exit is worth 10 MPH at the end of the straight. Remember to adjust brake zone into 1 with that in mind.
- Try to separate end of braking from turn-in in your mind as you adjust. Work on one thing at a time. If you can get on the gas before the apex, then your speed at turn-in isn’t high enough.
Stealth Ready for Shakedown
With more than 24 hours to spare, I finally finished the F-22 for the first track outing of the year. Since I was running out of time, I had Dan Martin’s shop finish the front suspension and fix the cam gear seal.
I’m really impressed with the Bavauto springs. The ride height is aggressive but not slammed. The ride is firmer but not harsh. I’m looking forward to getting it on the track and seeing if I still need to upgrade the sway bars. Compare the ride height to the 20 year-old stock set-up.
I also had them install the IE front strut bar as well. The bar looks really slick in basic black.
Now all I need are some go-fast stickers…
