I love vintage racing, but I really love rollcages, seatbelts, helmets, and firesuits…
VARA, the Vintage Automobile Racing Assocation, has added a new class to its vintage racing format. Seeking to expand their reach, they now have a ‘Club Racer’ class for modern race cars. Some club members had a modern race car they wanted to bring along as well, and some late model racers wanted to come out and check out the “vintage scene” while getting in an affordable race weekend. Either way, it’s a great idea and a great deal! VARA’s next event is their annual Octoberfest race weekend at Buttonwillow Raceway, featuring a special German car Challenge Race. The event takes place Sept 10/11, 2011.
*Click image to enlarge*
What a great word. HABOOB - noun, \hə-ˈbüb\, definition of : a violent dust storm or sandstorm, especially of Sudan.
Last night as we flew into Phoenix Sky Harbor Int’l Airport (PHX), my fellow crewmember captured this shot of a dust storm rolling across Mesa, Arizona. It was being pushed by a large thunderstorm behind it.
Trail braking is an advanced driving technique that all racers must eventually master, like ‘driving the line’ and ‘heel-n-toe shifting’. Trail braking is when the brakes are continued to be applied beyond the corner turn-in point and gradually released up to the point of apex, as opposed to the normally taught practice of releasing the brakes before starting the turn-in. This practice is used for creating weight transfer towards the front tires, thus increasing their traction, reducing understeer, and aids in steering the car more effectively. It also allows for a more accurate corner entry speed adjustment. Once a driver has mastered trail braking, it will help to enter corners at higher speeds.
The alternative is: do all of your braking in a straight line, release the brakes entirely, then turn in. The trouble with this technique is that when you release the brakes, weight and traction will be removed from the front tires just when you need them to be loaded enough to help turn the car into the corner. So the car may have the tendency to understeer away from the corner. This is typical behavior for street cars (engineered with built in understeer) that have been adapted for racing. Also if you do not trail brake, there is a period (from release of braking to apex) when spare grip is available. Overlaying your braking and turning inputs means that you can use the entire grip available in this section of the corner.
At first it’s recommended to brake lightly into the intial turn-in, and then as your skills increase, continue brake application deeper into the corner. This skill will allow you to delay braking on the straight-away even further. The best corners to first practice in are slow and sharp corners, where it is both easier and most beneficial. With further practice you can use trail braking with your left foot in medium-speed corners while continuing to use the right foot to cover the accelerator. Then once you finish braking, move to neutral throttle, and then to progressive acceleration just before the apex. Neutral (or balanced) throttle is when the driver feathers or covers the throttle, applying just enough power to keep the car at a constant speed, not accelerating nor decelerating.
TRAIL BRAKING BENEFITS:
- helps you turn the car into a corner better by maintaining the transfer of weight onto the front tires, giving them more traction, and helping compensate for any understeering tendency the car may already have
- braking deeper in to the turn, therefore being able to brake later on the straight-away and maintaining maximum speed longer
PITFALLS:
- requires additional finesse from the driver at a very busy point on the racetrack, possibly exceeding the driver’s skill level
- excessive use of the front brake can result in a loss of grip as the front tire’s adhesion is split between braking and cornering forces, actually causing more understeer
- due to an exaggerated weight transfer to the front, the rear tires may lose grip, and result in mild oversteer
- if the brake bias is set to nearly neutral (instead of the usual front-bias), heavy braking may cause the rear wheels to lock, effectively causing the vehicle to spin
- excessive braking - you may simply slow down too much
The Grip Circle
The maximum grip level that a tire can give is depicted by the outer circumfrence of the Grip Circle. A tire can give max grip while cornering, braking, accelerating, or a partial combination of these. Trailing the brakes gives you the opportunity of using 100% of the tire’s grip from the braking point on towards the apex of the corner. So as your cornering traction requirements increase towards the apex you must reduce the braking inputs so as not to exceed the tire’s limits.
Trail Braking
Yesterday I instructed at Laguna Seca Raceway with the TrackMasters track-day club. Doug Gale runs a great event, and we shared the track schedule with the Zoom-zoom motorcyle track club. The June weather in the Monterey Bay area can’t be beat, cool and foggy until 8am, then clear and sunny until 6pm, with highs around 75. I signed up to instruct with my buddy Chris in his Turbo GTI that was sporting a fresh set of sticky Kumhos. We had a lot of fun, and Chris is now fully hooked. Another addict created…
Mazda Raceway Laguna Seca (the official name) has VERY strict sound limits. Weekday track events have a max 92db limit, that’s stock quiet! Some stock bikes and cars can even pop the sound meters. First strike you get the black flag and are pulled off track, second strike you’re pulled off track again, third strike and you go home while subjecting yourself and the club to possible fines and future restrictions. Weekend club races have a scaled noise restriction, here is an example I have seen: 92db early and late in the day (8-10am/4-6pm), 98db next (10-11am/2-4pm), and 101db in the middle (11am-2pm). 101db is still pretty quiet for a racetrack. Laguna Seca only gets 5 open sound weekends a year from the county, and they get used by the pros (Indy, Moto GP, Trans-Am) and the Rolex Historics. Drivers get pretty creative to muffle their cars, I like walking around the pits and seeing some of the “unique” solutions.
This weekend VARA held their annual British Extravaganza race weekend at Buttonwillow Raceway near Bakersfield, CA. The event included the regular race series, as well as the British car only Challenge Race, the Classic Motorsports Magazine Small Bore Challenge Enduro, the Central Valley British Car Club carshow, lunchtime track drive-arounds, and the Saturday night BBQ and karaoke hoedown. Saturday’s weather was suprisingly cool and wet compared to the hot and dry we usually see in June, and Sunday was dry and just a little warmer, perfect for racing! Turnout was fair with about 120 entries over 5 groups, with my mid-bore group having 35+ cars. We raced track configuration CW13 with the Bus Stop complex, a fun config I had never run before. And Andy Reid from Classic Motorsports, and his recently acquired Volvo P1800, joined us for the weekend.
Overall the Wagon had a good weekend, no leaks and I drove it on the trailer Sunday afternoon. Unfortunately I DNF’ed the Sunday morning enduro with 3 laps to go (doh!) as the shift lever came out in my hand (yes, again). I guess I need to make that repair a little more permanent, lesson learned. With help from Joe Harlan of TopTech Motorsports I had the fix done in time for the Sunday afternoon Flag race, and I took the starting grid slotted into 5th. I had a couple great battles with two BMW 2002s and an Austin Healey Sprite, and finished 2nd with the leader in sight but out of range. I took home fast lap of the race for my first time which made the weekend worth every penny spent!
I’ve added a couple more red wagons to the fleet - one to carry my junk in the pits, the other to amuse me while I’m writing the checks for my junk in the pits.
And here’s a vintage Revell model in my buddies toy box…
Laguna Seca can be a tough track on a race car. The drop into the Corkscrew is like jumping your car off a small ramp, and at speed you pretty much bottom it out. Listening to the heavy big-bore cars go through there is downright scary, lots of sparks flying and metal dragging going on. Now do that for 50 laps and bad things happen… With the Wagon I had to switch to smaller spacers on the front wheels to stop the front tire-to-wheel well rubbing that was occurring. My post-race inspection found a bit more, I tore both frame rails at the TC rod mount. The direction of the damage shows the force was from the front end spreading upon compression. We had planned on putting a load-spreading plate on the frame rail prior to attaching the TC rod mount, but somehow that step was missed. So we now have added some reinforced plating and gussets. Thanks goes to The Moore Speed Co for their faithful assistance.
