Lime Rock Park, May 2000
Brandon Hull - Ersatz S2 running BIRA System 2
This is one of those "If you aren't already tracking your car, what-are-you-waiting-for" posts.
It's been said before, but I'll say it again: Driving fast on the race track has just about nothing in common with what you think of as driving fast on the street. Irritated that your 20v NA gives up 2 sec 0-60 to the guy in the 328? Doesn't matter on the track if you drive a better line: enter the straight going 5 mph faster, you'll pass him.
Lime Rock was my fourth drivers' school and the third track I've driven. It is much smaller than Thunderhill or Mid Ohio, and a "friendlier" track than those two: no nasty zero-gravity corner drop-offs like the cyclone at TH, or off camber/multiple camber corners like both TH and MO. Instead, the track is tilted in your favor, meaning that you approach two corners in particular far faster than your senses tell you should be possible. Then, when you hit the elevation change, the suspension compresses, all this grip happens, and you realize you could've gone even faster.
It's a simple track, and short enough that you learn fast.
Ah let us sing the praises of Big Brakes! I finished my System 2 installation about three weeks ago, and have been doing some ad hoc testing while on the street. But a dozen or so 60-0 stops on the highway don't compare with repetitive lapping on the track, and it wasn't until this weekend at Lime Rock Park that I got a chance to do a full workout.
My car is the Ersatz S2, a US-spec '91coupe quattro converted to European S2 specs. It has H&Rs and Koni adjustables set 75% firm. It weighs a bit less than the sedans, about 3200lbs. Consequently, I never had any major complaints about the stock G60s, which I thought hauled the car down nicely. However, I did notice at Mid Ohio last year, that they would fade during the last run or so of the session. I grew careful about my braking at the end of the back straight.
The stock rear brakes on the CQ are maybe the smallest rears Audi has ever installed on anything, an unvented, saucer sized rotor. We installed a Tilton proportioning valve when we did the brake install, and left it set to full rear bias. Initially, I thought even that was not enough. During my street driving, the rear rotors never really got bright, and began to develop rusty streaks. There was no brake dust accumulation (although my fronts were getting plenty dirty)
On the track however, the balance seemed fine. The rears got plenty of action and the rims loaded up with dust (interestingly, the fronts stayed clean except for accumulations around the valve stem, must be something about the airflow at speed)
The major test of brake power at LRP is big bend, the double apex right-hander at the end of the main straight. When I got a good line coming onto the straight, and using a pretty conservative brake point between marker 4 and 3, I'd be doing about 110mph. Three things were immediately apparent about the brakes:
Because my pedal firmed up so much, pedal placement for heel and toe just got a lot better. So the 4-3 shift while braking hard was easy and natural compared to before.
Secondly, the car really stops, and I was no where near testing the limit of braking capability. With more confidence in myself, and more experience at the track (this is an unusual curve, which really affords two braking boxes if you have the nerve) I could've been braking much later.
Finally, there was not even the suggestion of fade. LRP is a shorter track than I've driven before, with friendly, positive camber turns linking fairly short straights. So braking is often a quick stab, then on the throttle again for the corner. Since the track is shortish, the main straight comes up frequently and the brakes never wavered for an instant.
Again, thanks to the proportioning valve, the car's attitude is very confidence inspiring. Instead of dipping the nose, the whole car hunkers down. Although on the street I've managed to invoke ABS at high speeds, on the track I never did, no doubt an indicator that I was nowhere near my braking capacity.
Brandon Hull
5/8/00
http://www.200q20v.com/lime_rock/P5060269.jpg
Chris Miller - 1991 200q
I didn't have my 200q20v sedan ready for the recent Lime Rock track event; need to solve a 'wandering' problem and find a solution to fairly tired brakes. However, after a tough week at work, taking off Friday and going to watch the two day Northeast Region Quattro Club USA driving school event was irresistible.
I met up with a number of fellow quattro owners, including several 200q20v owners. Greg Amy (200q20v sedan) and Brandon Hull (ersatz S2) were kind enough to put me up overnight Saturday night, as well.
Neil Swanson was at the track with his new (to him) 200q20v sedan, recently shod with 16" wheels and new tires, and an H&R and Bilstein suspension. His car had UFO brakes and combo street/race pads, and seemed to be doing pretty well on the track. (UFO = internal caliper front brakes, about 17% more swept area than the G60 brakes on the urS4/6 and V8). Neil said he was getting some fade and warping after repeated runs, and he flushed the brake fluid a number of times during the event to rid any bubbles from boiled fluid.
Greg Amy has a similar 200q20v, same suspension setup as Neil, but using the System 2 BIRA brakes, consisting of the new S4tt rotors, Porsche Boxter 'S' calipers, and race pads.
The difference between Neil's UFO brakes and Greg's BIRA brakes were dramatic. I went along on at least 3 of Greg's black group runs, and he was easily outbraking the others in his run group (various track cars, such as 911s, a BMW, etc.). Every run, we'd try going a little deeper towards the corner before braking, and each time had more brakes than we could use. I later saw a picture of Greg's car entering the corner after the big straight at Lime Rock (typically at 115-120 mph); even with his stiff H&R/Bilstein combo suspension, the nose was down and rear lifted quite a bit. In effect, any more brakes on the car could not be used, as the limitation was now the tires (which were a new set of RE-71s in 245/40r17, a very sticky tire).
My impression of his brakes, from the passenger seat? DAMN! Whoo hoo! Brakes are as addictive as horsepower (especially as a passenger, where they're much more important!). I can't see needing more brakes than these BIRAs. After each run, pads were fine, no boiling of fluid, no change in braking feel or performance.
Brandon Hull was running his ersatz S2 (a 1991 coupe quattro converted to S2 specs, including an engine from a 200q20v), also equipped with the BIRA brake kit. What a fantastic car; he seemed extremely satisfied with the brake kit as well.
Am I sold on BIRA? Absolutely; already started saving my pennies.
Chris Miller, Windham NH, c1j1miller@aol.com
'91 200q20v ==> http://members.aol.com/c1j1miller/welcome.html
Greg Amy - 1991 200q running System 2
I just got home from Lime Rock Park, where I ran System 2 on my 200q. It was a gorgeous weekend, very hot today.
These brakes are un-freaking-believable. I've never driven something like this before.
It is absolutely UNREAL! There is more brake than I have balls to use. The only cars out there in my group (the black group - experienced and fast cars) that could outbrake me were a tricked-out BMW 540i with 6-piston Alcon brakes and a GT3 Porsche 935.
I encouraged Neil Swanson to drive the car, and he came back with a huge grin on his face. I was watching him drive and that car went faster and deeper into the long Turn one than ANYONE else out there. He gave me a freaking heart attack!!! He's Da Man!
Chris Miller drove with me a couple of times, and Brandon Hull has System Two on his car (HE was deep-braking everybody too!) and I'll encourage all three to post their impressions as well, but I'm freaking psyched. These brakes are hot stuff.
I was running Kerr Friction race pads all the way around, obtained from Paul Weston. No fade, awesome grip, repeatable and consistent every lap, very little wear (my brake fluid reservoir level never budged the whole weekend) and my rotors are still in great shape. Noisy as all snot, though, even worse than factory Carrera pads, so I need to get that set of street KF pads from him ASAP.
I really wish could have compared these straight up to the System 1. I did not notice a significant difference on the street between the two systems, and last year's experience is not a good comparison; it rained last year and I was on different rear pads. However, Giovanni Tomasi ran System 1 on his A6 on Friday, and I'd be interested to hear of his experience as well.
Speaking of rear brakes, I put new rear rotors on the car with Weston Motorsports' pads. I was watching Brandon and noticed that his rear wheels were getting dusty. Seems he put on a rear bias adjuster, which was turned full "on" (no reduction in the rear brake pressure). So, I removed the spring connecting my factory rear bias adjuster to the rear trailing arm, and jammed it fully in the up position, doing the same thing as Brandon's valve. Worked wonders. It dramatically improved my brakes, and the balance was beautiful. No lockups, very few ABS engagements, and that's when romping on the brakes from 120mph down to about 50 in 100 feet or so (Chris can correct these numbers if they're wrong; I was way too damn busy to look!)
Our name recognition is growing; I had a lot of folks see the BIRA.ORG decal and note that they have heard of the organization or even visited the web site. I was flattered as the number of folks that had heard of us.
I am VERY satisfied with these brakes. I am fully confident that these brakes will perform on par, or even OUTPERFORM, any of the other big brake combinations. These brakes are incredible. All that for about $1500. Damn!!
GregA
Photos courtesy of Brett Dikeman:
>...Greg Amy, driving the wheels off his 200, I mean flogging that thing into performance envelopes no 3X00lb car was meant to go. Major entertainment in the esses.
Yep. Some BMW guys really got a kick out of him. We called them the Greg Amy Fan Club :-) Not quite as good as seeing Greg in action, but here's some of the action Brandon was talking about:
http://www.200q20v.com/lime_rock/P5060253.jpg
http://www.200q20v.com/lime_rock/P5060261.jpg
http://www.200q20v.com/lime_rock/P5060265.jpg
http://www.200q20v.com/lime_rock/P5060267.jpg
http://www.200q20v.com/lime_rock/P5060282.jpg
http://www.200q20v.com/lime_rock/P5060285.jpg
http://www.200q20v.com/lime_rock/P5060289.jpg
