Nate at speed in Turn 3 at Loudon
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Over the winter we had the damage from the accident last year in Connecticut repaired.
More importantly, we had upgraded our front brakes to PBR calipers with 13" front rotors, which necessitated also going to SN95 front spindles. Now there is nothing left of our original front suspension! Spindle, control arms, brakes, shocks, and springs have all been replaced.
We also acquired some new wider rear wheels. New wheels were necessary because our beautiful custom Team III Halibrand replica wheels would not clear the PBR calipers. We had to sell those gorgeous wheels, which we had been using on the street.
However, Cobra R replica wheels are now made in 10.5" width (as opposed to the 9" width of our existing Cobra R wheels), so we bought enough of those to allow us to mount all our rear tires on them, plus a spare.
We were eager to try the car on the track with these new changes. We figured the brakes would be more powerful and more durable, and the pedal height would be more consistent. We also hoped that the wider rear wheels would stabilize the tire sidewalls and reduce the transient instability that the car has had since we built it.
The answer was no on all counts at first. Though the brake pedal had been high and firm on the street, after one track session it was spongy and reported Nate had to pump the brakes up every time he went into a turn. I didn't have to pump them but I found the sponginess quite unpleasant.
Overnight we switched to a set of Porterfield R4 competition pads that we had fortunately had the foresight to have on hand. This dramatically improved the brakes. The pedal came back up and stayed up, and pedal effort went down as well. Nate still had to pump them a little but we both were much happier. We're confident the brakes will be a big improvement over our stock 91 Mustang brakes, if not quite up to pure racing brakes like those made by Brembo and Wilwood.
On Saturday I felt the car was much more stable than before, and was able to get into the high 1:20 range while the track was warm. It seemed that the new wider wheels were helping. The day was chilly, though, and the grip went away as the sun went down and the track cooled.
Nate was frustrated that he was 3 seconds off my pace instead of his more usual 1 second. After reviewing our in-car videos that night, we decided to ask an instructor to drive our car so Nate could ride with him and see where he might be losing time.
Brad Pelletier kindly consented to drive the car on Sunday, and managed to work down to the 1:23's in only a few laps, all in traffic. When he came in, though, he was very emphatic that the car frightened him badly in Turn 8. This is a climbing right-hander taken at about 80-90 mph in the Cobra. Brad said the car felt like the rear was steering the car to the right as soon as he turned in. As soon as he unloaded it by easing off on the steering wheel, it steered itself back to the left.
We had to admit that Brad was right. We both had experienced this problem and we both also noticed an instability under braking which is probably a result of the same problem in the rear suspension.
We've had to realize that we have been driving around a fairly serious handling problem for the past year and a half. We're in the process of figuring out why this apparent toe change is happening and how to fix it.
Still, despite this problem and the cold weather, I managed a 1:19.8 in the time trial - by far my fastest official time on the chicane-chicane configuration - and took 3rd place. Nate, only about 1.5 seconds back, was 6th in a very competitive field of 12.
Both of the cars which beat me - a turbocharged Porsche 944 and a twin turbo Mazda RX-7 - are reputed to have in excess of 360 hp, well over our car's measly 225 hp. However, our car is very dirty aerodynamically (very draggy), and it is becoming very apparent that the lack of power is really going to hurt us at the longer tracks like Watkins Glen, Summit Point, and Mosport.
Most of the cars that beat Nate or finished close behind him have either much more power or much cleaner aerodynamics, or both. Loudon is a handling track, not a power track, and this allows our car's light weight, grip and balance to keep it competitive with more powerful cars. But on the fast tracks handling alone is not going to be able to make up our deficit in straight line speed.
We've got some work to do!