At the track

I talked to Ian today about my CAV and the track came up. I live in the Seattle area and am an instructor for the Porsche club. I am now the chairman for the HPDE events for the club. I really enjoy going to our local track which is called Pacific Raceways. It has about 150 feet of elevation change with 9 turns and 2.25 miles long. I have not had very much success with my GT40 at the track because I just keep breaking it. I went to the track on July 29. It was 108 degrees at the track that day. Hottest day on record in the Seattle area. It was also the first day that my GT40 went a whole sesson. It actually lasted 4 sessions and drove home on its own power. I did spin the car at about 130mph during heavy breaking going into turn 2. It locked up the back end and it swapped 180. Looking at the cars comming at me, I let off of the brake and whipped the wheel flipping the front back around, hit 3rd and away we went. Yes, we, I had a female student with me for the first time at the track. Whew, she enjoyed the spin. It was a very successful day with no issues. I am really beginning to love this car. Talking to Ian today about the spin and the rear lock, said that changing the uprights and lower control arms will help with this issue as it is not new.

Thanks for letting me voice my enjoyment of my car.

Tom

Better a big-time spin there than coming into 5, eh Tom? :lipsrsealed:

Very pleased to learn you didn't bring it home in a box. Although that track isn't very forgiving at times, I'm looking forward to getting out there with you one of these days.

Let's pick cooler weather though... :thumbsup:

T.

We have two more track days this year. One September 3 and October 1. PM me if you have any interest in either of those dates and we'll talk. Going with a club is more fiscally responsible than other track days.

Turn 5a, 5b and 6 are so much fun!! I have learned to slide the vette through 5b for more speed up through 6 and 7. Seems you have had experience with this track. As you have said, the track is not very forgiving. Very technical.

Good on you Tom. I have a set of Hoosier TDs on the way. Then it's off to Fordahl for track prep. Maybe we can get together for the October event.

Hi Tom,

Glad you're starting to enjoy the car. Sorting out the initial bugs can try your patience, this is not exclusive to CAVs however, the frustration is shared

About the rear locking, that is symptomatic of several CAV owners experience in that they cannot dial out enough rear brake bias to stop rear wheel locking in hard stops.

Intially we thought it was too much rear brake, the CAV GT rear calipers and rotors are the same size as the front, many replicas have much smaller rear brakes. Easy conclusion to arrive at.

The idea of reducing rear brake capacity to prevent lockup didn't appeal to me so further study was required. Why make the whole car stop as slow as the worst brake?

The culprit is control of the rear tire contact patch in hard stops. What occurs in the stock Series 100 cars is that the rear wheels change camber and toe dramatically in hard stops, resulting in far less rubber on the road, hence lockup. Adding to the unpredictable and twitchy handling is the tendancy of the suspension to momentarily bind up on the rubber bushings of the stock lower a-arm. So you have a rear end that locks easily on hard braking, gets nervous and twitchy on bumpy roads or high cornering and acceleration loads.

The CAV MotorSports parts have revised geometry built in and no friction. Now during hard braking the contact patch stays constant, maximum grip and no locking. The result is greater total braking capacity, shorter stops and more control. You can still spin the car of course but with a lot more provocation.

The same factors limiting the brakes prevent maximum grip in corners and acceleration out of corners or in a strait line. So the car can break away suddenly. The new Rear Uprights and Lower A-arm set also brings more progressive breakaway, if you want to hang the tail out, and greatly reduced tendancy to side step on hard acceleration.

All this translates into a better handling, balanced car that rewards driving skills without having to second guess what the car will do. The overall confidence level in the car is very satisfying even on public roads. In a way it's like having a real good pair of running shoes on with loose laces, tighten them up and viola!

Although we have hundreds of hours invested in getting the most out of the CAV GT, I suspect anyone tracking other brands of replicas have experienced similar challenges. It's all part of the passion (or obsession according to my wife)!

Cheers

Come on Ian, you are letting the side down "viola" ? I thought they spoke French In Canada

Iain

Hi Iain, Some do but not "French" french, we have French Canadian, quite the dialect for tourists from France to understand. Then of course there's my dependency on spell checker software LOL. How's the weather in the land down under?

Neal, what are you going to have Greg Fordhal do to your car? I hope you can get in, each time I try, he is either out of town or just too busy.