Trans brake question

63corvette · 05-02-2009, 10:27 AM

JJ, I run a set of 24" on the front. As I mentioned in the previous post every car is a little different even though they all come from the same jig. I have friends with the same car and we all use a little different setup. It also depends on the engine HP you run and the rear gear. I run a 4.30 rear gear.
I bought mine new from Davis and went through a long visit with Don on how and why the car works as it does. Don builds the car to be consistent on launch by planting the rear tires and pulling the front tires out of the beams and not driving them out. I have found mine likes to move up and out not just up. Last year I struggled with the tree and like I mentioned in the previous post ran far to much delay at times. The car was jerking the front end out of the lights instead of a controlled up and out. The launch would change with the density altitude and thus the more delay in the box with a low adjusted altitude. Over the winter I thought long and hard on how to tame the car down and make it consistent. I ended up lowering the launch chip and carrying the car out farther before bringing the stop on. That has worked well for me and has made the car more consistent on the launch. At my 3rd race of the year (Las Vegas Nats) my worst light was .028 and a best of .000 in 3 time trials and 4 rounds of racing. That was with .020 to .033 in the delay box. I always add time to the delay for eliminations as the starting line is usually better especially at the National Events. I have been very pleased with the way my car is working this year and we have been going rounds.
Don Davis also recommends you lube the 4 link hiem joints before every race weekend to allow the suspension to work as well as possible.
I use a B&M trans brake but all the pro tree brakes are about the same. I build race transmissions so I do have some experience there. If you have a pro tree brake and the clutch clearances are correct you should be able to go red easily with the Davis car.
I hope this helps and wish you the best of luck with the car.
S/G 5887

05-02-2009, 10:27 AM	#6
63corvette Senior Member Join Date: Mar 2007 Location: Canyon, Tx Posts: 553 Likes: 128 Liked 359 Times in 103 Posts	Re: Trans brake question JJ, I run a set of 24" on the front. As I mentioned in the previous post every car is a little different even though they all come from the same jig. I have friends with the same car and we all use a little different setup. It also depends on the engine HP you run and the rear gear. I run a 4.30 rear gear. I bought mine new from Davis and went through a long visit with Don on how and why the car works as it does. Don builds the car to be consistent on launch by planting the rear tires and pulling the front tires out of the beams and not driving them out. I have found mine likes to move up and out not just up. Last year I struggled with the tree and like I mentioned in the previous post ran far to much delay at times. The car was jerking the front end out of the lights instead of a controlled up and out. The launch would change with the density altitude and thus the more delay in the box with a low adjusted altitude. Over the winter I thought long and hard on how to tame the car down and make it consistent. I ended up lowering the launch chip and carrying the car out farther before bringing the stop on. That has worked well for me and has made the car more consistent on the launch. At my 3rd race of the year (Las Vegas Nats) my worst light was .028 and a best of .000 in 3 time trials and 4 rounds of racing. That was with .020 to .033 in the delay box. I always add time to the delay for eliminations as the starting line is usually better especially at the National Events. I have been very pleased with the way my car is working this year and we have been going rounds. Don Davis also recommends you lube the 4 link hiem joints before every race weekend to allow the suspension to work as well as possible. I use a B&M trans brake but all the pro tree brakes are about the same. I build race transmissions so I do have some experience there. If you have a pro tree brake and the clutch clearances are correct you should be able to go red easily with the Davis car. I hope this helps and wish you the best of luck with the car. S/G 5887