How much to undercut nose of car?

[tryingforspeed]

I'm building with my son our 2nd derby car. This time we are using as the front of the car the part of the block that is the longest from the axle cuts. Which is the 1 1/2 inch length end. We are using the top of the axle cut out to place the axles. There is just over the 3/8 inch clearance when on flat track. However, the track lane guide is spec'd out at 1/4 inch. So that gives just about 1/8 inch clearance on flat track. Now the question. When the car reaches the bottom of the ramp, the nose will tend to hit the track lane guide, so I've been told to round up the nose some to prevent hitting the lane guide. Since I'm using the longer end of the block for the front of the car, I believe this is more of an issue to get right. But I've never seen a spec on how much to cut upward if say measured at the front of the block. I have found that the track is typically 30 degrees to 0 degrees slope over about a 12 foot distance. But If I had a track to check my car on I could just mark a spot to cut. Unfortunally I may not know if I've got it right until race day. Can anyone provide so dimensions as to what is a safe amount to cut so that I don't nose into the track lane guide at the bottom of the ramp on race day? Thanks in advance.

[RacerX]

I don't think you will find a spec or standard on this, but it sounds like your track is a older home built model so possiably it is a manual starting gate also where the opperator pushes a lever down to start the race? The newer style starting gates are sprung open by releasing a lever. It it is the older one, designing a car with a bit higher nose will give you a advantage on the start and also allow you to remove some material from the bottom solving a clearance issue also.

The Orange car on the front page of the Derby Worx web site was designed for a manual open starting gate and will give plenty of bottom clearance as well.

In this instance, any time you can raise or roll up the bottom of the car at the axle holes or slots, it will benifit. Look at a long RV, it is raised in the rear from behind the axles to not hang up in low spots or dips, kind of the same theory.

Good Luck

Racer X