I want to build a couple of new cars for the March Madness. We sent my boys cars to the Cabin Fever and I thought we did ok. Now, I want to try and go sub 3 in the Stock class. I am familiar with it because those rules are essentially the same as our Pack and District. I do have questions about the Pro Stock cars. I have been looking closely at the photos of the cars. It seems all the cars moved back the rear axles and a few also moved the front axles up. I also noticed that the rear wheels are inside out, I assume to put the balance closer to the COG as well. Is there a rule of thumb for that and what should I start with for a COG in front of the rear axle? I also noticed white washers on the axles. Are these flush with the wood or are they attached on the surface? I am assuming these are the washers that DDH is selling on his site. It is tough not being able to travel to the races and inspect the cars up close. Any advise would be great.
Car for Pro Stock Class
- Thread starter jeffreyl7
- Start date
OK I will try to answer most of your questions. In the Street Pro class you can alter the stock wheel base, IE move wheels forward or back. I think that most use about a 5 inch wheel base, some more, some less. I usually shot for about 1/2inch-3/8 of a COM. there again some more, some less. The wheels are reversed on a lot of the street pro class because you can run a lighten wheel in that class, but do to the rules the tread area has to be at least 7mm. If you run them in the forward way you would get to much flex in the wheel through the transition, that's why they are flipped. Most do use some type of Teflon washer or spacer, which can be used in all classes, between the wheel and the body. You can flush mount or just slide in-between.
The reason for the rear wheels reversed is the wheels are lightened and very thin, when the rear is canted and the car hits the bottom of the transition the edge of rear wheels oval (round is faster) from the downward force, if reversed they are more rigid. Also you want the rear wheels about 5/8' from the rear of car. Keeps your weight on the hill a little longer. Try to get as much weight and as little wood in the car as possible.
You can put washers on the stock class as well? Thanks for the help. I have some sugar pine slabs on the way. I hope they get here in time. This will be my first attempt at not having to use the slots on the bottom of the car. Hopefully I can get some better alignment. All of my boy's cars ran from 3.0080-3.0350 at the Cabin Fever. It is always an unknown since we do not have a Best Track to test on. i guess that is what makes it so fun. I am having fun learning. I know the experience will help us next year with Pack and District Races.
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