Northy2 wrote:Why will the tub not be competitive?
Why will it steer more with a front sway bar?
G
CF Chassis:
Weight has always been the enemy of any type of racing, and the old gold tub design is a little on the heavy side. Going to a graphite chassis will shave a bit off. I always liked the Composite Craft foam core design as I believe they were more rigid than the thinner counterparts.
Weight comes off an RC car in grams, doing a lot of little things will add up to a significant reduction. For example, cutting the square motor protector off at a diagonal does not compramise the design and shaves a little weight. Don't run the rear lower motor guard if that's the setup you end up with. Plastic bellcranks are better than heavier aluminum. Small digital steering servo. One Piece wheels. Lightening carbon fiber shock towers (don't try to lighten the fiberglass variety). Shorter rear shocks, but leave the stock ones in the front.
One major weight savings is to go to a LiPo battery. Joule for joule LiPos weigh around 1/3 less than their nickel based brothers. Find out if it's legal and run it if you can.
Also, you can put RC10T shock towers in the rear and lower the body substancially, but then you might have to put the ESC on top of the battery, raising the center of mass. I would assume that a GTB would have to go there anyway.
If your race director enforces a minumum weight, you want to be right there. If not than make it as light as you can without compramising the design.
Sway Bar:
Modern tires have a lot more grip and side bite than the tire designs of the past. When you put moden rear tires on your gold tub you will find that it will push like a dump truck. To correct this you want to really plant the front outside tire and the sway bar helps you do this.
The best way to do a sway bar is to get the modern associated sway bar linkage and bend up several gauges of K&S steel wire. It's another tuning element you will have to deal with but a little experimentation should get you there.
Modern cars allow the battery to go forward to accomplish this as well. Might be a good experiment to hack up a battery cup for the rear and scooch the front cup forward to be able to adjust the battery position like on the modern cars..
Good Luck,
Bob