kevinkirk

I am experimenting with body angles on the Mazda speed 6 and LTCR. I assume that the bodies were designed to have the side cutting lines level to the ground but what do people do in practice.
Cheers
Kevin

TryHard

iTrader: (4)

Generally trim the splitter to be about 4-5mm thick. Then set the front so it doesn't hit the ground (a bit of scrapping is ok.. but not too much)
For the rear. Mount the wing on the posts, and set the height to be level with the roof (when the wing is trimmed to the 40x20mm box size). Then run a pen around the sides of the shell to give the new trim line for the sides.

HiH

oldrcr

iTrader: (46)

Basically, if you are running to the standard rules that are put in place by the major rules makers for different areas of the world, rather than any local club rules that may stray from these standards, it is hard to put rake on the body without a compromise of some sort. If you were to raise the rear, for example, the rules state that the wing has to be no higher than level with the roof of the body, so you would have to trim down the rear wing to keep that within this rule. If you trim the wing, it no longer creates the same amount of downforce, even though you've increased the rake to try get more downforce, you are trimming a good portion of that gain away. If you were to go the other way, the wing has a maximum surface area rule, so you couldn't gain any extra by doing that either, since you couldn't make the wing taller.

Generally, most move the body either forward or back in order to change the handling. This both changes the weight of the body effect on the chassis balance for and aft, as well as where the downforce is being applied on the chassis. Usually forward creates more steering, moving it back more rear downforce. There are also various wings available that fit the rules from an area standpoint, but have various shapes that have less drag and downforce, or more drag and more downforce, so you can tune for the track and class your racing in. Every body has its own characteristics to begin with, so that plays into what makes sense to do for your conditions.

If you aren't worried about legal configurations, it would be interesting to see what you find out, even though most may not be able to use it if they are racing where the rules are enforced.

In 1/12th scale, we don't have a rule limiting rake angle, yet.

Hope that helps,
-a
:-)

John Wallace2

I know this is an on-road discussion, but based on wind tunnel testing (not ours) we mounted our bodies for the velodrome with the nose slightly high - it made for lower drag at high speed (65 - 70 mph in modified)! It worked well: 2 TQs and 1 win in 3 years at Indy. Note the flat wing in the picture - not much down force there but those big side dams acted like the feathers on an arrow (stabilizing the car in its flight down the straights)!