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Questions on a batch of mods I'm considering
kestrel1596 - 14/2/05 at 07:43 PM

Hi All:

I'm collecting all the book errors and changes I want to use in my chassis and I've come across a couple that I'm wondering about.

1) While the upper part of the rear bulkhead (B1, O, K3, K4) is triangulated by O1 and O2, the lower part isn't. On some non-Locost chassis (Lotus, Caterham) the lower part is triangulated, but with what looks like small-diameter tubing. It seems simple to use a short O3 across the top of "e" and "f" and bend the outboard ends down toward B1, but is there enough lozenging force on this bulkhead to make it worthwhile?

2) W1 and W2 are 3/4 inch tube. Do they handle enough of the upward force from the shock mount to justify upgrading them to 1 inch?

3) Someone about one year ago suggested increasing the radius on the lower corner tubes to 3 (or more) inches from 2, but doing that and keeping the total width to 42 inches seems to mean moving RU1 and RU2 2 inches closer together. That means they would attach to B1 one inch in from the next longitudinal tube (maybe no biggie) and this would also move the Panhard Rod mount, and shorten the Rod by an inch. Does opening up that radius mean all these changes, or is there an easier way?

Thanks

britishtrident - 14/2/05 at 08:32 PM

quote:
Originally posted by kestrel1596
Hi All:

I'm collecting all the book errors and changes I want to use in my chassis and I've come across a couple that I'm wondering about.

1) While the upper part of the rear bulkhead (B1, O, K3, K4) is triangulated by O1 and O2, the lower part isn't. On some non-Locost chassis (Lotus, Caterham) the lower part is triangulated, but with what looks like small-diameter tubing. It seems simple to use a short O3 across the top of "e" and "f" and bend the outboard ends down toward B1, but is there enough lozenging force on this bulkhead to make it worthwhile?

2) W1 and W2 are 3/4 inch tube. Do they handle enough of the upward force from the shock mount to justify upgrading them to 1 inch?

3) Someone about one year ago suggested increasing the radius on the lower corner tubes to 3 (or more) inches from 2, but doing that and keeping the total width to 42 inches seems to mean moving RU1 and RU2 2 inches closer together. That means they would attach to B1 one inch in from the next longitudinal tube (maybe no biggie) and this would also move the Panhard Rod mount, and shorten the Rod by an inch. Does opening up that radius mean all these changes, or is there an easier way?

Thanks



Q1 --- adding lower diagonals between K4 and O3 will make better use of the backbone as a torsional member. Also it pays to add vertical bracing between O and the top of the tunnel if you are using it as a set belt mounting more so if you are fitting 3 point inertia real belts. Also to this end I am using 25x25x2mm for O

Q2 not required -- however it might an idea to beef up the spring abutment plates by other means.

Q3 Other than saying don't shorten the panhard rod I can foresee this would cause more knock on effects so I wouldn't do it but could be done with a little lateral thinking.

[Edited on 14/2/05 by britishtrident]

[Edited on 14/2/05 by britishtrident]