I've been making my chassis for years (locost) and i'm trying to decide if i should triangulate the transmission tunnel.

I know lots of manufactures dont, but what i want is opinions on if i should (my time is free so its more about weight vs performance).

I 've got triangulation in the main section by the prop on both sides (i care about my passengers).

Car has de-dion rear (so sierra diff - hence i think triangulating that bit would be a good idea to reduce stress on acceleration). Currently a crossflow up front (with various states of tune, i've got an ax block floating around the garage) but one day i may put in a zetec.

Triangulating the tunnel helps longitudinal beam stiffness, but very little else. The tunnel contributes little to the torsional stiffness, so triangulating helps this area minimally.

Just make sure that the outer frame is properly triangulated, and that the ali skin is properly secured, as this can add considerably to beam and torsional results.


Quantitive results for the above can be found on the aussie locost sites. Thank your lucky stars that we don't have to go through beam and torsional testing here!

Cheers,
Syd.

Without the diagonals in my tunnel the vinyl panels would fall out.

Paul G
Rescued attachment vinyl panels s.jpg

If you ever had a propshaft let go.....

I already had the bits Ron Champion says add for racing - for that very reason. The rest was a case of is it worth it?

Might do the ones by the diff for the same prop reason + helping the diff take hte power.

I triangulated the sides of the tunnel on my Westfield chassis, also added cross tubes underneath (I still can't fathom WHY Westfield don't at least put a cross-tube on the lower chassis between the two footwells).
Reason? Thoughts of my hairdrier throwing a prop or UJ.