Rear Trailing Arms, Reinforcements to Resist Twisting Options

[Heater Guy]

Lamont Welding & Fabrication in Antioch, CA (925) 754-7824 has a fixture to modify trailing arms. It holds the trailing arm in the correct stock alignment.

He mounts the trailing arm in the fixture, cuts it in half and welds in a 1/8" rectangular
plate. The 1/8" plate helps to reduce twisting deformation by breaking the twisting length
of the arm into two lengths instead of one long length. The charge is $80.00 per trailing arm.

I just had my trailing arms reinforced. This reinforcing method is better than plating the arms with heavy sheet metal.

[old914dog]

Brant and Chris,
Since Vintage racing does not allow "cage to suspension pick-up points," what is your opinion on the inner ear reinforcement which goes forward to the lower firewall. Can be welded or bolt-in as small radius rod. I also think the inner ear problems are partially due to the outer ear becoming loose or ?? Please opine for us vintage cars and more vintage drivers!!

[brant]

Brant and Chris,
Since Vintage racing does not allow "cage to suspension pick-up points," what is your opinion on the inner ear reinforcement which goes forward to the lower firewall. Can be welded or bolt-in as small radius rod. I also think the inner ear problems are partially due to the outer ear becoming loose or ?? Please opine for us vintage cars and more vintage drivers!!

I depends on the specific rules of each club
my club allows bolt in reinforcements, but not weld in reinforcements

I run bolt in console braces on both of the 914 race cars I've built

I ripped out 2 suspension consoles within about a year, before adding my first bolt in reinforcement

I consider it mandatory

prior to reinforcement the trailing arm shaft lock nuts would be loose each and every day the car was tracked. it was a daily ritual to re-torque these and would lead to a tear if not tightened.

since adding the reinforcements I haven't had a shaft nut come loose in 15 years.

I believe a cage to the suspension points would make the car handle better
but arm bolt in reinforcements make it not tear itself apart

brant

[Han Solo]

prior to reinforcement the trailing arm shaft lock nuts would be loose each and every day the car was tracked. it was a daily ritual to re-torque these and would lead to a tear if not tightened.

since adding the reinforcements I haven't had a shaft nut come loose in 15 years.
brant

I've noticed the same loosening on passenger side shaft at every autocross. Now tightening that is a ritual for me. That side has extensive long repairs so there's probably all kinds of flex going on. I really like JP's fix above (IMG:style_emoticons/default/agree.gif) That may be something I do this winter. That is... if I'm not too wrapped up in a 924S FP car build.