Add Lightness

[Aardvaark]

Maybe the Opelers should get together and build a large acid dipping tank.
Body and all kinds of parts could lose wt.

Like SS drag racers used to.

Hey. I never said my ideas were always practical.

[RallyBob]

Originally Posted by Redskinsjbs Bob - I really like that Swiss-cheese cross member. I would NEVER want it on my car, but just think about how cool that actually is!

If you're concerned with strength...don't be!

I removed the bottom and side reinforcement plates that are spot-welded to the crossmember, then drilled all the lightening holes in it. I then added thin steel (also drilled and flared) gussets within the crossmember, TIG'ing them in place prior to welding the bottom and side reinforcements back on. So it is in fact stronger and stiffer than OEM, but about 25% lighter overall.

When I first removed the reinforcement plates, I was a bit shocked at how flimsy the crossmember was, hence the addition of the gussets. At the lower flange where the reinforcements are normally spot-welded in place, I trimmed the flange down to nothing...it's about 1/2" wide so there's a substantial weight savings there!

On this crossmember I also made solid upper mounts, deleting the OEM rubber mounts (saves more weight!), and I took the anti-dive geometry out of the front end by relocating the upper a-arm pivot tubes. It's not needed with the spring rates I will run, and the caster stays more consistent too.

With the same mindset, here's the torque tube crossmember I prepped for my old hillclimb Manta back in 2001...I gave it to Samdog a few months ago for use in his '71 Ascona. It was the first crossmember I 'notched' for more exhaust clearance, and I decided that drilling a bunch of holes in it would save a little weight too.