So I am making aluminum brackets (3/8 inch thick) for my street/strip 69 GTX Corbeau seats. The Corbeau supplied steel sliders will bolt to the aluminum bracket - the sliders then bolt to the seats with 7/16" bolts.

How strong do the brackets need to be? Can I lighten them by drilling similar to what I have laid out or should I save weight elsewhere?

No opinions?

Looks plenty strong to me, I wouldn't have a problem with lightening them up a bit.

I'd say the sliders might be the weak link. Seen may an accident and that racket action fails on a hard impact. Check that 7/16" bolt is grade 8. Your aluminum bracket is lighter that the comparable steel one. I'd leave it intact with no lightening holes.I'd also use grade 8 bolts for the bracket and floor with grade 8 washers, lock washers and nuts securing to the floor.

You make good points. The car is built to go 10.0 but for now am targeting 10.50's. The car has a full roll cage (so has the support behind the seat that certainly helps keep things in place in the event of an incident) and also has a submarine belt which also helps.

I would feel comfortable lightening it up some, but maybe not quite as many holes as you have drawn...

How much of a weight reduction will that be?

I think your seat belts are more important than the seat itself. The seat itself weighs what? 25-35 pounds? I don't know how much they really want to move with a 200 lb. guy strapped in them and the 200 lb. guy strapped to the floor and roll cage. I don't know how much weight your layout there would save and probably isn't worth your time.

I built a set of seat brackets from SST and then decided they were too heavy so I switched to aluminum. These are 10 ga aluminum bent to fit my seat. I went ahead and put a truss design in them to take a little more weight out.

Would you hang 1000 pounds off the seat?

It don't take a real bad crash to see the G forces go way up

I remenber Monte talking about seat mounts.
Heres what he said.

The seat mounts DO NOT hold the seat in the car. For Christ sakes, Pro-Mods and similar have the damn seats held in with dzus fasteners. You think those keep the seat in the car in the event of a crash? The BELTS hold you AND the seat in the car. If your belts let you and the seat move around a lot in the event of a crash......either the belts are not mounted correctly OR you did not have them tight enough

It's a 1/2 lb savings. That's assuming 13, 1" holes in 3/8 aluminum.
Think of this: There are four 7/16" bolts holding the seat down. I'm sure they didn't get there because some engineer was too lazy to change the drawing.

I would not risk my life or health for a 1/2 lb weight savings. Your mileage may vary.

R.