Dusterbd13

so, 2000 NB with close to 200k on the chassis.

seam welded all per flyin miata guidelines.
roll bar (think hard dog hard core)
2x2 frame rails per a writeup I found here.
seam welded front and rear crossmembers.


~700 lb/in front springs, 400 rear.

300hp/300tq at the wheels from a boosted v6
slicks on all 4 corners.

as this is a GRM challenge car, I will be fabricating ALL braces from scratch.

I plan to do some overhead bars to tie the windshield frame to the roll bar, and butterfly brace between the frame rails.

but I see lots of "bolt on" braces offered and sold for the NA/NB. frog arms, cannon brace, 3 point strut tower brace, etc. all sorts.

if possible, id like to discuss all bracing options short of full cage. what are the positives/negatives of each? how will they benefit in conjunction with seam welding?

I'm a belt and suspenders guy. I believe thermonuclear overkill is just barely enough.

so, if you had a bender, welder, time, and talent, which ones?

hornetball

iTrader: (4)

You are considering overhead bars tied to the bent sheetmetal windshield header, but a cage is out of the question? I'm confused.

I'd do a cage and be done with it. As safety gear, it is almost always points-free for race classes. And it stiffens the heck out of the chassis. Plus, if you ever sell the car, a proper cage has value. That other stuff you're doing or contemplating, not so much.

curly

iTrader: (25)

Pros for any bolt on brace: less rattles

Cons: your car is heavier, therefore slower.

I really don't think any of the braces make the vehicle any faster, only quieter. Sure, the Miata is a wet noodle, but for most street cars I'd suggest frame rail braces only because it also protects the chassis and acts as a decent jacking point, door bar/roll bar for a track car, and a full cage attached to the windshield frame for a race car.

If it's already stitch welded and frame rail braced, I think you're done. You'll only slow your car down and waste time making more braces.

Dusterbd13

down the line full cage is a possibility. but not at this time. theres a bunch of different reasons, but the end result is still the same. no cage at this time. overhead bars are not for safety. triangulation.

primary purpose of this build is autocross (XP). will be street driven to and from local events. I want 12s minimum in the 1/4, and we will be under the $2018 mark.

so, chassis bracing. started making frog arms today. hence the reason for this thread. between that and the rails/butterfly, I think the basics are built. but I know I'm leaving much on the table.

curly

iTrader: (25)

If you want to be in the 12s, ditch any unnecessary weight. Like chassis braces. Or frog arms.

phocup

Assuming there's already a full cage, is seam welds still a worth while thing to do ?