Looking for some input on seam welding
 

Got a low millage 04 NB (MSM) that I've got mostly stripped down at the moment and looking for some input on whether I should bother with seam welding parts of it before I start putting it all back together. I've read the threads I could find and seen the diagrams on normal weld locations etc.

Mostly a street car with occasional auto-X (maybe some track days if I ever get to it but nothing serious). Not a daily driver, just building it up for a fun car. Already have a Blackbird Fabworx GT3, FM frame rails, Paco Motorsports Strong Arms, PPF brace, and am planning of fabbing up some door bars that will attach up in the foot well under the dash. Running all the factory bracing too. Rest of the car is pretty normal build with Xidas (800/500), 225 200 wear tires on 9's, 1.125" Racing Beat and 14 mm rear sways, SadFab bushing in poly, urethane diff/engine mounts, etc. In the middle of built motor, EFR, 3.3 ring gear, OS Giken etc install at the moment.

Was hoping someone with a little more experience might have some input on if I would even really notice much difference with those other mods and it being a later model NB to start with. I'm in the Midwest and there's not a big Miata scene here so have never been in a seam welded car to compare to. Since it is mostly a street car I was concerned I'd just end up burning some of the factory rust proofing etc away on the insides of some of the panels for little benefit. Don't drive it in the winter but plan to keep this car for a long time. Thinking maybe I'm getting a little carried away welding it up. Thoughts?

In the case of my NB2 that received a LFX engine swap, I seam welded the entire door, and A miller seam, and added the V8R front cowl brace's. I honestly did not notice any change in chassis flex, but figured that I was doing welding in and around the engine bay anyway, so why not? If I had done the complete seem welding drill on all the shock mount areas, etc. it may have been more noticeable. Based on that, I would not do it in future, unless it was a full tilt track project, and I'd weld everything possible. On my NA, I think the biggest improvement has been a hardtop bolted on with Garagestar mounts.

Thanks for your input. I probably would go ahead but I bought this thing a few years back as a pristine un-modded 1 owner 10K car a few years back and it's only got 30K on it now. Hard to find a clean car here in the Midwest and I'd hate to have it start to rust...…..

Sounds like a sweet ride! It is not hard to re-caulk all the area's you clean off to weld, so I don't think that would cause you issues later, but agree an unmolested car is getting harder to find, and may be smart to only do mods that are easy to reverse at a later date.

I was planning on seam welding, my plan was going to be to use a good weld through primer sprayed heavy along all the weld areas the final clean up for welding, then etching primer/ paint and reapply seam sealer