Originally Posted by akaryrye

So I just put together a setup for the 2003 I recently bought. Found a set of spec miata race car take-offs (NA HD) for $120. Got some Allstar sleeves, 550/350 summit springs, Integra bumps tops, and a few misc washers and ****. All in was about $600. I didn't buy the 5x NB tophat stuff. Instead I DIY'd it with a thick rubber washer on top, and a slice of bumps top on bottom. No sleeve nut, full thread engagement (if barely).

Anyway, I've read so much **** about the NA HDs ... I was a little worried (also about the spring rate), but these really aren't all that bad. Now, I am riding fairly high RN, like 13.5"" (ish). I can tell it's under damped, especially in compression, but overall it's not bad. Far from uncomfortable, and on par or better than the average mid-range coilover I've experienced. Not crashing on the bumpstops helps a ton. Eventually, I want to adjust the valving, but wanted to see how they ride as is first.

Anyway, thanks to everyone who contributed to this. It was hugely helpful for navigating through the weeds!

Originally Posted by Bronson M

Did you check wheel travel and trim the bump stops for your particular setup? I'm guessing you didn't because you didn't mention rear extended top hats.

These definitely aren't underdamped for those light rates, bet you're actually into the bump stops quite a bit and have a LOT to gain by by trimming and getting extended hats. Last car I setup we gained nearly 2" of rear bump travel over out of the box FCM stops.

Originally Posted by akaryrye

the integra stops are 46mm I think, and I cut the lower section to use on the tophat. That probably made it close to 36mm. Anyway, I used the NB OEM hats for now, and I'll probably get some extended rears down the road. Didn't check the travel either. For sure there is some optimization to be done with the setup, but I really wanted to see how it all felt before investing too much time, effort and $$ on it.

Originally Posted by Fireindc

I had to cut the **** out of integra bumpstops, even with my extended tophats all around.

I don't think there's a good way to "guess" bumpstop length on a DIY setup like this. Do it the right way, remove the spring, and cycle the suspension and see where the bumpstops engage. You want them as small as possible, but to engage before the wheel comes in contact with the tub or any hard parts.

I had an issue where I had guessed bumpstop lengths, I think I did the same as you and cut the first ring to use on top of the tophat. Anyways, long story short, I had snap oversteer issues which ended up being in part due to rear bumpstops engaging under track use, causing spring rates to spike to near infinite, and lots of oversteer when that happened.