I just got in some 7" coilover sleves I ordered from Summit Racing and after pairing one of them up with one of the Bilstein HD shock I have. Miata is a NA and I'm just a little worried about the sleeve being too close too the MSM bump stop (the one that looks like a flying saucer of sorts) and under a compression load, the sleeve goes crashing into the metal part of the bump stop. I will be running 450 front/ 350 rear springs. Will I need to possibly cut the CO sleeve down to prevent it from crashing? If so, how far should I cut it down? There isnt that much space, maybe 2" of shock travel, before things go bad.
The sleeve shouldn't protrude past the top of the shock. Cut it down so that it doesn't.
Awesome. I'll look into cutting them this weekend perhaps. For the rear Bilstein HDs, should I order the 5" coilover sleeves instead of the 7" ones? Will 5" be sufficient?
How do the 7" ones sit on the rear? I'm assuming you have a set of rear shocks there as well as the sleeves you were going to use for the front.
You really only need 1" of perch adjustment range. You can play with spring lengths outside of that.
I haven't got around to the rear HDs yet mainly because of a debit card fraud issue that just finally got resolved recently. If it werent for that, I'd prolly have everything set to go by now. I know the rear HDs are shorter than the fronts are by a good lil margin, so I'm thinking of the 5" sleeves for the rear. I will be putting in the rear HD shock order tomorrow before I go to work. I have the 2 front coilovers setup already, but I havent got the rear shocks yet.
I need to cut down those front sleeves and measure them out before I order the sleeves for the rear shocks. I have a set of 450/350 springs and I'm pretty sure they are shorter than the stock springs. they look about 6" or so long. I cant really have too much play on the spring length due to the springs.
Due to the fact that you already have springs, you mean 
Typically, Miata coilovers use a 7" front and 6" rear spring. That's not a hard rule - we stock one set that has a 5.5" front and another that has an 8" - but it's typical.
The springs I have are 6" front, 5.5" to 5" rear, I believe. Quite a bit shorter than stock, huh? I dont plan on keeping the factory springs in seeing as I already have a set of the performance springs
I never said anything about factory springs They have a very long free length.
In reply to Keith:
You are absolutely right.They really have long free length.
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I'm just hoping that the Miata doesnt drop too much. I know the sleeves are there for height adjustment, but still...I'm looking for a 2-2.5" drop at the most extreme, preferably a 2" drop.
Drop is not a useful measurement without knowing the starting point. With the length of your springs, I don't think you'll have issues with the ride height. Particularly in back.
The Tokico GC kit uses 5.5" front springs, and that coilover sleeve sits directly on top of the stock perch. The biggest thing you have to watch with such short springs is putting yourself in coil bind.
I plan on contacting the owner of 5X Racing this weekend about getting some help witg getting the suspension dialed in and getting the alignment set just right for autoX/ track days without being to harsh on the tires for street. He knows Miatas really well, so having him help set it all up will be a good way to get more knowledge about suspension.
