NA Bilstein coilover on the cheap
 

Hey guys,

I have been reading every thread I can find searching with every combination of "Bilstein + ebay + sleeves + coil over + NA + mounts + bumpstops" and here is what I have come up with for getting the best bang for the buck coilover setup. The car is a 1994 miata that I will be adding a turbo kit to over the next month or so. It will be street driven 99% of the time, so I need something that is good handling but complaint and something that has great suspension travel for these shitty DC roads.

I just bought a set of 94R billies with 100k on them. They are rusty but I got 'em for what ended up being around $100 shipped and none are leaking, so I don't mind the strip+repaint procedure. Now comes getting the setup ready for my occasional autox/daily driver, heres what I was thinking.

350lb QA1 8" springs for the front, and 275lb SSS 9" springs for the back
Ebay coilover kit for the sleeves and drill out included aluminum upper perch (haven't picked a kit out yet, any recommendations?)
ISC mounts all around (unless someone else has a better idea to have decent ride height and lots of travel).
Not sure on bumpstops, I hear they are unnecessary for the ISCs? Is this true?

I plan on running the sleeves on top of the existing shock mounts, provided I can get what I am looking for in ride height (12.5-12.75).

Anybody have any opinions on this setup or have any other suggestions? I love this car but the stock suspension leaves much to be desired.

Thanks in advance! -Charlie

If stock swaybars, then 400/275.

I use Summit Racing brand springs.

I run ebay sleeves on my NB Koni Yellows. The kit I went with is sold by a vendor by the name of "Jessie's Kits" on Ebay IIRC. A few members on the M.net ebay coilover thread have used that kit as well. It actually comes with a pretty stiff spring (~#550 front and back) so I ended up using the ebay springs in the front with #300 in the back. One problem you might encounter is the factory shock mounts not being low enough on the shock to get you your desired ride height. I had grooves lathed into my shocks for the circlips to sit on so that I could mount the sleeve lower on the shock.

The spring lengths you are planning on using will put you up at stock height. Typically people run 6-7" front and 7-8" rear.

I was thinking that was the case with the stock upper mounts but I was kinda under the impression that with the resultant 3/4" drop from the ISC mounts running a 8" front 9" rear might be possible and beneficial in terms of reducing coil binding. I am not opposed to a high-ish ride height, especially if it means more ride comfort and shock travel, but I would prefer some drop from stock.

Any thoughts about this?

At those spring rates 7" front 8" rear shouldn't bind and give you plenty of room for height adjustment.

Fwiw I run 6"/#450 for the front and 7"/300 in the rear with no coil bind issues.

FCM (fat cat motorsport) bump stops. Also watch his informational videos while your on his site for some useful suspension knowledge.

I figured I would get the FCM bumps, any recommendations on length for use with the ISC mounts?

usually 36 mm is recommended but contact them to verify

I didn't know the ISC mounts provided so much drop on their own. I used FM rear mounts which don't provide any extra drop (ISC didn't exist when I go them). I would probably still use the 7'"/8" springs.

I'm not sure that the mounts are necessary for the front. I've had the tire rub the fender liner using short bumpstops and NA mounts with lowring springs.

I second emailing FCM and describing your planned setup they might have some input on which height mounts would be good for the front.

racelands>>>

You like penis.

ISC tophats do not alter ride height at all vs. NB tophats. The top spring perch location remains the same, yielding the same ride height. They recess the bumpstop further from the shock body to allow additional travel before contacting the bumpstop. Therefore you can lower the ride height using coilover adjusters and still maintain some suspension travel. But the tophats do not lower the ride height themselves.

If you have NA tophats it will lower it as much as switching to NB tophats, about 3/4 inch.