I've never done anything to the stock suspension. I knew it was worn out and I hated that it harshly slammed against its bump stops, but I needed to spend my money elsewhere.

Well, I scored a Craigslist deal on some barely used Bilsteins. They were bought by a NB owner through a Mazda dealership to upgrade his 99 to "Sport" or "R-Spec" or something (he didn't remember what it was called). His wife HATED them so he took it all back off. He bought the upgraded springs as well and I got those, too.

I wasn't really finished researching what to do with my suspension but I had read enough to know that low mileage Bilsteins = good.

The funny part- I decided I'd slap those puppies in there Sunday afternoon since it was 70* and sunny, without reading a little first. I started with the rear. NB shocks + NB Sport springs + NA tophats = back end jacked up like a '72 Chevy Nova. It was pretty silly looking. I took it back apart and put the stock rear springs back in and it still sat 1/2 to 3/4 higher than stock.
I searched though 22 pages of search results and related links (plenty of good info and details here on MT.net) and learned all about NB tophats, coilover sleeves and even how AbeFM couldn't get his stock aluminum spring perch off with a hammer two years ago.

I've ordered a set of NB tophats from Rosenthal/Finishline.

I am thinking of acquiring some of the cheap ebay coilovers just to get my hands on the adjustable height spring perches. What keeps the perches from sliding all the way down the shock bodies? Are there tabs or tangs on the outside of the shock body that I've never noticed?

I have read about the F/R spring ratios but after fiddling with the calculator for awhile I haven't discerned the formula you guys are using. Please advise. And if I get the ebay kit and decide to use the 350# spring for the front what rate spring would be appropriate for the rear (remember this is a *****-assed non-turbo street car on street tires that will one day be a *****-assed turbo street car on street tires)? Or do you think the "R-spec" or "Sport" valving on the Bilsteins can handle more than the upgraded NB springs that were included in the deal (~180/130)? This must be able to transport me seven hours to Atlanta and seven hours back in a weekend and I should still be able to walk upright and eat solid food when finished.

Your ideas and information are welcomed and encouraged.

 

There is a ring around the shock that the perch is sitting on. Did you tighten everything on the ground with weight on the suspension?(Also naturally that nb setup will sit higher than an na setup)
I believe the NB has slightly longer shocks (IIRC) so travel will be less. I would really suggest getting ISC racing tophats because they will actually allow you to regain some of that travel and lower your car a bit because they are thinner than the NA and NB mounts. If you have already ordered the NB ones thats fine but you may not be able to go too low.

If you are using a 350 front spring I would go with something like a 220-200 in the rear. There is also a group buy on shock revalves in this forum and they can shorten your shocks while they are being revalved, which would help you out with your travel.

Not sure if you considered it yet but Flyin' Miata makes a great spring for the average daily or sporty driver. Seems a better idea than ebay perch/spring for your purpose. Moderate ride height with a smooth ride.

Did the shocks you got come with softer bumpstops? If not you definitely need to pic up some new ones. FatCat and Flyin' Miata both have them as well as other places. They make an enormous difference in ride quality.

 

I ran across ISC in a couple of the threads and talked to the owner yesterday. I may need to go that way. Thankfully, they are in the next county over from me. They offer the option of custom increased height of the shock mounting point for additional shock travel as well.

I agree on the bumpstops but haven't ordered any yet. I'm thinking if I end up with the ISC tophats I'll probably want to measure allowable travel distance to determine bumpstop height. Especially if they move the bumpstop location higher. Good idea or no?

 

A complete set with all the bushings and washers?

rest the sleeve on the perch.

200-250

stock bilstiens can handle a 500/300 combo...

 

Get the right ebay kit with the aluminum top spring locator instead of the plastic one. Send it to me and I'll machine it into a perch which you can press fit the threaded collar into.

 

That's really stout. That would probably be overkill for my needs.

So you take the piece that would normally be the top spring mount and machine out the hole to fit over the shock body or over the threaded collar? Like these:


What's the benefit of doing it that way (I'm feeling dense)?


EDIT:

I was actually looking at some like this and wondering what the o-rings were for, and wondering if they used set screws to hold the threaded collars in place on the shocks (it looks like there are holes in the threaded collars in the pic).


Why would I need to machine perches when it looks like the spring just sits on the adjuster?

 

I literally rest mine on the perches....

 

Not much over what you've got (pictured above).

I thought you had a full NB suspension. The NB perches are angled for the open ended springs, as well as thicker and higher in the center. This causes you to miss out on about 1.5" inches of adjustability on the collars, as well as requiring you to cut the collars to clear the top of the shock body.

They are a pain to get off as well.

Your flat perch could be machined just as easily, and would actually be superior to my collar retainer ring, as it would use an internal retainer, giving another 1/2" of adjustability.

 

I do have the full NB shock assembly, complete with the angled bottom perch you speak of.
I figured out something from Brain's pic.
You guys aren't needing to remove the bottom spring perch anyway because you are using shortened springs and it isn't in your way.
With stock length springs the choice would be to ride high or higher.

 

Stock springs are also too big (diameter) for the adjustable collars. I think stockers are ~3" ID, eBays are all 2.5" IDs. I was assuming you'd use them with QA1 springs or something similar.

 

something like that. the GC sleeve are nice because they rest on an inner notch and extended further down past the cir-clip allowing you to adjust the springs lower than the perch if needed...but you usually don't.

the o-rings fit between the sleeve and shock so it sits centered and doesn't move around...since they just pump out one ID size and shock bodies vary.

 

So the GCs will be a better choice than these, for instance?

 

It just depends...I'm using those without issues.

 

By "those" do you mean GCs or those I've got pictured?

Thanks for the help.

 

He means the ebay ones. He just posted a pic of his setup lol.

I think even with the added travel from the isc racing hats you will still have room to bottom on the bumpstop rather than the frame with NB billies. (I'm not completely sure about that so don't set that in stone) Personally I like really short bumpstops if possible, because I don't like them to interfere with my spring rate etc.

If you are buying from fat cat, give him a call as he will know which stop would work best for you, with testing to back it up. Plus he has a bunch of different sizes and densities.

 

With the 5.5" springs that come with it yes.

Getting a lower perch allows you to run 7" springs, and therefore pick your rates.

 

I'm a member

 

Aha! What rate and length springs did you use?

 

well...

I was running 7" 550/300 on Konis. The fronts on the lowest perch and the rears on the middle.

In the front, at the lowest spring height, I was just around 12.5", I had the spanners maybe 1/8" above the perch, if I wanted to go lower I could have added NB tophats or remove a spanner or both.

In the rear, I think I was sitting at 13" I'd see closer to 12.75" on the lowest perch height but hit bumpstops way too easily. Again, on NA tophats, so if I did NB or ISCRacing or alike I'd have no issues getting a bit lower.





with that said, if looks like on the front, the bilstein's perch is level with the lowest KONI:



and on the rear, it's level to the middle KONI perch:




so the moral of the story is, add NB tophats and you'll be fine.

 

Thank you. I appreciate the additional information and the effort you went to to find the pics. I'm going to order the ebay coilovers for the adjustability and then work on selecting the right springs for my situation. I have swapped to the Bilsteins all the way around now and have the NB tophats up front. The rears still have to come back apart for the switch to the NB tophats in the rear.

I must reiterate just how much difference there is with the change to the sport valved Bilsteins even with the stock springs all the way around. I really did hate the car's ride before the swap. The rear bottomed out consistently over any road irregularities or railroad tracks. The left front shock was blown and leaking oil and would float over interstate heaves and falls. When cornering on the autocross track, the rear end would try to come around very easily because it would hit on the bumpstop and the effective spring rate would go through the roof.

I didn't realize how bad it was or how good it could be with just a proper shock change. I know that the addition of height adjusters, proper rate and length springs, and properly chosen bumpstops will only enhance the experience.

I took the car for a spirited drive down many roads with a few curves (we don't get many curves in this part of the state) with my buddy chasing me in his turbo 350z. While he was much faster in anything close to a straight line, he claimed to be having trouble keeping up my pace in the big steady-state curves. He has a top of the line Tein electronically controlled suspension and 19" by 10" Volk Racing wheels with idk what kind of tires. I'm currently running stock 14" hollow seven spokes with RS2s.

Sincere thanks for your guidance in helping to make my car enjoyable to drive for a change.


UPDATE EDIT FOR THOSE WHO SEARCH HERE LATER: