Koni shocks / stock springs?

[Kev_T]

I'm brand new to the joys of MX5s, and this is my first post. I've just purchased a lovely low kays NA8 Clubman that's fantastic fun, but needs a few mods to suit me. And I'm sure this topic has been broadly covered heaps of times, so sorry to repeat, but there's just a couple of specifics that I can't find in the archive. The car currently has Koni Sports (8041s) with Eibach springs and, frankly, is too low and harsh for an old fart. So I'm looking to revert to OEM springs with 5X bumpstops, and then fiddle with the Koni's adjustable rebound damping. That seems to get a general tick on most forum posts. However are there any other options I should consider (and I don't want to replace the Konis unnecessarily)? Are secondhand OEM springs OK? Will I need new shock tops and are there options there as well? The car is/will be used for "spirited" cruising and some long distance touring on sometimes indifferent roads, no track use and not particularly hard driving. Thoughts from your collective wisdom?

[MX593]

I have a set of standard length Kings springs that will work well for you. $200 plus freight. They were part of a Koni/Kings set up in my old NA8 and were pretty good on the track and the road. Good height and not stupid low like the Eibach.

[Code4]

New replacement spec. Koni STR.T shocks and standard springs on my NB8A with Fat cat bump stops.
Very, very happy with that comfortable and quiet combo for daily driver duties and the odd squirt through the twisty bits.
Standard springs last forever.
All shocks, even quality ones have a life span. How old are yours ? The shocks I replaced were 180,000km factory fitment and totally stuffed.
If your going to strip out the suspension (not hard to do) you may want to calculate how old your existing shocks are and if it's worth replacing them.

[93_Clubman]

Welcome & congrats!
Some years ago when Konis on NA6 & NA8 were more popular than today, Kings springs were commonly used with them. You should get a used set of King springs for $100 or so. However, you'll need to check the King springs aren't also going to make it as low as the Eibach, which were also a very popular spring on the NA6 & NA8. Re confirmation of NA8 Clubman & other Clubman info: viewtopic.php?f=76&t=30041
I only mention that as a number of NA8 are being advertised as Clubmans, when they're not, due to the lack of advertsing option fields on some selling sites.

[project.r.racing]

I would just get some OEM springs. The Eibachs are normally double the OEM spring rate. Someone will have a set they'll probably give you if you can wait for a response and let people know a location of residence.

[Kev_T]

Thanks for the advice. I'll bear in mind project.r.racing's King springs and check out the going price of 2nd hand OEM springs (pretty cheap I'd assume). Insofar as the condition of the Konis, the car itself has only done 100,000ks so they're almost certainly younger than that (which begs the question as to why the original Bilstiens weren't satisfactory...but who knows). And thanks 93_Clubman for the interesting link, I'm confident it is a genuine Clubman..it's got original papers, L/S diff, no P/S, and dealer-fitted A/C, but I'll contact Mazda for further verification for when/if I decide to sell it (not in the near future that's for sure!!).

[pcmx5]

The Clubman had a very stiff combination of springs and shocks standard,just about needed a kidney belt .The best I had on my NA6 and NA8 were standard (not Clubman) springs with Komi adjustables.I went the Eibach route but also found they drooped and I was hitting the underside on secondary roads.I tried Kings as well and hated them and cannot understand why they are so popular.
Buy some second hand NA6
springs and use your Koni's. Good luck ,

Peter.

[93_Clubman]

Yeah, the NA8 Clubman originally had Bilsteins & NA8 standard springs, which were poorly suited to each other for city & suburban driving. Highway & freeway driving I find them fine. Following gives an idea of the evolution:

Early NA6 164/97 lb/in with 19/12 mm sways
Later NA6 154/94 lb/in with 19/12 mm sways
Std NA8 154/94 lb/in with 19/11 mm sways
USDM NA8 R package 154/94 lb/in with 20/11 mm sways, but that might have been the US version only
All NB 162/118 lb/in with 22/11 mm sways
NB Mazdaspeed 215/158 with 23/14 mm sways (presumably the same on the AU delivered SE?)

Just going on those figures alone the first model NA6s had the sportiest handling (lowest FRC of 58.9%) then they got progressively worse from there until you got a Toyota Corolla-like 66.9% with the stock NB.

PS divide lb/in by 55.88 to convert to Kg/mm

MX5 sway bar sizes with some slight variation:

NA6: 19mm Front & 12mm Rear (except on the 1993 NA6 red LE which were 19 & 11mm - note USDM 1993 NA6 red LE had Bilsteins which ADM didn't so variation may be possible)
NA8: 19mm F & 11mm R (USDM standard Packages: 19mm F & 11mm R)
ADM NA8 Clubman w TorSen & Bilsteins: 20mm F & 11mm R (USDM NA8 R Package w TorSen & Bilsteins: 20mm F & 12mm R)
NB8A: 22mm F & 11mm R
NB8A 10AE w TorSen: 21mm F & 12mm R
NB8B: 22mm F & 12mm R
SP: 22mm F & 12mm R
SE w Torsen: 23mm F & 14mm R
NC1: 21mm F & 12mm R
NC2: 23.5mm F & 11.5mm R