Monday, July 7, 2008

Bilsteins for S14's

I have been wanting some Bilstein HD's for my S14 for some time. They are super beefy, cheaply rebuilt/revalved and monotube. I ran the PSS9's on my Miata and as very happy with their performance.

Bilstein makes struts for the S14 but they do not import them to the US. So I have been randomly searching around for the past couple of months trying to find struts from other cars that might work. From my research, the S14 is an odd sort. The fronts are REALLY short and the rears are REALLY long. At first I thought I was goning have to go with the A2 VW Golf/Jetta front struts. They are the smaller 30mm shafts.

I was browsing ebay and stumbled upon a set of EVO 8/9 struts and they looked like they might work. I emailed the owner and he measured them for me. As I was awaiting his response I was further searching for pictures of EVO struts and found some pictures of 3000GT/Stealth shocks. Just eyeballing them they looked like they would work. So I called Bilstein in Mooresville, NC and Keith is the man. Within 3 minutes he told me all I wanted to know.

R36-5022-H0 insert

OD 45.8mm (1.8")
Extended Length 480mm (18.89")
Collapsed Length 380mm (14.96")
Body Length 266mm (10.47")

On paper they looked like they would work. So, I bit the bullet and bought a set, here is what they look like compared to my Koni Yellows

Ok, more measurements. I inserted the struts into the my Techno Toy Tuning camber plates, the strut rod sticks up .3" beyond the threaded portion (you can see a mark from a sharpie in some of the pics).

That will be perfect! I know this setup may not be appealing to alot of folks. There is no adjustablity. However they are cheaply re-valved to whatever spring you may want to run. These front inserts ran me less than $200 TOTAL from Tire Rack.

Well the T^3 camber plates do not allow the shock shaft to articulate but rather bend the shock shaft. I took a steel 7/8" OD, 5/8" ID sleeve bushing about 7mm long and put it on top spring hat. It spaces the tophat down to allows the spherical to do its thing.

To finish things off in the front I needed some coilovers. I purchased a set of Ground Controls when I first got the car 8 months ago but really wanted to get rid of them. I scored a "grab bag" of circle track coil over tubes and collars on ebay for $40

Excellent, I actually got MORE than what is pictured there. I cobbled together the fronts to look like this

The "tubes" need to be around 5" long to sit like I have these sitting.

On the car:

Now all I need is a HD strut for the rear. The rear 3000GT's MAY work with the stock S14 uprights but I have not had a chance to call Bilstein about them. The G35 front struts MAY work with the Z32 uprights but they are kinda pricey at $200/ea.

As crazy as it sounds, Monroe shocks have been a GREAT resource for comparing various shocks/struts. They are one of the few companies to give out dimensions.

Rear 240sx Dimensions according to Monroe Shocks
Body 18.625"
Compressed Length 19.25"
Extended Length 26.625"
Travel 7.375"

Thanks to another assist from NRR member WishIhHadaSilvia the measurements for the 3000GT rear shocks are

F4-B46-1743-H0 rear struts

Extended - 23.48"
Collapsed - 15.63"
Shock Body (from where the piston goes in to the end of the eye ring) - 16.32"

Much like everything else I do in life, I jumped in head first and bought a set of rear 3000gt Bilsteins for my S14.

The first issue to tackle was the lower mounting eye. The hole in the eye is 40mm long and is 23mm in diameter for 37mm and then flares out to 25mm for the last 3mm. The lower mounting hole is approximately 2.2mm bigger than the mount on the 240. I see no reason for it not to work by just adding a metal bushing to take up the extra space.

First things first, get a simple 7/8" OD x 5/8" ID steel bushing from Lowes racing supply and drill it out to 25/32". 25/32"? yeah, not the most oft used drill bit size but my local Napa sold me one for $25Drill the bushing ID to 25/32" and everything slides on like a glove. I pressed the steel bushing in with my 20 ton press but could have easily been hammered in carefully. The fit is nice and tight so there shouldn't be ANY play.

The upper end of the rear shock shaft is the same OD as the Koni/OEM, so no modifications necessary except I decided that I didn't want to risk having too SHORT of shocks on the rear. The total length and body length are roughly 3" shorter than the Koni's. I am hoping this isnt TOO short but I think it will be ok. To help things ourI took all of the extra rod out at the top by using steel bushings from Lowes Racing Supply to space the shaft down an extra inch.

I still had parts left over from my front coilover project, so I just continued the theme on the rear.
That's about it as best I can tell. I'll try to get some more pics of the rear when I put my new rear tophats on next week.

So as a recap parts needed:

(2) F4-R36-5022-H0 front inserts
(2) F4-B46-1743-H0 rear struts
Coilover tubes, collars
Camber Plates
Rear Upper hat with spherical bearing
(2) 7/8" x 5/8" Steel spacers (Lowes Racing Supply)
(4) 3/8" x 5/8" Steel spacers (Lowes Racing Supply)
JB Weld
25/32" Drill Bit ($25 @ Napa)
Something larger than a 3/8" drill bit for the smaller steel spacers.


Anonymous said...

amazing write-up, and thanks much for the honorable mention!!

twistedsymphony said...

This is an awesome write up... I've wanted Bilsteins for my S14 for some time... now it might actually happen.

I've posted a link to this on my local 240sx forum here: