Building coilovers suggestions

[Whoodoo]

Hey everyone, I am throwing around the idea of building my own custom coilovers using evo MR bilsteins. I have already played around with evo suspension, but never really got the ride height I wanted and I was not satisfied with how the springs ended up sitting. I'm also pretty sure I messed up the spring rates pretty badly. Don't get me wrong, the suspension feel improved greatly over the 20 year old stockers, but I was never really happy with the tradeoffs required to make it work.

First of all, I have to give credit where credit is due. Dennis Grant of Far North Racing has put a lot of time and effort into his online book 'Autocross to Win', and it is chock full of very useful information and lots of his own personal insights. If you havent read it, you should. His work with suspension has inspired me to do some of my own.

Here is what I have mapped out to do so far for this project:
1) buy MR bilsteins
2) modify rear bottom mounts like any other evo suspension
3) cut off old spring perches and add a snap ring groove for the coilover sleeve
4) add a schrader valve at the bottom for filling the nitrogen chamber
5) slap on the coilover sleeve and spring, do all the necessary mods to the top hat and pillowball mount

In order to do this, I'll need to source a few items
-bilsteins (~$300)
-schrader valve (~$5 ea x 4 = $20)
-torrington bearings and races (~$40 for all of them)
-coilover sleeves
-springs (hypercoils are ~$75 ea x 4 = $300)
-maybe some helper springs (hypercoils are ~$35 for a set)
-maybe a bilstein rebuild of the shocks need it (~$100)

So, I'm looking at around $900 (depending on how much the sleeves cost) plus some of my time for a complete coilover setup that can potentially be tuned specifically for my own car. Not bad i would say. Here's where i would like some advice. I have looked and looked for decent coilover sleeves that are long enough to use helper springs (7in), but I am unsure about quality and the functionality of the locking mechanism on the bottom spring perch. Most of the ones I have found use a set screw on the bottom spring perch to lock it down. It seems to me like that could potentially mess up the threads on the aluminum sleeve. I would love to find a set that has a second locknut instead, but it looks like you can only find those in the cheap ebay kits which have short sleeves. Can anyone give some insight on the different locking mechanisms and/or give suggestions on where to find good quality but inexpensive sleeves?

 

[Barnes]

Is there enough thickness in the shock body to machine in a snap ring groove? Or maybe I'm not understanding what you are saying. /ubbthreads/images/graemlins/confused.gif

 

[Whoodoo]

The groove only needs to be .032" deep and I cant imagine the shock body is too thin. It does have to withstand a substantial amount of hydraulic pressure during operation. I don't really know for sure though... I hope that doesn't blow a hole in this whole thing.

 

[EMX5636]

This was a message sent to Koni about cutting a ring groove on the miata forum. There is a thread about this topic there.

FYI:

I sent my question to Koni, and got the following response (same day!):

"It is not recommended that you weld on the shock. A groove can be added
to the damper and done at either a good machine shop or at our facility
for $35/each (per shock, not groove). If you have any questions, please
let me know. Thanks.

Gordon"


Then apparently someone called Bilstein too.

Hmm, Bilstein only charges $10 a shock for the same service.

 

[alansupra94]

I know Bilstein does tons and tons more rebuilds/modifications to their shocks than Koni does so that might be a factor.

 

[curtis]

Heres my take on it. Shock bodies are rather thin but may just work the rears are machined this way but cutting then in half is the only way to know. But and here it comes. You may be able to have a sleeve cut that has an external ring cut and is a perfect snug fit up the sturt like the factory evo rears already have. If you do it out of steel your adding weight but could be tack welded to the ears that attach to the hub. Now Afco's factory is in the next county north . Over the years I've scored some rather sweet sh*t from the recycler. Like trash cans full of radiators, cnc cut radiator full necks, aluminum tanks, brake caliper halves etc etc. If I still have them some coilover sleeves. I know I grabbed a few that were just aluminum tubes with square threads cut on them and screw on ends that had a hole for the strut tube. I know I've used a few for catch cans over the years for people but not sure if I have them anymore I'll check after the storm passes.........


Ok I'm back just looked and there gone and since some Mennonite kid got hurt up there at the recycler they don't let anyone outback anymore. But if the ID is close these would be perfect and since they have a top on them no welding required. Let me do some internet searching for you

 

[curtis]

summit

Afco page
click me
home page


Really miss going out back up there. Took Aaron and Chris there during there visit down south and about 2 trips later at the new lot they locked it down. If i could get outback up there I'm sure I could get everything you need for a buck a pound. Scored 125 lbs of stainless bends once all from Dynatech headers, a 5 gallon bucket half full of sch 40 weld bends for my header and various other cool stuff. God I miss that place /ubbthreads/images/graemlins/banghead.gif


Hope the afco site helps with the build but you may be able just to have a machine shop build what you want cheaper and easier than ordering something that doesn't fit on a metric sized strut body. /ubbthreads/images/graemlins/dunno.gif

 

[curtis]

One more thing. Paul bought a set of bilsteins from KC and sent them to bilstein for re-valving. Those bastards didn't even bead blast and repaint. You would think they would at least knock the rust off.

 

[iceman69510]

I may be able to find a picture later, but I used shaft clamps on the bottom my AGX when I made coilovers out of them using Eibach springs and some hypercoil or some other tops (with Tein camber plates).

Shaft collar clamps:

shaft collars

 

[pagosadsm]

I have a 92 Talon. I made coil overs from 1996 3000gt Bilstien HD inserts. I have a thead on www.dsmtuners.com. I also used 3000gt shocks for the rear. I had to do some modds on the strut insert to install camber plates. It is all explaned in the thead.
Rick

 

[Whoodoo]

Curtis,
I saw the afco sleeves on summit before, but the only spring perch locking mechanism i found was a set screw. I am concerned that using a set screw would damage the threads of the sleeve and was hoping someone could steer me towards a lock nut type setup. I know they are out there, but I haven't found any sleeves available seperately with a lock nut system.

 

[tektic]

Anyone know where I can get brackets like this to fit our spindle?

Id love to add 3000gt bilstein HD #R36-5022-H1 inserts to my car too. I Just don't have the 50 hours to spend Like this guy. They did come out awesome though.

 

[vr4play]

From BC. They are $50 ea. part number B-21. That is what I am using to make my custom coilovers. I have KONI race inserts for the front and am having the housings custom machined and threaded. I am using the same insert a guy who used to make coilovers for evo's used to use. Hope it comes out good. The Gordon in the reply from Koni is a buddy of mine and is helping me to get this all figured out. The rears are going to be the expensive part.

 

[tektic]

Do I have to contact them or does someone list and sell this separate?

 

[vr4play]

You have to buy straight from them as far as I know. That's where I got the part # and price from.
BC RACING NORTH AMERICA
1-321-206-6381 TEL

 

[tektic]

BC racing said that their lower spindle bracket is set up for a 54mm shock body.

So here is the shock for the 3000gt

And here is a KYB GR2 dissected:



Now with a little persuasion using a file or a brake cylinder hone what's the chance this bilstein will fit in here?

Also is there a benefit for a longer or shorter springs if they have the same rate?

 

[tektic]

For anyone interested in this topic you should check out the post by Trucho-951. Good read!

click