Rod Thomson

I need some help from "You who have been steeped in the lore."

I bought a pair of Bilstein struts and now I want to match them up with rears. What I have are 0399 VE3 61258 MO height adjustable struts with stock diameter springs and perches. Cylinder diameter is 40mm. This is where it gets interesting. I have tried to source information on these but I have come up blank. Nada. I called Bilstein USA and they were helpful but their database did not contain a listing for these units. Humm... They told me they were likely OEM units or made for a third party. I called 20th Street and Matt (where I got them) said they were off a local car and that he would have a further look to see if there was anything remarkable about it. He has not gotten back to me yet.
I am wondering if any of you guys might help me pick up the trail? Maybe just to see where it ends.

Rod Thomson

Here is what they look like:

PorscheDoc

Those are escort cups from the look of it. I have seen them in green and silver bodies as well.

Rod Thomson

Thanks Doc,

I figured they might be as the cylinder size was a larger diameter than the Firehawks should be. Still would like to find out where they came from. For my next trick I have to calculate the spring rates and figure out what to do about the rears.

PorscheDoc

I would get the 2.25 spring perches and convert them to run a spring with a lot more spring rate choices. I use to have a damn box of those things around here somewhere......

samluke

I have the perches and lock rings for the 2.5 or 2.25" diameter race springs, plus a whole range of springs if you need them .

MO30 springs were about 150-180lb progressive.


The rear shocks to match are the coilover Cup units with whatever spring rate you prefer. 968 MO30 helpers were 100lb, depending on what you do up front the rears have to be increased accordingly, either by Torsion bar or helper spring.

ehall

I'm not sure what you are running now, but be prepared for a much stiffer ride.

Rod Thomson

I have already installed them and yes, the ride is much stiffer. I think I like it fine. The rear is noticeably softer. The handling is much changed. In situations where I would expect push, I get great tracking. Though I have not had the opportunity to see how the rear breaks out, the car does not feel wag happy under normal driving.

Rod Thomson

Thanks Richard,
You would not happen to know the specs for the MO30 968 torsion bars? I think I will try the factory setup first.

samluke

The T bars on all the late cars MO30 or otherwise are the same 25.5mm for an effective spring rate of 175lb.

968 MO30 added the helpers, as did the Cup Cars. 968 MO30 is a 100lb spring for an effective spring rate addition of 75lb. Cup cars used whatever spring rate they preferred.

968 MO30 also had the 2 position adjustable rear sway bar.

968 used the koni shock, per the picture. Cups used the Bilstein threaded body.

ehall

If you are looking to stiffen the rear, I would move to a heavier spring rather than fool around with the t-bars. You might also look into the 968 M030 rear sway bar.
I ran my Escort Cups without T-bars. I used a 550# rear spring. I prefer a car that is a bit loose rather than tight, so that worked for me, but it could rattle a moler or two!

Rod Thomson

So there it is then: Got to get my hands on some Bilstein K4-BE5-59376H0 threaded body shocks with 100lb springs. Will start with that and see how it goes. Anybody giving some originals away?

ehall

Sure! ...but you'll have to pay for the original cup car.

samluke

I have a spare pair but they are my race spares so unfortunately not for sale. I have springs and perches, 125, 150 and 300lb if you need any.

Rod Thomson

Thanks for the offer Richard,
I'll keep you in mind. I'll look about for a set of used but if it takes too long I'll be buying new. I'm pretty sure I can pick up a pair for 500 or so.