Tiger2

I have a question on the 968 M030 rear shock option with the helper springs.
Were higher than 60lb springs available for these rear shocks? If so can they still be sourced?

Thanks
ken

Oddjob

Ken,

As far as I know, there is only one barrel spring that was available 951 333 531 31. That is the only part number shown for the 968 M030 rear shocks and is the same part number as used on the '86 951 Turbo Cups.

There is some variation in what the spring rate supposedly is. I have read anywhere from 60 to 80 to 120 lb/in.

I never tried it when I had the set, but you could pull the spring and stack weights on it to compress it. Will need to find a way to stabilize it, but should be able to keep it standing while placing enough weight to compress it a couple inches. Because of the large change in coil diameter, it will have somewhat of a progressive rate, but probably can get a feel for whether its closer to 60 or 120.

FRporscheman

I have a pair of Eibach coil springs for the 968 m030 rear shocks, I forget but I think they are 90 lb/in. I'll double check the stiffness. They're for sale, PM if you're interested. I don't know if they are still available or not, I got them used a long time ago.

951Saga

Arash, if Ken is not interested please send me a PM with your price shipped.

FRporscheman

The part number on the Eibach springs is 0800.225.0150 which I believe translates to 8" long, 2.25" wide, and 150 lb/in. They are cylindrical, not barrel shaped, and painted red from Eibach.

Jason, got you 2nd in line.

FRporscheman

I might be wrong on the translation of Eibach part number, it's just a guess. I do know they are a step stiffer than the factory springs, and my notes say the stock springs are 120 lb.

Oddjob

The springs you are offering are just standard linear coil springs, nothing specifically made for the 968 M030 shocks (?)

I think an 8" spring is too long to fit. Might be able to use a 6" spring. Perches will probably work w/ 2.25" diamter springs. But dont want to get too carried away w/ spring rate, since the shock valving will not be setup for a significantly higher rate spring.

Makis

From the pictures above I would say the Koni barrel spring are definitely not 60lb springs. They look more like at least 120lb springs to me or more.

Eric_Oz_S2

With regards to the m030 barrel springs, what is the dia of largest and smallest coil and what is the wire dia and spring length? With this (if anyone has the info) I could calculate the spring rate range. I doubt they are 120 lb/in, suspect less.

Tiger2

Porsche rates them at 60 pound.

951Saga

So the ’86 TC cars came with rear barrel springs and nonadjustable shocks while later years were fitted with progressive rate 2.25’ ID springs and double adjustable shocks?

I’m looking for rear springs that can be paired with the Koni DA shocks. Which single rate springs would most closely match the TC spring specs?

I don’t mean to hijack here, just got a bit foggy between the 968 M030 and TC rear setups.

Oddjob

Ken, where did you find the factory info? I have never stumbled across factory #'s for them.

What torsion bars are you using and what front spring rate are you trying to balance w/ the 968 rear shocks?

The '86 German Turbo Cups came w/ those barrel helpers on non-adjustable bilsteins. The handful of '86 Clubsports imported to the US for the SCCA Escort series used the same springs on Koni double adjustables. The front springs were a progressive coil that looked very similar to the welmeister 200 and 250# coils

The 87+ Cups all used the later tapered diameter progressive coil front and rear springs. Probably around a 400 lb/in front spring, 25.5mm t-bars, w/ a 250 lb/in rear spring would be similar to the factory spring setup. But know that the turbo cups did have a tendancy for oversteer.

M030 shock valving is softer than the Euro Cup Bilsteins and the Clubsport/US Escort Cup double adjustable Konis.

FRporscheman

No, I don't think they're specially made for the m030, but I don't know if this size is readily available or not. They are listed on Summit Racing here but are NLA. Ground Control has them here for $69. Either way, they're standard linear coil springs, like you said.

They DO FIT on the koni yellow SA m030 rear shocks though! They came installed on a pair of rear shocks that I bought, so they definitely fit!

Tiger2

Oddjob,
My car is a 1990 S2 with an LS1 fitted.
I've got koni adjustables with barrell springs (968 M030) on the back just like your first post picture on this thread above with stock torsion bar that came on a 1990 S2.
On the front I've got koni adjustable shock inserts with 250 pound springs with a ride hight adjustment kit that I purchased from paragon products.
I'd post pictures but can't seem to get it to work

Oddjob

Since you asked about higher rear spring rates, I assume you want the car to have more oversteer/rotation?

Street, Auto-x, or track use? W/ 250s in front, 24mm t-bars (stock S2) and 60 lb/in rear helpers (assuming that is the correct rate) - that is not that bad of a setup. Maybe a little push, and maybe the V8 generates more push than the stock I-4 (?). Does it have LSD? What are you running for swaybars?


I was just clarifying, as I incorrectly inferred from your first post that you had a set of unique eibach springs that were made to replace the M030 barrel springs. Any of the eibach (or hypercoil for that matter) 2.25" ID linear coil springs are readily available from various sources.

I am guessing that you bought that set off rennlist or pelican, probably the actual set shown in the pic below? If they are 8" free length springs, they were compressed about 2" when installed on the 968 shocks. So w/ that much preload, it would require a large change in the t-bar index to keep from raising the rear ride height when installed. I would expect a 6" length spring may be preferred for that shock arrangement.

The scale in this side-by-side pic isnt perfect, but gives you an idea of comparable spring lengths. The Cup spring is 8" long as installed, so an 8" eibach would have a lot of preload and require a spring compressor to install.