Race Engine Forum UK

Guys

As some you you know I am currently working on my rear suspension trying t install an original Abarth setup.
In standard 131 suspension the springs are supported by the rear axis/diff assembly. On the Abart the strut bodies are bolted to the rear hub and the springs are supported by adjusting rings in the strut body . This moves the spring upwards. The problem is that on standard 131 the top spring support is a neck (for lack of a proper word) welded in the turret at the wheel arch level. Proper length spring will not fit not this distance and a smallest diameter spring ( big enough for the strut bodies) fits too tight into this neck.


Change one : Th neck has to be cut off to provide wider opening for the spring ( as well as to be wide enough to allow installation of a standard front strut mount - see below) .

The second problem is the rear top strut mount. On standard 131 this element is fitted from the top and far from strong enough to withstand the forces involved in absorption or shocks developed by the suspension of a driving car. In the modified version it has to be supported by a top strut mount which is installed from underneath and will be strong enough to hold the rear suspension Thus this has to be changed .
Change two : the standard top mount has to be strengthened. I plan to put a front strut mount ( installed from underneath to support the spring as well as bold in the strut.

Anybody has any experience or ideas on this type of modification ?


I therefore need the part that goes on top of front shock and bolts to the body front underneath the turret.
An the top cup washer that goes on top under the nut.
I now there is a another type of this mounting (type 2)
These could also be used ( I think ) provided he neck of type 2 will fit onto the top turret opening of 70 mm and the bolt opening on top is large enough to accommodate a nut and a wrench I must use to bolt the shock.

Actually these may be even better , provided :

1/ the distance between the bolts is 90 mm and not 95 as in type 1

2 / the largest diameter of the bottom part is smaller than 130mm .

Does anybody know the measurements and or has any of these parts sapre ? ]

Miro

Hi Miro

stay calm...just 2 small things:

on the 124 Abarth (with similar rear suspension) the rear springs also sit in a turret (thing..) and directly touch the body on top.
I don't know about the 131 Abarth. Why dont you ask Guy Moerenhout if he can provide some pictures?
Or try to find a car which you can inspect and measure?

Be patient with the cutting. In contrary to the "live" axle setup you removed, with the independent suspension the upper mounting points of the rear struts are points that define the suspension geometry and thus should be selected carefully and precisely. Therefore mark some reference points in the body, which allow you to place the modified parts correctly.

Thomas

Here is how i have cut my turrets.

Thanks Thomas and Walezy !

Today's research suggests that what Walezy has done is exactly as it appears on 131 FIA homologation.
Homologation for rear shock travel limiter dated 1 July 1979 shows exactly the same opened up turret as Walezy did.

As the FIA documentation is public domain I am attaching this page.
I have also found a picture of a Zannini 131 Abarth replica . It is based on original abarth diff but BMW suspension arms. This also has a totally opened up turret.
All I am missing now is picture of the Stradale boot showing if there were any modifications of the top part of the turret , or were they using original top strut mounting location and rear arch with turret ( rear wheel off ) to be sure. Anybody has pictures like this or can make them ?

Miro

We are working on developing proper top strut mounts ( probably will use a BMW type with 90mm bolt spacing and diameter of 1200 mm top fit in the current standard turret top and the existing holes.This is still in development.

Miro