Hello. I am fairly new here at Rennlist, and I have learned a lot already from you all, but I have so much more to learn. I am enjoying the process, and spending time here at Rennlist has enhanced my ownership experience of my Porsches, and has provided a nice "boost" to my mechanical knowledge.

Addressing the topic at hand, I have been thinking about upgrading the stock suspension of my 1990 S2 to match that of my 1989 951 with the standard M030 package. Although the S2 is my daily driver and I have enjoyed its excellent balance between comfort and sportiness, I dream of taking the S2 on the twisties with the same level of handling as I enjoy in my Turbo S. I am willing to sacrifice comfort in my S2 for the improved handling the M030 specs will provide.

I would like some advice from those of you who are knowledgeable in this area, and would especially appreciate the comments from those of you who have made this upgrade to your stock suspensions.

Thanks,

Jonathan

 

Mmmm, twins!

First, let's establish what's different:

- Bigger front brakes
- Heavier front and rear springs
- Koni Shocks and Struts
- Adjustable front ride height
- Control arms

Brakes aren't too hard, but largely unnecessary. The S2 brakes are quite good. Usually, performance pads will give some real bite if there is worry in that department. The new Pagid Sport pads are quite streetable but have some very potent stopping power on tap.

M030 springs are up a bit in front, but not too much more than 20#. The problem is that the rear springs (torsion bars) are 24.5mm (S2) where they would need to be 25.5mm (951S) to mate effectively with the front springs. Torsion bars are a big deal for most - or, at least a big shop bill. If you're going to that trouble to update, it would be wise to upgrade. Maybe jump to 28mm. Then, you can use even heavier springs in front - say 250-300#.

New M030 struts are NLA. If you find some used, they likely need to be rebuilt ($150/ea plus shipping and wait time). The option to get a Koni Sport in there and also emulate the M030 ride height adjust is to use Koni 8641-1414S with an aftermarket Adjustable Ride Height Kit (threaded sleeve and collar similar to M030 but uses 2.5" ID spring) - estimate ~$600 for this complete if you do the work yourself.

Another balanced suspension option that leaves the torsion bars alone, increases the front rate and reduces ride height is the H&R lowering springs (progressive 195-235#) mated with a larger rear sway bar like the 968 M030 19mm adjustable one. This saves you money in both parts and installation (no torsion bars to do) but still upgrades the effective spring rates nearer to the 951S.

The front control arms on M030 cars aren't really much different and are basically unobtanium. The best idea up there is to just update the caster mounts to 968 type (less rubber and relatively inexpensive).

Sway bars should actually be the same at 26.8mm front and 16mm rear.

Good Luck!

 

Thanks for your thorough response, Skip. Very informative! I am looking at the products you have mentioned at the Paragon website, and I will probably be in touch with you next week.

 

To illustrate Skip's great post, here's Karl Glynn's "M030 Suspension Conversion Page" with diagrams and part numbers of everything:

M030 Suspension Conversion

 

Wow, thanks so much, Luis!