Well, although we often distinguish the difference between the Porsche stock suspension and the Porsche sport suspension as a matter of spring rate and/or progressive rate vs. linear rate, there appears to be some empirical data that suggests that perhaps the M030 springs may not be progressive at all...or at least the data does not clearly show a progressive spring rate response during test.

I did a quick search and stumbled upon this testing that compared the springs for the 996 stock suspension and the 996 sport suspension. Although the 993 spring are probably different with regard to actual numbers, I suspect the principles illustrated in the article might equally apply to our suspension discussions here.

I'd love to hear from those that have actually tested the 993 springs to find out what the data actually showed so that many here can make a more informed choice between the two. Any takers?

Here is the article: http://www.pca.org/panorama/sample_article_3.html

 

A superb read!

Gerry

 

US M030 springs are linear by design and coil layout. I dont have actual spring rates, sadly. Martin S. does, IIRC.

 

I would expect US M030 springs and ROW M030 springs to respond similarly--i.e. same spring type (linear/progressive) with the same general spring rate. Chris, are you suggesting that US M030 springs behave differently than ROW M030 springs?

 

I get some ink at the very bottom for editing..what a guy!

The 3 authors of that article are to be commended. Russ Dickerson and Bob Gagnon really understand mechanics as most of us wish we did. Mike Schatz, a wonder wrench and also owner of Schatz Motorsports, a great place for Euro parts. Both Bob and Russ have had many articles in Panorama. These guys know their stuff.

I have personally tested the stock springs ( before I threw them in the dumpster), and the M030 (YS). They are linear, NOT progressive. The 993RS suspension IS progressive.

I have my data in a pdf, Excel too, too large to attach..drop me a PM if you want a copy.

 

Stock 993(C2) front wire is 11mm, non progressive

the corresponding M030 wire is 8/11.1mm progressive, rates are 150/200 lbs/in(I can't verify the spring rates from factory docs.)

stock 993(C2) rear wire is13mm non progressive, M030 is 13.5mm nonprogressive

You can tell by looking that the M030 are progressive front, linear rear
These are RoW M030 f/r

 

How to resolve these two points of view?

 

I get my dat from factory docs and measuring my old M030 suspension

 

Man, I wish I'd saved my old springs :-)

Bill - were your old springs US or RoW?

 

RoW

 

So the RoW M030 springs are progressive and the US M030 are linear?

 

Good reading

As I mentioned before in another post, there certainly IS a difference in ride height between the US m030 and ROW m030. Not saying that this has anything to do with spring type BUT it does show that even in the m030 spec, there are differences between the two AND that opens up the possibility that other specs are different. Not 100% logic I know BUT it certainly leads one to think that there can be differences even in the sport spring package.

Just a thought

 

If the spring diameters are constant from the top of the spring to the bottom, I'd guess they are linear....I don't have the springs so I can't really recall. I always defer to Bill.....he knows more than me about these things.

 

US 993 M030 are the same as US & RoW 964 C4 92-
RoW 993 M030 are the same as US & RoW 965 T3.6

Ride height at the front is a function of adjusment, ride height at the rear is a function of shims.

 

Very interesting. Are the US 993 M030/ US+RoW 964 C2 94-up progressive or linear?