M474

[Dave L]

I am looking to replace the 18 year old struts in my '88 944S. I have recently found out about option M474 that use Koni shocks and may also have stiffer springs. Does anyone have a reference for what option m474 includes?

Looking for a way to upgrade yet still stay in a stock class

[Zero10]

I have M474. It is sort of half-way between stock and M030. It has Koni yellows, but I am not certain about the spring rates. IIRC it also involves larger torsion bars for the rear.

My M474 Koni's are worn out. I get a lot of bounce when I hit bumps, and there is almost no dampening. However every parts place I call knows nothing about them, and won't give me replacement cartridges for them

[OnTheRun2]

Originally posted by jwade944
The two yellow dots indicate a spring rate of 21.8 N/mm (1 N/mm = 5.71 lb/in) The wire diameter is 12.0 mm. The free length is 396 mm. The spring force is 3118-3202 N at 251 mm compression. These are the middle tolerance springs - between the standard and M030 groups. Porsche made each group of springs the same and then placed each spring into a tolerance group based on tests. These struts and springs were offered as the M474 option on the 944S and the springs were standard on the 1986 through 1988 951.

This was taken from the classifieds here on pelican on the '944 struts' thread.

[Dave L]

the ad is what started me on the quest for more info. If I upgrade to Option M474 then I need to be sure I have all the parts, springs, struts, sway bars. I cant find much infor using google, so am looking for info on what M474 entails.

Zero10 this is for you;

http://www.ianseuroparts.com/cgi-local/ASI_Store.cgi?Product+skukey_20052106+DailySpecial s+

[Zero10]

Holy cow, $1200US..... I think I'll live with bad struts for now
The rears are Bilstein HD's, and are very recent. For $1200 I could put on a really nice coilover setup on the front with stiff springs.

Funny how m474 is more expensive than M030, even though it's worse

From what I have read, M474 is only different shocks, springs, struts and possibly torsion bars. Unlike M030 where the sway bars and spindles are different. If you are interested in M474 you would need everything I listed. For the cost, you might as well go with a proper coilover setup.

Somebody correct me if I am wrong.

[Dave L]

I think the kit is expensive because it comes with the strut. I have also seen instructions on how to modify the strut housing to accept the Koni inserts.

I think the $1200 is out of the question. However picking up used bits and pieces may be the way to go. I could upgrade to coil over but I think that would put me a prepared class where I would get killed; even more than ussual.

[Zero10]

Ah yes, racing classes. If that's the case then M474 is for you

I am interested in modifying the strut housing to accept inserts. However with the cost of a lot of inserts it still might make sense for me to go to a coilover setup.

[Dave L]

More info (in case someone searches) from jwade944

Tom Pultz posted this information on Rennlist in 1998:

3 white dots indicate a spring with part no 951 343 531 00, which is a 944S with standard shock absorbers. It has the following properties:

Spring rate 21.8 N/mm.
Wire diameter 12.0 mm.
Free length 407 mm
Spring force 3445 3535 N at 251 mm compression (highest tolerance group)

2 yellow dots indicate a spring with part no 951 343 531 01, which is a 944S with M474 Sport (gas) shock absorbers OR 944 Turbo up to MY '88 with standard and sport type shock absorbers. Properties are:

Spring rate 21.8 N/mm.
Wire diameter 12.0 mm.
Free length 396 mm
Spring force 3118 3202 N at 251 mm compression (mid tolerance group)

The two springs have the SAME nominal spring rate, but the M474 spring is shorter and actually has less spring force at the same compression distance.

Not what you wanted to hear, but I hope this helps.

[95186]

Originally Posted by OnTheRun2

This was taken from the classifieds here on pelican on the '944 struts' thread.

This is not true. Option m474 was not standard on a 86-87 951.

[guru944]

Front/rear Koni sport struts upgrade works well. Recommend the conversion. Also Gabriel new rear shock works well. All for under$ 750-550
Later.

[9FF]

iirc you have two choices with M474. Send them to Koni for a rebuild or cut them open and mod them to fit the Koni inset. The Koni inserts are less than $400 for the pair, you will have to check with a koni agent for the cost of a rebuild.

As for springs you can further mod the struts to fit a coilover sleeve and choose any spring rate you want. Don't bother even calculating stock rates unless you have a class restriction, the highest rate fitted to our cars was iro 160 lb-in and that is much too low for today's driving style.

[mhariush]

You can also get them rebuilt at TrueChoice Racing Service. I did mine and they came back factory spec and look.

This is the quote I got from them initially "The cost is $170.00 each plus parts. The parts are usually $30.00 to $40.00" But the final price was higher. But still cheaper than buying new ones. And they're factory spec and OEM, if that matters to you...