Originally Posted by ninefiveone

Are you alright? Lots of rage and anger. I know the history of the 917 very well. Actually I know the history of Porsche really well, too. I can talk all day about any of those guys if you like. Do some research on the 917 and it's development. It's a really interesting story and while Andial has a place in that story, there's a pretty specific scope to it. If you want, I'd be happy to talk about it but not if you're going to have that kind of attitude. It's also completely irrelevant to this thread.

I've been doing this for years. owain, 333pg333, and porschefile are on target.

Originally Posted by 333pg333

It seems that many of us are forgetting the shocks and more importantly how they're valved. You can run high rate springs that will make life a lot of fun on the track but aren't teeth rattling on the road. It's just a matter of finding something that is more advanced than 20-30 year old Mo30 technology or similar to it. The days of stiffening up your suspension to go racing, but impossible to drive anywhere else are a thing of the past. Just do a bit of research and you'll find that some of us have their cake and they eat it too with lots of Ice cream! Or should that be Gelato, Rob? lol

Originally Posted by RolexNJ

And as we say in Italiano, molto bene gelato = very good ice cream.

Originally Posted by tommo951

Oh dear the Mafia is in! Next Rob will be singing "my way"!!

Originally Posted by owain

I have 250# springs on height adjustable coil-overs on the front and 28 mm tbars in the rear with 968 M030 swaybars both. With 225 tires on the front and 245 tires on the rear and the rear swaybar set at the middle position I get very neutral handling bordering on slight oversteer. Very good for autox. It's also not at all harsh on the street. A good compromise, in my opinion.

Another setup I'd like to try is with ~300# springs on the front and the same size tires all around. A bit more front-end grip and hopefully similarly neutral handling. I have no experience with that, though.

As was pointed out you might want some lighter wheels for autocrossing. You can probably pick up some 8x16" sewer lids pretty cheap and they're a good strong light forged wheel. They're not very expensive 'cause they're ugly and no one wants them . Unfortunately 8" is as wide as they come, but maybe you can find a couple of sets of club sports for a decent price which came with 9" wide rears and are essentially the same design of wheel. Set them aside until you can afford some r-compounds to put on them, then watch your times come down.

It might seem obvious, but sometimes it helps to put these things into words: a heavy wheel takes more energy to accelerate, and that's in all directions and states. More energy from the engine to speed it up and more force from your brakes to slow it down, but just as importantly more energy from your springs and shocks to arrest and deal with upward movement due to bumps in the road surface. All else being equal, the lighter the wheel (actually, the lighter the sum of the unsprung components) the suppler the ride and the more control over irregularities.

Good luck!

Originally Posted by SimonK

And i got to wondering what stock 951S springs are in lb?

Originally Posted by cincy944

Anyone know how to convert from N to lb, spring rate? Spring rate for 951 front springs is listed as 3286 N. I think it should be somewhere in the neighborhood of 160 lb, but not sure.

Originally Posted by SimonK

Thanks 4 the conversion Trucho-951. But 4 anyone who wants to know precisely... here is the confusion...

Originally Posted by Oddjob

The info on Clark's page is incorrect (related to spring rates).

The factory info page listed above shows groupings/ratings for the tolerance groups - which are then paired and marked (the number of colored dots on the springs). Those are not the spring rates. The factory is listing the force it takes to compress the spring to a length of L1 (i.e. 251mm).

For the first part number shown, the first tolerance group (single yellow dot) is in the range of 3034-3150 Newtons to compress the spring from 396mm to 251mm long. So it takes between 3034-3150N to compress the spring 145mm. 3034/145 to 3150/145 = 20.92 to 21.7 Newtons/mm = 119 to 124 lb/in. I recall the nominal rate for N/A, S, and Turbo springs (non-M030) is 21.8N/mm which equals approx 124 lb/in.

The M030/Turbo S Springs are nominally rated at 28.0 N/mm, which is approx 160 lb/in. The actual tolerance groups shown are 27.9 to 28.9N/mm (160-165 lb/in) and 28.9 to 29.8 (165-170 lb/in).