333pg333

In view of the recent group buy kindly put together by Brian, a few of us are wondering what spring rates to go with? Of course it's a car to car proposition but would you keep the same rates as you currently run? As a real layman's comparison we pushed down on some Clubsport strut pistons (?) and they seemed noticeably stiffer than my KW race struts. No springs.

So do these run a lot stiffer and harsher than some others and therefore do we order less stiff springs?

Also someone else who has the Clubsports in his 951 suggested to ask;

"If you get quick disconnects on the hoses and slightly longer hoses than original the installation is really easy as well."

What does he mean by quick disconnects? Not sure how much longer the hoses need to be either? Can't seem to raise him back on here to substantiate his claims.

Also, would the Clubsports and Motorsports versions necessitate differing rates too?

I'm sure these are very simplistic questions, however being Capt. Simpleton, it is my prerogative.

Brian A.

I spoke with Lex and for a 2800lbs track car with a cage he recommended 800f/900r. He also said there were 3-4 944 track cars local to him and none of them have used the quick disconnect. Installation of the front is very easy with the preferred canister placement is just in front of the wheels well. In the rear he suggested the down bars or cross bars of your cage

CS & MS do not require different spring rates. For the 944 the new Clubsport is the old 2-way Motorsport.

jerome951

With the hose disconnects it keeps you from drilling a large hole through your chassis to pass the canister through for mounting. I wish I had bought that option.

For hose length I'd suggest determining what you need (based on placement location) and see if the standard hoses will be long enough. You don't want a lot of extra hose you have to coil and protect somewhere.

The spring rates that Brian mentioned sound like a good starting point for smooth tracks. I'm just slightly less than that (stock weight) and will probably go slightly stiffer in the future.

CWhaley

Brian,
Thanks for all your efforts on the group buy.

DanR

when the shop worked the numbers on my 2930 951 to get a frequency rating of 3.7 I was told to run 800f and 1050 rear

RickBetterley

I have Moton Club Sports; my 993 ex-club racer has 700/900 lb springs and the car weight is @2975 lbs (this is with a full cage).
Hope this helps someone; the car is fantastic on the track with these shocks and springs.

Larry Herman

You cannot compare spring rates between 911s and 944s. The motion ratio for the rear suspension is completely different and because it is low for the 944 (.65 or .56, I forget which) you wind up needing a much, much stiffer rear spring, like the combo that DanR has.

RickBetterley

Jeez, that's for sure.
I imagine the group buy isn't restricted to 944 owners (or for that matter, 911 owners).

333pg333

Thanks for the info guys. There's some good stuff right here. I don't have the fighting weight of my car for next season yet, but springs are springs. They can be replaced. If I'm going to be lighter than the 951s posted, would I go a lighter spring (apples for apples)?

Rick I'm sure Larry was only referring to 944/51 owners in this particular case, but feel free to answer for the rear engined guys too. The rates are quite different but you don't want the effective rate to finish 1:1 either. It needs to be up in the 1.5:1 to 2:1 region on the front engine cars. Larry, it's actually 42.5% from memory. Another 951 racer that I know runs 900 / 1000 which works out at 738 / 465 at the wheels.

IcemanG17

I know the 928's have a VERY high motion ratio...some guys are running 2000lb front springs

333pg333

2000!!! WTF!!

Larry Herman

I was.

That sounds really soft in the back. I can't see how it wouldn't sit down in the rear under hard acceleration.

HJK

Using 110/220 n/mm (600/1200 lb) springs on my almost 2400 lb (1060kg) 944 and I do feel the front could use a bit more, so DanR's numbers are not that strange to me. Will wait for the CF fenders and bumper and then re-assess. Have fun with your moton's.

"So do these run a lot stiffer and harsher than some others and therefore do we order less stiff springs? "

I dont think the shock stiffness/hardness affects spring rates, only the weight transfer time and the setting.

H

Van

DanR's ratio looks correct. I'm just surprised by the high frequency #s. I'm running just over 2 Hz. (But Dan's faster, so there might be something there! )

333pg333

Ok so what do you throw into the mix before coming up with your own personal recipe?

951
approx 2600 wet no driver
Wide body = wider track. ie 315 f / 335 r
Lowered as much as the wheels / tyres allow.
Power = plenty
Aero = some, but I have no numbers. Decent splitter and rear wing.

Oh, with this point about getting quick release and longer hoses, the thought occurred to me, if there was nothing in the rules to ban it, why couldn't you have all four adj cannisters dash mounted or within reach of the driver? Dial as you drive? ....Ouch, that hurt. Stop throwing rotten fruit at me....it's just an idea on a forum.