Geoffrey

The HR Spring rates are as follows:

EDIT: The editor keeps kicking out the spaces. Sorry for the hard to read tables. It looks correct in the editor.

Lowering Springs - Progressive Rates
C2/C4 front 190-225 rear 220-265
RSA front 250-275 rear 270-295
Turbo front 230-265 rear 280-320

Coilovers - Progressive Rates
C2/C4 front 250-270 rear 265-285 year 89-90
C2/C4 front 250-285 rear 265-285 year 91-94
Turbo front 260-285 rear 275-320

Stock spring rates **
89-91 C2/C4 front 158 rear 189
92-94 C2/C4 front 169 rear 189
91-94 Option M030 front 169 rear 263
93-94 RS America front 169 rear 263
91-92 Turbo 3.3 front 169 rear 263
1992 Carrera RS (European) front 247 rear 440 Progressive Rate
1992 Carrera Cup USA front 247 rear 440 Progressive Rate
Carrera Cup Racing Car front 200-600 rear 240-800 Progressive Rate

** The above stock spring rates were compled by someone else, maybe Bill Gregory, I can't remember.

The Koni adjustables are gas not oil like traditional Koni shocks

Bilstein HD shocks are designed for stock spring rates, the sports are designed for upgraded springs. Unfortunately, the sports don't seem to be available for the 964. You can see the varied spring rates, particularly in the rear where one damper is available. This may result in less than ideal dampening for a particular spring rate.

I have factory M030 and am going to simply install the lowering springs that were on my race car when I bought it. They are Red with no markings. I have been in a C2 with M030 and Red H&R springs and thought it was about right for the roads here and the ride height visual was nice.

kgorman

I recommend the Bilstien H&R setup for a mainly street, sometimes track setup. DIY install is pretty easy, check out http://www.porsche964.co.uk/technical/jclowering.htm for a HOWTO.

For just track work, I have been very very happy with my JIC-Cross setup. I think my spring rates come out to 580f 800r or something close to that:
http://www.pelicanparts.com/catalog/..._pg1.htm#item2

I did the install myself on both sets, it's fairly easy. You should have a large breaker bar ready for those rear lower bolts. Once done, go get a good alignment and corner balance.

MassGuy

Thanks for the link I will read up on it....

Mike_964

Like Geoffrey I also have the M030 suspension, and I where also considering the red HR lowering springs with the original shocks/dampers.
The car can still perform well on the german autobahn at topspeed so neither the shocks or springs are finished yet, but I would like it a bit stiffer for the track days.
I know that it would be best to buy new shock/dampers as well, but frankly I just feel that I have spend so much money on the car the past year so....
I would of course still need an alignment and a corner weighing.

JasonAndreas

If you use the "code" command then UBB willl leave whitespacing intact and display text with a proportional font.

The Bilstein HD and Sport were valved exactly the same and for stock rated springs (not M030/Turbo/H&R Red). The difference was in the length of the shock body or shaft. I can't remember exactly which one and I can't find the email I received from Bilstein.

ilko

Slightly off-topic but relevant: Does anybody have the part numbers of the two hex bolts that connect the bottom of the front shocks to the wheel assembly? I know they have to be replaced with new ones when installing the suspension but I can't find the part numbers. Any help will be appreciated!

Geoffrey

900.067.310.09

fore!

Anybody want to swab a set H&R reds for a set of H&R greens? I find the reds a little tough on the roads (rock pits) of Houston. No wonder there are so many SUV's here...

dougn

for what it's worth.....i installed the H&R greens and the bilsteins but first had the shocks re-valved for more rebound damping. i felt the front end was too bouncy so i had the rebound increased another 12 percent on the front only. then i thought the front end was still too stiff compared to the rear so i intalled some 200lb/in 2.5 inch diameter springs from hypercoil. this required some custom parts and some mods to some existing perches.

i like this set-up very much so far. the car feels more balanced front to rear. compared to the H&Rs that were on the front, the car feels like there's weight in the trunk. it handles good during normal semi aggressive driving. i haven't pushed it real hard yet.

BTW I have the H&R rates at 190 to 255 front. since i could really feel the difference, I can tell for sure they (the H&Rs) were greater than 200lb/in

delftvanp

Hi Brian, I have a 1990 c2 and ordered h&r sport springs from pelican parts.
I also dropped the engine for a clutch replacement and to fix some oil leaks.
I live in Doylestown and are welkom to stop by for advice, Paul

DWS964

Can you provide some pictures and details on how you modified the perches to allow use of the Hypercoil springs? What length springs did you use? This approach makes a lot of sense to me. In fact, I have a good selection of 8" and 10" coil over springs left over from my previous endeavors in street rodding.

Darrell

dougn

i kept meaning to take pics but i didn't. it goes like this:

you have to make a perch for the top. it's conical with a 45 degree angle. i have the sketch. i'll scan it and load it tomorrow. this is the hardest part

the springs are 10 inch, 2.5 inch I.D. 200 lb

you need the helper springs also. they just take up slack when the suspension is unloaded

you also need the spring separator thing....i forget what they call it

you have to do some lathe work on the separator and the lower perch

if you want to do this we can talk on the phone ...