Russ359

How long should original struts last? Mine are the original on a 1992 C2 with 45K miles. I was thinking of replacing/lowering. How can you tell is they need to be replaced?

I've read a lot of threads here on H&R lowering springs. Anyone have an opinion on the H&R verses the Eibach's? Car is for street use only but I would like to lower it a bit. Seems a little high. I'm located in the US and I think theyt were raised a bit from what Porsche intended due to US laws.

thanks

Russ

Adrian

Dear Russ,
At least 100,000 of your miles. If they fail they leak fluid, they make horrible sounds and your handling starts to suffer. The first sign is normally leaking fluid.
US 964s are 10 mm higher than ROW versions and use different springs. My advice to you is to purchase a set of ROW springs. This will lower you 10 mm and then you can add another 5-10 mm by spring perch adjustment.
I do not like progressive springs on the front. The H&R lowering springs and the Eibach Pro-kit (US version) use progressives up front. I use Eibach linear springs. However it is purely personal.
Ciao,
Adrian
911C4

horst

Adrian: I like the idea of ROW springs, and adj perches. Sounds like a inexpensive way to go. BUT: would this not perhaps cause strut failure? By doing this the struts assume a different position, and in a 10+ year old car, isn't this likely to provoke a leak / failure?

UMP

I've got a set of Bilsteins that I used on my C4 for about 1,000 miles. Too stiff for my taste. I think I paid a gazillion bucks for them. I'll sell all four for $1,000 total + shipping.

Drew_K

You can buy a new set of Bilstein HD's for around $650. UMP's Bilstein's must be adjustable, custom valved, or OEM.

UMP

Or maybe I got ripped off. I'll check the serial number and get pictures. They mentioned Carrera Cup suspension. Sways and shocks. As far as I know they are non-ajustable. Normaly I'm not this stupid regarding cars, it's something I did several years ago and ended up racing an E36M3 for several years, so I forgot about the Porsche part specs.

Arnold

"at least 100000 miles" Wow! mine didn't last 60000miles.
Arnold
90C2 137000kms

UMP

Can anyone tell what these are? They were on my car for less than 1K miles. <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" />

<img src="http://members.roadfly.com/ump/Dcp00074.jpg" alt=" - " />

Jim Michaels

They look like the Bilstein HDs that are on my car.

Jim Michaels

Russ: Although the OE Boge shocks sometimes leak and fail suddenly, they also wear so gradually that it is difficult to tell when they have worn enough that they are no longer providing good dampening. Because I track and autox, I replaced the OE Boge HD (come with the M030 sport suspension) shocks with Bilstein HDs at 45k miles. There was a noticeable improvement in dampening, and the thump I used to sometimes hear in the left rear in slow corners was gone. I also have the H&R lowering springs, which lower the USA 964 just right for street; about 1.25-1.5". They are progressive, which I like for the street, but stiffer linear rate springs would be better for the track or autox. The Bilsteins should give much longer wear than the OE Boges.

Drew_K

We'd need the part numbers to be able to tell. You mention "Carrera Cup," so these may be the shocks from the RS or Carrera Cup suspension. If that's the case, the $1K price sounds about right because these are only available from Porsche as far as I know.

I recently had the original shocks replaced on my 92 C2 with 68K miles. They were pretty worn out but not to the point of causing any handling problems. As Adrian pointed out, check for leaks. Otherwise it's pretty hard to tell when the shocks are worn out.

Russ359

All,

Thanks for the input. I'm leaning toward replacing the struts with Bilstein and the H&R lowering sport springs. Jim is that what you have? do you have part numbers? have you had any negatives to your set up? Clearance issues or ride too harsh?

How is that set up diff. than H&R coil overs? seems for what I want the lowering springs and replacement struts should work.

Jim Michaels

Russ: My car (a '93 RS America) came with the M030 sport suspension standard. The H&R lowering springs I have are for the RS America. They are a little bit stiffer than the H&R springs for the non-M030 equiped C2. They worked well with the OE Boge HD shocks, and they also work well with the Bilstein HD shocks. The only negatives I can think of (other than spending money, of course) are having to be more careful entering driveways, less clearance for grabing the tire and shaking it to check wheel bearings, and having to lift my old hulk up out of the seat another 1.5".

The H&R springs for the RS America are 250-275# front and 270-295# rear, while the H&R springs for the regular C2 are 190-255# front and 220-265# rear. I do not consider the RSA H&R springs too stiff for street. I think they are just right for me. Your butt may vary. I don't have the origional parts numbers for the springs because they were on the car when I bought it. The Bilstein HD shocks parts numbers are: left front, V36-0384; right front, V36-0385; both rears, B46-1547. I paid $639 for the set last year.

The H&R coil-overs are a hand-built coordinated system with similar spring stiffness (250-285 front; 265-285 rear). They have adjustable lowering from 1 to 2". They are a fine system, so I've heard, but they are a bit more expensive (like about $2k retail). There are also other options; the RoW M030 suspension is one, and I've heard that a PSS-9 suspension system popular for the 993 is now also available for the 964. In short, there are a number of options that you might like, but I'm only familiar with the one that I have. Remember that the suspension (springs, shocks, sway bars, and even wheels and tires) is a system, and you want to have the various components to be happy working together, so you might also consider an adjustable sway bar to fit the system you choose. I've got the stock bars are each end, but they were the somewhat thicker bars that came with the M030 suspension. There is a saying that you can't just change one thing. Good luck.