sicoyne

Hi all

This is my first post on here so I hope this question hasnt been asked thousands of times before.

Has anybody ever tried to change their front RS struts to Cup ones. I have been told that they improve the front end compliance over the standard RS items that can be too hard on road surfaces at times.

I have been led to believe they eliminate the bouncy feel of the normal RS set-up.

I think the items are part numbers Shock absorber - left 964 343 509 70 Shock absorber - Right 964 343 510 70...and they are Motorsport parts!?

Thanks in advance

jimq

no answers until you post pictures of your car. Welcome by the way. Oh yea i have no idea

ThomasC2

You can buy the RS, Cup or RSR from every Bilstein dealer. They are all stock products.

kusee pee

sicoyne, you win the prize for 'most specific and technical first rennlist post'! Congratulations! Alas, I am with jimq in having no clue...but rest assured that we are not typical of rennlist and I'm sure an answer will follow with more detail than an original Stuttgart engine-assembly manual!

Bill Gregory

Those are the 964 Cup front shock part numbers.

Fundamentally, you need to match springs and shocks. The RS springs are different than cup springs, as the rates are quite different. The working rate on the progressive RS springs are front=247 lb/in and rear=400 lb/in versus Cup Cars at front=200-600 lb/in and rear=240-800 lb/in.

If you think the RS shocks/suspension is creating too hard a ride, the Cup suspension is not the right solution for you. You can work with a mechanic/specialist or Bilstein directly to revalve the RS shocks to something that works better for you.

tonytaylor

IIRC the 993RS coilovers can be used on the 964RS to solve this problem

ltbrkm3

I have the front and rear Cup shocks with 650lb front springs and 850lb rear springs, and yes they are tough to drive on the street, but at Watkins Glen they are wonderful. Lime Rock however, not so good. Mine are starting to seep and I'll have to have them rebuilt over the winter...unless someone can convince me that they are old technology and I can get better suspension control with something newer......and oh yeah, Welcome aboard!
Scott

SimonExtreme

LOL

It is incredible, this internet thing! Welcome, sicoyne! I wonder where you got those part numbers? I suspect that the person who provided them to you got them off this forum in the first place!!!

Small world!

sicoyne

SimonExtreme.Indeed you did supply those part numbers over on our PCGB forum. Thanks.

I have been told that the Cup shocks have better rebound than the factory RS items. I'm no expert so please correct me.

Have been told that the problem with the front end of the RS is created by cars being lowered a little too much and therefore the shocks dont have enough time to rebound, particularly noticable when driving on the road due to lots of uneven surface.

Do you think that Bilstein could supply the spec/valving for the standard setting to iron out the bounce or am I better looking into the alternatives available...for example KW or Ohlins etc?

The reason I am looking into this is when driving on the road the front end often feels light and then understeers quite badly. The geometry has been set-up recently by a reputable specialist and I have tried altering the roll-bar settings but with no success.

SimonExtreme

sicoyne

IMO, I think you are trying to tackle this the wrong way. From the sounds of it your problems are because you need a more road focused suspension, rather than a more track focused one. There are a number of proven solutions, ranging from the 993RS solution to getting a propritary set up. Do a search on PCGB for recommendations or even ask here!!

The strange thing is, that while I have heard your comments from people, I have never experienced it and I have tried to get the car to do it. I find that under many circumstances the rear is too twitchy, but that is how I like a car. Maybe, the suspension settings I use dial out some of the understeer and I have managed to get total understeer washout on an airdrome. However, it did involve 90mph and a hard 90 degree turn done over agressively.

Now, I am not suggesting you are driving the car badly, just that your current set up doesn't suit your current driving style. You can make the car suit your style, which is common in racing, or you can learn to drive the car differently.

The final thought is whether your current set up is a bit tired because if it is, the handling characteristics won't be good. I have seen this on a few cars. I am fortunate, my suspension is new and has been properly set up, including corner weighting. Whatever you go for, ensure that the car is properly set up after, with full geo and corner weighting.

sicoyne

Simon

You raised a good point there...I had totally forgotten, but my car was never actually corner weighted. I took it out for a drive after the engine rebuild and they never got round to doing the corner weightying just toe-in, camber etc.

Plus I have a feeling that my suspension is tired. I bought the car with 80k khm's on and I have to say the previous had neglected a lot of the car so I am taking a wild guess that the suspension was no exception.

I think a newer set would be useful and possibly get those revalved before I put them on the car.

One of my friends experienced the same thing with his previous RSL, but his Clubsport doesnt suffer at all. I have driven his car a number of times and the front end does feel more compliant and planted than mine on the road he makes the same comments and owned his RSL for 7 years.

What is the cost of re-valving etc?

Thanks

Simon

sicoyne

I have seen the Bilstein part numbers as follows K4-VE3-04891-TL and TR. Waiting for a response from Bilstein to confirm they are the same parts as the Porsche numbers above.

A new set would be great if they are!!

Laurence Gibbs

Beware you can't revalve the standard 964 RS Front shocks.

Bill Gregory

Bilstein in the US revalved mine, although a friend of mine ran into difficulties (don't recall the exact issue) and had to upgrade.

sicoyne

Anybody know if these are the same as the Porsche items?

Porsche 964 Cup – Bilstein references are

V36-59118H0 and V36-59117H0