964 Cup shocks!!
#1
964 Cup shocks!!
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
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
#4
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!
#5
Technical Specialist
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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.
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.
#7
Instructor
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
Scott
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#8
Burning Brakes
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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!
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!
#9
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.
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.
#10
Burning Brakes
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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.
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.
#11
Originally Posted by SimonExtreme
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.
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
#12
Originally Posted by ThomasC2
You can buy the RS, Cup or RSR from every Bilstein dealer. They are all stock products.
A new set would be great if they are!!
#14
Technical Specialist
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Beware you can't revalve the standard 964 RS Front shocks.