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Old Apr 9, 2007 | 01:41 PM
  #1  
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Default Revalved Shocks Question

I have a chance to get some revalved front Bilstein struts that are revalved for 21mm torsion bars.

I'm going to be using 22mm torsion bars and I'm just wondering if anyone knows if the valving for the 21's will be close enough or will they need to be revalved for the 22's.

I called Bilstein and they are closed today because of Easter. And I need to give the guy I'm buying them from an answer today.
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Old Apr 10, 2007 | 03:21 PM
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crickets....crickets....No replies?

Well...I answered my own question yesterday. The struts were revalved by Smart Racing and they are set to their F10 setting which is supposed to be a Street/Competition setting. And I verified with them that 22mm torsion bars will work. Now here is the new dilema.

I have a set of used Bilstein Ralley/Sport rear shocks that I was planning to have revalved to match my 29mm torsion bars. Steve Weiner had mentioned in another post that these shocks were taller than the Sports...(I don't know if that's a problem or not). However Smart Racing confirmed that they could be revalved and there was no height issue with them.

Now Smart Racing will charge $ 120/shock to set these up to match the valving I will have on their front struts. Bilstein charges $ 65/shock (about half the price). And all Smart Racing does is send them to Bilstein with their own specs. The problem is that Smart Racing keeps their valving specs a secret so that you have to go through them and pay double.

I'm wondering if I just tell Bilstein what I have, if they will be able to valve it so that it is the proper match. I've already called and left a message for Jack French at Bilstein. But I'm impatient and wanted to see if anyone here had any input.
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Old Apr 11, 2007 | 12:45 AM
  #3  
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Matt:

FWIW,...When you pay for custom valving (no matter if its done by ourselves, Smart Racing, or Bilstein) you are paying for MANY hours of track testing/shock dyno work as well as the service itself. Its a trial and error process to arrive at valving that best matches the spring rates, vehicle weight, and how the car will be used.

Its a value judgement on the part of the user,...

Last edited by Steve Weiner-Rennsport Systems; Apr 11, 2007 at 10:16 PM.
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Old Apr 11, 2007 | 01:02 AM
  #4  
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At $240 that is the best deal going to improve the performance of a Porsche.
Phil
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Old Apr 11, 2007 | 08:24 AM
  #5  
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Originally Posted by Steve Weiner-Rennsport Systems
Matt:

FWIW,...When you pay for custom valving (no matter if its done by ourselves, Smart Racing, or Bilstein) you are paying for MANY hours of track testing/shock dyno work as well as the service itself. Its a process that takes a trial and error process to arrive at valving that best matches the spring rates, vehicle weight, and how the car will be used.

Its a value judgement on the part of the user,...
Fair enough.

Ok...so price aside. Looking from a technical stand point.

If I have front struts that are valved by Smart Racing....is it recommended that I go through them to do the rears so that everything matches? Or can you or Bilstein (I'm not really asking you to speak for Bilstein) do it and make it match as well?
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Old Apr 11, 2007 | 09:29 AM
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Just as a data point, I followed Steve's advice a few years ago (can't go wrong there ) and couldn't be happier with my setup. I already had new Bilsteins (HDs on the front, Sports on the rear), and matched them with Sanders 22/29 torsion bars. Although I've got a Carrera, she's lost at least 150 lbs, so we're probably pretty close to your SC. I suggest you try the combo you have "as is" since you're already "right there" with a proven combination that works. You can always have them revalved later if you're not happy. Irregardless, follow Steve's suggestions, and you will not be disappointed.

Keith
'88 CE coupe
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Old Apr 11, 2007 | 10:59 AM
  #7  
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Keith,

If I leave things as is right now...I'll have front struts valved by Smart Racing for Competition/Street with 22mm T-bars. And Bilstein Rallye/Sport rear shocks with 29mm torsion bars. So I want to get the Rallye/Sport shocks revalved to be correct for the 29mm T-bars and match the Competition/Street settings of the front.
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Old Apr 11, 2007 | 11:08 AM
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Hi Matt, that's why I made my suggestion to try it "as is". My Bilstein Sports on the rear are matched up with my Sanders 29s, and my Bilstein HDs on the front are matched with my 22s. This was a 'proven combo' that Steve recommended, so you may find that you already have a "correct" combination that works great. Good luck!

Keith
'88 CE coupe
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Old Apr 11, 2007 | 10:39 PM
  #9  
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Originally Posted by arbeitm
Fair enough.

Ok...so price aside. Looking from a technical stand point.

If I have front struts that are valved by Smart Racing....is it recommended that I go through them to do the rears so that everything matches? Or can you or Bilstein (I'm not really asking you to speak for Bilstein) do it and make it match as well?
Hi Matt:

Since I'm no fan of Bilstein's custom valving recommendations, my best advice would be either to try them (as suggested by Keith C.) or have them revalved by either Smart Racing or ourselves, to suit.
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Old Apr 18, 2007 | 02:09 PM
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Default Additional Questions

Ok...So I decided to do the right thing and go through Smart Racing (since the front inserts I have are revalved per their specs). I'm sending the rears out today.

I have some additional questions though:

The front Bilstein inserts I have (for Boge Struts) look like they require some kind of small spanner wrench to hold the top thread. Is this the case? And where can I get one, if so?

They also did not come with any bump stops. Can I use the ones I have on the car now?

Lastly, Smart Racing recommends cutting down the front/rear bump stops if your car is lowered to a certain point. Does anyone know what this point is? If If I'm looking to lower to Euro ride height, do I need to do this?
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Old Apr 18, 2007 | 10:15 PM
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Although I agree with Steve I have to say that Jack French has always been pretty good at the shock valving numbers over at Bilstein.

Bill Rudtner

www.rudtnersracing.com
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Old Apr 19, 2007 | 01:42 AM
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Euro ride height is pretty conservative ...not nearly as low as many track setups. As good measure, it's good to have as much travel anyway, and as you've already been told, the Sports have a shorter body and as such is better suited to a lowered car. So remove the bump stops? Personally, I would ...it'd give you just that much more shock travel.

Edward
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Old Apr 19, 2007 | 02:49 AM
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Originally Posted by Edward
....So remove the bump stops? Personally, I would ...it'd give you just that much more shock travel.

Edward
Hi Edward:

Its not a good idea to remove the bump rubbers. One of their roles is preventing damage to the shocks internals, specifically the hydraulic & floating pistons in this example.

One can however, cut off one of three sections of bump rubbers as long as the shocks do not bottom from the car being too low.

Lowered cars require several measures to maintain proper suspension travel, control bump steer, and roll centers. If one doesn't have the budget to buy the necessary hardware, its better to be conservative about lowering.
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Old Apr 19, 2007 | 11:20 AM
  #14  
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I didn't want to remove the bump stops. I was asking if I should cut them down per Smart Racing's instructions.

http://www.smartracingproducts.com/p...hock_front.pdf

http://www.smartracingproducts.com/p...shock_rear.pdf

Any comments on the spanner wrench for the top of the strut nuts?
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Old Apr 19, 2007 | 11:24 AM
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Thanks for the correction/clarification, Steve ...especially since I don't want to be responsible for spreading mis-information As always, your expertise and experinece is invaluable!!


Edward
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