Revalving Bilsteins for "S/T"-Tribute Project... need expert advice

[docdan200]

I'm currently in the process of fine-tuning the suspension of my Project "Estée", and was hoping that I could hear from our Forum's experienced brain trust.

Here are the details of the build:

- Total weight of car with driver and half-tank of fuel : 1129 kgs.
- Bilstein Sport fronts and HD rears...both of unknown valving figures
- 22 / 30 hollow Sanders torsion bars
- 22mm front/rear Tarett adjustable sway bars
- Toyo Proxes R888's on 8's / 9's
- Primary use: mostly track...but I plan to drive the car to and fro

My quandary is with the Bilsteins, and I was planning to acquire new ones with the proper valving for my current set-up.

Hoping for some proper guidance in this regard...

[don911]

nice car. For valving, I'd recommend Steve at Rennsport Systems. He can set you up with everything you need. Rennsport Systems | Porsche Performance Systems and Support
He also posts on this forum.

[docdan200]

Thanks for the head's up, Don.

Paging Steve (Rennsport), Clint (Rebel Racing), Dave (TRE), as well as our other respected "gurus"...

[Bill Verburg]

Originally Posted by docdan200

I'm currently in the process of fine-tuning the suspension of my Project "Estée", and was hoping that I could hear from our Forum's experienced brain trust.

Here are the details of the build:

- Total weight of car with driver and half-tank of fuel : 1129 kgs.
- Bilstein Sport fronts and HD rears...both of unknown valving figures
- 22 / 30 hollow Sanders torsion bars
- 22mm front/rear Tarett adjustable sway bars
- Toyo Proxes R888's on 8's / 9's
- Primary use: mostly track...but I plan to drive the car to and fro

My quandary is with the Bilsteins, and I was planning to acquire new ones with the proper valving for my current set-up.

Hoping for some proper guidance in this regard...

You shouldn't need to purchase new shocks, just have the ones you have rebuilt and revalved

You can certainly work through a shop, I don't know for sure but suspect that they do provide their own tweeks to what Bilstein will recommend, but you can also work directly w/ Bilstein San Diego

These guys are very knowledgeable

ThyssenKrupp Bilstein of America Inc.
14102 Stowe Drive
Poway CA 92064, San Diego
United StatesTel.: +1 8583865900
Fax.: +1 8583865905

[docdan200]

Thanks for the info Bill... I will surely look into that route.

What I was specifically looking for are the pertinent rebound/damping numbers that I need for my particular set-up, which to my knowledge, I have to convey to whoever will revalve my dampers.

And going through the numerous threads about revolving Bilsteins, I get the notion that these numbers have become "proprietary trade secrets" of the different companies that revalve dampers. Hence, I can understand why there were no definite responses to my query.

My other problem is that I am half-way around the globe...in the Philippines, to be exact. And although we do have an authorized Bilstein distributor here, they will still have to send the dampers elsewhere (...Australia, I think...) to have the revalving done. They will still need the new rebound/damping numbers for this job.

I also read that the rebound/damping numbers of new Bilstein SPORT / HD, front/rear shocks fall within the range of my car's current set-up, based on weight, TB's, sway-bars, etc. But the information seems anecdotal at best.

If I will do this exercise, I want to do it properly.

[Bill Verburg]

Originally Posted by docdan200

Thanks for the info Bill... I will surely look into that route.

What I was specifically looking for are the pertinent rebound/damping numbers that I need for my particular set-up, which to my knowledge, I have to convey to whoever will revalve my dampers.

And going through the numerous threads about revolving Bilsteins, I get the notion that these numbers have become "proprietary trade secrets" of the different companies that revalve dampers. Hence, I can understand why there were no definite responses to my query.

My other problem is that I am half-way around the globe...in the Philippines, to be exact. And although we do have an authorized Bilstein distributor here, they will still have to send the dampers elsewhere (...Australia, I think...) to have the revalving done. They will still need the new rebound/damping numbers for this job.

I also read that the rebound/damping numbers of new Bilstein SPORT / HD, front/rear shocks fall within the range of my car's current set-up, based on weight, TB's, sway-bars, etc. But the information seems anecdotal at best.

If I will do this exercise, I want to do it properly.

All you need to provide them is the cars weight, spring rates and intended usage, the techs at Bilstein will take it from there. If you doubt their skills(I don't) work w/ a trusted shop, I worked w/ Dan J. at Hairydog Garage for mine. As I said I'm sure that each shop has their own preferred tweeks based on the tracks that their customers see.

I don't know about the valving in the 911 Bilsteins but the mid '90s oe Bilstein damping used in 964/993 Cups was horrible compared to what you get today. Back then linear or progressive damping was the norm, these shocks were very harsh. These days digressive valves are the magic component.

[Flat Six]

Originally Posted by docdan200

Completely unhelpful response, but -- very nice!

[theclaw]

Originally Posted by Flat Six

Completely unhelpful response, but -- very nice!

Yeah. What he said!

Beautiful car.

[myamoto1]

If you're looking for a set of Bilstein inserts (for Bilstein struts), I have a set that I could send directly to Bilstein for you. I had originally planned to go the custom valving route, but through a comedy of errors, ended up keeping my Boge struts. I think I only have $60 (plus shipping) into the inserts if you're interested. PM me if you are.

[theclaw]

Originally Posted by myamoto1

If you're looking for a set of Bilstein inserts (for Bilstein struts), I have a set that I could send directly to Bilstein for you. I had originally planned to go the custom valving route, but through a comedy of errors, ended up keeping my Boge struts. I think I only have $60 (plus shipping) into the inserts if you're interested. PM me if you are.

I heard that's going around. I've experienced a similar comedy of errors. I now have 22/29 hollow TBs and shocks to match but,

1)Bilstein inserts (stock valving) and Bilstein struts, inserts need revalving

2)Boge inserts (valved properly) and Boge Struts (on the way), struts need refurbishing

Thanks to a chat with EPN I'm sticking with the Bilsteins.

[myamoto1]

Originally Posted by theclaw

I heard that's going around. I've experienced a similar comedy of errors.

Mine was a result of sellers confusing Bilstein inserts for struts. I had purchased the inserts in prep for a "full Elephant" treatment. After 3 failed attempts to get Bilstein struts or a usable set, I finally gave up and did Billy inserts with my Boges.

[moneymanager]

Your Bilsteins, if in good condition, are probably fine for your setup. There's no mystery about valving values. Stock at the front for the early cars is 147/122 which most people leave alone. At the rear, stock is 194/150. The sport settings, probably about right for you with 30mm rear torsion bars, are 310/150. I tried 360/135 which Bilstein recommended and needed to visit my Dentist to have fillings replaced... very harsh. Driving to the track with these was for me unpleasant. Unless you are a really talented and accomplished driver, you will derive little benefit from anything beyond the Sport settings at the rear IMHO.