Boge vs Bilsteins?

[sundevil64]

So if Boge strut assemblies can use a Bilstein cartridge or Koni cartridge for that matter why is a Bilstein strut assembly preferred over a Biltein strut assembly assuming restoration is not the goal?

[RSTarga]

i think im more confused than you

[DanielDudley]

Originally Posted by sundevil64

So if Boge strut assemblies can use a Bilstein cartridge or Koni cartridge for that matter why is a Bilstein strut assembly preferred over a Boge strut assembly?

I hadn't heard that it was, so I would also be interested in the answer. Could be the physical size of the shock cylinder though, as this come up with other cars and Bilsteins.

[uwanna]

It's all about "BILSTEIN mono-tube/Upside-Down technology". The shocks built for
Bilstein struts are designed to take advantage of that feature. The shock "rod" is pointed downward, secured to the control arm and therefore the only moving part in operation is the rod/piston. Therefore reducing suspension unsprunt weight. Conversley the Bilstein insert when mounted into the Boge tube, the rod is pointed up top and bolted to the chassis. Thus the whole shock tube assembly moves up and down when in operation, ergo added unsprung weight.
Virtually all race cars with struts use "upsidedown shocks" for this reason.

EDIT:read my mea culpa in post #7

[sundevil64]

Thank you for clarifying that.

[Arne2]

Umm...

I'm not sure about Bilstein inserts for Porsche Boge housings, but my experiences with Bilstein inserts for other German cars is that many of their inserts are upside down. The rod is hidden inside the cartridge tube, but still "points" down. As seen here:

[IMG]http://www.**********/images/wp/bilstein/w01331911000bil.jpg[/IMG]

[uwanna]

Originally Posted by Arne2

Umm...

I'm not sure about Bilstein inserts for Porsche Boge housings, but my experiences with Bilstein inserts for other German cars is that many of their inserts are upside down. The rod is hidden inside the cartridge tube, but still "points" down. As seen here:

[IMG]http://www.**********/images/wp/bilstein/w01331911000bil.jpg[/IMG]

After your comment, I did some research, and you are correct! The Bilstein inserts for Boge struts ARE upside down design. Now I'm really not sure of the benefit of the the Bilstein strut vs the Boge with a Bilstein insert. Perhaps a suspension Guru like Chuck Moreland could answer that question. Sorry if I led anyone astray, but sometimes you
find out a long held belief is just wrong! I do know however, most serious 911 racers
use Bilstein struts with raised spindles.

[chris_seven]

Dampers are never 'upside down'.

The bump and rebound always move in the same direction regardless of how they are mounted.

There are two points that need to be considered- the first is the benefit of the 'gas' used in the Bilstein and there are many articles about this on the web and they don't need repeating.

The second is the effective diameter of the piston rod and the influence on stiction.

In effect the Bilstein insert in a Bilstein body has a 40mm dia piston rod and this runs in DU Bushes which are installed in the strut body. (This diameter may be 36mm in a Bilstein/Boge Insert)

This diameter provides very good resistance to bending particularly under braking and allows wheel movement to occur in a smooth and linear manner.

Small diameter piston rods tend to bend more and bind in seals under heavy braking so their response is less than ideal and some wheel patter can result.

[uwanna]

Originally Posted by chris_seven

Dampers are never 'upside down'.

The bump and rebound always move in the same direction regardless of how they are mounted.

There are two points that need to be considered- the first is the benefit of the 'gas' used in the Bilstein and there are many articles about this on the web and they don't need repeating.

The second is the effective diameter of the piston rod and the influence on stiction.

In effect the Bilstein insert in a Bilstein body has a 40mm dia piston rod and this runs in DU Bushes which are installed in the strut body. (This diameter may be 36mm in a Bilstein/Boge Insert)

This diameter provides very good resistance to bending particularly under braking and allows wheel movement to occur in a smooth and linear manner.

Small diameter piston rods tend to bend more and bind in seals under heavy braking so their response is less than ideal and some wheel patter can result.

Thanks for the enlightenment, but just one thing on upside down shocks. Why does Blistein use "BILSTEIN mono-tube/Upside-Down technology" as part of their copyrighted logo? It is my understanding that the rod/piston being the "moving"
element attached to the suspension vs the entire tube being the moving element with the rod/piston attached to the chassis, is what Bilstein means by
" mono-tube/Upside-Down technology"

[chris_seven]

I think it boils down to how you define the 'body' versus the 'piston rod'.

In the Boge the piston rod is visible and the body of the damper is clamped in place into the strut housing.

The part you see move is the piston rod.

In the Bilstein the piston rod is very small diameter and is fixed into the strut. The housing is the part you see move.

If you take a rear Bilstein Mono Tube Damper it looks just the same externally as a Twin Tube and has a smaller rod diameter.

It doesn't matter which way you mount it into the car the bump direction is the bump direction so how is this upside down?

I think it is just a great advertising statement to try to differentiate Bilstein from their competition. The fact the 40mm dia body moves is, I believe, a significant benefit for a Macpherson strut.

I also believe Penske, Ohlins and many other companies make similar inserts now.

[uwanna]

Originally Posted by chris_seven

I think it boils down to how you define the 'body' versus the 'piston rod'.

In the Boge the piston rod is visible and the body of the damper is clamped in place into the strut housing.

The part you see move is the piston rod.

In the Bilstein the piston rod is very small diameter and is fixed into the strut. The housing is the part you see move.

If you take a rear Bilstein Mono Tube Damper it looks just the same externally as a Twin Tube and has a smaller rod diameter.

It doesn't matter which way you mount it into the car the bump direction is the bump direction so how is this upside down?

I think it is just a great advertising statement to try to differentiate Bilstein from their competition. The fact the 40mm dia body moves is, I believe, a significant benefit for a Macpherson strut.

I also believe Penske, Ohlins and many other companies make similar inserts now.

The bump/rebound characteristics/direction is not the issue, works well either way,no argument.
What I'm saying is the actual tube containing oil/gas is mounted stationary to the chassis and the strut body/rod is tied to the control arm i.e. "upside down", vs the Boge and many others, which is just the opposite, much like twin tube shocks. I'm sure given Bilstein's success in the shock business, this design is not just marketing hype or a slogan! And yes Ohlins does make Bilstein replacement cartriges for Bilstein struts.