Thinking of Bilstein RSR struts

[Maxhouse97]

Building the parts list for my suspension refresh ... thinking of struts. I currently have Boge with Koni inserts. I would like to raise the spindles to at least 19 mm.

I've heard Bilstein are superior to Boge, with the upside down shock reducing unsprung weight. So I thought about buying used Bilsteins and sending them to ER to raise the spindles.

Question is, should I just buy new Bilstein RSR struts intstead? They:
- already have the raised spindle
- come with fresh Bilstein inserts (which I would have bought with my Boge anyways)
- have gussets for added strength
- I can get them for 600 vs 400 used +175 for raised spindles
- they are new ... some consider struts a wear item

Any downsides to RSR struts? Car is 90/10 street/track. I read that they may force me to go monoball, is that true? Are they too harsh?

[Canada Kev]

Here's my opinion on a couple points...

RSR Bilstein struts don't force you to go with mono balls.
Many find the dampers a bit harsh for street use on the front suspension. What are your front torsion bar sizes?
I wouldn't consider the struts as a wear item, perhaps some might consider the insert as such, though.
You should also think about custom valving for any inserts you get, whether the RSR or used struts.
And RSR struts are more than $600. Think about double that.
Suspension is a system; they need to kinda work together front and rear when it comes to damping, and selecting the correct damping for the front and rear to match your springs.


I have those struts on my car with custom valved dampers specific to my springs. I moved to them from my OEM Boge struts. They were the best value for me to go that way from a situation similar to yours. Except I didn't have the opportunity to get used Bilsteins. If I could have, I might have done that and got them refurbished.

Another tip if you go with the RSRs: The RSR struts are set up to use as coil overs and will not have anything to protect the shock shaft from road damage. Keep your damper shaft covers/protectors from your old struts. You can paint and reuse them on the new units.

[Maxhouse97]

Thanks Kev.

- When I said 600, I meant per strut.

Here's one at 630, not sure if it's the right part number:
VS 1453 R | VS1453R | K4V3658773H0 | Porsche 911 Strut Right Front Racing "RSR" Valving 161/160 Bilsetin Brand New | New-Part.com

Here's another at Summit, at 700. Does that look right?
https://www.summitracing.com/parts/bsn-35-587743?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-bilstein&gclid=CjwKEAiArIDFBRCe_9DJi6Or0UcSJAAK1nFvx03IKaY8 L0jLGNe3XMRyJ9bMpMVB5MCbRadfyERV6hoCQB_w_wcB&ibanner=MobileSwitchNo

- More on my panned suspension. I am planning on 22/29 t bars. Want to keep rubber everything as it will be predominantly street, but I keep getting drawn back to some version of monoball/polybronze (must resist!). I want to raise spindles and custom valve shocks. Here's how I see the struts (again per strut):

400 used Bilstein strut (or even keeping my Boge, 150 for used Bilstein insert)
175 to raise spindle (ER)
40 to add gussets
150-200 sell my used Boge
Net 405 cost, and I have a used strut

700 new RSR
150-200 sell my Boge
Net 500, and I have a brand new strut (don't plan on coil over, but capability a plus)

Why wouldn't I do this? Again I think it comes down to how much of a wear item struts are, and what risk you take in buying a used strut (may be out of specs once you measure it).

(BTW I've found a set of used Bilstein struts for cheap, but one of them has a bad spindle, and I can't find spare spindles for sale).

[Tom '74 911]

On a 90% street car, I don't see the need to use RSR struts, although I do follow your logic.

Why are you raising the spindles? Is your ride height really low enough to necessitate that mod.? The RSR struts have a shortened insert I believe to match the shorter travel of lowered cars. Again, is your car really set up low enough to need that?

As Kev. mentions, the RSR struts don't have a dust cover, which maybe seems like a small thing, but for a "set-it-and-forget-it" kind of component like a strut on a street car, no dust cover means shortening the life of the insert as dirt and grit will make its way inside and accelerate wear. There are ways around that, but they are just that - work arounds.

Also, RSR struts also have no provision for the little tab that holds up the front brake line. Elephant makes a sweet little bolt-on part for this, but it's another $100 added to the total...

Given the 100% rubber/stock suspension bushings, there's no need for the added stiffness etc... the RSR strut provides.

My opinion is stay w/stock green Bilsteins. Revalving the insert will give you the single biggest tangible performance benefit.

[Tom '74 911]

Also, see this thread: Unforeseen issue with raised spindles...

[Maxhouse97]

Thanks Tom. Appreciate the thread on raised spindles.

My car is at euro height now. I'd like to go lower, but agree that it doesn't need to be that low. But while I was having the shocks revalved I figured I should have the spindles raised. So I was thinking raising to 19mm, therefore keeping 15" wheel capability for future a backdate, and lowering to the appropriate level (maybe 1/2 below euro?). Are you saying I can go 1/2" lower than euro and not have to (not that I have to, but preferred for optimum suspension geometry) raise spindles?

I'll do some research on this. I hear you on the rubber and gussets.

[Flieger]

Struts themselves are not a wear item, but the guide bushings are, and so are the inserts.

[Maxhouse97]

Just bought a set of these for $1300. Had my eye on a set of used Bilstein that already had spindles raised and gusseted, but I ended up in the same place money wise with a used strut of unknown origin. Can't see how that is better than a brand new strut.

[Steve@Rennsport]

FWIW,....

Stock RSR valving is FAR too harsh and these really need to be revalved for decent ride quality & handling.

We sell & install quite a few of these for lowered cars and they work very nicely. One of the main benefits is to roll center location which reduces lateral weight transfer and the car's propensity to lift an inside front wheel under hard cornering loads.

I use the old steel shock cover to protect the seals and simply paint it to match the strut body.

[Maxhouse97]

Thanks Steve, I was planning on custom valving either way so thes should work.

[jamesjedi]

Reduced roll center? I would have thought that torsion bars would reduce roll center when compared to coil-overs. Perhaps I do not fully understand roll center.

[Flojo]

Get used Bilstein green Strut (Turbo) and new upside down Inserts.
Racy enough for a street car