ANOTHER Bilstein question...

[BGCarrera32]

Too lazy to search the archives today....yawn...

I have Bilstein HD shocks on the back with 27mm t-bars. I have less than 2,000 mi on them. I'm interested in Sport shocks now, I think I NEED (yeah right ) something firmer in back. I am also lower than "Euro" ride height.

Can my Bilsteins be sent in and revalved, or am I better off selling the HD's and buying a new set of Sports?

-BG

[Randy Webb]

There is a moratorium on Bilstein questions now. Please resubmit your question after the budget crisis has passed....

But, I think so. Bilstein will know and can give you the price. About $70 as I recall.

[ChrisBennet]

I run HD's with 29mm rear torsion bars. Seems to work fine.
-Chris

[Eugene at Pelican Parts]

Curious... about how long is the turn-around time for a set of old Bilsteins to be serviced?

[BGCarrera32]

Chris-

Tell me a little about your setup if you wouldn't mind, here's why I ask my questions...

I am running 21/27 tbars with 22/21 sway bars. I have Bilstein HD's all the way around. In general I like my ride, but sometimes it seems as though when pushing it a little on the street, if I hit a twisty section with some short rolling sections to it, that as I crest the roller the car kinda bounces a little in the back. You can definetly tell it is sprung stiffer, but feels as tho it may be dampened a little light. I have Dunlop Sport 8000 tires (with a 245 in the rear) and I upped the cold pressure by 5 all the way around...I'm at about 38 front 40 rear. The car also has been aligned and corner balanced twice, although I do not have my alignment specs with me, the car weight is as 2600 right now. My 911 has no front or rear spoiler, and also seems to blow around a lot in the wind at freeway speed compared to my Civic Si. Like am I in a mini-van? Not...

I just feel like the car could use a few more tweeks. I've got turbo tie rods, bump steer washers, soft poly bushings in front, Weltie strut brace. Ride height at fenders is about 24" rear 24 3/4" give or take in front, car has a 1 degree rake back to front. I keep it at around 1/2 fuel load.

Also at 28 I didnt' grow up with the heavy muscle cars/camaro/mustang stuff. Could be a figment of my imagination, as my autocross and the majority of miles have been in the GTI and Civic world. Perhaps I need more miles in the slightly heavier 911, but I seem to lack that go-cart type ride in this car I keep hearing about.

Maybe I just need a DE (I know I do)...

I'm open to anyone's suggestions at this point, but need reasons before I spend any more money or time chasing something.

[Noel]

I was told by the guys at Smart racing that Euro Height 25.5 and 25 doesn't call for the shorter shocks, but the valving on yours is surely not optimized for the larger bars. I heard that the turn around time is about two weeks, depending on transit time to/from your location.

Noel

[Wil Ferch]

I've also heard that the valving for Sport and HD is the same for the rear. Might want to contact Bilstein and ask what the valving characterics are for both types....jounce and rebound. You may be surprised.
---Wil Ferch

[mm86911]

Valving for rear HD and Sport are different (based on PNs for Carrera). The compression is 10 nm higher on Sports while Rebound is ~100nm higher. I'll post exact numbers tonight. I just received my revalved rear shocks from Bilstein and used their custom recommendation for my setup - was 360 rebound / 140 compression - stiffer ride on the rear and looking forward to testing on track next month at Barber.

[BGCarrera32]

Thanks for the info. I will contact Bilstein at this point about re-valving...my NEW shocks...the wife will love that...

[BGCarrera32]

While I'm at it mm86911, is there any particular Bilstein location/phone number you contacted for revalving?

Thanks!
BG

[rattlsnak]

I'm under the understanding that the HD are stiffer than the Sports.

Im now under the understanding that I said that backwards.

[Noel]

Use the safety card with the wife. It always works. "Honey, I wish I didn't have to get those shocks revalve, but it is matter of safety."

Good luck!

Noel

[mm86911]

Here's the Carrera PN Rear shock specs according to Bilstein:

Rebound / Compression

HD 194 / 150
Sport 311 / 160
My setup 360 / 140

So the Sports are "stiffer" in that they have a higher compression valving and much higher rebound valving. This means it takes longer to compress and rebound - more dampening overall. I chose (per their recommendation) to use less compression and greater rebound than both Sport and HD. My understanding is that this will allow the car to "squat" a bit quicker and let the t-bars hold the position while a bit more resistance to rebound. Cost was $55.00 per shock plus shipping both ways - turnaround was less than a week once they had the shocks.

Note that if you have anyone revalve make sure to remove all hardware including the dust sleeves - they don't need these parts and you will on the reinstall. Bottom line for me was it was less expensive than buying new Sports and I got a shock custom set to my car.

The ride is noticeably stiffer in the rear of my car now. The true test will be at the track and autox - yet to experience either with new setup but will share results when available. I would definitely suggest further consultation with someone more experienced with 911 suspensions as I am learning like most of us on the board.

[Noel]

Mike,

Thanks for the info. Any idea on what the compression/rebound numbers were for the factory Green "Sport" shocks? I had always thought they were equivilent to the HDs, but don't know for sure.

Thanks,

Noel

[mm86911]

Noel - not sure but I bet if you have the PN and call Bilstein they will confirm.