Opinions Needed On Shock Upgrade Please

[Hodgey]

All,

I come seeking opinons on my suspension refresh and shock replacement....

I am going to change the A arm bushings for neatrix / rubber not polybronze, and I will be changing the shocks front and rear also....

So, what are the pro's and cons of putting Bilstein HD on the front with Bilstein Sports on the rear versus HD all round or Sports all round?

Car is mainly street with plenty of DE action...

Thanks in advance

Neil

[JAR0023]

This is going to sound like a canned response but have you searched the forum? I went through this last fall and while I had to wade through a bunch of "I like sports, no I like HD." type of threads there were several good long threads with lots of technical info where all the experts weighed in. Try a google search with this topic.

" site:forums.pelicanparts.com bilstein hd vs. sport, 911, pelican"


I have an 86 coupe, lowered, uprated torsions but a daily driver. I ended up with Heavy Duty all around. If I were in your shoes and using the car on the track I might have went to Sports in the rear. One thing that swayed me was a posting on one of the long previous threads that had the actual compression and rebound numbers for the rear Bilstein HD and Sports. IIRC the compression numbers were similar with the significant difference being heavier rebound numbers for the sports. I wanted the extra bit of compliance for the bumpy roads around here.

FWIW I'm very happy with the HDs. My car came to me with Koni reds up front but the PO had replaced the rears with KYB. A mismatch and the more I drove the car the more I felt it nagging me each time I drove. I won't pretend to know all the technical details but with the Bilsteins the car just works so much better as one unit.

-J

[JAR0023]

Start here.


Bilstein HD & Sport rates please.


More here.


Bilsteins: HD vs. Sport?

Shock rates, stock, HD, & Sport???

Bilstein and Sport Spec Query

[Hodgey]

JAR,
I didn't intend for it to turn into 'one of those threads', but looking for real life feedback from someone who has actually done what I am contemplating.....

I appreciate the links....although I am still none the wiser....

[Bill Verburg]

Originally Posted by Hodgey

JAR,
I didn't intend for it to turn into 'one of those threads', but looking for real life feedback from someone who has actually done what I am contemplating.....

I appreciate the links....although I am still none the wiser....

I strongly agree w/ Chucks analysis in this thread

all the older design shocks had a linear valving setup that is just plain harsh, they will greatly benfir from a digressive setup matched to the springs/weight/ and purpose of the car they will be used in.

My C3 has stock Bilstein hd in front and sport in back, these shocks come w/ linear valves and it's great but is harsh. I re-valved the Cup/RSR shocks on my 993 w/ a digressive setup, the difference between the old linear valves and the new digressive valves is eye opening. The C3 shocks are slated to be rebuilt ASAP

[GaryR]

Originally Posted by Bill Verburg

I strongly agree w/ Chucks analysis in this thread

all the older design shocks had a linear valving setup that is just plain harsh, they will greatly benfir from a digressive setup matched to the springs/weight/ and purpose of the car they will be used in.

My C3 has stock Bilstein hd in front and sport in back, these shocks come w/ linear valves and it's great but is harsh. I re-valved the Cup/RSR shocks on my 993 w/ a digressive setup, the difference between the old linear valves and the new digressive valves is eye opening. The C3 shocks are slated to be rebuilt ASAP

Hmmm... Makes me wonder what the mysterious "custom valving" is that Dan J. specifies for the Bilstein Sports on our heavy TB'd 911 race car's is... I'm going to move to an adjustable/remote res. at some point now that we know they are legal, but curious about what we have been running as they seem to work for the curb jumpers that we are.

[RWebb]

Can stock Bilstein HD or Sport shocks be changed to a digressive valving?

or would he have to buy entirely new shocks?

[JQ911]

JAR, not the hijack the thread, can you pm me your set up specially torsion bar numbers front and rear. I just lowered my car a little below euro height and still running on OE TBs and HDs. I would like to compensate on recommended TBs 22/28??? I don't intend to track nor DE just use it regularly for street. Thanks

[Craig_D]

Originally Posted by RWebb

Can stock Bilstein HD or Sport shocks be changed to a digressive valving?

or would he have to buy entirely new shocks?

Yes they can. Chuck at ER revalved my Bilstein struts with digressive valving. I'm looking at the shock Dyno right next to me, even.

[wildcat077]

I've been doing approx 16-18 track days yearly for the last three years and i find that i should have went with Sports all around rather than HD fronts and Sport rears ...

Although now i'm at the point of revalving due to all the other suspension upgrades you might as well go for Sports all around if you're going to be driving on the track with your car.

I asked all the same questions four years ago when i got my 911

Cheers !
Phil

[Craig_D]

Here's the dyno read out that Chuck sent with my struts. You can see the digressive "knee bend" between 3.0-4.0 ips compression (top), and then between 4.5-6.0 ips rebound (bottom). This is essentially hydraulic lock, forcing to a freer valving at those damper-movement speeds.

[RD911T]

Craig, so new Bilstein's are not digressive valving, but can be modified? What does ERP charge to modify new strut inserts bought from them?

[911dean]

Von shocks are also an option. I'm thinking about going with them. Talk to Chuck.

Dean

[Richard C2S]

I re-did the suspension when I bought my 911SC about 8 (?) years ago. It was sitting at factory SUV height for American bumper standards.

After reading lots of threads and paying close attention particularly to Bill Verburg, I chose to go to 22/28 torsion bars with Bilstein Sports front and rear. The car is lowered, I did a bump steer kit. I didn't use the polybronze bushings but think I used Neatrix, IIRC.

I have done lots of days on the track and it has been great. But the car is a street car and I love the setup on the street as well.

I hope this helps a little.

[Bill Verburg]

Originally Posted by GaryR

Hmmm... Makes me wonder what the mysterious "custom valving" is that Dan J. specifies for the Bilstein Sports on our heavy TB'd 911 race car's is... I'm going to move to an adjustable/remote res. at some point now that we know they are legal, but curious about what we have been running as they seem to work for the curb jumpers that we are.

Not to let any secrets loose but....

The best feature of all the newer shocks is that they all come w/ digressive valves, the external reservoirs are nice for heat control and an additional tuning tool

Bilstein has recently revamped their entire line, don't know if they changed the olde 911 stuff but they sure should have

[Bill Verburg]

Originally Posted by RWebb

Can stock Bilstein HD or Sport shocks be changed to a digressive valving?

or would he have to buy entirely new shocks?

Yes, Bilstein SD can rebuild them and maybe Chuck M does at Elephant too

monotube Bilstein/H&Rs are rebuildable, twin tube are not

[wildcat077]

Originally Posted by 911dean

Von shocks are also an option. I'm thinking about going with them. Talk to Chuck.

Dean

Dean,

I was told by a good source that VON shocks are just a set of Bilsteins that have been precisely matched and valved more diligently than a regular set of Bilsteins ...

It's a lot cheaper to send in your own to have them rebuilt/revalved by one of the many shock gurus out there !
If i didn't already have a brand new set of Sports sitting in a box i would have sent mine out over the Winter.

Cheers !
Phil

[RWebb]

Thx, Bill

After I bought new Bilsteins, I thought I'd never change the shocks during my lifetime, but...

[Craig_D]

Originally Posted by RD911T

Craig, so new Bilstein's are not digressive valving, but can be modified? What does ERP charge to modify new strut inserts bought from them?

I would check with Chuck Moreland at Elephant Racing, as I don't know if the new ones come stock with digressive valving, and if/what he charges to revalve Bilsteins bought through his shop. He's the man, he knows the whole deal.

[911dean]

Originally Posted by wildcat077

Dean,

I was told by a good source that VON shocks are just a set of Bilsteins that have been precisely matched and valved more diligently than a regular set of Bilsteins ...

It's a lot cheaper to send in your own to have them rebuilt/revalved by one of the many shock gurus out there !
If i didn't already have a brand new set of Sports sitting in a box i would have sent mine out over the Winter.

Cheers !
Phil

Phil

Elephant will be raising the spindles on the struts and rebuilding the inserts. Vons for the rear are being considered because they are already shortened. Rebuilding the rears was my first thought, but the cost difference is negligible after having the bilsteins shortened. This is at least the direction Chuck pointed me.

Dean