Bilstein Revalve Settings for FX-3

[emmvette]

Does anybody know what the Marlin or Morocco revalve setting are? Unfortunately Bilstein will no longer revalve the shocks for us. From Bilstein: "I know that we have serviced OE Bilstein dampers in the past, but management decided that the aftermarket group would only service and revalve aftermarket Bilstein’s and no longer service or revalve original equipment Bilstein’s"

So our options are now to buy new OE Bilsteins with stock setting for about $850 / set, or buy from a Bilstein distributor and have them request new shocks get revalved (they will do this). I didn't get a price but suspect it will be $1,200 ish. Our other option is to have the existing shocks revalved elsewhere. I spoke with http://deltavee.net/services/ and they are happy to do the work, for about $800 / set but they don't know what the Marlin or Marocco spring rate / settings are which have already been successfully developed.

Does anybody have this info that could share it? As time goes on there will be others in the same situation that will want custom valved shocks. It would be great to be able to have a supplier for us to work with that wants to do the work and for us each not to have to reinvent the wheel.

[secondchance]

http://www.corvetteforum.com/forums/...s-on-a-c4.html

I thought above post may shed some light.
Also, talk to Randy with DRM. He is very familiar with C4 suspension mods.

[emmvette]

I'm surprised; I was expecting somebody to have some quantitative information on this. Anybody out there who can shed a little light on this?

[mike100]

Back in 2012 or so Bilstein was still doing custom damping and I asked for 10% more compression and 20% more rebound on my set. this was less aggressive than the "Marraca" valving.

In my experience, there is plenty of compression to be had by programming the actuator to turn up the stiffness sooner in the speed range, but mainly I felt the oem shocks seemed floaty and wanted a little more rebound damping. I dropped mine off in person and talked to the guy doing the work. He had more than just the one damping profile on record- he straight up asked me for percentages. They have shock dynos. Too bad they won't let them do it anymore.

[rkreigh]

that's a real shame. the revised maracca (sp?) valving takes the soft setting and steps it up. Firm is REALLY firm and I would recommend you seek out and drive a car setup with this as it can be a bit too harsh for the "mean streets" and others find it just fine.

The revised valving seems to really help keep the car better planted.

Good mod, I wonder if we can find an alternate source for this work, it's not really very complicated to do, but the parts are nearly gone.

[emmvette]

Originally Posted by rkreigh

...Good mod, I wonder if we can find an alternate source for this work, it's not really very complicated to do, but the parts are nearly gone.

As mentioned the original post, Delta Vee will do the work for us, but I'm wanting to stay away from re-inventing the wheel with what others have already found to work.

[VikingTrad3r]

apologies for bringing up an old thread, however, has there been anyone who has successfully obtained morocco valving spec rebuilds from the oem fx3's lately? i am posting here before following up with the delta vee company mentioned above.

Thanks.

[emmvette]

No, never was able to obtain. But Delta Vee seemed to know what they were. Please do contact them and show some interest. I emailed them a month back with no reply. Maybe if they see there is interest they will do a run of them for interested parties. I suspect we could garner some interest in send them a batch over the winter.

[Demps]

Who else but Hib back in the day? Maybe not all you are looking for but more than was here. Ted



Hi ZRoners-
I've been reading this thread for several days now and I'd like to clear
up some misconceptions about the SRC system and modification of same.

First, the so-called "motorsports" controller made and sold by Bilstein
and other retailers: The motorsports controller fits all 89-95s with SRC
including ZR1s. I should add that it is significantly less expensive than
either of the two OE-replacement controllers, so, if your stock
controller gets fried, buy the Bilstein motorsports controller.

There is a BIG difference in calibrations (which come in replaceable
PROMs or "chips") depending on which model year system you have. 89-91
SRC systems use one type of PROM and 92-95 use another. This difference
is *regardless* of what the program uses for shock settings and MUST NOT
be ignored when you go to buy the calibrations for the motorsports
controller. BE ADVISED that some retailers, including the somewhat
technically-challenged people at Mid-America, will sell you a controller
and *will not* tell you there is a difference. If you use a motorsports
controller fitted with an 89-91 cal. with a set of shocks from a 92-95,
the system WILL NOT work properly. The reverse is also true.

The main difference between the two series of systems, with respect to
the controller and the cals., is that the later shocks have about half
the travel in valving adjustment than do the early shocks. This does not
mean the valving range of the late shocks is half of what the early
shocks had, but IT DOES mean the design of the system was changed to
reduce the movement necessary to change settings. The end result was the
response time of the system was cut in about half--a good thing.

If you have a 90-91 ZR1 and you're going to have the shocks rebuilt
and/or revalved, it is best to upgrade the shocks to the 92-95 design.
The reduced travel of the valve adjustment along with some changes in the
shocks bypass circuit, has the 92-95 system a better choice
performance-wise and a good upgrade. If you choose to upgrade the shocks
you MUST either upgrade to the late OE-controller or buy the Bilstein
motorsports controller with 92-95 calibration. When you see the price of
the OE-controller, you'll call Bilstein.

Now---the calibrations themselves: there are several. I have data for two
different slalom/autocross cals, one road race cal., and the
OE-calibrations. Both the autocross cals when set to sport, fix the front
shocks at 60 deg. and the rear shocks at 75 deg. In perf they both lock
all shocks at 75deg. The difference between the two comes when the system
is set to tour. With the AA208/AK2117 cal, tour is the same as sport in
the OE cal. With the AA230/AK2118 cal, tour is the same as it was in the
OE cal. The road race cal. is too difficult to describe, here, but I do
not recommend it for street use because the ride will be extremely harsh
at around-town speeds. I do not have data on the drag race cal. but
typically, drag racers will lock the front shocks at the softest valving
(so the front will rise as much and as quickly as possible) and the rear
shocks at the most firm valving (to reduce squat).

There is little or no performance advantage in buying just the
motorsports controller to use with stock shocks of either series. The
actual damping will not change. What will change is the strategy with
which the controller sets the shocks.

If you are considering modification of your SRC system for improved
performance, the first step should be rebuilding and revalving of the
shocks. If that is to be done with a 90-91 system, I strongly suggest the
upgrade of the shocks to 92-95 specs along with replacement of the OE SRC
controller with the Bilstein motorsports controller. If you are an
aggressive street driver and occasional racer, use an OE 92-95 cal with
that controller. If you're a frequent autocrosser, use one of the
autocross cals, but KNOW that in sport and perf. the shocks are locked at
a single valving adjustment and do not change. If you are a frequent road
racer or drag racer and want those calibrations, I'd call Bilstein and
ask to talk to their tech. rep. Bill Hindorf. Please tell Bill, I
suggested you call. The number there is 800 537 1085.

> Also they do not
>change the bushings, I have not been able to find anybody else who can
>supply them either. I have Energy Suspension urethane bushings throughout
>the rest of the suspension except the shocks. If anybody can point me
>towards a source of shock bushings I would appreciate it.
To my knowledge, no one makes SRC shock mount bushings in urethane. I
wouldn't worry about them too much. The change in performance will be
small.





cYa
Hib Halverson

[ZR1 MK]

Originally Posted by VikingTrad3r

apologies for bringing up an old thread, however, has there been anyone who has successfully obtained morocco valving spec rebuilds from the oem fx3's lately? i am posting here before following up with the delta vee company mentioned above.
Thanks.

See attached file.