Bruce_in_MN

Hi

Found a car with what is called an FX3 suspension. It has different settings depending on your needs.

Is this a good thing to look for in a Corvette? It appears most Vettes don't have it.

Thanks,

Bruce

mike100

I just got a 95 with the system, and although the electric variable damping actuator system still works, the shocks themselves have completely had it (77k miles). Bilstein USA has their place locally here in SD Co so I'm going to look into rebuilds rather than new ones...

they are known for problems and replacing with conventional shocks is cheaper.

Goldcylon

Bruce, FX-3 was an option for all C4s from MY89 - MY95. FX-3 was standard equipment on all ZR-1s and referred to as selective ride. The system uses speed to adjust the firmness and responsiveness of the suspension based upon the ride characteristics selected by the user from a switch at the console. The weakness in the system is the ride actuators that ride on top of each if the Bilstein shock absorbers. These however can be rebuilt. If these are maintained the system is very dependable and a very desirable option.

c4cruiser

You can use the search function (try the C4 Tech section) to get information about FX3. Just enter FX3 as the search term.

Considering when FX3 was designed and made available in C4's, it was an excellent system for the time. Bilstein and IIRC Ferrari worked to build a similar system in Ferrari's and Corvette engineers approached Bilstein to work on a similar system.

There are 3 major components to FX3. The shocks themselves, the actuators at the top of each shock and a controller. Most of the problems in this system are due to breaking of a small gear at the top of the shock rod or the failure of the actuator. Neither of these are cheap to fix. Bilstein can replace the gear and they can even rebuild the shocks. They also can re-valve the shock for high-performance use.

There was a member here that rebuilt actuators that used an aluminum ring instead of the plastic ring inside the actuator. These apparently worked great and at a much lower cost than buying a replacement OEM actuator.

The controller sits in the storage compartment behind the driver's seat and is typically worry-free.

FX3 uses not only the switch setting to select shock stiffness, but it also uses vehicle speed. The controller sees input from the speed sensors at each wheel and that is used to-fine-tune" the shocks at each setting. The shock stiffness can actually overlap some depending on the switch setting and the VSS input. As an example, the "Tour" Setting at 70MPH is actually stiffer than the "Performance" setting at 20 MPH.

FX3 was available in two ways; you could get FX3 as a stand-alone system with the base suspension (about a $1600 option ) or FX3 was part of the 89-90 Z51 suspension package or the Z07 suspension from 91-95 (around $2000 ). As mentioned, all ZR-1's had FX3 but these cars had Z51/Z07 as the standard suspension.

So FX3 can be a desirable option if it's working fine or if you don't have a problem with spending extra to fix the components. Keep in mind that the shocks do wear over time even though they are gas/oil-filled. Bilstein typically charges $125-150 per shock to fix the gear and do a basic rebuild. OEM actuators can run into a couple hundred bucks each.

My old 92 vert had FX3 and I really liked it. Made track days that much more fun

Flame Red

I have FX3 on mine and I like it a lot. Makes a significant difference. I remember there was a vendor that sold a different chip that would change the ride but I don't have it myself. I have not had any problems with the system but it can be expensive to fix. Bilstean will rebuild the shocks for a reasonable fee. I did not know that someone was able to rebuild the actuators - good to know. If I had a choice I would definitely get another FX3 system.

rodj

"In '89, Selective Ride (FX3) was only available in combination with the Performance Handling Package (Z51), but when you ordered those two, the car was downgraded to softer, base springs, stabilizer bars and front lower control arm bushings.
In 1990, FX3 no longer required Z51 but, if you ordered both, again, you got base springs, bars and bushings. This downgrade was not widely known. Many unsuspecting '89/'90 customers, wanting the stiffer springs and bars, ordered Z51 along with FX3 but never knew their cars had base parts."

http://www.corvetteactioncenter.com/...fx3/index.html

wmupaprmkr

captain z cnc is the man to rebuild the actuators with aluminum gears as opposed to the plastic oem gears. I have had great experience dealing with him.

Blue Cheese

Hey guys,

So, from what I can gather, to delete the FX3, take out the "black box, the actuators and replace the shocks by normal non adjustable ones? Do I still need to take out the bulb in the DIC?

I have my eye on a sweet ride but has this only option I really never wanted. If easy to delete, will be worth it for me.

Thanks for the info and I'm looking fwd to be part of the community.

Sniperfox1617

My 95 came withe FX3. The maintenance light was on for the suspension. When I removed the black box the light went out. I kept the shocks on because I can manually adjust the gears on top of the shocks. The rear shocks have to be removed to adjust them though. The reason I didn't repair the system is I had two defective actuators$$$$$. I thought about making some sort of cable and pulley system to manually adjust the rear ones so I wouldn't have to remove the shocks. One day I will have the actuators rebuilt.

Photoguy000

When I bought my 92 the Service light was on. Turns out the front left Actuator was the culprit. Captain Z CnC was the man, redid the actuators with metal gears and only was about $125 each if I remember.

http://www.captainzcnc.com/id4.html

Excellent work, highly reccomended. I still need to do the back two, and rebuild the shocks themselves as after 62k miles they are a bit worn out, but the $125 per shock is WAY better than the $500 per shock that anybody has one new for...... Thus far I have no regrets keeping the system in working order. I love it.

Blue Cheese

Guys, thank you so much for your input.

Gives me confidence.

92ragtop

Basically, Yes. However, you can just unplug the black box which is in the compartment behind the drivers seat, and just leave it there. On my 92, it is simply held in place with velcro. You don't have to pull the bulb.
Also, when you pull off the actuator wiring on the back shocks, it will slip down inside the frame rail if you just let it go. When I did mine, I just secured the harness to the top of the shock with a length of soft wire.

Blue Cheese

Thanks Ragtop.... sound advice.

mchenpa

Great thread for me ... thanks.

I have a ‘92 ZO7 and the right front shock keeps coming lose and making a pinging noise and causing the gear to return an error as it cannot adjust. I fixed it last year because it was easy but it came lose again. Unlike some of the other threads that say you can feel a difference, I cannot so I don’t intend to spend the money to maintain/repair a system that has not been state of the art for a quarter century.

I want to replace with non FX3 shocks but I was concerned about the system and the light. This thread answers my questions … much appreciated.

kostas86

Have it on the '90 vert, nice feature.

aklim

I wouldn't waste my money in rebuilding the shocks unless you must have a certain valving. IIRC, for about $800, you can get a new set of shocks which aren't that much more than $400 for the non FX3 ones. Here is the rub. If you rebuild the old ones, they are considered OEM. That means you have a 90 day warranty. If you buy new Aftermarket Bilsteins, they are lifetime warranty. When my 10 year old FX3 shock had a leak, we sent them both the front ones in and within 2 hours of receiving it, they had a new pair coming to me free of charge. So much for "we will take them apart and check them out.". I suspect they logged it as received and tossed me a couple of new ones.

Not sure about track days but it definitely makes rough riding better when you switch to tour for days when you do city driving and it is bumpy. No sense in making life any more difficult when there is no need.

aklim

Why did it comes loose? Did you put the clip in correctly? Is the shock bolted down right on the top and bottom?

rfn026

I never like FX3. It never seemed to do anything.

Then I found out that you could swap controller boards around. I'm not sure if that's still even possible Here's some information from 2006. I would start by calling Bilstein.

The following is just some info that maybe of help to you if you don't already have it.
Shocks-
You can get the shocks rebuilt by Bilstein at between $100-$140 a piece. They can also change the valving for you custom to your needs when the rebuild is done.
Bilstein (1-800-537-1085) is in Poway CA (near San Diego)

Another option is to buy new Bilstein shocks. The main advantage of buying new ones is that they come with a lifetime guarantee. I bought mine from Shox.com www.shox.com Ph: 800-683-2890 They are in El Cajon, CA. A set of new Bilstein FX3 shocks from them run about $699. If you not from Calif. you don't have to pay sales tax and the shipping was free.

Actuators-
If you need a new actuators they are available from Shox.com at $279 ea. Front and rear are different (length of wire pigtail)
You can also get them rebuilt by a forum member, Capt Z, www.captainzcnc.com for about $125 each.

I just finished doing my shocks and it's a pretty straight forward job.
I found both the Shop Manual and some of the tips in "101 Projects for Your Corvette" by Richard Newton , very helpful.

From all the Forum posts on FX3 system I have read I've come to the conclusion that FX3 is very misunderstood system and that when it is working correctly is very beneficial and well worth the cost of restoring

Daddy J - Corvette Forum

Richard Newton
Tech Stuff

Hillbillymafia

Just checked, Shox.com has the shocks new for
$781.00/ 4 and the actuators for $334.00Thanks for the info, greatly appreciated

jay23ls

This thread was already full of good stuff about FX3 and this is another addition. Thanks!

Do have a question. Are you supposed to hear something or feel something each time you turn the switch? You know is there a way to tell its working besides trying to feel out the ride difference?