I bought a 91 coupe and love it! I bought the factory manuals off of ebay and they help a lot. As i dig into the car, i found these actuators or something tie wrapped to the chassis. I learned they are actuators or servos or whatever that control shock absorber tension, I guess? Someone at some time took out the shocks and installed something else. The car rides rough, and i would like to be able to use the original feature the car had. My questions are: To those of you that have selective ride, can you tell much of a difference when switching from "tour" to "sport" to "performance"? Is it worth trying to bring the system back to factory new condition? Can i somehow verify the condition of the actuators before buying the shocks? Last question, since the whole system has been corrupted, why do i not see any codes telling me something is wrong? Steve C.

 

You can certainly feel the difference, and mine is even more pronounced since I had them rebuilt to Rippie specs...

My "Tour" setting is where "Performance" used to be and it gets progressively stiffer from there.

Hard to say why you get no indicator...dig through the manuals and find the troubleshooting section on the FX3. Some simple checks could tell you what you need to know.

 

double post sorry

 

For someone doing an FX3 delete the last step would be to pull the bulb in the DIC to remove the service SRC warning.

Like 1991Z07, I have a Z07 car with FX3. The settings feel different true enough. There is a bigger difference tho in the non Z07 cars with FX3 tho. On the Z07 cars a realistic labeling would be stiff, stiffer, stiffer still.

Check to see if the bulb is still in the DIC.

Check to see if the control module is still on the car. FX3 code retrieval is posted in this link http://forums.corvetteforum.com/c4-t...n-96-cars.html post number 28.

Try to retrieve your FX3 codes simply as a way of seeing if the control module is there.

Watch eBay or contact one of the recyclers like vette 2 vette for the shocks. Even broken FX3 shocks are rebuild-able by sending them to Bilstein.

New FX3 shocks and actuators cost the Earth, btw.

 

I have a 1990 with FX3 suspension. Car has done around 44k miles. My take on the system is that you do feel it but not as one would imagine.

The actuators control shock valving, that is how much damping the shocks are doing. For me in touring mode, the car is softer but it feels bouncy and sloppy (read: under damped). Personally it doesn't as some people say, rides as smooth as a Cadillac in this setting. It rides more like a pogo stick and gets annoying. As a result I never use it.

In sport, (the middle setting) the car immediately feels tighter and flatter. Its the best setting for normal roads, where there are pitches, bumps, rough bitumen. You feel the bumps and crashes but no where near as bad as the Perf setting. Hey its a Corvette, design intent to ride rough.

Performance mode is what I call the US Interstate setting mode, smooth roads and the car feels very tight on turning. If the roads have undulations but smooth its actually nice in this setting. Smooth and twisty, this is the mode to use and demonstrate what the engineers wanted to get out of the C4. However, start getting a series of sharp bumps, (freeway joins are also bad) and you can feel crashing and bumping and you will need a trip to the dentist as ones teeth will fall out.

I too am keen to hear others and their experiences with FX3 on their Corvettes.

I think if your car is already has the FX3 disabled spend the money on good quality shocks and talk to someone who actually knows spring rates and dampers for C4s and who can understand what you want out of the car.

 

If the FX3 module was removed or disconnected, there will be no light illuminated on the DIC. SO, check the storage well behind the driver's seat, to see if the module is there, and it's connected.

 

Many opt to ditch the FX3 system when they need shocks since the damn things cost about $200 each

I'll have to make that decision soon myself as my stock FX3 shocks have about 130k on them.

 

Thanks for the feedback regarding what i now know as FX3!. I will start investigating per your replies, starting with finding out if i still have a control module!

This car has been interesting. 40 years ago i had a 68 T top coupe with a 427 that was easy to work on. This one has been eye opening with the level of complexity for a 20 year old car. Whomever worked on it before didn't always do a good job on it. I found that the distributor cap was turned a full 90 degrees off of where it should have been. The locator tab didn't fit in it's slot, so they just cranked down the 4 retainer screws and broke the cap. The car still ran OK even like that.

Thanks all

I would still be interested in any other posts regarding FX3

Well, just went out and looked. Lots of electrical wires and connectors. Looks like the module is still there and hooked up. Actually looks like there are two electrical boxes there and another Bosch unit with what looks like brake lines going to it. From what i can tell, it is still there and hooked up. i did see one connector with two white wires and two brown wires that is not hooked up to anything. perhaps a diagnostic link?

Steve C

 

Steve,
My '90 Z51 coupe is VERY different in all three settings. Tour is nice for the lousy roads here in Tucson but Sport and Performance are GREAT over in CA where most of my trips take me. My shocks are like new at 31K miles.
Here is some good reading on the subject of Selective Ride Control:
http://www.corvetteactioncenter.com/...fx3/index.html

Mick

 

The unit with the brake lines is your ABS pump

The connector with the brown & white wires is the test plug for it (I think)...or for the ABS controller which is the silver unit in front of it.

 

I'm opposite to most, my 93 ruby did not have the fx3 (or ltpws>not related but 2 most common missing options for my year) in it, I sought out the parts and installed the system into the car. I had the shocks rebuilt by bilstein to normal specs.....added the wire harness's in, and all is fully functional. When we went on the corvette caravan, we started on performance, and found we had to pee every 1.5 hours.....on tour, we were able to last 4.5 with the same habits......so there is truly a difference with the system. You can also here the "impact" difference on bridge joints on all the settings when you ride over them at 65mph, so you can hear the difference in ride also.....

I'm an EE by trade, so for me, it was a challenge and reward to make it all work like the car did right out of the GM factory line.......

Cheers

 

Yeah i'd have to agree with this point.

Mine is a z07 with FX3 and the ride is stiff to say the least.

I've actually always wondered why i cant feel much difference between the settings but I think you just told me why. The combo of z07 and FX3 is different than non fx3 cars.

 

The difference between FX3 and Z07 w/FX3 was fairly significant as well!

Starting in 1991, the front spring rates were:

1991
Z07 - 115.5 nm
FX3 - 93.1

1992
Z07 - 90.1
FX3 - 73.2

1993
Z07 - 90.1
FX3 - 73.2

1994
Z07 - 90.1
FX3 - 60.0

1995
Z07 - 90.1
FX3 - 60.0

As you can see, towards the end there was a 33.3% difference in the front spring rates...that is a VERY noticeable difference between the two systems.

The FE1 rates were identical to FX3 until 1994 where they put it somewhere between FX3 & Z07.

I planned to Autocross mine when I ordered it...so I knew what I was getting. Although you can't feel much of a difference in your butt, the feedback through the steering tells me when it changes.

In "Performance" mode I can feel a frog's fart on the road surface, every pebble, every crack.

It is fairly amazing when you think about it...quite sophisticated for the day.

Of course, the new C6 magnetic shocks makes you throw dirt at this ancient stuff...

 

I love my Z07 car because of the selective ride control. Although Tour does feel under-dampened, it's nice for bad Pennsylvania roads. Sport and perf give a noticable increase in how tight the car feels. I'll definitely be replacing the components with FX3 stuff if they do go bad.

 

I had mine revolved to the Moraca valving like mentioned in the link. Anyone here buy the upgraded actuators w metal internals instead of the plastic?

 

Not yet...who sells them with metal gears?

I have an actuator that just went south on me...if I'm gonna replace it, I want something better than plastic.

I can't really complain much...I've had the car 21 years and have replaced 2 actuators. And it doesn't get driven like grandma owned it either.

 

Captainzcnc is the only one I know of.

 

Thanks...

My right front actuator gear is broken...flagged a code last week.

 

Yep I had one break years ago, but light has been on again for a while and I figure it is the same thing. I might do the metal one's next, but they are $. http://www.captainzcnc.com/id3.html

 

Do you think it is possible for them to revalve a shock so that Tour is like OEM then Perf is like the Moraca Perf, or can the system not make that great of a change?