Fx 3

[Glen C.]

When I bought my C-4 the FX 3 had been replaced with Konis and I inherited the actuators loose in a box. I intend to reinstall the FX 3 option - if for no other reason that to get rid of the warning light. I was curious as to how well this suspension performed. I'm trying to decide on my next project and it's between restoring the sound system or the FX 3.

Any insight is appreciated.

[Tom H.]

Re: Fx 3

This is just my opinion, and only an opinion, but i have sold HUNDREDS of C4's. My thoughts is that you will get 10 times more enjoyment from the sound system than you will from the FX3.

Of course, it would be nice to have it working, I never noticed much difference in the three modes.

[Joe L.]

Re: Fx 3

When I bought my C-4 the FX 3 had been replaced with Konis and I inherited the actuators loose in a box. I intend to reinstall the FX 3 option - if for no other reason that to get rid of the warning light. I was curious as to how well this suspension performed. I'm trying to decide on my next project and it's between restoring the sound system or the FX 3.

Any insight is appreciated.

Glen-----

Before I ordered my 1992, I drove cars with and without FX-3. I could see very little difference between the 3 settings, so I decided to not order that option. Still, if I had ordered a car with FX3, I'd want to keep it that way and not revert to standard shocks.

The FX-3 shocks have been discontinued by GM and Delco. When they were available, they carried a very high price---about 700 bucks, each, GM list.

They are still manufactured by Bilstein, though, and you can get them from sources like Corvette Central and Mid America for about $200 each. Their configuration is substantially the same as originals, but I think the labeling is different. I would expect that "DELCO-BILSTEIN" is now just "BILSTEIN".

[Bill M.]

Re: Fx 3

I agree that the adjustment is very subtle. My '92 has the Z07 package (stiff springs with FX3), and I autocrossed the car a lot. I always ran in the Performance setting for autocross. If I forgot to reset to Tour, I could tell on the way home, but it is not much of a difference.

One point of interest: The shocks adjust with speed. That was the big advantage to the computer control. In Tour, the shocks are full soft up to 50 mph, but adjust to stiffer at 50, 75, 100, 125, and 150 mph. I have to believe that the FX3 shocks were softer than the standard shocks at low speeds, and I expect that the car would feel "floaty" at high speed if the FX3 shocks didn't get stiffer with speed. But the better ride at low speed from the softer FX3 shocks is barely noticeable. (Maybe over 150 mph, the FX3 shocks would feel much more stable than the standard shocks!)

[Joe L.]

Re: Fx 3

I agree that the adjustment is very subtle. My '92 has the Z07 package (stiff springs with FX3), and I autocrossed the car a lot. I always ran in the Performance setting for autocross. If I forgot to reset to Tour, I could tell on the way home, but it is not much of a difference.

One point of interest: The shocks adjust with speed. That was the big advantage to the computer control. In Tour, the shocks are full soft up to 50 mph, but adjust to stiffer at 50, 75, 100, 125, and 150 mph. I have to believe that the FX3 shocks were softer than the standard shocks at low speeds, and I expect that the car would feel "floaty" at high speed if the FX3 shocks didn't get stiffer with speed. But the better ride at low speed from the softer FX3 shocks is barely noticeable. (Maybe over 150 mph, the FX3 shocks would feel much more stable than the standard shocks!)

Bill----

I almost ordered Z07, just because I wanted the J-56 brakes. However, I DID NOT want the the higher rate springs and stabilizer bars. I figured that the standard Corvette suspension was harsh enough for normal street driving. Since no dealership had any cars with Z07 for me to test drive, I did not want to take the chance that if I ordered the car with Z07, I would find it too harsh on the road, even with the suspension set at the "touring" setting. I tried to have the car built with J-56 brakes only, but they would not do it.

So, I decided I would just purchase the J-56 brake parts over-the-counter and install them when I did the first brake job. The Only difference between standard brakes and J-56 was the front rotors, calipers, caliper brackets, pins, and brake lines. So, I bought all those parts. I still have them in the boxes since with only 40,000 miles on the car, I have not performed the first brake job. Based upon my last inspection of the pads and the kind of mileage I put on the car now, I might never get them installed in my lifetime.

By the way, please do me a favor: Inspect the rubber suspension bushings on your car and tell me what color they are. These would be the front a-arm bushings, sway bar bushings, and rear control rod bushings.

[Bill M.]

Re: Fx 3

Bill----

I almost ordered Z07, just because I wanted the J-56 brakes. However, I DID NOT want the the higher rate springs and stabilizer bars. I figured that the standard Corvette suspension was harsh enough for normal street driving. Since no dealership had any cars with Z07 for me to test drive, I did not want to take the chance that if I ordered the car with Z07, I would find it too harsh on the road, even with the suspension set at the "touring" setting. I tried to have the car built with J-56 brakes only, but they would not do it.

So, I decided I would just purchase the J-56 brake parts over-the-counter and install them when I did the first brake job. The Only difference between standard brakes and J-56 was the front rotors, calipers, caliper brackets, pins, and brake lines. So, I bought all those parts. I still have them in the boxes since with only 40,000 miles on the car, I have not performed the first brake job. Based upon my last inspection of the pads and the kind of mileage I put on the car now, I might never get them installed in my lifetime.

By the way, please do me a favor: Inspect the rubber suspension bushings on your car and tell me what color they are. These would be the front a-arm bushings, sway bar bushings, and rear control rod bushings.

Joe:

The '92 Z07 is softer than the earlier Z51 and the '91 Z07, but it is so stiff that I have gotten the car airborne on some very rough pavement. I would have loved it at 23, but at 63, I tolerate it.

I did a track day with the bigger J-56 brakes at a local small road-racing track, and I could tell that even the big ones aren't big enough with stock pads. That was my first and last track day. The pedal feel just wasn't right on the way home, but the pedal feel quickly returned to normal. I think they just got too hot at the track. I read that the Corvette Challenge cars had to get down to 2700 lb. for the brakes to be adequate. My '92 weighs 3337 with a full tank...

I will check the bushings. I store the car at a rented garage, so it may be a while before you hear back. I won't forget (wrote a note to myself!) As far as I know, only the lower control arm bushings are stiffer than the standard suspension.

Bill

[Joe L.]

Re: Fx 3

Joe:

The '92 Z07 is softer than the earlier Z51 and the '91 Z07, but it is so stiff that I have gotten the car airborne on some very rough pavement. I would have loved it at 23, but at 63, I tolerate it.

I did a track day with the bigger J-56 brakes at a local small road-racing track, and I could tell that even the big ones aren't big enough with stock pads. That was my first and last track day. The pedal feel just wasn't right on the way home, but the pedal feel quickly returned to normal. I think they just got too hot at the track. I read that the Corvette Challenge cars had to get down to 2700 lb. for the brakes to be adequate. My '92 weighs 3337 with a full tank...

I will check the bushings. I store the car at a rented garage, so it may be a while before you hear back. I won't forget (wrote a note to myself!) As far as I know, only the lower control arm bushings are stiffer than the standard suspension.

Bill

Bill----


Yes, the PRODUCTION J-55 pads were exactly the same as the standard brake set-up. Some folks think they were different, but they were not.

[Bill M.]

Re: Fx 3

By the way, please do me a favor: Inspect the rubber suspension bushings on your car and tell me what color they are. These would be the front a-arm bushings, sway bar bushings, and rear control rod bushings.

Joe:

I inspected:
front and rear upper and lower control arm bushings
front and rear sway bar bushings
front and rear upper and lower control rod bushings

They were all black. Let me know if you want any pictures.

Bill

[James W.]

Re: Fx 3

When I bought my C-4 the FX 3 had been replaced with Konis and I inherited the actuators loose in a box. I intend to reinstall the FX 3 option - if for no other reason that to get rid of the warning light. I was curious as to how well this suspension performed. I'm trying to decide on my next project and it's between restoring the sound system or the FX 3.

Any insight is appreciated.

Glen

I have a 90 ZR-1 with the FX3. At lower speeds there is almost no difference, but around 70 or so you can tell the difference in turns or when changing lanes. If I had to choose between the sound system and the FX3, I would do the sound system first.

JIm

[Joe L.]

Re: Fx 3

Joe:

I inspected:
front and rear upper and lower control arm bushings
front and rear sway bar bushings
front and rear upper and lower control rod bushings

They were all black. Let me know if you want any pictures.

Bill

Bill----


Thanks for checking this for me. No pictures are necessary. I was once informed that Z07-equipped cars used special bushings in the various chassis components and that these bushings were color-coded BLUE. That's, apparently, not the case.

These various bushings were generally not available separately from GM; they were supplied only as part of the control arm, control rod, etc. If there were different bushings used, whether they were blue or black, for Z07-equipped cars, chassis pieces which included these bushings were never available from GM in SERVICE. For SERVICE, only control arms, control rods, etc. using the standard bushings were available.

[Bill M.]

Re: Fx 3

Bill----


Thanks for checking this for me. No pictures are necessary. I was once informed that Z07-equipped cars used special bushings in the various chassis components and that these bushings were color-coded BLUE. That's, apparently, not the case.

These various bushings were generally not available separately from GM; they were supplied only as part of the control arm, control rod, etc. If there were different bushings used, whether they were blue or black, for Z07-equipped cars, chassis pieces which included these bushings were never available from GM in SERVICE. For SERVICE, only control arms, control rods, etc. using the standard bushings were available.

Joe:

I just looked for the color of the bushing material. I will check for a blue color code anywhere on the lower control arm when I transfer the car to her winter digs later this month. I would expect a visual indicator for the stiffer bushing. Stay tuned...

Bill

[Joe L.]

Re: Fx 3

Joe:

I just looked for the color of the bushing material. I will check for a blue color code anywhere on the lower control arm when I transfer the car to her winter digs later this month. I would expect a visual indicator for the stiffer bushing. Stay tuned...

Bill

Bill-----


You might also check for any parts tags (actual paper labels, not casting numbers) which might be on the various components. Part numbers would provide useful information. However, I don't actually recall seeing any tags on these parts, but I have not really looked closely.

[Glen C.]

Re: Fx 3

Thanks everyone. I think I'll focus on the sound system next.

Glen

[Bill M.]

Re: Fx 3

Joe:

I just looked for the color of the bushing material. I will check for a blue color code anywhere on the lower control arm when I transfer the car to her winter digs later this month. I would expect a visual indicator for the stiffer bushing. Stay tuned...

Bill

Joe:

Moved the '92 from summer storage to winter storage yesterday. I couldn't see any color code. I didn't see any indication that the lower control arms are different than FE1, but I'm sure they are.

Bill

[Joe L.]

Re: Fx 3

Joe:

Moved the '92 from summer storage to winter storage yesterday. I couldn't see any color code. I didn't see any indication that the lower control arms are different than FE1, but I'm sure they are.

Bill

Bill-----


At least as far as SERVICE goes, there was never any different part available for FX-3 versus base suspension.

I believe that we have now determined that the "blue" colored bushings were for the crossmember bushings for cars with Dana 36 rear ends. I don't think they had anything, at all, to do with FX-3.