FX3 Ride Control Billstein stock settings

[LancePearson]

I saw this in the book of 101 C4 Corvette projects or something like that. It's probably been on here before and this is stock for a C4 with the FX3 shock system from Billstein. The book says Billstein can tailor a chip of some sort for your specific needs such as racing where you want a certain shock stiffness from the get go and not have it be speed related.

As I understand it the basic settings, tour, sport and race, are the basic settings for the rotation of the rod in the shock with the holes in it for damping effect. Rotation from 0-180 degrees. Then as your speed in any one of the three settings increases/decreases, the stock chip function rotates the rod more or less but tailored to that setting. Each of the three settings appears to have six unique smaller gradation settings within it. Sort of like a ladder with different starting points for each ladder so you end up with 18 possible settings for stiffness.

Lance P....At least this is what I got out of the article..and I'll submit it in case other new people are here. If anyone knows this to be incorrect, please correct. Was surprised to see it was not 3 but 18 possible settings.

[efnfast]

Lance P, where did you get that chart? I knew what you stated, but have never seen the chart. -Steve

[LancePearson]

It is project 58 on page 145 or so of: 101 projects for your Corvette, 1984-96. A lot of modest info on the C4 in. It's a Richard Newton book and the title of the chapter is "FX3 chip replacement."

I'm learning a lot about the ZR-1 and so I bought this book, The Heart of The Beast, a couple manuals and am slowly understanding the Z's systems as a result. I'm not an engineer by training but I can follow along on the principles and thought this was a pretty decent graphic way to explain what happened when you switched the ride control settings and drove it. It does all within any one setting automatically. If you can sense speed or anything else nowadays then you can begin to use that data in relative ways. Any new c4 owner with the FX3 system on it would fairly quickly grasp it looking at the chart I'd think.

It seems for a general use driver as opposed to flat out race only car to be a reasonable system. Not sure how the newest Corvette's magnetic adjustment shocks work though it has something to do with a charge in the shock fluid which has metal particles in it that are magnetic and when charged viscosity and hence damping changes. Might even be infinite within a range for all I know. Don't own one of those.

Lance Pearson

[mike100]

notice how low the tour curve is...you will bottom out over speed bumps with the shocks in the lowest setting at 2 mph. So really it is 12 different set points (since the lowest setting is nearly useless), and if I had my drothers, I would probably step up the Perf settings one notch and make the sport setting exactly like the Perf setting.

Anyhow, I re-valved the shocks when they got rebuilt and that helped enough that I don't feel the need to get the programming done with other projects left to spend $ on.

[mike100]

.... Not sure how the newest Corvette's magnetic adjustment shocks work ...
Lance Pearson

They sense instantaneous wheel movement and also monitor vehicle speed, yaw, and pitch from the stability system inputs.

So you can see that it isn't just adjusting solely on vehicle speed. On the magnetic system, the car will compensate when you hit a giant hole at 20 mph where the FX3 will just be in the soft setting when you hit the same dip at lower speeds.

[PhillipsLT5]

Lance, read this
http://corvetteactioncenter.com/tech/c4/fx3/index.html#.UP3j1x1EGSo

[LancePearson]

That's a very thorough article. Thanks. Mike, mine does not bottom like you said at slow speeds. Perhaps it's been revalved or something. Billstein can do a lot with them if you want it for single purpose like racing according to what I read.

Lance P. Thanks.

[mike100]

That's a very thorough article. Thanks. Mike, mine does not bottom like you said at slow speeds. Perhaps it's been revalved or something. Billstein can do a lot with them if you want it for single purpose like racing according to what I read.

Lance P. Thanks.

My car is lowered a little in the front so it has more problems with speed bumps- I have to ride over them in the firm setting. But honestly, don't you find the soft setting a little floaty- even at the speed limit?

btw- I revalved mine, although not aggressively, but more than stock.

[LancePearson]

Mike,
I only use "Tour" when I'm on an Interstate in sixth gear at 73 mph and coasting along on cruise control. Were it me, I would not have bothered with a tour setting at all. It's fine with me. If I don't like "tour" I just use either of the other two settings.

I have no need to lower mine as I'm not road racing full time and at what, maybe 6.5" of clearance below the front spoiler, it is a car you have to be careful of deep gutters and steep driveways as it is. My son's I have to crab on and off at an angle just to clear poor grading on the driveway to begin with so I won't be lowering mine. it's already lower in the front by design than my 1976 is.

Lance

[XfireZ51]

I have coilovers w Moracca valved Bilsteins. I drive around in Sport. I like a more taut and immediate feel in my suspension. The Germans know how to do it.

[LancePearson]

I have coilovers w Moracca valved Bilsteins. I drive around in Sport. I like a more taut and immediate feel in my suspension. The Germans know how to do it.

Nice! Corners pretty flat at speed?
Lance p

[XfireZ51]

:oNice! Corners pretty flat at speed?
Lance p

The 12's in back don't hurt either.

[LancePearson]

:o

The 12's in back don't hurt either.

What do you mean, the 12s?

[Hib Halverson]

Unfortunately, the Newton book on C4 projects lacks on some technical stuff and the article on FX3 chips is an example. The article implies that Bilstein can supply chips for FX3 which change the shocks' damping. In reality, all the chip does is control the speeds at which the system changes the bypass valve setting. Unless you're drag racing or road racing, I'd leave the SRC calibration alone. You're better off having the shocks rebuilt and revalved.

The Moracca-valved SRC shock absorbers completely eliminate the "floaty" feel of the car when the SRC is in "tour" and the ride movements are low-frequency. The practical result in that, is the car's tendency towards drop-throttle or trail-throttle oversteer is greatly reduced.

For more info on the work Bilstein can do to the shocks, call Bilstein, 800-537-1085, and ask for Lou Laurenzana.

[LancePearson]

Hib...I understood that and got the message from the article that the changes would be speed setting modifications from the article but if my shocks need anything the revalve is the way I will go. Thanks for the input. For me, getting starting knowledge the book was fine to present a starting point. It was just a good beginning article for me and I'd do more research before doing anything if and when I did. The article quoted above is excellent and very detailed. Some pretty competent people own and work on these cars it seems to me. Right now mine are fine and I tend to keep it in sport or race. Overall for my use I agree, it is fine as is.

Lance Pearson
Chester, Virginia

[RICKYRJ1]

What do you mean, the 12s?


He's running a 12" wide wheel in the rear with I beleive a 345 tire. :saluting:

[LancePearson]

Got it!

[LancePearson]

Ricky,
I know it's done all the time for traction off the line with powerful engines but what impact is there when front tires are one width and rear tires another dramatically wider width when cornering rapidly carving up turns with the car? Shocks and suspension control lean on the body and keeping the tires flat to the surface but tires control traction in that sense.

Having more grip behind you with engine weight up front than you do up front does what in those circumstances?

My 76 has 255's front and rear and the Z of course comes with different front to rear by about 50 mm's then the 12's make it another 10 mm's in addition. That's getting to be a big difference and I'm wondering what the effect is in road handling.

Lance Pearson
Chester Virginia

[XfireZ51]

More accurately, the tires are 325 x 19 on the Z06 wheel