Wondering if any one whould have interest in a droped spindle for the 88-96 C4? 1 inch lower than stock. Give me your thoughts. Maintain the suspension geometry.

 

If you did this along with have it take rebuildable wheel bearings I would think it would be a winner. I have not lowered my car because of the geometry issues and not looking forward to the day it needs wheel bearings at all. It is hard to justify changing FX3 shocks and wheel bearings on an 7000 dollar car to the tune of 2000..


If I had to do it again knowing what I know now though not as much as many here I am sure I would have bought whatever year that did not have a CCM SIR or ABS... The only options I would want are sports seats and AC that does not have the C68 computer...

 

glad I have it simple with a base 90
no real extras

 

There was a thread in the autocross and road racing section about rebuildable wheel bearings. As far as replacing a hub, it's a simple operation; Remove the calipers and rotors and there are only 4 bolts that hold the hub in place. I installed new made in USA Timken hubs in my 87 and it took about 2 hours (including a beer break or two) to do from the time I drove the car into the garage to it being back on the ground.

But a lowered spindle could be a big engineering deal as there is not a whole lot of room in the existing knuckle design to allow for something like a 1" drop. And given the relatively low cost of the lowering wedges currently available (in spite of the work involved to remove the front spring ), it might be difficult to justify the cost of a new knuckle to get the same drop.

FX3 shocks can be rebuilt by Bilstein for around $150 each and they can even provide custom valving.

 

What year cars would that be?

Edit: Looking in my book I see FX3 as an option starting in 1989. I see JL9 (ABS) going in the RPO list until 1993. Did ABS become standard in 1993?

What does CCM SIR stand for?

 

About 1" drop doing the spring mod got my A-arms level. I think the amount of work would be similar as changing out the spindles. What other gains could be had doing so?

 

not to big of a deal on engineeing. there is room for a 1 inch. yes the wedges are cheap. So with a 1 inch drop and a lil triming on the wedges..its possible to have a 2 inch or so lowered car with correct geometry. Got a link to the thread for the rebuildable wheel bearing???

Ever man want 2 inches more and it still work as it should Bolt on bigger brakes would be a big gain. the thought of a different bearing for racers is a plus. I am jus looking for ideas.

 

Since he ruled out ABS, he could get an '84 or an '85. Removing ABS from the equation allows C4s up to and including 1989 to meet the criteria.

 

I edited my post above, but some may have missed it.

I looked in my book and it showed FX3 and JL9 (ABS) as options up through 1992. My 1993 list doesn't show JL9 though, so did ABS become standard in 93? I'm wondering if a 92 can be found without JL9 or FX3, yet have the 6spd. If so, that'd be what I'm after.

 

ABS became standard equipment in '86

 

ABS appeared in 1986. The system got improvements as the years went by, but it has been on Corvettes for 23 years now.

FX3 appeared in '89 and when RPO Z07 appeared in 91 (Z07 replaced the Z51 performance handling package) it included FX3. But FX3 by itself was also available as a option on the base FE1 suspension cars. Z07 was a coupe-only option and it could be ordered with either the 6-speed or the A4 automatic. FX3 by itself was available on both coupes and verts and either tranny up through the '95 MY.

In '96, Z51 returned but FX3 was discontinued and replaced by RPO F45 Selective Real Time Dampening. The new Z51 did not include F45.

CCM refers to Central Control Module which is sometimes called the BCM or Body Control Module. It's a computer that controls body electronics. It stores odometer mileage, the VIN, and stores certain error codes or diagnostics for things like the C68 electronic A/C system and SIR. It also communicates with the PCM (engine computer). I think that the CCM appeared around 90 or 91.

SIR is the Supplemental Inflatable Restraint system (air bags).

 

What would the spindles cost?

 

I think the drop spindle would peak the interest of the few on this forum that are looking for a more aggressive strance. Although the racer's can certainly benefit from it as well. Typically, the R&D involved in developing a geometrically correct spindle will yield a relatively high cost for the spindles.

 

Would going too far down cause front tire clearance issues? Stock height cars can run a 315/35-17 tire in front with a stock offset wheel but effectively raising the tire 2" upwards in the wheelwell could be an issue.

 

So, with a 92-96 car, then avoiding the FX3 is the best option in some peoples opinion, but there's no getting away from ABS then? I can appreciate the selectable ride control, but it's more electronics and complexity I'd rather not deal with.

To be honest I'll end up taking the best deal I can find, FX3 or not, but NOT would be preferable I suppose. All I'm gonna do is chuck it all anyway.

 

Price is unknown as of now

There are ways to make them cheap. they will be made of 6061

Yes that could be a issue. For a all out track I suppose you could use flares like the rear..I have seen a few cars with them and think they llok good if the euro fenders are installed.

 

FX3 is a good suspension system once you begin to understand what it can be made to do. To be sure, OEM replacement parts are very expensive but there are workarounds. Bilstein can rebuild the shocks and they even offer custom valving. In fact, a Forum member worked with Bilstein some years ago to develop an very good high performance valving package. IIRC, it's called Moracca (sp?) and is a big improvement over stock. There is another Forum member that can rebuild the actuators for much less than the cost of a replacement part and it's better quality.

At one point, Doug Rippie offered a custom FX3 controller that would accept replaceable proms that provided even more control for the system. These may still be available.

There are plenty of 89-95 cars without FX3 but they would be base suspension cars. To build a good performance suspension package, you would be looking at aftermarket stuff like that sold by Vette Brakes. Figure on $2000 for a good properly set up system. If you don't do the install yourself, add another $800 or so for labor.

As far as the ABS system, you can always remove the fuses or disconnect the harness connector. Maybe for track days or competition use, ABS may not be that good to have. But for street driving, ABS is a good thing.

You didn't say anything about ASR which first appeared in the 92. It's another electronic system that is a basic traction control system developed by Bosch for the Corvette. It's integrated with ABS and diconnecting that keeps ASR from working.

 

What are the benefits of the dropped spindle.

O P you may want to start a new thread this one seems to be

 

Lowering a car by wedges (or adjusting coil over sleeves up) changes the geometry as the suspension is now in a different place in it's travel. This changes all sorts of things, such as bump steer, roll center, and instant center.

By lowering it with drop spindles, the suspension will stay in the exact same place in it's travel, keeping the geometry where it was originally designed. I haven't done an analysis of the suspension to see what happens when you lower it, but BrianCunningham might be able to chime in.

Mustangs, for example, are notorious for having geometry problems when lowered. The front roll center will drop below ground level, and this causes all kinds of issues, one of them being increased body roll.

I would be interested, but the real issues with aftermarket spindles, particularly aluminum ones, would be a proper FEA analysis, as some of the Mustang spindles have been known to break (which puts you in a world of hurt). LG makes drop spindles for C5's and C6's, but I've never seen such a product for a C4.

 

Its ok ever one needs to learn as much as they can


This is true for the geometry. Analysis havent been run yet..ackerman is the killer in dropped spindles...since the C4 is limited to travel this could be a plus. stronger and beefier 6061 should work