Lowering The Front of a C3

[BBShark]

I was interested in dropped spindles for a C3 but couldn't find anything that was less than 2" drop, probably too much. Also found that these cause a number of issues and may no longer be available. I started a thread about this and came to the conclusion that raising the lower cross shaft might be more doable and avoid issues.

http://vettemod.com/forum/showthread.php?t=5620

So I have done some CAD modeling to find out if this was an option and I think this will work. This is with the inner mount raised 1". Still need to add a brace between the fromt two mounts since the load is offset from the mount bolts.

 

[phantomjock]

Thats a clever idea! And nice CAD too.
Will you just build the cross arms or the rest as well?
Have you considered these guys for parts:
http://www.spcperformance.com/PROD_DIR/PERF_MUSC_DIR/SPCPerf_MUSCLEINDEX.html

I bought a set for the front and the guy I was working with was very helpful,sorted out the right ball joints (using circle track bits etc) with a drop/extended adapter-thingie - technical word there.

I didn't get direct from SPC - but a rep/distributor. Not only helpful - but a better price too.
Cheers -
here ya go -- details:

Mark Savitske
Savitske Classic & Custom
Phone: 610-346-8154
they had a webpage too - haven't looked yet -- Jim

 

[BBShark]

The arms in the CAD model are VBP but others could be used.

 

[010752]

Can you just bend the arms past the spring point?

 

[vette427sbc]

How bad does the geometry get when you lower it without spindles? I was running mine very close to the bumpstops for a little while (less than 1" from the frame). Im finishing up some control arm mods to bring the shock down about 1" lower than stock so I can shave the bumpstops and get more travel.

 

[BBShark]

Lowering the front with shorter springs raises the LCA ball joint in relation to the inner pivot. This screws up camber gain during bump. Also, moving the pivot up moves the IC inboard.

This might help (from the Tech Section):

 

[mfain]

You might look at Howe Racing's precision ball joints. The studs come in various lengths (and are interchangable), so you could use a longer stud on the lower ball joint. This, in effect, lengthens the spindle and moves the wheel up in relation to the lower ball joint pivot point -- lowers the car while keeping the lower control arm and spring relative positions the same. It also raises the outboard end of the upper control arm, which gives you more camber gain with suspension travel. Possible adverse effects, depending on your situation, are a slight raising of the roll center, and you must re-bump steer the car because you have also raised the steering arm (outboard end of the tie rod) with respect to the inboard tie rod end pivot point. I know several guys using longer ball joint studs to lower their cars an inch or so without any adverse effects. Some guys use the longer studs on the upper control arm, but that only improves camber gain, but does not lower the car.

 

[BBShark]

The lower ball joint on a C3 is upside down so extending it, raises the car. That's the heart of the problem. None of the traditional methods will work.

 

[mfain]

The lower ball joint on a C3 is upside down so extending it, raises the car. That's the heart of the problem. None of the traditional methods will work.

You are absolutely correct. I forgot where I was in a long series of modifications to my car. Several years ago I welded in a C3 front crossmember and ran basically stock C3 components. To get the ride height and geometry I wanted, I switched to ATS AFX spindles (now marketed by Speedtech) -- not for the faint of heart! They have about the same king pin inclination angle as C3 stuff, and they have bolt on steering arms. To use them with the C3 LCA, you have to weld in a screw-in ball joint adapter from the bottom up (opposite the standard C3 configuration). I opted to rebuild the LCA pick-up points to accept a late C4 LCA. You also have to build steering arms to accomodate the rear steer drag link and tie rods. I chose to go with a front steer rack. The AFX spindles use C5/C6 hubs and are set up for C5/C6 brake packages. This picture is not great, but you can see the spindle, steering arm and LCA.

 

[damoroso]

The lower ball joint on a C3 is upside down so extending it, raises the car. That's the heart of the problem. None of the traditional methods will work.

I'm certainly no expert here, so, would Chevelle, Camero or even older two wheel drive truck parts work for what you want to do? Seems the A-arms are very similar if not the same in some of these instances.

 

[mrvette]

The lower ball joint on a C3 is upside down so extending it, raises the car. That's the heart of the problem. None of the traditional methods will work.

I'm certainly no expert here, so, would Chevelle, Camero or even older two wheel drive truck parts work for what you want to do? Seems the A-arms are very similar if not the same in some of these instances.

Nope, lowere BJ mounts the other way around....spindle sets on top of joint, not below it.....I dunno about the uppers.....methinks the arms are a different shape too, so the shaft would not fit....

I always wondered why they did it upside down but never saw a reason....

can't see it being a good one either....

:hissyfit:

 

[neki67]

Have you considered these guys for parts:
http://www.spcperformance.com/PROD_DIR/PERF_MUSC_DIR/SPCPerf_MUSCLEINDEX.html

I bought a set for the front and the guy I was working with was very helpful,sorted out the right ball joints (using circle track bits etc) with a drop/extended adapter-thingie - technical word there.

I didn't get direct from SPC - but a rep/distributor. Not only helpful - but a better price too.

Mark Savitske
Savitske Classic & Custom
Phone: 610-346-8154
they had a webpage too - haven't looked yet -- Jim

Mark Savitske is idd very helpful and knowledgeable. His webpage for C3 parts: http://scandc.com/old/corvette.htm

You might look at Howe Racing's precision ball joints.

Mark is also selling the Howe BJ's and can tell you exactly which combinations work best.

 

[Stingxray]

Spindles in the news ...............

Here is something to look at from "HotrodsUSA

65-82 Corvette 2" Drop Spindles
ZER 310-1120
Coming in Feburary! New Fabricated Steel 1965 to 1982 Corvette 2" dropped spindles. Includes custom Zero Offset aluminum hubs with 1.5" and 1.0" inner/outer bearings. Grease seal to wheel flange 1.5" to tuck your wheels inboard. Use your stock steering arms or one of our drop arms which allow you to locate your rack lower. This is a special order item we can move the track width from -1.5" to +1.0"/side Call us for additional information.

Spindle/Hub Kit includes: Drop Spindles, Zero Offset Hubs, 2" or 3" x 1/2-20 Studs, Bearings and Seal.

We will be taking preorders with a 10% discount.

http://www.hotrodsusa.com/store/chev_spindles.html

 

[BBShark]

I found an old C2 racer at an auction over the weekend and noticed right away that the inside pivot point of the lower control arms had been LOWERED about an inch with spacers. So now I'm not sure of the theory here now.

See the spacers between the cross shafts and the crossmember:

 

[mfain]

Lowering the inboard end of the control arms without changing the outboard (ball joint) end will significantly lower the moment center -- not necessarily a good thing. Also, if the control arm is angled up from the inner pivot to the ball joint center, this would tend to reduce negative camber gain with suspension travel (droop). IMHO the control arm and ball joint pivot points should be equal distance from the ground (level) at ride height. Ride height is then adjusted (lowered) by increasing the length of the upright from the ball joint to the spindle -- dropped spindle or a longer ball joint stud in those applications where the stud enters from the bottom up (not a C-3). This gives you a predictable configuration from which you can adjust the upper control arm angle to achieve the moment center and camber gain you want. I guess you could also raise, vice lower, the inboard pivot points into the frame (essentially lowering the frame closer to the ground while the control arm stayed in its original, level position -- a lot of work). This would lower the car with a side benefit of increasing the upper control arm inclination angle, providing increased camber gain with travel. There are probably other ways to "skin the cat"........

 

[BBShark]

Lowering the inboard end of the control arms without changing the outboard (ball joint) end will significantly lower the moment center -- not necessarily a good thing .

I agree, that is kinda the point of this thread, raising the inside pivot. However, someone intentionally lowered the inside pivot of this car. Like to hear some reason why, maybe this is common with early racers?

 

[Grampy]

I don't remember this mod from back in the day but there are historic racers and there are successful historic racers.

Lowering the lower inner pivot all other things being equal will raise the IC and shorten the VSA length. The most noticable change would be a raised front roll center. The cosine change for small angles is minimal so the camber gain curve would flatten but not significancantly.

 

[Grampy]

my bad lower not raise

 

[redvetracr]

I don't remember this mod from back in the day but there are historic racers and there are successful historic racers.

just curious but in which category would you put a car that entered 36 vintage races and has six overall wins in the big bore group? not "class wins" but overall wins.

 

[mrvette]

I don't remember this mod from back in the day but there are historic racers and there are successful historic racers.

just curious but in which category would you put a car that entered 36 vintage races and has six overall wins in the big bore group? not "class wins" but overall wins.

:smash::smash: The love to hammer it category....:surrender::rofl: