Running coilovers "upside down"?

69427

The Artist formerly known as Turbo84
Joined
Mar 30, 2008
Messages
2,972
Location
Clinging to my guns and religion in KCMO.
I'm currently modifying the UCA mounts to allow a bit more dynamic caster and camber. While I've got things apart I'm kicking around running the coilovers upside down (if it will package worth a darn). They're gas shocks, so the position shouldn't be an issue (correct me if I'm wrong), and there ought to be a slight reduction in unsprung weight in the process.

Outside of a bit more possible debris hitting the ram/shaft of the shock due to its lower position (possibly a protective sock of sort might be a good idea), I'm just looking for any ideas of problems that I haven't thought of yet.

Thanks for any constructive input.
 
I've always heard that the seal/rod should be down on gas shocks to lubricate the rod. So, the trade off might be shorter life but, for a vehicle that is not a daily driver, maybe it's not a big deal.
 
I'm currently modifying the UCA mounts to allow a bit more dynamic caster and camber. While I've got things apart I'm kicking around running the coilovers upside down (if it will package worth a darn). They're gas shocks, so the position shouldn't be an issue (correct me if I'm wrong), and there ought to be a slight reduction in unsprung weight in the process.

YES. Just a quick thought ... If you transitioned to a composite spring mounted transversely, that would reduce the weight of the coils, and you could eliminate the ARB and its mounting hardware too.

EOC; Every Ounce Counts!

Cheers - Jim

Which shocks are you using?
 
I'm currently modifying the UCA mounts to allow a bit more dynamic caster and camber. While I've got things apart I'm kicking around running the coilovers upside down (if it will package worth a darn). They're gas shocks, so the position shouldn't be an issue (correct me if I'm wrong), and there ought to be a slight reduction in unsprung weight in the process.

YES. Just a quick thought ... If you transitioned to a composite spring mounted transversely, that would reduce the weight of the coils, and you could eliminate the ARB and its mounting hardware too.

EOC; Every Ounce Counts!

Cheers - Jim

Which shocks are you using?

I'm using stock type Bilstein shocks, converted to a c/o configuration. My main headache is that the spring(s) outside diameter (3.25" IIRC) make it a headache to install or fit the setup inside the upper control arm, and have nothing rub as the suspension moves up and down. I'm currently modifying the UCA mounting location (for increased caster and camber gain) and the shock upper mount to give me a little more spring clearance. I'm going conservative at the moment with the shock orientation in case my UCA mount relocation effort turns out to be counterproductive, and I have to go back to the previous configuration.

I kicked around running a transverse spring when I first installed the C4 suspension years ago, but due to the C3 trackwidth I would have to narrow the spring each time I swapped springs. I came to the conclusion that it would be simpler to run coilovers (given the wide variety of rates) and a sway bar, given the similar wide variety of bars available (I'm currently running a modified tubular bar off a '93 Firebird).
 
Just gotta bitch/vent a moment. I was putting things together (the modified UCA mount and the coilover) to do a test fit, and I dropped one of the four "disc" spacers that goes between the C4 upper A-arm shaft and the bolts/shims (didn't hear anything hit the floor, oddly). Looked all over hell for it, and still can't find it. My "spares" have also been MIA since the move. Pisses me off when I waste this much time on unproductive activities. I'll look some more this afternoon.

Another frustrating part of this project is how damn tight it is to fit a coilover in a C4 UCA. Also, it's damn hard to predict how much clearance I need to allow for future movements of the UCA for camber/caster adjustments.

I like the selection of available spring rates with coilovers, but they're a PITA with the short length of late C4 UCAs. I'd like to put in (longer) early C4 UCAs, but with the narrowed suspension, they would be butting up against the engine.

Thanks for letting me vent.
 
Kinda off topic but I have to ask, You are changing control arms so obviously you need to re-align your car. Do you take it to an alignment shop or?
 
Kinda off topic but I have to ask, You are changing control arms so obviously you need to re-align your car. Do you take it to an alignment shop or?

I'm keeping the same '96 C4 control arms I've been using the past ten years. I'm just relocating the UCA mounts slightly rearward to allow me to increase the static caster, and also put the UCAs in a slightly better position to help increase dynamic caster during cornering.

I just do the alignment on my four post lift in the garage. I frequently tweak the front geometry stuff in an effort to increase the front grip, and I'm too parsimonious to pay an alignment shop to get things pointed the right direction each time. I bought a caster/camber gauge a few years ago, and it's paid for itself a couple times over.
 
I flipped the shocks on a lowered 05 express van, it helped on the rebound but the dive was worse

Why use c4 front control arms?
 
Why use c4 front control arms?

I'm pretty sure 69427 will chime in here, but for my C3 front suspension, I've moved on to a C7 upright with the SKF racing bearings. So that is point #1 - better bearings - even the c4s are better than C3s IMHO.

Adjustable positioning of the CAs and more control of front geometry. When/if you add in multiple height ball joints to swap out - even more control (guess that would be point #2).

Coil overs are an easy install - compared to a C3. Point #3.

Drop height front end. One of my big issues having dropped the rear by about 2 inches! (That would be my point #0!!)

Depending the route you take can be as cheap (or cheaper) than any front end mods on a C3 to get better performance.

I'd suggest a talk with Mark Savitske at Savitske Customs and Classics. He is always willing to talk about front end geometry and what steps to take - but he will often suggest that the mod to a C4/5/6/7 on a C3 is a Rabbit Hole he discourages most folks to avoid. He sells parts that will really improve the front end - SCS adjustable Upper Control Arms, and many choices of ball joints too. [Author of How to Make Your Muscle Car Handle]

Take-it away- MIKE!

Cheers - Jim
 
Last edited:
I flipped the shocks on a lowered 05 express van, it helped on the rebound but the dive was worse

Why use c4 front control arms?


A C4 suspension is about half the weight of a C3 suspension, the front spring anchor position on the LCAs are farther out (ie: better), coilover springs are lighter than C3 springs, a complete C4 suspension is pretty inexpensive, and I like the looks of a factory aluminum suspension (my looks reasonably stock to the casual eye).
 
I'm currently modifying the UCA mounts to allow a bit more dynamic caster and camber. While I've got things apart I'm kicking around running the coilovers upside down (if it will package worth a darn). They're gas shocks, so the position shouldn't be an issue (correct me if I'm wrong), and there ought to be a slight reduction in unsprung weight in the process.

Outside of a bit more possible debris hitting the ram/shaft of the shock due to its lower position (possibly a protective sock of sort might be a good idea), I'm just looking for any ideas of problems that I haven't thought of yet.

Thanks for any constructive input.

Your theory is sound, they inverted the shocks on crotch rockets to improve handling. I am willing to bet that aside from mounting issues stock shocks/coil overs wont function correctly inverted and may require locating some that are designed to work inverted..would it be worth the expense?
 
I'm currently modifying the UCA mounts to allow a bit more dynamic caster and camber. While I've got things apart I'm kicking around running the coilovers upside down (if it will package worth a darn). They're gas shocks, so the position shouldn't be an issue (correct me if I'm wrong), and there ought to be a slight reduction in unsprung weight in the process.

Outside of a bit more possible debris hitting the ram/shaft of the shock due to its lower position (possibly a protective sock of sort might be a good idea), I'm just looking for any ideas of problems that I haven't thought of yet.

Thanks for any constructive input.

Your theory is sound, they inverted the shocks on crotch rockets to improve handling. I am willing to bet that aside from mounting issues stock shocks/coil overs wont function correctly inverted and may require locating some that are designed to work inverted..would it be worth the expense?

I don't have a good answer about that. I've read in magazine articles before that gas shocks will work fine upside down, but I've never tried it.
 
Top