Coil over spring orientation

Question

Coil over spring orientation

blueoval55 (Mechanical)

(OP)

27 Sep 22 14:38

So my friend has a mod lite race car. These are the purpose built cars that have motorcycle engines. This car is very similar to a dirt latemodel, in a smaller package. The car is fast, but at times wants to bounce or pogo. (Load unload right rear). So last weekend the manufacturer provided a coil over to test on the right rear. It made the car handle poorly. Came in under a caution, crew member put the old coilover on in what I would consider upside down position (adjusting collar down instead of up, spring higher in car). Starting on the back the car rocketed to third before running out of laps. Driver says car is better than it has been in a long time. So the question is, what difference is made by turning the coilover upside down techically?

BrianPetersen (Mechanical) · Answer 1 · 2022-09-27 16:15:08

Disclaimer: 0 familiarity with circle track suspension. But every coilover that I can think of, is either mounted with the spring at the top (chassis-attachment end) or sits horizontally.

Depending on the internal design, it could make a difference to the air space inside the damper. If the damping valves are in air, that is no good! Lots of dampers that don't have a floating piston separating gas from oil (and lots don't) are designed to work right side up. I am thinking that your opinion of right side up might be the manufacturers idea of upside down. Again, no specific knowledge. I could be wrong.

GregLocock (Automotive) · Answer 2 · 2022-09-27 21:24:20

twin tube shock or monotube?

Cheers

Greg Locock

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SwinnyGG (Mechanical) · Answer 3 · 2022-09-27 22:19:27

All shocks have a specific orientation in which they should be mounted.

*most* shocks that *most* people encounter will have the adjuster, and thus the shock body, on the bottom with the shaft on the top. But not all. Some companies - King, etc - design their shocks with the shaft on the bottom and tied to the reciprocating element, and the shock body tied to the fixed side. It just depends on the shock itself.

cibachrome (Automotive) · Answer 4 · 2022-09-28 12:38:42

Jegs brand ? First glance would be an oil reservoir or flow problem if pogo = lack of damping. gas gone ? Otherwise, spring seat(s) out of position. A third condition would be necessary to lock in the solution: return to correct orientation with the original part, as if it was not installed properly in the first place. Problem re-appears or not ? Then install a different shock in 2 conditions: normal & reversed. A dyno test on the part(s) would be useful at this stage...

Tmoose (Mechanical) · Answer 5 · 2022-09-28 14:35:55

Like others said more info needed.
Also like others said, floating piston monotube probably doesn't care how it is oriented because 100% oil gets pumped around.
Naturally reservoir shocks with a floating piston in the remote reservoir don't care. If there is such a thing as a remote reservoir with an "air" space and no piston it might be the same as long as the reservoir is mounted upright.

In my dirt bike days of the last millenium "gas shocks" might be twin tube with a gas bag in the outer space so 100% oil was available regardless of orientation.
There were even kits with gas bags to make your conventional shock a "gas shock." I might still have an un-used kit, but I think the freon (?) leaked thru and out of the bags long ago.
Girling did an "oil emulsion" thing so no gas bag. I don't recall if they were monotube or not.

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Coil over spring orientation