5th Coil Discussion

[strong08]

-Id like to hear some discussion on the 5th coils. Its something that its talked about very much. When taking rounds out of (raising the coil nut up) taking spring load out will that make the car loser or tighter. And the opposite when putting rounds in (lowering the coil nut) putting spring load in. -Is this how one would take bite out of the care or put bite in the car.-And how would it affect things with two different springs with different spring rates say a #250 vs. #300 spring.

[TheJet-09]

I don't look at the 5th coil as a loose or tight adjustment (but maybe our definitions of those terms differ). I look at it as how quickly it comes in and how long it will last.

There's been some pretty good discussions on the topic here in the past...with some very good/technical information.

[MasterSbilt_Racer]

Aside from moving it backwards or forward, or shock adjustment, most any other adjustment is a bad idea, IMO

All the 5th coil is attempting to do is smooth out the shocks the tires see from anything that causes tire load to change or tire speed to change. It's a complicated spring and mass oscillating system. You can remove traction by tuning it poorly, but it doesn't make traction. Any load the rear gains from compression of that spring is equal to load removal from the springs at the 4 wheels. It's essentially redistributing the total load of the cars weight.

[Austin34471]

Aside from moving it backwards or forward, or shock adjustment, most any other adjustment is a bad idea, IMO

All the 5th coil is attempting to do is smooth out the shocks the tires see from anything that causes tire load to change or tire speed to change. It's a complicated spring and mass oscillating system. You can remove traction by tuning it poorly, but it doesn't make traction. Any load the rear gains from compression of that spring is equal to load removal from the springs at the 4 wheels. It's essentially redistributing the total load of the cars weight.

The only way it can “make traction” is by biasing the anti-squat it generates in a way the helps load the tire that is insufficiently loaded on the rear axle [at the expense of other tires). However, I am firmly on team: for the most part, the 5th coil is stupid and doesn’t matter.

[ZERO25]

Depends on car and setup. My buddy regularly drives Whiteners backup car. They only adjust pre-load all night long!

[MasterSbilt_Racer]

Depends on car and setup. My buddy regularly drives Whiteners backup car. They only adjust pre-load all night long!

True preload (5th coil is statically shorter, but pinion angle remains constant) simply increases the value of the force required to make the 5th coil stop acting like a solid rod and start acting like a spring. (There is no spring compression until applied force overcomes preload.) It will speed up that load redistribution that Austin34471 described. The 5th now has zero damping during that window of time of no spring compression. Does that matter? Did they allow pinion angle to change and did that benefit drive line alignment?

I don't think Whiteners crate victories or super defeats prove any science.

[Burke1118]

Depends on car and setup. My buddy regularly drives Whiteners backup car. They only adjust pre-load all night long!

And they adjust how much the tires are doped!!!! That extra pre load probably just keeps the shock from breaking as easily when he monster trucks whoever is around him

[Punisher88]

So if I read Austin's comments correctly, then moving the 5th coil left or right to try and add load to one side versus the other under acceleration could simply be done by using load itself in the spring and not moving the 5th around left to right on the housing? I have spoken to a few people that believe in moving the pickup point to the left side of the housing is a large improvement in forward traction and planting the lr. It's quite a contraption to clear everything though.

[MasterSbilt_Racer]

So if I read Austin's comments correctly, then moving the 5th coil left or right to try and add load to one side versus the other under acceleration could simply be done by using load itself in the spring and not moving the 5th around left to right on the housing? I have spoken to a few people that believe in moving the pickup point to the left side of the housing is a large improvement in forward traction and planting the lr. It's quite a contraption to clear everything though.

If you move the lift bar closer to the lr wheel more of the load it steals from other corners will be deposited at the lr wheel. I can get all the lr drive I could ever want with a normal lift bar, so I don't see how that's needed. It would do the job though.

[Punisher88]

Understood. Thanks mbr

[ZERO25]

True preload (5th coil is statically shorter, but pinion angle remains constant) simply increases the value of the force required to make the 5th coil stop acting like a solid rod and start acting like a spring. (There is no spring compression until applied force overcomes preload.) It will speed up that load redistribution that Austin34471 described. The 5th now has zero damping during that window of time of no spring compression. Does that matter? Did they allow pinion angle to change and did that benefit drive line alignment?

I don't think Whiteners crate victories or super defeats prove any science.

Maybe, maybe not! The driver said he felt each change!

[Burke1118]

Maybe, maybe not! The driver said he felt each change!

Drivers say a lot of things...

[ZERO25]

Drivers say a lot of things...

Not this driver, hes been a friend of mine for 15 years!

[CCHIEF]

...Think about how increased dropout setups on the LR might affect the necessity for preload on the 5th coil dynamically ...from what has generally been considered the norm.