Compiled 80 series suspension component spec thread... shocks, coils & more. (1 Viewer)

[Nay]

If you keep adding dead coils you will, at some point, get to a coil bind problem and need to limit bump travel. Also if you are taking the same travel shock and spacing it down you will need to add bump spacer. This is fine if that's the height you want and you are limiting bump to run 37's. However you often get to a point where total travel is the same but now CG is higher.

If I ever go to 37's I will do body work to make them fit and not limit bump travel.

You definitely can’t add dead coils forever - if you look at the FOR and Flexi coils side by side in my pics, the active winds are essentially the same, so the base rate of the active coils on the Flexi has to be lower or I would have gained a couple inches of lift.

As far as spacing down suspension travel goes, this also happens with a longer shock due to increased collapsed length. It’s just more difficult to keep the longer shock 50/50 up and down travel where you aren’t putting the ‘pivot’ of axle articulation on a limiter on one side while the other side is still moving in intended range of motion. In practice, that’s what ‘balance’ is. IMO, balance is more important than minor increases in CG and way more important than extra droop on one end.

Here’s my shock setup with 2” bumpstop drops and the upper eye mount adapter:

That’s 5” up and down, with the last cm of up travel protected by the bumpstop with a 2” drop. This is just dead easy for 37’s with a properly designed 4” coil and garden variety flex should always be nice and balanced.

This vid isn’t super flexy, but in the middle there are a couple points on the driver’s front where it’s easy to see the quick interaction between the dead and live coils and just the general overall balance as the front and rear interact.

 

[DylanICON]

Limiting bump travel is never a benefit. So it is done as a compromise to attain other things. Tire clearance, longer shock, coil bind, ect.
It should always be done sparingly. I do it sometimes, but I will often go to great lengths not to, or even to increase it (see post #75). It is worse in the back for balance and safety at speed.
I understand that most people following this thread are looking for maximum articulation. 80's are pretty flexi and well planted with even the basic modifications.
I've gone to far in the past and its not good.

 

[GW Nugget]

@DylanICON that YOTA looks like it was all rear flex which created lots of body roll...

 

[DylanICON]

@DylanICON that YOTA looks like it was all rear flex which created lots of body roll...

It actually has decent front flex but WAY to much rear. And yes lots of body roll.
That was an example of what NOT to do.

80's with radius arms are limited on front flex as well unless you 3 link it or blow out your bushings.
I think I may make an adjustable rear sway bar for my 80 and run it stiffer most of the time on the road because the rear out flexes the front even though straight travel is about the same front and rear (~12").

I rarely disconnect the sway bars and if it occasionally lifts a tire (almost never) who cares, it has lockers, and is more stable the rest of the time.

 

[DylanICON]

FYI
To get all the droop on that old truck it was triple rate. 45/90/200.

 

[GW Nugget]

Rumor has it that @Fosters is sporting some 3" Tapered coils...

 

[LFD2037]

What or who is Fosters?

 

[DylanICON]

Its Australian for beer

 

[Dragos80]

What or who is Fosters?

It's Australian for beer.

 

[Box Rocket]

Limiting bump travel is never a benefit. So it is done as a compromise to attain other things. Tire clearance, longer shock, coil bind, ect.
It should always be done sparingly. I do it sometimes, but I will often go to great lengths not to, or even to increase it (see post #75). It is worse in the back for balance and safety at speed.
I understand that most people following this thread are looking for maximum articulation. 80's are pretty flexi and well planted with even the basic modifications.
I've gone to far in the past and its not good.View attachment 1590947 View attachment 1590948

Good info. I agree with avoiding adding more bump limitation if possible. I always try to run as small a bumpstop as possible and it seems to behave the best. One of my worst experiences was with an 80 with OME springs and 3" bump extensions. That truck would flex and then pitch the truck hard when you didn't expect it to. Scary on the trail.

The Slinky kits are much better balanced in my experience with very little additional bumpstop added. For running 35's there is no additional bumpstop used in the front (just the factory "in-coil" one) and a 1" taller frame mounted one is used in the rear.

 

[Box Rocket]

I've been really pleased with the balance of the Slinky kits. They might be set up for a bit more droop than compression compared to some other dual rate coils but still have fairly equal travel front/rear. Truck stays very flat and the axles move as they should. Oh, and I run both swaybars all the time and Im planning to add a stiffer rear swaybar soon.

 

[Nay]

Good info. I agree with avoiding adding more bump limitation if possible. I always try to run as small a bumpstop as possible and it seems to behave the best. One of my worst experiences was with an 80 with OME springs and 3" bump extensions. That truck would flex and then pitch the truck hard when you didn't expect it to. Scary on the trail.

Out of curiousity, what was the intended purpose of 3” bumpstop extensions? Given how OME designs their base kits, what you experienced sounds like a proper output of the design.

The Slinky kits are much better balanced in my experience with very little additional bumpstop added. For running 35's there is no additional bumpstop used in the front (just the factory "in-coil" one) and a 1" taller frame mounted one is used in the rear.

This makes sense. If you change a ROM limiter in isolation, it’s going to have an effect.

“Articulation” is usually thought of as maximum suspension travel (noted a few posts above), but it’s meaning in terms of movement is “jointed” or “divided into joints”. So if we think about suspension motion as an interrelation of movement at multiple joints, “how much” usually doesn’t produce as relevant an answer as simply “how” those joints and their various motion limiters are interacting over a range of motion.

A lot of people choose “how much” as the mountain to die upon, and it usually delivers.

 

[GW Nugget]

@reevesci
Will you post up your stock height suspension options?
Also do you have a spec chart of your available shock options?
Is there a link I can go to for those?

 

[GW Nugget]

@David Otero has been working behind the scenes to get the specs on the Dobinson coils... Thanks David.

David wrote:
"Hey Mate, after much talking to Australia they provided the specs".

Has anyone noticed the tapered coils are triple rate?

 

[Lumpskie]

Whoa! @GW Nugget does it again!

What are the units of measure for each column?

 

[Box Rocket]

Out of curiousity, what was the intended purpose of 3” bumpstop extensions? Given how OME designs their base kits, what you experienced sounds like a proper output of the design.



This makes sense. If you change a ROM limiter in isolation, it’s going to have an effect.

“Articulation” is usually thought of as maximum suspension travel (noted a few posts above), but it’s meaning in terms of movement is “jointed” or “divided into joints”. So if we think about suspension motion as an interrelation of movement at multiple joints, “how much” usually doesn’t produce as relevant an answer as simply “how” those joints and their various motion limiters are interacting over a range of motion.

A lot of people choose “how much” as the mountain to die upon, and it usually delivers.

The OME equipped truck I referenced wasn't mine. I believe it was setup with 3" bumps because a 1" extension had been recommended for the J springs used. The truck also had 2" coil spacers so the extra 2" of bump were intended to address that. Again, wasn't my setup, just one I experienced that clearly wasn't an ideal setup.

On my own truck (previous 80) I had OME J springs and 2" spacers with no bumpstop extensions. Never had issues per se and only minor rubbing of the 35's in the rear, but that was more because of the wheels moving forward in the wheel wells as a result of the lift and stock length control arms. However, even with that arrangement the OME kit wasn't as balanced. I believe the reasons there are that the OME shocks are too short (even with the L's). Removing the 2" spacer would have helped but tire rub was more pronounced and would have required bumpstop extensions or trimming to eliminate.

Part of what has impressed me with the change to the Slinky kit on my own truck is that with a 2" decrease in ride height, and essentially no bumpstop modifications, I gained roughly 6" of suspension travel ROM with very little tire rub. It's a well put together kit IMO based on that and bodyroll is much more controlled and as I said the body stays much flatter as the suspension moves.

Whether it's Slinky or another kit used, that kind of balance is most desireable if you're wanting a good setup for good all-around performance and not just a ramp queen.

 

[David Otero]

Whoa! @GW Nugget does it again!

What are the units of measure for each column?

Part number, Free height, Turns, Wire diameter, Spring rate

 

[GW Nugget]

@David Otero sir what lift or application is this C59-175V coil for?
It looks close to the 2" Flexi rear C59-223V coil but shorter free height...

Is a 2" Flexi really a triple rate? All other Flexi coils are dual rate.
2" front C59-222V 180/220/260#

 

[David Otero]

@David Otero sir what lift or application is this C59-175V coil for?
It looks close to the 2" Flexi rear C59-223V coil but shorter free height...

Is a 2" Flexi really a triple rate? All other Flexi coils are dual rate.
2" front C59-222V 180/220/260#

C59-175v is a 65mm lift coil for no load but if you add some weight the stronger spring rate will kick in


When you see 3 rates it's really a dual rate. It’s just the coil where it progresses from the big gaps to smaller gaps is in between a big and small gap. In example it’s 70mm pitch and 40mm pitch but where it progresses to the small gaps it’s about 55mm pitch so right near full compression that coil closes and increases the rate

 

[crikeymike]

When you see 3 rates it's really a dual rate. It’s just the coil where it progresses from the big gaps to smaller gaps is in between a big and small gap. In example it’s 70mm pitch and 40mm pitch but where it progresses to the small gaps it’s about 55mm pitch so right near full compression that coil closes and increases the rate