[TC.Barky]

Hi all,

Thought I'd just dump some numbers, images and thoughts on EFS vs OME suspension with reference made to what was on the car when I bought it (presumably stock leaves). Almost immediately after I bought it I changed to an EFS kit (their shocks and springs). I ran it for prob 1500kms at most with one 4wd trip. Wasn't happy with the ride quality (even derated) so changed to OME.

Before we get into dumping my notes, initial impression on the OME suspension (~100kms highway, city and a small amount of high speed dirt) is that it is worlds apart in comfort from the EFS setup (derated or not). In particular the rear is FAR less harsh.


Shocks
REAR Measurement(Centre of eye to centre of eye)

EFS
Open ~495
Closed ~310
quite hard to push. Full unloaded droop not quite hitting the shackle stopper with derated EFS springs

OME
Open ~475 MUCH easier to push. Maybe half the effort
Closed ~285

Ultima (?360005)
Open ~455 still harder to push than OME, closer to EFS but not as bad
Closed ~293



FRONT Measurement(centre of bottom eye to top of lower "cushion")

EFS and OME fairly similar to compress. EFS noticeably slightly harder but not by a massive margin

EFS
Open 530
Closed ~330

OME
Open 430
Closed ~277

Monroe GT Gas ?110c07 A (these shocks were shagged)
Open 426
Closed ~275




You can see when you also put the rear EFS shock in there, the front is longer than even that.




Springs
Rear



Rear leaf pack weight (these won't be 100% accurate but close enough to show there are marked differences)
OME 10.7kg
EFS 12.2kg (less bush and sleeve)
Factory 9.36kg (less bush sleeve and bolt)

Rear main leaf thickness (approx)
OME 6.2mm
EFS 7.2mm
Factory 6.2mm

Front weight
OME
Side A 8.41kg
Side B 8.46kg

OME Front Side B length 93-94cm

Ride Heights

Pre lift 24/6/20. Using 'Eye Brow Height' (centre of hub to lip of stock guard)
RR 430
RL 435
FR 420
FL 430

Immediately post EFS list (no driver, 0 kms driven). Swaybar in.
RR 530
FL 540
FR 500
FL 515


Well post lift EFS, springs derated (2 bottom leaves in rear, bottom one in front removed) no swaybar
28/8/21

RL 520
RR 510
FL 510
FR 500

Front at max droop (EFS, derated)
FL 555
FR 550

Rear at max droop
RL 560
RR 560


OME**
Immediately post install
Rear droop 570ish both max
Resting (only post a few bounces no drive) rear is about 500 both sides

Front resting
460 PS
470 DS (note no transfer case or driver)
Droop
FPS 510
FDS 500
100% shock limited (shock length measurement matches full open). Front shocks are limiting droop.

Shackle Angles
EFS



OME





Proof is in the pudding, could not climb this rock (little over knee height) at all due to running out of travel and spinning unloaded wheels with EFS setup. Now climb it with ease (reduction gears may be helping there too though )





My personal conclusions:
If all you want is suspension lift and you aren't overly fussed on ride comfort EFS is what you want (don't let anyone tell you otherwise - it is HARSH. I run extra heavy duties in all my other cars so I'm used to firm springs but this is next level).
OME definitely sits significantly lower than even the derated EFS springs and it will be interesting to see if the front shock length comes into play much given there is a lot less droop as the shock length is the limiting factor now (it MAY still tuck better though). Shackle angles look better and the spring sits much more flat at rest.
FYI, believe it or not EFS was a few hundred bucks MORE expensive than OME though there was a much longer wait time for OME (still less than two months) while EFS was available next day (this is in Melbourne).

If you want any more info before I try and sell on the EFS kit let me know.

[Brenno]

Well put together. Some good quality tech in there nice work

[fordem]

It would have been nice to have a "side by side" of the front springs as well, and maybe you could go back & edit in a line under the shot of the rear spring "side by side" to say top = original, middle = EFS, bottom = OME (at least I think that's the order.

Great job though, I remember taking the measurements & pictures when I put OME on my Grand Vitara, they never made into a write up though.

[pete_79]

Good comparison there mate.
I guess it really shows that there’s no perfect solution.
Gain comfort from OME, but loose heaps of travel.

For reference this is EFS front shocks with stock rear leaves up front.
I run a very small (10mm) front bumpstop spacer to avoid rubbing on the headlight buckets. But as you can see here EFS shocks on the standard mounts give plenty of travel.
Personally I wouldn’t be happy with how short those OME shocks are.

[Gwagensteve]

pete_79 wrote:

Good comparison there mate.
I guess it really shows that there’s no perfect solution.
Gain comfort from OME, but loose heaps of travel.

I don't think that's the real world outcome though Pete. I appreciate your car on derated rear springs flexes well, but that's outside of the parameters of this discussion, which isn't about RUF.

Quote:

could not climb this rock (little over knee height) at all due to running out of travel and spinning unloaded wheels with EFS setup

Whilst EFS have long shocks, the stock spring rates result in poor real-world wheel travel because they don't permit the car to get close to the bumpstop.

EFS appear to have sized their shocks to work with the (IMO excessive) camber of their springs. I'd be interested if the front shocks weren't actually too long to work at full flex. I recall some tech that 300mm (or maybe 310mm) was the absolute longest front shock that could be run without bumpstop spacing. I wouldn't be surprised if the car as taken to full flex with the EFS shock length that the axle started coming away from the bumpstop because the shock was acting as the travel stop. Most owners wouldn't notice this as the EFS springs won't get near the bumpstop.

[TC.Barky]

If I had access to a ramp or something could be interesting to run the OME springs and compare the OME shocks to EFS shocks on the front. The EFS shocks are sooo much longer closed, I've of the suspicion they're too long. The valving of the EFS and the OME on the front aren't worlds apart though, so if they do provide better full travel (ie not compromising compression) maybe that's a better combo to run?

[pete_79]

Agreed, my setup isn’t all totally relevant, but it is a clear example of the possible front shock travel of EFS shocks on standard shock towers.

If I unbolt the shocks at full droop they have a tiny little bit of down travel left in them.
But that up travel is hard on the bumpstop with a 10mm packer and not bottoming out the shock. So the EFS shock does not limit up travel in my situation either.

The thicker spring material and excessive camber on the EFS springs are sure to contribute to the harsher ride compared to the OME
But my statement that the OME shocks are too short and limit travel is also relevant.

[Gwagensteve]

OME shocks don not limit travel using an OME front spring, with the spring clamps in place and a stock shackle. In fact, the brake line goes tight at full flex on an SJ70 with the swaybar removed so there's no more droop in the design of the front end without other modifications.

With some other combination of parts they are definitely too short.

Please take this as nothing other than interested discussion. However, this is what's confusing me.

EFS front shocks are 53mm longer fully compressed than OME, and have 100mm more travel, so internal construction is basically the same. If EFS have allowed for the industry standard 25mm of free shaft at full compression to allow for bumpstop deformation etc, that means that at full compression (not flex, level compression) there would be 3" of shock shaft unused on an OME shock. It's only a 6" travel shock, so there would only be 3" of travel from bumpstop to full droop, which isn't the case, for the OME shock it's ~5" (i.e, 6" shock with 1" free shaft at the bumpstop)


Out of interest, I had a quick search on Suzuki Sierra front shock compressed lengths. Except for the Skyjacker, they're all for 0-2" of lift, so no implication of bumpstop extensions.

Rancho: 258mm
Bilstein: 262mm
Monroe: 275mm
Trailmaster: 275mm
OME: 277mm
Skyjacker "3-4 lift": 292mm
EFS 330mm

I just can't see that all these manufacturers have left so much shock travel on the table if, in fact, a 330mm shock fits while still allowing designed bumpstop deformation / safety margin, Especially the skyjacker shocks designed for 3-4" lift, which are 3" shorter than the EFS shocks fully open (!)

[Beery]

This was hurting my brain, so I went a chucked the measuring tape on my sierra.





This is just the front of my car at ride height (factory setup, no bump spacing) - shock is open about 352mm, clearance before touching the bump stop about 35mm.

So once the car is touching the bump stop you could fit a 317mm shock, however accounting for bump stop deformation of 25mm you're looking at a shock around the 292mm mark (spot on with skyjacker), quite a lot shorter than 330mm of the EFS shock. The bump stop definitely deforms quite a bit too with a soft spring, I've just been on a trip over the weekend so it's quite clear on my axle tube where the bump stop has deformed to, I'd say that's easily 25mm, possibly more, so I think OME are pretty spot on at the 277mm mark to keep the shock from bottoming.

seeing this I would question whether Pete's car fully compresses the bump stop. I think there might be a mix of it bottoming out the shock but also slightly compressing the bump stop, a hard hit in the front that sends both wheels to max compression would be hard on the shocks I think, (and the loss of compression travel) even with the 10mm spacer, unless the spring doesn't let it get that far.
unless the leaf pack is substantially thicker where it mounts compared to mine, moving the bottom shock mount down, but It wouldn't be that much of a difference to make up the 30 odd mm.

[Gwagensteve]

Thanks for your work on this Beery, I was pretty sure I was right that 300mm was about as long as you could go without spacing the bumpstop.

As I (sort of) said, I think EFS have sized their shocks based on open length, not compressed length which is, to put it politely, surprising.

[pete_79]

Gwagensteve wrote:

Please take this as nothing other than interested discussion.

Didn’t take it any other way mate.

This chat has prompted me to dig out the old notes that I took when I first started playing with my suspension setup.
I was stock everything except for a set of very old 235/75r15 tyres that measured 28.6x8.8 inches.

Average of each side measured to wheel arches;
Front stock = 769mm
Front EFS = 840mm
Front RUF = 820mm

Rear stock = 780mm
Rear EFS = 856mm
Rear same EFS after 2 years of wheeling = 828mm

Shocks open/closed.
Measured eye to washer (no rubbers) on front and eye to eye on rear.

Front
Old = 485/300
EFS = 525/310

Rear
Old = 497/312
EFS = 510/310

I didn’t take note of the part numbers on the EFS front shocks. But I did write in my notes that the front shocks were “stiff as hell”….

[Gwagensteve]

I think the convention for measuring shock length is from centre of eye to centre of bushes on the pin.

[Beery]

Agreed, I'd say that's the same shock once you add the bush thickness.

Out of curiosity, what were your old shocks Pete? they are longer than usual too. (compressed)

[pete_79]

Just went digging through all of my old photos, I thought I had a shot of the bumpstop deforming at full compression on the front, but apparently not.
The Sierra is still on the trailer otherwise I would have quickly flexed it up on my driveway flex ramp and got a snap.

I did find a pic of the old shocks though, they were Drivetech 4x4 Enduros.
Pretty sure that’s just a cheap eBay brand.

[RhysG]

Just came across this thread while trying to decide between EFS and OME for my Sierra so super appreciate the write up mate. Where did you get all the OME parts from? Plenty of places offer the full EFS kit but can't find anything for OME.

[Zook_Fan]

ARB retail all of the Old Man Emu gear, go into your local shop.

[Gwagensteve]

I believe there's issues with stock/supply, especially for OME shocks.