Subaru Outback Forums banner
1 - 20 of 31 Posts

·
Brucey
'17 3.6
Joined
·
13,512 Posts
Discussion Starter · #1 · (Edited)

The purpose of this post is to serve as an in depth review, test, and analysis of several lift suspensions available for Subaru vehicles.

Why lift your Subaru? It has excellent ground clearance from the factory for its class. But of course, it can always be better.

Even Subaru thinks there is an advantage to lifting and now offers Wilderness versions of vehicles that come with even more lift from the factory.

Before recently most lifts for Subaru worked by spacing the body of the car away from the suspension.

This left the vehicle with near factory handling and simply added height.

There is inherently nothing wrong with this style of lift if extra clearance is the only thing desired.

But with a suspension lift there are more possibilities.

The springs can be designed so that they sag less from load, there can be more suspension travel, and handling can be tuned to handle the extra ride height.

We will be testing some of these factors. I previously had tested the standard suspension on a spacer style lift and compared it to the Ironman suspension set up. (Link)

For the front lift of the car the design of both the Ironman, Ironman Spec C, and Flatout GR Lite extends the strut assembly down while leaving the rest of the front in its factory location. There is no need to extend the steering shaft or drop the front sub frame here.

For the rear lift of the car all the designs do the same practice of spacing the rear subframe of the car down. This moves all the control arms for the multi link design away from the car but uses a longer strut assembly. This keeps the suspension operating within its normal range of motion and fixes the issue of the front wheel being pushed forward if the rear subframe is not dropped.

Flatout includes these spacers in their kit however Flatout does not and a spacer kit from Rallitek must be purchased.

In the interest of time the Ironman spacers in the rear was left installed for both the Ironman and the Flatout spacers.

They are functionally the same and I saw no reason to exchange them.

An alignment was done by a professional after the Ironman was installed and again after the Flatout GR Lite was installed. This ensured everything was installed correctly and that there would be no weird or adverse handling effects from a bad alignment.

I tried to keep the review as objective as possible with as little subjectivity in it.

As such I have kept pretty strict guidelines for myself for this test.

At this time, the test will consist of:

Ironman 4X4's lift for the Gen 5 Subaru Outback.

Ironman 4X4's Spec C version of the same lift for the same vehicle.

Flatout Suspensions GR Lite Adjustable Coil over lift for the same vehicle. This is with their camber plate top and overload spec coil. Since these are adjustable I will be repeating some tests with the valving set to the softest versus the firmest setting.

At the time of the tests the vehicle had roughly 90-100k miles and all suspension bushings looked to be in serviceable condition.

I am breaking the accompanying video up into two parts because of the length of the individual video being quite long and will post both above for those that prefer to watch instead of read.

TEST 1: Suspension Travel.

Suspension travel is helpful when going off road as it's how much the wheel and tire is able to move up and down to conform over uneven terrain. Having 4 tires on the ground is more helpful than having 3 tires on the ground, or even 2.

Traction is one of the most important measurements of how far a vehicle can go off road. If a vehicle can't get its power to the ground, it can't go forward (or reverse).

It can also help with comfort as the suspension is less likely to bottom out and transfer the load to the chassis and occupants.

Both Ironman and Flatout claim to have increased travel over the standard suspension Subaru equips from the factory.

Ironman on their website says:

"Extended travel twin-tube struts improve control and comfort"

Flatout is more specific with their claim with:

"8” front travel 8” rear travel"

To test the travel as objectively as possible I built an RTI ramp.

Tire Wheel Car Vehicle Sky


It's commonly used in off road vehicle build circles to test suspension travel so since that's what we're testing here I felt it would be great. I constructed it out of wood and while sketchy, it's much less sketchy than the first ramp :)

It's a 20 degree ramp approximately. 22.5" tall and 61.5" long.

It's even strong enough to hold the weight of my 7000 lb Suburban.

I also have a built-in marker added for the ramp. Note that this measurement isn't accurate to the actual length up the scale but only accurate to itself since the end of the yardstick has been cut.

To say it another way, we will only be using the built in yard stick as a reference point and not an actual measurement of how far we travelled.

We will travel the driver's side tire up the ramp until the rear tire just comes off the ground and loses traction.

Remember, we want that traction so the car can keep moving. VDC, X Mode, Limited slips, and Lockers will help but all 4 is still best.

For the purposes of this test we will have both the front and rear sway bars disconnected on the vehicle.

To get a baseline for comparison, we used a couple stock vehicles for measurement. 2004 Nissan Xterra 5 Speed 4WD, 2022 Forester Wilderness, and a 2019 Subaru Outback. All these vehicles are stock. The RTI score is added as an approximate since the gauge on the ramp is up to 2" off actual.

2022 Forester: 30" (18") APPROXIMATE RTI SCORE: 285

2004 Xterra: 43" (5") APPROXIMATE RTI SCORE: 415

2019 Outback: 31" (17") APPROXIMATE RTI SCORE: 285

Ironman: 45" (3") APPROXIMATE RTI SCORE: 415

Flatout: 38.5" (9.5") APPROXIMATE RTI SCORE: 355

As we can see, Ironman is the clear winner in this scenario.

It consistently made it to 45" (3") up our ramp before losing traction.

The Flatout suspension was roughly 6" shorter up the ramp. Using some calculations for right angle triangles and using a 20 degree ramp this comes out to roughly 2" less travel compared to the Ironman.

This is also impressive for the Ironman 4X4 lift since a Subaru, a unibody vehicle with independent suspension is able to compete with a body on frame, solid axle vehicle for suspension travel.

What that amount of travel does for suspension bushings and ball joints has not been tested but in my experience the end links do not like that amount of travel.

Test 2: The Speed Bump Test

The purpose of this test is to test wheel travel as well but at speed in a controlled environment.

Unlike off road with speed tests that come later, these speed bumps are static and do not fluctuate. This will also be a good test for an individual who drives regularly on roads with uneven conditions or pot holes or multiple speed bumps in a real world test.

For this test, I will be recording the accelerometer from a cell phone mounted to the ceiling (sunroof) of the car as well as recording the interior and exterior.

I will set cruise control at 35 mph and drive over a series of speed bumps to see how the car handles the scenarios.

The best scenario here is the suspension soaks up the bumps and it is not transferred to the frame or occupants. The worst case is I break something. :)

IRONMAN DATA:
Azure Rectangle Slope Font Parallel


FLATOUT DATA:
Rectangle Slope Plot Font Line



This test (subjectively) felt smoother in the Ironman but the Flatout did well. It more quickly settled with the Ironman rebounding more.

There was one exception for the Flatout, however: There was a loud clunking noise when the coilovers would rapidly move.

This noise was also experienced over potholes on roads and some off road obstacles.

The preload in the suspension was triple checked to make sure everything was tight but had no change.

After contacting the manufacturer we were told that it was a manufacturer defect and they were aware of it.

They said they would ship new strut assemblies to correct this issue but at the time of this video nothing has been shipped and it's been several weeks.

Test 3: Sag from Load

This test is more simple than many others. I measure the height of the rear wheel arches and then put 1000 lbs of concrete in the trunk and measure the height again.

Why do this? Why 1000 lbs?

Well, the curb weight (no cargo or occupants) of a 2017 Subaru Outback is approximately 3800 lbs.

The GWVR (the maximum the car is rated to carry including cargo and passengers) is 4800 lbs.

This means the Outback chassis from the factory is designed to carry a maximum of 1000 lbs (450kg)

Do most people regularly carry 1000 lbs of excess weight?

Of course not. But some do. Especially over landers, campers, off roaders, people that tow, use their car as a truck, etc.

Sag here not only affects ground clearance but also affects handling.

If the rear is 6" lower than the front there is going to be some serious handling issues. The front tires are going to not have enough to steer.

So this is a simple test.

Measure the height of the car empty.

Load up 17 (60lb) bags of concrete and measure the drop.

At least I got some exercise. :)

Average Loss Ironman: 3.71" (94mm)

Average Loss Flatout: 2.5" (63mm)

Looking at this data it's clear that the winner is Flatout for carrying heavy weight.

It showed a 33% better performance than the standard Ironman.

For that reason if one carries a lot of weight I would recommend the Flatout suspension set up over the standard Ironman set up.

This test went to the extreme end of the realistic scale to show the most results and many are only likely to regularly carry a few hundred pounds of cargo.

It is unlikely that they would see much if any sag with the FlatOut.

Test 4: Off Road Handling

The purpose of this test is straight forward but it and the following two road tests are probably the most subjective.

However, I'm trying to maintain objectivity in this analysis. Due to that, I've done some things to help address this issue:

I've had my wife (camera wife Nita) drive the car for all these tests.

I've also logged the accelerometers on my phone and attached the phone with a mount to the roof of the vehicle.

The same as used for the speed bump tests.

I will also be using another phone to display the decibel (dBA) readings that it picks up.

I have made no changes to the vehicle between these tests, not even some necessary repairs that I have been putting off in the form of new skid plates and I have not changed tires. I checked to make sure the tires all maintained 35 psi on all 4 corners.

The ambient temperature is also recorded for the sake of posterity here.

We drove down a short access road here, approximately 1 mile. The speed was maintained to 10-20mph and this is the type of the road that Subaru has always excelled at, in my opinion.

The test was conducted on the Flatout Suspension with the valving adjusted to the softest possible (fully counter clockwise)

IRONMAN DATA:
Product Rectangle Azure Slope Font


FLATOUT DATA:

Blue Light Rectangle Product Azure


Nita: The Ironman feels great on this terrain. It's like a rally car how it soaks up bumps. The Flatout is stiffer but not uncomfortable. I would want to air down the tires if I was to drive on similar terrain with the Flatout.

My thoughts were that the increased spring rates on the Flatout over the Ironman kit were too stiff for this type of travel. There was a lot of back and forth or rocking motions over uneven areas of the road. This combined with the previously mentioned valve bottoming out caused it to be more rough in this scenario.

The mounts on the FO kit are not as quiet as the OEM style used in the Ironman kit.

This transfers a good bit of road noise to the cabin and is small but measurable.

To drive comfortably with the FO it would be wise to slow down here, air down the tires, or both.

I would consider this test a win for the Ironman and if driving quickly over uneven terrain is a goal then I have not experienced anything better.

Test 5: Highway Handling

This test is also simple. The same standards were handled for the highway speed tests. Logs were made as well.

We drove a few miles on the interstate at 75 mph (120kph) with cruise control on as much as we could.


IRONMAN HIGHWAY:
Rectangle Slope Font Line Parallel



FLATOUT HIGHWAY:
Product Blue Rectangle Azure Slope


Nita: I didn't notice much difference here. The Flatout is slightly louder than the Ironman. Other than that, the car handled well at highway speeds with both suspensions.

I think the FO kit works well here. There is less sway with it versus the Ironman and we are still running the FO in its softest setting. We are also not running any sway bars on the highway which I do not recommend but left off for the purpose of these tests. The loss of the sway bar was not noticed.

The increased road noise from the Flatout coil overs are not very noticeable here and the natural wind noise from the car equals or even overtakes it.

I do not have a roof rack or basket and so the wind noise in the vehicle is pretty minimal while on the highway.

Test 6: Twisty Road Handling

This one is easy. Same conditions as before. Drive a twisty, windy, country road :) at a set speed.

IRONMAN TWISTY:
Rectangle Azure Slope Font Plot


FLATOUT TWISTY:
Blue Product Rectangle Black Slope



Nita: I really prefer the Flatout here over the Ironman. It feels more composed and less like a big boat. Even with sway bars off I think the car felt it handled better than stock with sway bars.

I think the Flatout wins the tests for twisties in handling. The more firm spring rate works to its advantage on mid speed handling in the 35-55 mph (85kph) range. There is an increase in road noise which is noticeable but not unbearable for my palette.

It feels like it has sway bars installed even with none connected.

I can understand with the sway bars connected how well this might feel to some.

CONCLUSION/SUMMARY:

Thus far, I would say between these two specific suspensions on this specific car the Ironman has won out for my purposes.

The Flatout won out on many tests for on road capability, load, and handling and I can understand why some might prefer it.

The increased ride comfort over uneven terrain as well as the increase in suspension travel is a huge factor in this for my preference of the Ironman kit.

In our original testing for the Ironman suspension last year I found no increase in road noise over the factory suspension but since that was with only subjective testing I do not want to go further into that subject.

We did find a minimal increase in road noise for the Flatout GR Lite setup but it was nothing that was not unbearable.

Having ridden in an SCCA AutoCross prepared CR-X I was expecting much worse from a true coil over setup but was pleasantly surprised.

Stay tuned for part 2 where we compare the Flatout GR Lite in the firmest settings as well as the Ironman Spec C.
 

·
Registered
Shmoobaru
Joined
·
23 Posts
Nice work, Brucey! A real world objective suspension test and comparison. The first one I have ever seen for Subaru suspension.
Personally, I would like to lower my ride, most likely with coil overs, but am very hesitant to do so for lack of objective test results.
 

·
Registered
2018 3.6R 1" lift with Flatout GR Plus
Joined
·
312 Posts
Brucey, thank you for the effort! Your videos are always a treat.

What was the Flatout spring rate? I'm sorry I didn't see it in the text above and have just started watching the video.

I have an experience with the Flatout GR Lite as well as the Flatout GR Plus, both with different spring rates. I'll be posting a review soon.
 

·
Brucey
'17 3.6
Joined
·
13,512 Posts
Discussion Starter · #5 ·
Brucey, thank you for the effort! Your videos are always a treat.

What was the Flatout spring rate? I'm sorry I didn't see it in the text above and have just started watching the video.

I have an experience with the Flatout GR Lite as well as the Flatout GR Plus, both with different spring rates. I'll be posting a review soon.
They recommended a heavier spring due to weight regularly carried. The paperwork I have does not list a specific rate.
 

·
Registered
2018 3.6R 1" lift with Flatout GR Plus
Joined
·
312 Posts
They recommended a heavier spring due to weight regularly carried. The paperwork I have does not list a specific rate.
I addressed the specific rates and a spring preload in my review: Flatout GR Lite and GR Plus coilovers LONGTERM REVIEW
I think the harshness you were experiencing with Flatout was due to the incorrect spring rate (I got my GR Lite with 350 lb/in instead of 190-225lb/in) and the spring preload.
 

·
Brucey
'17 3.6
Joined
·
13,512 Posts
Discussion Starter · #7 ·
I addressed the specific rates and a spring preload in my review: Flatout GR Lite and GR Plus coilovers LONGTERM REVIEW
I think the harshness you were experiencing with Flatout was due to the incorrect spring rate (I got my GR Lite with 350 lb/in instead of 190-225lb/in) and the spring preload.
I triple checked the spring load after contacting Flatout and adjusted it to 1/4" instead of 1" as they originally recommended.

It helped but there is still a terrible clank noise over large bumps.

I have been waiting over a month for the updated struts at the time of this post.
 

·
Registered
2018 3.6R 1" lift with Flatout GR Plus
Joined
·
312 Posts
I triple checked the spring load after contacting Flatout and adjusted it to 1/4" instead of 1" as they originally recommended.

It helped but there is still a terrible clank noise over large bumps.

I have been waiting over a month for the updated struts at the time of this post.
The clank was due to the manufacturing defect and I remember it was crazy loud. It can't be fixed by adjustment, I have tried everything before the replacement.

The waiting times are very long with Flatout, one has to be patient, which you obviously are very much working on your videos but it is to no avail if you need the product for the shooting.
 

·
Brucey
'17 3.6
Joined
·
13,512 Posts
Discussion Starter · #10 ·
So just to clarify, this first round of testing, results, and summary was with the regular/original Ironman? The Spec-C review is coming later?
Correct.

I have it partially tested (the flatout at maximum firm setting) but haven't gotten to installing the Spec C kit yet.

The thesis length of the post/video made me decide to cut it up into sections.

I will likely eventually do a highlight/summary reel only.

But I'm just an enthusiast trying to give information to a community so I tend to be slower. :)
 

·
Registered
'22 OBW (moonroof, OEM underguards, Pedal Commander)
Joined
·
520 Posts
Thank you for doing this! May your tires and beer never go flat!
 
  • Like
Reactions: Brucey and walker

·
Brucey
'17 3.6
Joined
·
13,512 Posts
Discussion Starter · #12 ·
I think the harshness you were experiencing with Flatout was due to the incorrect spring rate (I got my GR Lite with 350 lb/in instead of 190-225lb/in) and the spring preload.
Got an update on this:

"375/325 noted here, but that seems awfully high. We normally do a 275/300 on the 3.6R now. 275/350 on overload."
 

·
Registered
2018 3.6R 1" lift with Flatout GR Plus
Joined
·
312 Posts
Got an update on this:

"375/325 noted here, but that seems awfully high. We normally do a 275/300 on the 3.6R now. 275/350 on overload."
Brucey, that is the explanation. 375/325 is crazy high and also incorrect, it would move you into a Rally / Racing car territory, which is what you don't want with an Outback and most importantly, because you can't match the amplitude of the ride frequency if the Front is higher than the Rear and that certainly makes the car ride harsh.

If I calculated the equation correctly provided I got all the variables right the OEM Front spring rate has to be 178lb/in.
So that is what Ironman is offering and as you have (and most importantly, your wife) confirmed with your delicate butt-o-meters, it feels right.

Product Font Line Parallel Rectangle


I'm running 225/250 and while it feels good, the ride is stiffer than OEM, works great but I'd recommend going lower to Ironman's values or 200/225 at the most to retain the Outback's character and more forgiving Off Road manners.

 

·
Registered
2017 Outback 3.6r white
Joined
·
126 Posts
Brucey, that is the explanation. 375/325 is crazy high and also incorrect, it would move you into a Rally / Racing car territory, which is what you don't want with an Outback and most importantly, because you can't match the amplitude of the ride frequency if the Front is higher than the Rear and that certainly makes the car ride harsh.

If I calculated the equation correctly provided I got all the variables right the OEM Front spring rate has to be 178lb/in.
So that is what Ironman is offering and as you have (and most importantly, your wife) confirmed with your delicate butt-o-meters, it feels right.

View attachment 540045

I'm running 225/250 and while it feels good, the ride is stiffer than OEM, works great but I'd recommend going lower to Ironman's values or 200/225 at the most to retain the Outback's character and more forgiving Off Road manners.

I currently have the Gr Lites with 300F/325R on my 2017 3.6r (originally bought them for a 2.5i). The front with the 300lb springs dives a lot, not sure you would want anything lower than that spring rate. Also waiting on replacements. 9 weeks plus. Seriously not impressed with their customer service. A little update or "hello" now and then would be appreciated. The clunk is very annoying and unnerving. I also have the dreaded nasty low speed wobble, for which no one has found a definitive answer to this issue (my car only has 45k miles on it).
 

·
Registered
2017 Outback 3.6r white
Joined
·
126 Posts
Got an update on this:

"375/325 noted here, but that seems awfully high. We normally do a 275/300 on the 3.6R now. 275/350 on overload."
I am getting a very noticeable dive with 300F on my 3.6r, so not sure why Flatout would recommend an ever lower rate. Albeit mine have that "manufacturing defect" which I still don't understand whether it is actually bottoming out (which would explain the nasty clunk) or in my case the 300F springs cannot handle the extra 275lb engine. Guess we are all doing R&D for them, though, in some round about way we should be compensated somehow as these seem to not be consumer-ready versions (IMO).
Appreciate the video Brucey. Looking forward to the update. (y)
 

·
Master Caster
🖤💔💙 3 Beautiful OBXTs
Joined
·
16,419 Posts
@Masonjarbeer99

The low speed wobble does have a remedy. The CKE CVT mount insert helps. The problem comes from the new CV axle angles and mis-matched pinion angles.

You ( or a shop) can mess around with shimming the transmission mount cross member to pitch down and the rear subframe to pitch up to correct the mismatched pinion angles and you can replace your front CV axles with OEM new. This should correct the issues that cause the wobble.

Or.

The CKE insert can stabilize the mount and quell the symptoms. The latter is quite a bit less $
 

·
Registered
2017 Outback 3.6r white
Joined
·
126 Posts
@Masonjarbeer99

The low speed wobble does have a remedy. The CKE CVT mount insert helps. The problem comes from the new CV axle angles and mis-matched pinion angles.

You ( or a shop) can mess around with shimming the transmission mount cross member to pitch down and the rear subframe to pitch up to correct the mismatched pinion angles and you can replace your front CV axles with OEM new. This should correct the issues that cause the wobble.

Or.

The CKE insert can stabilize the mount and quell the symptoms. The latter is quite a bit less $
Thanks Chris. We spoke about this before (via email) as a remedy. My car only has 74k kms (so approx 45k miles). So not going to invest in any new axles.
Still a mystery as to why some people get a wobble and some don't.
Was actually happy with the stock suspension on the 3.6r (much more sporty than my previous 2.5i was).

Not sure if I want to fully remove my Flatout GR Lites + spacers. Between low speed wobble, clunky (defective front struts), front spring rates that don't match the 3.6r engine weight as suspension was bought for my previous 2.5i (currently have 300F and car dives pretty good, not sure why you would want less weight, cost of having a mechanic make adjustments every time (don't have access to lift, tools, skilled help etc), poor to non-existent customer service from Flatout, just not a "happy camper" still with this whole setup. I have calmed down a bit. Just want the ride to be "acceptable"
 

·
Registered
2017 Outback 3.6r white
Joined
·
126 Posts
@Masonjarbeer99 can you firm up the rebound damping on the rears of the Flatout and see if it decreases dive?
wouldn't that make the rear "hop/bounce/rebound" more?
the front spring rate should counter the dive of the engine/car weight, correct?
still trying to wrap my head around what an acceptable front spring rate range should be for the 3.6r engine, along with the bottom out/clunk of a potential manufacturing defect in the struts (acknowledged by Flatout).
 

·
Premium Member
2020 Onyx
Joined
·
17,097 Posts
Suspension tuning is complicated and things may not interact in as simple a fashion as we imagine in our heads, so my suggestion might cause other issues, but the reason why I suggest trying it is that dive is both a function of the front dropping AND the rear lifting. Increasing rebound damping will help prevent the tail from rising. When the tail rises it tilts the car more and increases dive.
 
1 - 20 of 31 Posts
Top