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.
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.
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)
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.
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.
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.
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.