Beatrush ALK - my quick review

[mrsaturn7085]

Since I haven't seen a review for this kit before, I figured I'd throw one up now that I finally got the Beatrush ALK installed on my '06 STI.

A quick summary of the other non-stock suspension bits:

TiC SST coil-overs, 7k front/6k rear - set to 9 down front, 7 down rear
Whiteline Com-C front strut tops, set to max camber, max caster
Group N rear strut tops
Whiteline 22mm F/R adjustable bars, set to 22.5 mm front, 23 mm rear
STi Pink Rear Trailing Arms with spherical bearing
STi Aluminum Lateral Links with sway tab, 6 spherical bearings, 2 Gr.N bushings
SPC Rear Camber Kit (the newest version with the highest torque spec.)

Parts still sitting in my garage:

Whiteline Roll-Center/Bump-Steer Kit (going on this afternoon - alignment tomorrow)
Group N Rear Trailing Bushings (going on... eventually)

Car is roughly aligned, though I've switched the rear transverse bushing (ALK) and swapped the strut tops due to some Com-C bearing issues since (still Com-C, just using an older bearing revision now). Settings were:

Ride Height 14" F/13.5" R
Camber -2 F/-1.65 R (was shooting for -1.5 R)
Toe 0 F/0 R

Now that all the boring bits are out of the way, here's the actual review:

I picked the parts up used, but in good shape for like $50. Considering they retail for around $700, it was hard to walk away from the deal. I did eventually find one of the mounting tabs was bent, and had to order a replacement housing from Laile, but the cost still came in lower than a comparable Whiteline kit (barely). With the purchase, I also got a set of steer control arm rods, which made the install a trivial job that took less than 1 hour (I did not do the free caster mod, in case anyone is wondering).

The Beatrush kit does have spherical bearings, but they have a unique solution for sealing them to prevent wear. A urethane washer is installed against the bearing on both sides, and sandwiched in place by the steel rod and nut. This provides a very stiff seal and also works to scrape debris off the of mount itself. I'll snap a few pictures when I'm back under the car today.

I spent some time analyzing the kit compared to Whiteline and OEM mounts, and found the Beatrush kit to be somewhere in between in terms of removing the Anti-Lift/Dive properties. It is my understanding that the Whiteline kit removes it entirely, and I'd say the Beatrush kit removes about 75% of it when compared to OEM. A plus side to this, is that it clears the OEM sub-frame by a few millimeters.

As far as the caster change - it is VERY noticeable the first time out driving, but I hardly noticed the steering effort difference the next day. I'll know more after the alignment Friday, but I expect the caster change will be comparable to the Whiteline kit. I did notice a bit of extra effort required during braking, but this was minimal, and likely due to a slight change in toe after installing these. Added dive and lift is apparent, but not excessive by any means.

Now, the biggest question - how does it feel? Going into this, I had my suspension set up in a way that feels like a stock STI, while being more composed and solid (accurate, yet not harsh). I used the Litchfield Type-25 and RA-R set-ups as my inspirations for selecting each component, and this was the first part that I installed that really challenged my design goals (one of which being: having one or less rubber bushing per suspension link, and using no urethane). Having now driven around with the spherical bearings, I can honestly say that anyone online who warns you away from a "harsh" ALK is just drinking the Kool-Aid and spreading misinformation. The added compliance from reduction of anti-lift/dive characteristics completely balances the added NVH (which is minimal). When driving over road turtles, minor bumps, train tracks, etc. I can feel a hair more vibration, but that's it!

I've said it in other threads but I'll say it again - the two biggest contributors to NVH, in my experience, have been aftermarket Japanese coil-overs which are typically too stiff (springs) and under-damped, and the use of spherical bearings in a strut top mount.

Questions?

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[Uncle Scotty]

let us know how long the bearing last....

[mrsaturn7085]

Originally Posted by Uncle Scotty

let us know how long the bearing last....

I will, though this is another forum thing that gets blown wildly out of proportion.

Before I sold it, I ran spherical joints (some unsealed) on all links on my S2000 that was purely street driven. I put over 50k on it without issue. Obviously, where you live is a factor, and corrosion isn't a big problem in Oregon.

To put that in perspective, I've had rear ball joints go bad on a Turbo MR2 within 30k miles. When a bearing or ball joint in a critical location goes bad, you WILL notice immediately once you get up to speed (55+). I had to drive the MR2 home up a freeway and felt like the rear end was just waiting to rip around and spin me.

Prior to that, I had a spherical bearing on the trailing arm of a CRX Si. The car had a full roll-cage but was driven to and from the track, as well as street driven 2 days or more weekly. Put 80k on that before pulling the arms for inspection and the bearings had no measurable play.

FWIW - Subaru installed spherical joints on the rear arms in some of the JDM models, and it's well known that the Evo ran spherical bearings in many links. Spherical bearings obviously do wear out (a little faster), but so do bushings. And you can replace the bearing cartridge on the Beatrush kit. The seal design of the Beatrush kit is pretty slick, and works both as a seal, and as a scraper.

Having spent a 4 years on a racing team, I've learned to trust actual engineering analysis and information from parts manufacturers over that of colleagues (especially on forums).

So, as a quick update today - I installed the Whiteline RCA/BSK last night, and the car feels entirely different after setting front toe to a rough zero point. Cornering is VERY noticeably flatter, and there was an increase in NVH roughly 2-3 times greater than the ALK added (small potholes/train tracks/rough roads only). That being said, the amount added is still extremely manageable.

[Uncle Scotty]

man...there is good reason for spherical bearings getting bad reviwes

they can and DO get loose and make all sorts of noise

and maybe you just dont hear it or care...but.....many of us do and care

and many of us have grown out of driving race cars on the street

[mrsaturn7085]

If you have a loose bearing at a pickup point, it will cause a lot more than noise. Spherical joints are a black and white thing - they are either good or bad. If they are bad they will not hold alignment and will cause vibration. I wouldn't consider the Evo a race car.

Have you personally had this happen on a sealed bearing? In all the cases I stated, I have not.

For those that are interested in the technical side of things, based on my suspension model and calculations, my changes and alignment produce the following when compared to the stock measurements:

50-52 mm lower roll center (considering the ~30 mm drop, this is a roll couple less than 1" longer than stock!)
~1 mm increase in scrub radius
1.71-1.73 deg increase in SAI

The minimal scrub radius change means the Stock BBS rims (or other Subaru rims, such as the RA-R 18" wheels) will work GREAT without a spacer. The added caster should balance out the increase in SAI (which would be a LOT worse if I hadn't bumped the camber from -0.5 to -2.0). I have not factored in the bump steer yet, but once I get it all aligned, I hope to have some time over a weekend to get a read on this, as well.

[Uncle Scotty]

and most of us are smart/mature/experienced??? enough not to try to drive race cars on the street

race cars use spherical bearings.....street cars do not

there IS a reason for this....and many of us been there done that and KNOW better

[mrsaturn7085]

If you'd like to continue to stomp my post that started as a simple review, or simply to have the last word, go ahead and take it... but what you are saying is incorrect.

The Evo VIII and IX use sealed spherical bearings throughout their suspension. A number of Impreza trims did on the Japanese market, as well. If you'd like to define those as race cars, be my guest, but you are perpetuating a broad generalization that is, for the most part, false.

I did not say anyone was not smart, mature, or inexperienced. I do however, have a background in automotive engineering, though I am currently employed in aerospace/defense. I tend to look at things from a technical standpoint rather than listening to people that say the equivalent of "this is a bad idea because the majority of anonymous forum users say it is".

[trev762]

Originally Posted by mrsaturn7085

If you'd like to continue to stomp my post that started as a simple review, or simply to have the last word, go ahead and take it... but what you are saying is incorrect.

The Evo VIII and IX use sealed spherical bearings throughout their suspension. A number of Impreza trims did on the Japanese market, as well. If you'd like to define those as race cars, be my guest, but you are perpetuating a broad generalization that is, for the most part, false.

I did not say anyone was not smart, mature, or inexperienced. I do however, have a background in automotive engineering, though I am currently employed in aerospace/defense. I tend to look at things from a technical standpoint rather than listening to people that say the equivalent of "this is a bad idea because the majority of anonymous forum users say it is".

Hate to say it but there is truly a reason why spherical bushing r not used for the street bc when things do go wrong can be fatal!! Not so much to do with nvh.

With u having an automotive engineering background I would be stressing the point about preventative maintenance also as most of these kids don't consider this like u or other people that know what to look for.

I think as far as the type RA models r basically an all out track car for the street and I can bet the maintenance schedule on them would be horrendous. Here in canada they're black listed and for good reason more so do to with climate just like u had already mentioned.

It is a good right up and for people to find out what works and what doesn't especially for people that r taking their cars to the track but I would not advise to use them for the street with out stressing implications of going this route.

[mrsaturn7085]

Originally Posted by trev762

Hate to say it but there is truly a reason why spherical bushing r not used for the street bc when things do go wrong can be fatal!! Not so much to do with nvh.

While this *could* be true, it is no more true than what happens when a ball joint goes bad (which is, again, another black and white thing - it's either good, or it's not). A rubber bushing twisting free (not common on our cars, but it happens on MANY other vehicles) would be just as "fatal" as a bearing having excessive play.

Essentially you'd have a wandering pick-up point causing the alignment to shift constantly while in motion.

A more dangerous situation when replacing a rubber pick-up point with a spherical bearing is forgetting to consider the increased forces the mount to chassis points will see. Having a mount rip out of the frame is far worse than having highway vibration (that should warn you early enough that you need to address a problem).

Spherical bearings are used in a plethora of street cars; typically, in high-end sports cars, but I used the Evo VIII/IX as an example as it is probably the most "tame" of all that I can think of.

I'm glad you touched on maintenance - maintenance on sealed spherical bearings, assuming the seals were well engineered, should be less than that of Urethane bushings, which many people seem to have no issue putting it a rotational location (such as lateral links, trailing arms, and most ALKs).

[trev762]

Originally Posted by mrsaturn7085

While this *could* be true, it is no more true than what happens when a ball joint goes bad (which is, again, another black and white thing - it's either good, or it's not). A rubber bushing twisting free (not common on our cars, but it happens on MANY other vehicles) would be just as "fatal" as a bearing having excessive play.

Essentially you'd have a wandering pick-up point causing the alignment to shift constantly while in motion.

A more dangerous situation when replacing a rubber pick-up point with a spherical bearing is forgetting to consider the increased forces the mount to chassis points will see. Having a mount rip out of the frame is far worse than having highway vibration (that should warn you early enough that you need to address a problem).

Spherical bearings are used in a plethora of street cars; typically, in high-end sports cars, but I used the Evo VIII/IX as an example as it is probably the most "tame" of all that I can think of.
B
I'm glad you touched on maintenance - maintenance on sealed spherical bearings, assuming the seals were well engineered, should be less than that of Urethane bushings, which many people seem to have no issue putting it a rotational location (such as lateral links, trailing arms, and most ALKs).

Ball joints and spherical bushings is like comparing apples to oranges as ball joints r designed to make clunking sounds when worn and usually from the protective boot being ripped or split plus will make a mess around the area where the ball joint is boot is torn. Ball joints r designed to wear in an up and down type wear not like at spherical bushing where it wears in every direction.

In most if not all high end sports cars use sepherical bushings but don't forget these r people with deep pockets that can keep up with the rigorous maintenance schedule plus these cars r only used in fare weather conditions. But when u consider Porsche or the new maclaren P1 in which these 2 alone were designed to run in any type of weather and do not utilize spherical bushings for this reason.

Now a booted hymjoint (sepherical) bushing like what subaru did with the 2011 sti on the front lower control arm would be the most optimal for the street just like Porsche has bin doing for quite some time.

The problem with open sepherical bushings if not checked "regularly" is there is no tolerance allowed for any play when they're starting to wear out unlike a regular bushing or balljoint. All it would take is a sharp hit in the wrong direction and it will literally shatter in which can cause a really bad accident.

All of the sepherical aftermarket alk I've seen either says for Off Road use only or motor sport use only.

[Blitzcrank]

Every car has bearings.

Your typical tie rod end is a bearing. As is your typical ball joint end. A ball (aka stud) inside a housing (aka socket).
As has been mentioned there are many vehicles which use spherical bearings in the suspension.

Just like with any other part of the vehicle, the safe use of bearings must be engineered. By bearing design and it's mount. A tie rod end achieves both of this with the design of the bearing, the way it bolts on and the tapered design of the mount.

There are 2 reasons why bearings are not used more in suspension related areas. One is NVH and the second is cost.
Disregarding NVH. To achieve a similar lifespan of a bush (worth only a few dollars), you would usually need a bearing that retails for upwards of USD20.

The bearings I use for suspension arms start at around USD80.

NVH and cost are the only reasons I would ever hesitate to use spherical bearings on a road car. If designed properly they are perfectly safe, as can be seen by their use in 'tie rods' and 'ball joints'.

[dobie0791]

Subaru spherical lateral and trailing links are booted heim joints just like the 2011+ STI front control arm bushings are. Are there issues with those control arm bushings failing prematurely? I have not heard about any problems with them.