Hi guys, I am trying to plan production for the MEGA ARMS for you Gen 2 GS guys and I have limited parts that are shared with the IS300. I am wondering how many parts I should build up and how many are interested. I will release these for order next week at an intro rate of $350, normally $375. and with powdercoat, $400.

Again these will resolve Toe and camber issues with a drop to 2.25" and mitigate some of the other extreme drops I am seeing in this forum. I am also designing a toe link that should be able to be undermounted and that should eliminate the rest of the toe scrub tire wear issues for the rear.


a few pics, also look at the other thread in this forum for install pics and review.

Let me know, thanks, Fig

 

is the price 350 included powdercoat?

 

PC is another $50 intro.

 

how does that help toe?
also, is this for front or rear?

 

These are for the rear. It helps toe, by counteracting the toe link's influence...pulls on the rear of the hub equally when shortened to equalize things in a short travel suspension (lowered.)

I see alot of you posting up your alignment specs, while this is important for stock geometry suspensions and ride heights, you have to remember the suspension acts differently when lowered. With less travel and the arc of the connecting components made more steep, things will pull in different ways. So you have to think of how the suspension travels, not how it sits statically if that makes sense.

Fig

 

If you make rear arms, you should also offer front arms as well. By adjusting for roll center on only the front or the rear, this may throw off the balance and cause unpredictable handling.

i would also recommend a tie-rod adjusted for bumpsteer. i'm getting raped by these things and it's pretty dangerous if i don't pay attention to the road. i'm pretty sure half of the forum has this same issue but never talks about it.

cliff: roll center adjustment for front and rear, bumpsteer adjustment.

 

Hey Fig,

I'm still confused on how your arms are better / different in application compared to rear RCA's. Your arms don't lower the car like a RCA would from what I gather and I was under the impression that lowering the car with the RCA was a good thing.

So ... your knowledge and information on this is appreciated along with if your arms help increase ride quality or are they just to correct camber. Let us know. Thanks,

Scott

 

the arm is adjustable length. see that 1 end, its got a screw on it. so u screw it in and out of the welded nut on the arm to adjust the overall length.

probably a lot more complicated than that....P

 

Hi Scott, IMO it is not a good thing to lower the vehicle in an RCA, at least in the case of the GS and IS. When RCA’s were first thought up they applied to the parallelogram of a double wishbone suspension. In the case of the GS, this is a virtual double wishbone, meaning the lower wishbone is really two links, the trac link and the rear lower control arm. If both of these pieces were tied together, it would simplify the rear suspension significantly. Also, there is a toe link, which influences the suspension under compression…that’s right, rear steering. When other RCA’s lower the car with a single link, the other is still left unchanged, which means the two links now have a different arc path than they did before. Its hard to describe with words, but think about two gauges with needles at 0 degrees flat. As the dial travels around, it starts to move a lot on the x axis, but as it approaches 90 degrees, it moves less and less on the x axis. It is now travelling more on the Y axis. Similarly, when two links are meant to travel together and locate a single point and you take only one of those links, and you change where it mounts within its arc of travel, you change the suspension by adding a rotational element. It certainly changes the roll center, but it also puts more control in the trac and toe links when the suspension travels. This is how the GS multi-link differs from a true double wishbone. By changing the ride height in a single link, it will affect the way the whole suspension cycles, in this case I would say negatively.
Its also not a good thing to add weight to the suspension. This is unspring weight, weight that impacts how the damping in the suspension works, weight that is accelerated when you hit a bump. It will make things…harder to control and put more demands on your damping, especially on rough road surfaces.
Also, I think it is important to retain the stock alignment adjustment on the outside. So my arms allow a length offset to be set on the inner mount and also allow alignment adjustment by the OEM mechanism, the cam bolt. Other solutions require that you chose a setting and leave it there. Adjustment of the alignment requires the changing out of spacers and inserts to come up with a workable solution. This means time and expense at the alignment shop. It may also take a special shop to get a mechanic that understands what is going on…maybe even multiple visits and hassles.

My solution is a simple resolution to the problem that replaces the whole control arm with one that has the correct adjustment and mounting points. Consequently I added improvements to the OEM design by replacing the inner mount with a spherical bearing, adding multiple mounting locations for the sway link and making it very close to stock weight so the damping control is kept unchanged.

The correct way to lower a vehicle is with an adjustable coilover shock or in the most cost effective case, a shorter, stiffer spring. The GS, like the IS, is a complicated sum of link angles and constraints on each. It was important to add the spherical bearing to allow misalignment in the mount and still keep the suspension from binding and also keeping all links within the intended influence of their design. Also by making the link shorter in its original arc path, it allows the rear control arm to fight the toe link under compression…less bump steer, more control once again.

The biggest misconception I see on forums regarding suspension is that if the suspension can be "aligned" to factory specs, all problems are fixed. In reality, alignments are a single sample of the suspension along its travel curve and may or may not mean you have a problem at the extremes of travel or at another point. If the suspension stayed in one place, it would not be effective in its job...which is to maintain traction and control over multiple surfaces. Stock specs apply to stock suspension at stock ride height and if done properly, you will need to make adjustments to a lowered suspension to get things aligned, but they may not be the specs that they have loaded into the computer.

There are too many suspension combinations for me to suggest alignment settings at each intersection point, but my arms do allow easy adjustment of the rear suspension in the manner it was intended by design. They also provide a few extra features that make it a complete integration into the system. I have been meaning to make an animation of the stock suspension to illustrate how changes affect the travel path or dynamic alignment, but I simply have not had time to do it quite yet. I am happy to offer my solution to GS members but I also realize you guys have different needs that the IS crowd. So please give me feedback on what things concern you when lowering you vehicle. The development of these arms was driven by two goals.
1. Elimination of inner tire wear on the rear, especially with low profile tires and high positive offsets.
2. Increased control in the rear through mitigation of bump steer and reduction of energy storage in the rear control arm due to the rubber bushing. When the arm twists, the bushing makes it twist back, torsional storage of energy..this impacts the location of the suspension.

I believe both of these things were accomplished while also keeping the costs significantly lower than similar products offered in other markets that do similar things.

I look forward to your feedback and your continued questions. Someday I will have an illustration for all of this.

Thanks,
Mike

 

Hey Fig,

Thank you for your explanation of how it all works.

One more question: With your arms is there a degridation in ride quality, same ride quality as stock arms, or an improvement in ride quality?

Again, I appreciate your information. Thanks,

Scott

 

Hi Scott, there will be no degradation in suspension ride quality as felt daily driving. Perhaps slightly more high freq noise will conduct through the spherical bearing, but no popping or clicking like other "pillow ball" interfaces. In terms of handling, there will be improvement in rear traction feel and more precision in how the rear end functions over uneven road surfaces, less bump steer from the rear etc. Also, technically these arms are not an RCA in the classical sense, which would be a adjustment of the vertical roll center, but rather an link arc correction device, that limits rear toe link steering in lowered applications and allows for camber correction in this lowered geometry.

 

i have been praising these arms since you came out with these. this is a much better solution to the camber problems then rcas much more adjustability i would love to get a set but funds are tight right now and still trying to finish my paint and new leather. anybody that has there car lowered more than an inch should have these! if they want there tires to last.

 

just installed my set, gonna post more when i get a few miles on them.

 

Mike,

Are you still making these? I have a friend with a 2003 GS300 who is interested. Can you PM me a price with and with out PC? Thanks.

 

yes I am, just built a few sets last week.