There are a few different options out there for adjustable front lower control arms for the EVO 8/9.

One option is Deck Mechanical. 0 or 15mm wider per side: http://www.deck-japan.co.jp/



Another option is Nagisa/NAMS. Up to 15mm wider per side: http://www.nagisa-auto.com/products/...shi/index.html



The above picture is the only one that ALL places show as the CT9A arms. I, for the life of me, can't figure out how these would mount on the car. Does anyone know if this is perhaps a file photo of the NAMS arms for some other model car?

I found one set of NAMS control arms that were sold on here a couple years ago with the following picture:



Is this what the NAMS Evo control arms look like, or is this in fact a Deck unit? Or are they one and the same?

Here is the HRS/Cyber EVO control arms: http://www.garagehrs.com/hotparts/cy...vo-widearm.htm



They are about double the price of the others, and I believe are +25mm/side and aparently come with longer front axles.

There is also talk of AMS working on their own brand of aftermarket front control arms. . .

I know there are several guys on here who have used one or the other of these units. Any feedback on quality, durability of the spherical bearings, ease and amount of adjustment, etc. . . ?

EVOlutionary

 

Noob question - but besides the adjustability, what are the benefits of having adjustable control arms up front and how do the mechanics if it work?

I was looking at the Nagisa Auto arms just a couple of days back and the PR talked alot about being able to adjust the roll centre with these.

Assuming one already has the Whiteline Roll Centre kit, I'm just curious about the additional benefits of these given the price.

Also, Evolutionary, when you speak of "wider" in your post are you referring to the front track? From my days of racing Off Road R/C cars back in the day I can vouch that using a wider arm with a higher offset wheel would give you much better suspension geometry than running spacers with the stock control arms to acheive a similar increase in track.

Just curious what the objective is here - more front grip I asume but I'm curious about the theory and real world benefits.

 

Besides the adjustability, I don't think there is any real benefit. I doubt they save more than a couple # of weight, and may even be heavier than the stock aluminum pieces.

I believe that any of the examples above allow a bit more roll center adjustment than the Whiteline kit. If you want more RC adjustment than the WL kit but do not want to spend as much as a set of arms, look at the Moonface ball joints. They appear to be even taller than the WL ones.

As for the width and caster adjustment, those are made by turning the inner spherical rod ends either in or out. As you said, the width adjustment can allow you to increase your track width without causing some of the issues associated with huge spacers.

I used to race quads and found the same thing as you found with RC cars - when you throw 2" spacers on each side it really f's up your steering response. Every little bump would try to rip the handlebars out of your hands. Getting rid of the spacers and going with +2" control arms fixed this and let the front tires turn about a point around the center of the tread width rather than swinging in a big arc (I think this is called "scrub radius")

Anyway, that's my thoughts. I'd love to hear from anyone else with some experience with these producst. . .

 

Yes sorry all I can really do is speculate as well. WOuld love to hear from someone with experience using these.

 

Try hitting up Robispec, I beleive he has used the Nagasai Auto ones. From what I can remember he liked the stock arms better but I cant remember why...sorry

 

The Nagisa pic is not for the CT9A. I have posted it a few times in the past, thats for the CP9A. NAMS site has the CT9A somewhere though.

 

I was thinking about these things. Won't they allow for a good bit more camber adjustment too?

Think about it, the outer BJ moves further outward, so without moving the upper mount you are creating more camber. This is probably one of the ways some of those crazy track nuts are getting into the 5-6 degree camber range.

 

JB - that is the pic they have listed for the CT9A. They probably just didn't have a pic of the correct version so they used a CP9A photo. . . Makes sense now.

With that said, then it looks like the Nagisa and Deck Mechanical units are exactly the same. I saw one post somewhere that said one company made them for the other. Can anyone confirm that the Nagisa units are made by Deck, or vice versa??

Kekek,
I think you are right on. I think one reason why some severely lowered track cars run so much static camber is because they are in a really bad area of the camber curve. Just a little suspension compression or body roll leads to a loss of a ton of camber. They crank it way in so that it is optimal in corners - but GEEZ - I couldn't imagine trying to launch a car with 5* negative camber!! It would be like driving on ice!

 

I just wanted to bump this up, I started a thread on tire size vs. track width in the evo suspension section. I linked to here for the control arm info. Love to hear any additional opinions in either thread.

 

If you have to run 5 degrees of camber, you've got issues.

I see a large benefit here being the replacement of the bushings with spherical bearings.

- Andrew

 

Actually, I've heard quite the contrary about some track/race cars. Tire temps and all the other BS out the window mega camber can result in faster lap times.

If the OEM control arms and most coilovers lent themselves to 4-5 degrees of negative I'd try it. Biggest problem is strut to chassis clearance and the brake line clearance between those parts. IMO the biggest downside would be braking, followed by some loss of acceleration, but if the suspension setup is good and the chassis is kept flat I see no reason it couldn't work.

 

braking would be terrifying with 5 degrees of neg camber, haha

 

But why would you need to? How many degrees of body roll do people really have with 12k+ spring rates on a proper set-up even with slicks? The camber curve is bad, but it's not that bad. I'd rather add caster.

- Andrew

 

Just to confuse myself....Australian V8 supercars! They run a weird set-up i don't know much about with like -8 degrees of camber in the rain on a bumpy track.





- Andrew

 

Haha Drew, you crack me up ....

Sorry I don't have any personal experience with adj. front control arms but I can give you my worthless 2c based of book knowledge and analysis. Since the front axle length doesn't change, I would assume the adjustable control arm would allow you to change the suspension geometry so that you can:

1. Improve the camber curve for you current suspension set up.
2. Improve the roll center and roll center migration, thus lowering the roll couple.
3. Change the caster, camber and toe on the vehicle

To overly simplify, if you could measure the max lateral load transfer and max roll on the vehicle, this can be a great tool to optimize the front suspension geometry to optimize the camber curve. Sorry I just don't see how it will help increase the max front track as I was under the assumption that it is based on the length of the front axles ... may be someone can explain that part to me.