Alfa Romeo 4C Forums banner

1 - 18 of 18 Posts

Vendor
Joined
923 Posts
Discussion Starter #1 (Edited)
We are proud to finally launch preorder on GMS performance rear arms. Product is now officially available as a preorder and expected to be dispatched within 30 days. As a preorder, free shipping is offered with the use of coupon: "PREORDER PRA". You can choose between incognito black electrophoretic anodizing or classy polished and clear coated raw finish to show off the state of art hand TIG welds in its beautiful, color spectre of heated 25CrMo4 tubes.

You are welcome to place your order here: 馃弫GMS Performance rear arms馃弫

P.S.: Also preorders for GMS OCC system are opened now here: GMS OCC system

Thank you all for your support.
116434286_155249429486665_7867515562813677426_o.jpg 116617523_155249392820002_4936010036412363827_o.jpg 116608323_155249349486673_4365076211555678211_o.jpg 117125637_158727322472209_1934066044638609108_o.jpg 117125142_158727292472212_3187161725518222005_o.jpg

PRODUCT DESCRIPTION:

From the very beginning of its launch, the Alfa Romeo 4C is a subject of poor handling reviews from journalist and users. If you have ever wondered why your 4C has all the potential of a high performance car, fully carbon monocoque, excellent power to weight ratio and looks like a supercar, but it drives less so, here is the answer.

Design of the rear arms of 4C in conjunction with stock soft rubber bushings is not engineered appropriately for a performance driving. Under heavy cornering, acceleration or braking, rear arm rubber bushings cannot withstand the forces transferred from tires to the suspension and the arms, so they flex, which causes a massive dynamic toe changes and therefor the rear end of the car feels floaty, disconnected and very unpredictable at the limit. The more grip the car produces, more noticeable the problem gets. Replacing stock rubber bushings with GMS uniballs solves the flex in rubber bushings, but as the flex cannot occur in the uniballs it does occur in OEM rear arms and dynamic alignment change follows. Solution? GMS performance rear arms for Alfa Romeo 4C. The next level handling upgrade.

GMS performance rear arms are CAD designed and made of CNC laser cut aircraft grade CroMo tubes with superior strength, ductility and resilience material properties and then hand, TIG welded into the state of art performance Alfa Romeo 4C part. They utilize GMS uniballs and GMS ball joints, provide zero flex, 800g reduced unsprung weight, hassle free, 100% plug and play installation and unparalleled durability. GMS performance rear arms are available in incognito black electrophoretic coating or polished and clear coated raw finish, to show off the state of art TIG welds and its renown colorful pattern.

PRODUCT INFO:
  • Unmatched handling precision
  • Zero flex and dynamic alignment change
  • 800g lighter per pair
  • Reduced unsprung weight
  • Aircraft grade, 25CrMo4, laser cut tubes
  • Superior strength, ductility and resilience material properties
  • Hand TIG welded
  • GMS uniballs rubber sealed uniballs for weather proof use
  • GMS ball joints rubber sealed uniballs for weather proof use
  • Rust free
  • Superior durability
  • Maintenance free
  • Sold as a set (1x left rear arm + 1x right rear arm)
  • Plug and play, hassle free installation
  • incognito black electrophoretic coating or polished and clear coated raw finish
  • Fits all Alfa Romeo 4C Coupe and Spider models
 

Premium Member
Joined
1,650 Posts
So this new offering has your bushings installed, and is overall stiffer than the existing A-arms... is this correct? So what is the real benefit to owners who have already installed your bushings? I'm moving to 265 rears, so it the flex that much that I could feel it?
 

Registered
Joined
924 Posts
Rudi talked about an extra gain, similar to the uniballs in the first place (so double). For semislick and slicks the advantage will be the most, of course.
 

Premium Member
Joined
1,118 Posts
...zero flex and noticable weight reduction - 900g lighter / per arm than OEM. That's unsprung weight, the enemy of suspension, acceleration and decceleration performance.
Is it worth doing this to the front arms as well?
 

Vendor
Joined
923 Posts
Discussion Starter #9
The length of front arm is very short, they are four per wheel, the front end is much lighter and tires narrower, so the force at cornering the front arms are exposed to is nothing compared to the rears, so from the point of rigidity no upgrade is needed. We are working on it anyway. Why?

1. Substandard quality of OEM arms. Significant dimensional difference between two arms (length, weight, angles), poor welds and rust is bothering me
2. We can save a decent unsprung weight as there are 4 of A-arms per side. CAD drawing and analyze is showing about 30% lighter weight than stock, but that's just a guesstimate for now
3. We need to develop solution for replacing stock rubber bushings

But as mentioned before, GMS adjustable ARB's need to be finished first.
 

Vendor
Joined
923 Posts
Discussion Starter #11
Some insight in to the production of GMS performance rear arms. 25CrMo4 tubes, end joints, ARB brackets and reinforcements, all CNC'd. From here on, our TIG welder does its magic and then the arms go in to electrophoretic treatment and powder coating. After that, back to the workshop for uniball and ball joints installation.

Rear arms 2.jpg Rear arms 1.jpg Rear arms 3.jpg
 

Vendor
Joined
923 Posts
Discussion Starter #13
Above you have MIG/MAG welds and below you have TIG welds. Different techniques, different materials, that's why the final results are different. However, I'll be honest with you. This is how my welds would look like too, or perhaps even worse, regardless of the welding technique. I do some basic MIG/MAG welding which does its job, but looks poor compared to TIG, but when I tried TIG welding I realized it it is no joke, especially ultra thin wall tubes like we have here for the rear arms. You burn a hole through the wall in a moment. The more welds and welder's products I see, the more I realize that our guy that is doing all the welds for us, is out of this world.

Rear arms 5.jpg Rear arms 4.jpg
 

Registered
Joined
245 Posts

Attachments

Registered
Joined
924 Posts
I truly appreciate the quality of work, but I don't live under my car.
Hence, when I need to choose between black or having an argument every year during technical inspection, I'd take the black...
 
1 - 18 of 18 Posts
Top