A-Arm Suspension

Updated: Nov 2, 2019

So the A-arms and front suspension geometry on the truck was mostly designed by my good friend Mr Stephen Hall Jnr. At the end of the day he is the one with a Motorsport degree in engineering and i am just a sparky that can bend tube and weld metal together. Sometimes you need to know when to get some professional help. When it comes to things like Camber, Caster, ackermann, bump steer and bump camber ect I had little idea of what the optimal amount would be for a trophy truck but Jnr worked his magic and designed some awesome Arms which fit the design criteria of the truck.

Some of the issues we were faced when designing the arms, were clearance issues in regards to Tyre size. The truck is actually design to take a 40" tyre!!!! well i figured if i was going to build a truck might as well build it properly to take a 40" for #Finke desert race. So fitting a 40" tyre into the truck was a bit of a packaging nightmare. We actually keep joking about the fact the truck is so huge however it has no room to fit anything anywhere.

Another huge hurdle to overcome was i wanted to fit a 3.0" Coil over and 4.0 Bypass shock in the front arms. Now this is where programs such as Fusion360 and Solid-works are worth their weight in gold. Because we had an accurate model of the frame and after many emails to FOX i was able to obtain the CAD drawings of the bypass and coil over shocks we were able to assemble them all together in the model and not only look at how they fit, but we were able to cycle the suspension arm to show any clearance issues and make the appropriate changes all before any manufacturing takes place.

First off the laser cutter were the top Arms. These are made from 0.120" chromolly plate. They are fully TIG welded on a jig to hold their shape and minimise warping during the welding process.

Next off the laser cutters were the lower A-arms. These things turned out amazing! There is so much thought gone into them. They are clearanced for the large coils at full droop and they maintain bombproof strength. The lower arms come in at around 15kgs each which is pretty awesome considering how much plate is in them. They also took a huge amount of time to weld together, with one lower arm taking close to 24 hours of Tig welding to complete. when you are doing this much Tig welding it is pretty much an necessity to have a water cooled Tig welding machine. If you don't have a water cooled machine don't worry as it is an easy DIY upgrade that you can do for very little money and get a huge gain out of your current welding machine which will go from welding from say 5-10 minuets non-stop then needing to cool down the hand piece to being able to weld at full current up to 250amp continuously with no time limit and your torch will be cool enough for you to tough with a bare hand!