A fan of my facebook page "Offroading Subarus" suggested people here may be interested in the modifications we did to our race car to ensure we stopped bending struts over jumps.
Just a quick disclaimer... I would do many things differently if I were to do it again. Mainly I would make a completely custom wishbone instead of using one from another car.
I found the shortest wishbone I could at the wreckers, which was from a Daihatsu Feroza.
We cut out the "chassis rail" and welded in some 60x30x6 made up C section. Bolted the arm to it. Made up plates to go where the strut used to on the knuckle with 18mm holes for the top ball joint. These plates have two tabs going down to where the two bolts hold the strut in usually and also part of an old strut welded to the top plate going into the knuckle.
The wishbones were used upside down and the mounting of the ball joint changed by making two more holes closer into the pivot point. The wishbone arms were then shortened and reinforced to clear the wheels.
I had my brother in law make up some 24mm wheel spacers for the front for a little bit more clearance from the wishbones for when turning under travel.
I used late model Nissan Pathfinder/Navara front struts/coilovers with Mitsubishi Pajero springs cut down to about 70% length.
Using the lathe I drilled out 25mm bar with a 12mm hole to take the 190mm long M12 bolt. The struts had a 14mm bush so I made an adapting bush from part of the bar.
Top strut tops were original Subaru, rubber pressed out while being heated. Pathfinder strut top cut down to make a top spring perch only which was welded to the bottom of the Subaru strut top while a Pajero strut top was used on top of the Subaru strut top to hold the shockers thread. Holes had to be cut in the hood to clear the shocker threads.
Extra plating over the "chassis rail" was welded/bolted on
Hopefully I didn't miss anything...
We survived the entire weekend with only needing to replace one slightly bending radius rod. There is a little bit of bend on the left hand side but I can't pick where it is, I can only tell because the left wheel has negative camber now where as after these mods both were a little positive.
If you want to see the punishment we put this car through have a look at my video post in the other section under rallying.
And to give you an idea of how weak the factory struts are last year we went through 7 struts over 8 two minute laps of racing.
Edited by Phizinza, 24 November 2013 - 06:08 PM.