MacPherson strut to Top Wishbone conversion

[Phizinza]

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 November 24, 2013 by Phizinza

[monstaru]

NIce job!

I would definitely build my own A-arms.

Keep up the good work. And don't forget what the Toyota world has to offer with stock replacements via King Shocks.

cheers

Edited November 25, 2013 by monstaru

[Uberoo]

So did you get anymore suspension travel?

[Phizinza]

No, not with this wishbone setup. But we weren't after more travel so it didn't bother me.

[Vegablade]

This is a sweet setup.  Looks way strong.

[apintonut]

sorry i didnt catch how the taper of the ball joint was mated to the subaru knuckle?

[Phizinza]

look at the middle pic. I made a plate with two tying plates using the original bolts and put an 18mm hole in the plate to take the taper of the Rockey ball joint.

[81EA81]

Now that is definitely thinking outside of the box! I like it! A great way to fix a weak link.

[apintonut]

i was thinking mustang 2 upper control arm

you can get tube ones from speed way cheep

Edited December 16, 2013 by apintonut

[Uberoo]

i was thinking mustang 2 upper control arm

you can get tube ones from speed way cheep

if $100 per control arm is considered cheap to you then go for it.

[apintonut]

ok then use some ones stock take offs till you can upgrade or use saab 900 from ~1989

[Uberoo]

Whats with the reference to 79-93 saab 900 control arms?While they have a arm suspension they are not the only ones.Heck even truck/suv ifs has a arm suspension-granted it is suspended by torsion bars...

Edited December 16, 2013 by Uberoo

[apintonut]

are you just listing the cars with twin a arm suspension?FYI saab 900's had A arm suspension until 94 with the introduction of the NG900 or gm900. Even then though for an application like this you don't even need a front control control arm,independant rear a arm suspensions are fairly common.

the mustang 2 (pinto is the same) i have 

the saab is somthing i was going to use for another project so im familiar with it (and think may fit a subaru axle)

[Uberoo]

the mustang 2 (pinto is the same) i have 

the saab is somthing i was going to use for another project so im familiar with it (and think may fit a subaru axle)

adapt the saab axle to the subaru,because saab axles are very beefy,unless you need the subarus greater operational angle