MX73 strut into AE86

[Hen]

Mino Rob - If you are using MX73 steering arms, use MX73 tie rods. And RA60 rack ends. They will screw together fine. Just check that length is ok.

If you say AE86 tie rod tapers are too small for MX73 arms then I think RA60 tapers will be too small too.

Hen

[minorobsession]

Thanks Hen seems that the piece are falling into place, I will just need to get the pieces and try it out.

[Grant]

Can I ask why you are wanting to do this? The MX73 brakes are not what I'd call a performance upgrade (no offence intended). If you want a cheap upgrade why not use RA40 struts (I assume they fit on the AE86 steering arm) fitted with RA60 discs and brakes. You'll probably have to modify the brake mounting plate but that gives you a 258mm disc instead of the 248mm MX73 discs. Once you have the RA40 strut though upgrade options are plenty if you are prepared to make a new brake caliper backing plate. RA60 hub + Peugot 283mm or Volvo 288mm discs; RT104 hub + 294mm rear RX7 discs. Calipers range from single spot VR, twin spot VT or 4 spot RX7.

Years ago I simply bolted the RT132 struts (266mm solids with twin spot calipers) to my AE86 and that gave a substantial brake increase. That is another option too.

[slide86]

you dont need a caliper mounting plate with these struts to run nissan 4 pot calipers. they bolt straight on, thats one of the main advantages.

[Grant]

Which struts are you talking about and what disc can you run if mounted in the standard position?

[takai]

You can run a R33 4spot caliper, along with the BA Falcoon disc on the MX73 and MX83 gear. For 73 you have to redrill the holes in the caliper, and for both you need a small spacer ring to centre it on the hub...


Cheers BigPerm for teh photoz.

[Grant]

Interesting. I guess it depends on the guys budget. Personally for an AE86 I think the RA60 upgrade would be more then satisfactory for a bang-for-buck ratio. I considered the BA/ VT discs for the Celica but didn't want to increase the unsprung weight to that extent.

[takai]

The R33 caliper is actually quite light, and i daresay it would offset the extra weight of the disc....

[BigWorm]

Oh, help yourself to the photos!
And the redrilling is required on the disc, not teh caliper. Also the hub needs a few mm shaved off the outer edge. Dunno which hub you'd use with when sticking it all in a sprinter.

[Grant]

Personal choice in the end. For me, I'll probably be using the 283mm peugot disc on a RA60 hub and VR calipers. Great conversion for an MX73 or 83 though!

[terryo]

the king-pin angle on the RA40/RA60 strut is nearly 4 degrees different to AE86. that means positive camber unless you use 35mm longer bottom arms. what is the angle on the MX73 struts????

[Grant]

Are you sure about the RA40? I thought the RA40 was the same as the RA23 and that was the same as the AE86? Been a while since I had my AE86 so memory is fading a bit.

[Hen]

I was just out researching at Pick a part this morning and I found:

RA60 brakes definitely do not fit RA40 struts. Hubs and discs fit, but the brake mounting is totally different. RA40 brakes mount to a backing plate bolted to the strut, RA60 brake mounts are cast onto the strut. Also RA40 mount holes are spaced wider than RA60 mounts. Also RA60 disc will not fit through RA40 calipers.

RA40 steering arm bolt spacing is smaller than RA60, so I assume the same as Sprinter/early Celica.

By eye, RA40 king pin angle seem to be less than RA60. I've also heard from other sources that RA40 KPI = AE86 KPI.

Hen

[slide86]

You can run a R33 4spot caliper, along with the BA Falcoon disc on the MX73 and MX83 gear. For 73 you have to redrill the holes in the caliper, and for both you need a small spacer ring to centre it on the hub...
.

do you need to space the caliper back to change the offset, or does bolting it straight to the strut work.

i know i mine, i had to use a spacer to move the caliper back so it fitted on the disc properly.

[BigWorm]

No spacer on the caliper is required, was yours the exact same conversion? I know if you use the skyline discs a spacer is needed to space the calipers further out (only 10mm or so IIRC), but that makes finding wheels with the correct offset that also clear the caliper an absolute PITA. That's why I went for the BA falcon disc.
Even then I my wheels hit the caliper, but a 3mm spacer behind the disc was enough to solve this problem, and just meant that the disc wasn't perfectly centred in the caliper, but only by 1-2mm. Without the spacer the disc is about 1-2mm inboard of the centre of the caliper, with it's 1-2mm outboard of the centre.