AE86 vs RA40 hub and strut measurements --- HELP

[takai]

Ok, im mid way through doing my new brake package on the race car and its turning out to be a sweet pain in the arse.

This is a stock AE86 strut and hub with FC caliper with an S13 disc, which according to DBA has a 49mm overall height.


This is a RA40 strut and hub, with FD caliper and S15 disc, which according to DBA has a 54mm overall height.


Now that sits a hell of a lot more than 5mm closer to the strut, and im not sure why.

With that in mind, i think there could be only a few variable factors, one that the AE86 mounting thickness (i..e. the thickness of the area where the hub mounts to the disc) is thinner, or that the entire hub itself is taller to push the disc out a chunk.

I.e. can someone measure A and B on this picture:


Does anyone have measurements for the AE86 hub around, as i dont have any AE86 hubs left.

[fergo308]

I've been trying to sort this out myself for a while now on my project AE86.
Matching RA40 coilover-converted struts to AE86 control arms,with 45mm RCAs and getting big brakes in there under a 15x7.5" -8 wheel,and making it all clear nicely hasn't been easy.

I gave up on using nissan callipers as the brackets required would be extremely complex,and a 30mm disc just won't fit. Noone's going to want to machine down the sumitomo callipers to suit the thinner disc,so the R32 GTS-t callipers I have on hand aren't going to be any good.
the widest disc I could get to fit in was 22mm thick,a Z31front,which is 280x22.
the calliper I ended up choosing as it will fit in once brackets can be made was a spoon 4 pot for the DC2 Integra. these aren't cheap unfortunately,about $1400/pair. the pads are easy to get though,in any compound you like,so living with them once they go in will be easy. easier than something like a willwood,which was my previous choice.

I might be able to get an AE86 hub and an RA40 hub out of storage sometime this week,and I'll post the measurements if I can find them for you.
I DO remember that the RA40 hubs are bigger in diameter and are both taller and wider in the hub and bearing areas respectively,when compared to the AE86 hubs. I'll put numbers to that when I get a chance.


Justin...

[takai]

All good, ill post pictures soon of my solution. It all fits though.

[fergo308]

Cool,I'd be very interested to see what you came up with. does your car run a similar setup to what I posted?


Justin...

[takai]

What i was worried about was whether the RCA would fit in, which it does.... just:


And this is a 280x30mm S15 disc and Mazda FD caliper poking out from underneath a 15x6.5 Simmons V4, which has possibly teh worst caliper clearance ever:

From the back:


Clears the nuts by about 3-4mm.

[fergo308]

Looks like it'll be all sweet. is a bit too different to my setup to be a solution for me unfortunately.

Have you got someone to do the calliper bracket?


Justin...

[takai]

Ill sort it out myself, just have to get some time to mock it all up.

[jondee86]

I.e. can someone measure A and B on this picture:


Does anyone have measurements for the AE86 hub around, as i dont have any AE86 hubs left.

I measured 20.75 and 41.95 on an AE85 hub, and I'm sure they are the same as AE86.

Cheers... jondee86

[Sam_Q]

I am surprised to see you using an NRCA, a normal scaper won't fit?

[takai]

Normal RCAs do fit, but we have to run stock LCAs in our class, but "strut spacers" are free.

[Sam_Q]

oh I see, nice way to get around the rules!

[takai]

Its not really getting around at all, perfectly legal and a fair few people run them.

[cri_ag]

do you think it would fit without the nrca? looks like the lower control arm (with a standard rca) would be hard against the back of the disk. what the reason for the ra40 strut? bigger stub/bearings?

[CrUZida]

The RA40 hub is near identical to the MA61 hub, except the rim mounting flange is either 8 or 10mm further inboard on the RA40 hub.

I never looked at the disc mounting flange as it didn't concern me.

If you get really stuck I have both an RA40 and AE86 hub on the bench at the moment, PM me and I'll get measurements over the weekend.

[takai]

Is the MA61 hub the same bearing?
Because if it is then i could possibly use the MA61 hub for extra track (wheels are now +20) and to make the caliper adaptor easier to make.