stephen115 Posted August 30 Share Posted August 30 (edited) Hello everyone, I'm on a mission to 5-lug swap my 1981 BRAT. The goal is not to make any modifications to the existing BRAT components. If it has to be made or cut, it has to be removable. I've been following the Subarino videos and website for some time now. Dave said they had yet to do a lot of research on the Gen 1, so I didn't bother buying their kit. I've decided to make my own. I've purchased backing plates, rotors, and brake calipers from a 1994 Subaru Impreza(GC8). This era seems to be the most versatile for this type of swap, and parts are readily available. For reference, I've attached a 3D rendering of the 5-lug hub and backing plate centering ring. Remember, these are not final, and I still have some minor tweaks to make. I went to test fit my backing plate centering ring today. While the ring works, the backing plate hits the BRAT trailing arm/control arm, where the caliper bolts to the backing plate. I'm curious to see what others have done or if anyone has some ideas. I was under the assumption that the Impreza backing plate would work, but I just realized the Gen 2 cars have a different style trailing arm/control arm. I appreciate any input and plan to share my updates and final materials once done! Edited September 4 by stephen115 Pictures Quote Link to comment Share on other sites More sharing options...
el_freddo Posted August 30 Share Posted August 30 If you can fit Gen2 BRAT brakes you can fit the Subarino 5 stud brake kit 😉 There may be some slight differences with the hand brake cable etc. Quote Link to comment Share on other sites More sharing options...
stephen115 Posted August 30 Author Share Posted August 30 4 minutes ago, el_freddo said: If you can fit Gen2 BRAT brakes you can fit the Subarino 5 stud brake kit 😉 There may be some slight differences with the hand brake cable etc. Do Gen2 Brat Brakes swap directly over? Quote Link to comment Share on other sites More sharing options...
stephen115 Posted August 30 Author Share Posted August 30 5 minutes ago, el_freddo said: If you can fit Gen2 BRAT brakes you can fit the Subarino 5 stud brake kit 😉 There may be some slight differences with the hand brake cable etc. Do the gen2 Brat brakes swap right over? Quote Link to comment Share on other sites More sharing options...
el_freddo Posted August 31 Share Posted August 31 9 hours ago, stephen115 said: Do the gen2 Brat brakes swap right over? I don’t know mate, I don’t have a gen1 to play with and they’re quite scarce around this part of the world. It would be a cheap way to find out if the 5 stud conversion would fit - you’d need to ensure the rear stub axles fit the gen2’s drum brakes as the fabricated rear hubs adapt the EA81 stub axle to the EJ 5 stud pattern - if this works that’s a major hurdle over come. If not maybe the EA81 rear swing/trailing arm can be swapped in. Big maybe though. Once the rear is sorted the next thing is to ensure the front control arms can be reamed out to accept the larger EJ ball joint. From there it’s working out the master cylinder situation as you’d definitely want to upgrade that to EJ spec! Lastly and probably the most frustrating bit is sorting the front CV shafts. It’s probably best to go custom here for ease of just getting it done. There are ppl who have fitted EJ brakes to the Gen1 brat. I believe over here in Oz a fella had an emerald green one that had the brakes and an EJ fitted, I just can’t remember if it was EJ turbo. I’ll see what I can find. How’d you come up with the designs? You must be good with cad! Something I’d like to learn more about with complex components. Cheers Bennie Quote Link to comment Share on other sites More sharing options...
el_freddo Posted August 31 Share Posted August 31 This is all I can find at the moment: https://ausubaru.com.au/viewtopic.php?f=26&t=10858&p=106517#p106517 From what I remember he had a WRX drivetrain and brakes fitted. I can’t find any pics of it now though as all the photo links are broken ;( Quote Link to comment Share on other sites More sharing options...
stephen115 Posted August 31 Author Share Posted August 31 14 hours ago, el_freddo said: I don’t know mate, I don’t have a gen1 to play with and they’re quite scarce around this part of the world. It would be a cheap way to find out if the 5 stud conversion would fit - you’d need to ensure the rear stub axles fit the gen2’s drum brakes as the fabricated rear hubs adapt the EA81 stub axle to the EJ 5 stud pattern - if this works that’s a major hurdle over come. If not maybe the EA81 rear swing/trailing arm can be swapped in. Big maybe though. Once the rear is sorted the next thing is to ensure the front control arms can be reamed out to accept the larger EJ ball joint. From there it’s working out the master cylinder situation as you’d definitely want to upgrade that to EJ spec! Lastly and probably the most frustrating bit is sorting the front CV shafts. It’s probably best to go custom here for ease of just getting it done. There are ppl who have fitted EJ brakes to the Gen1 brat. I believe over here in Oz a fella had an emerald green one that had the brakes and an EJ fitted, I just can’t remember if it was EJ turbo. I’ll see what I can find. How’d you come up with the designs? You must be good with cad! Something I’d like to learn more about with complex components. Cheers Bennie Thanks, Bennie. I've been doing a lot of research over the past few months. It all made sense until I realized the EJ backing plate hit the trailing arm of the gen 1 brat. That doesn't appear to be an issue on the gen 2. So a minor work around. RX and GL's came with rear disc brakes. If I can get my hands on a set of those that would be great. Then all I'll need to do is make the 5 lug hub and find a rotor that will work with the caliper. Shouldn't be too hard to find. Another thought is to make a 25mm spacer for the EJ backing plate. This would provide enough distance to clear the trailing arm. Which brings up another question. Would it space it too far to where the hub won't fit? All things I need to find out. Quote Link to comment Share on other sites More sharing options...
stephen115 Posted August 31 Author Share Posted August 31 18 hours ago, el_freddo said: How’d you come up with the designs? You must be good with cad! Something I’d like to learn more about with complex components. Cheers Bennie I found an old thread on here that shared the dimension of the XT6 hubs. I then modified it from there to suit the Gen1. There are a lot of similarites. The spline count is the same 27T. Thank you! I use Fusion 360 and have been learning on my own for about a year now. Much to learn. Quote Link to comment Share on other sites More sharing options...
stephen115 Posted September 4 Author Share Posted September 4 (edited) I was able to successfully print the backing plate spacer this weekend. It's 20mm thick and spaces the backing plate just enough to clear the BRAT trailing/control arm. I also printed version 2 of the rear hub. Everything mounts up nicely, I just need to install the caliper and check spacing. Edited September 4 by stephen115 Pictures Quote Link to comment Share on other sites More sharing options...
el_freddo Posted September 4 Share Posted September 4 If you’re spacing out the backing plate you’ll need to space out the hub to line up the disc. No chance of modifying the backing place to avoid the swing arm? Got pics? Cheers Bennie Quote Link to comment Share on other sites More sharing options...
stephen115 Posted September 4 Author Share Posted September 4 (edited) 43 minutes ago, el_freddo said: If you’re spacing out the backing plate you’ll need to space out the hub to line up the disc. No chance of modifying the backing place to avoid the swing arm? Got pics? Cheers Bennie Correct. I did a dry test last night and I'll have to add a little to the hub to make it work. Maybe 5mm. See attached pictures below. Reached my photo limit so had to provide links. I do want to play around with modifying the backing plate. I'll look at that this week. Edited September 4 by stephen115 Quote Link to comment Share on other sites More sharing options...
stephen115 Posted September 4 Author Share Posted September 4 Spacer - https://drive.google.com/file/d/1aBSHDnm3UdSgHC8wtRKf7uouvCC512nj/view?usp=sharing Rotor Test Fit - https://drive.google.com/file/d/1a-R_kf9hrH0LO0OeemjTytNVXBwuwX5m/view?usp=sharing Backing plate - https://drive.google.com/file/d/1aWbyM5eWUuXAmpmGfgSsBuzZMr3aag-i/view?usp=sharing Quote Link to comment Share on other sites More sharing options...
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