xrotaryguy

I'm having the machine shop where I work make a pair of sleves that would make it possible to use S3 rotors on an Rx2 or Rx3. They're for my Rx2 but I am assuming that an Rx3 has the same spindles as an Rx2. Maybe you guys could help me with that. Any way, all I'm doing is having a sleve made that would slide into the outer wheel bearing. The sleve would then have the proper inner diameter for the spindle on the Rx2.

The rest of the conversion the way I'm doing it requires:

Rotors from an 84-85 Rx7
Stock calipers from a 79-80 Rx7
Inner race from an 84-85 Rx7
Inner wheel bearings from an Rx2/3
Outer wheel bearings from an 84-85 Rx7
Seals are the same from the Rx7 or from the Rx2/3

Is there any on interested in purchasing such a thing? Im not going to sell a complete kit but if there are enough people interested in the sleves then I might be able to get a quote from the machine shop on having a batch of them made. If I can get even 5 people interested then I can look into haveing maybe 10 or 20 made up so that I have some more on hand for people in the future. That might also help bring prices down a bit more than they would otherwise be. After all, we don't want to pay a bundle for a silly little sleve.

xrotaryguy

Haha ZERO! Thats not much interest. I guess I'll just make some for myself.

trainwreck517

iTrader: (1)

haha, you expect everyone to give you a responce in a day?

I'd be intrested, what price are we looking at though?

And you have a how to just so I don't **** anything up?

I need BRAKES on my rx-2.. stock brakes just plain suck.. even with hawk pads.

Also, you think you could make a braket to for FC four pistons on there? Perhaps FC vented disc also?... well at least the calipers.

Jesuscookies

iTrader: (1)

Yep, FC brakes would be better.

xrotaryguy

I know I was half kidding and half just haulin *** to get my own brakes done before the race this weekend.

I agree that fc brakes would be betteer. But if you're talking FC rotors then you would have one bolt pattern in the front and a different one in the back. That is unless you changed the rear some how. Redrilling the axle flanges etc. Thats pretty spendy. I think that we would be looking at a kit in the thousand dollar range that way. Heck redrilling the rear axle flanges pretty much makes it not a kit. I guess there is the possability of making a rotor that would bolt to the back of an Rx2/Rx3 hub. Again thats getting pretty crazy though. The reason that I am going with what I have is that well... it's what I already have , its easy to do and the parts are easy to come by. A redrilled axle flange is not that easy to com by from a "kit supplier's" point of view. Not that I'm really a kit supplier but you get the idea.

The FB rotors are nice because they have a larger outer wheel bearing than the SA rotors. The outer wheel bearing on the SA will not slide onto the Rx2 spindle and the Rx2 outer wheel bearing is too large for the SA rotor. The FB rotor has an inner race that can be used with the Rx2 bearing and so it will go right on. The inner seal is identical.

The SA brake calipers will bolt right onto the Rx2 backing plate. The volume that SA the caliper displaces when you press on the pedal should be close to if not identical to the Rx2 caliper so there is no need to change the master cylinder. If we were to upgrade to a 4 piston then we would have to do the master cylinder, proportioning valve etc.

I have more to write but its time for Calculus

Mre to come.

Jesuscookies

iTrader: (1)

Redrill the brake rotors, not the axles.

xrotaryguy

Oh yeah huh. Duh. I guess that's still more than I was looking to do. What size wheel do you need to run an FC rotor? Does it have to be a 15 or somethign? I am running 13's right now. 15's are too big for my car and I don't want to have to cut up the fender wells. I just welded one of them back together. Besides... 45 series 13's are bad *** Even with redrilling the rotors you would need a different master cylinder.

I think that if I was going to offer a better setup than what I have suggested so far, then I would go with 81-85 FB calipers. Then you could run the caliper bolt pin type setup instead of the wedge style sliders. Im not sure how easy of a bolt up affair that is though. Im sure its not too hard but I'm trying to keep it simple. Though, if those calipers will bolt onto the Rx2 backing plate then that would be better from a parts sourcing point of view too. Then the rotors and calipers would come from the same car.

The problem that I have with the Rx2 brakes is not that they do not stop well. The stop great. The particular ones that are on this car don't stop well because they have been road raced... alot. But thats besides the point. The rotors on my other old school and on my first gens have all worked great. The thing that needs to be improved upon is the cooling of the rotor. I delaminated a pad because I got it so hot at one race. It was not the pads fault either. I could smell it getting hotter and hotter for about an hour and then it finally failed from the rotor being so hot. I just want a vented rotor setup that is easy to afford and that uses easily available parts. What I have so far does just that with the exception of the outer wheel bearing not fitting. By simply placing a sleve over the spindle the setup will work great with very little work.

The less money we spend on these cars to get the desired result the better. We will never get out of these cars what we put into them. It's best to try to keep our losses to a minimum.

xrotaryguy

The machinist at work finished up the sleves yesterday. I owe him a 12 pack. I'll be doing the swap soon.

trainwreck517

iTrader: (1)

Let us now how it goes... and TAKE LOTS OF PICS!

good luck

xrotaryguy

Ok good, Im glad to see that you're interested. I'll have the camera ready to go.

trainwreck517

iTrader: (1)

So how did the swap go, or how is coming along? What kind of racing are yuo doing on the car? Auto X or road racing? I want to start road racing my rx-2.. but the stock brakes.. just fade out after a few hard stops. I also need to figure out something for the steering.. has a little bit of play/speed woble. Replaced all front bushings with new polyurthane ones. Seemed to make the car a bit stiffer, but the play is still there. Going to try to get a hold of tie rods, ball joints, and what ever else to see if that helps a bit. My goal is have it road race ready by september.

xrotaryguy

Sounds like fun man. I only auto cross my Rx2. But I know what you mean about the brakes fading after a few hard stops. One of the pads delaminated at a driver school while my wife was driving the car. She was making quite a few consecutive runs and you could smell how hot the brakes were. There is a provision for air ducts on my car. They're not hooked up right now but I'm sure that they help. I'll try to include some pics of that too. I have no pics now because I'm at school.

The project stalled again yesterday. The collar that I had the machine shop make for me worked great! Yay auto cad! I had to use some spindle washers to space the bearings out a little since the bearings on the FB rotor don't ride in the same place that the Rx2 bearings do. That much seems to be going well.

What is not going well is that the FB caliper requires that you use the FB backing plate. The FB backing plate however does not have the same bolt pattern where it mounts to the strut assy. I guess I'm going to redrill the FB backing plate now. I'll have pics of that too.

I want to continue with this project for a number of reasons. I don't want to retain solid rotors. Even though a new pair of solid rotors would be a huge improvement over my totally destroyed ones. I want to use as many compatible parts as I can. Other people have swapped the entire strut assy. There are several reasons that I am still not going this rout dispite the incompatability issues I keep running into. I don't know how much the tie rods and ball joints etc will be compatible. My car has redrilled strut towers and the strut mounts have been "reengineered" as well so I don't want to have to deal with messing with things there either. Also my springs and shocks are not factory units and I don't want to mess with that because I'm happy with the way that the car handles now. If I werent so concerned with some of these issues then I may go the more conventional rout and just swap the whole strut assy like others have done.

Any way, thats it for now. I'll get on here and let you know how my redrilling goes when I figure out which one of my neighbors has a drill press.

xrotaryguy

Ok here are some pics of what I have done so far.

Heres a shot of the sleve that I had the machine shop make. With this, the Rx7 outer wheel bearing will fit the Rx2 spindle.



Sleve being installed.



Sleve installed. You wanted a lot of pictures right



Sleve installed, outer wheel bearing going on.



Bearing installed with sleve.



I did some grinding on the back side of the rotor thinking that there was more meat back there than on the Rx2 rotor. I see now that the inner wheel bearing is just set further into the Rx7 rotor than it is on the Rx2 rotor making that part of the rotor interfere with the backing plate. I am likely going to use a spindle washer to space the bearing (and rotor with it) out on the spindle a bit further. Any way, heres a picture of the cutting that I don't think that I had to do.



More unnecessary work



Here I am measuring how much work I didn't need to do.



Again, I think that I am going to have to place a washer behind the inner wheel bearing. I don't think that I had realized that in this picture though. I instead have a washer on the outer bearing side so that the spindle nut doesn't run out of threads. So this is pretty much a complete stack up with the washer in the wrong place.



Again, its a shot of the Rx2 spindle with an Rx2 spindle nut (naturally), a spindle washer (in the wrong place), an S3 Rx7 outer bearing (which uses an adapter sleve to fit the spindle, an adapter sleve, and an S3 Rx7 inner wheel bearing (which fits the spindle fine but need a washer behind it and an Rx2 race in the rotor.

I'll post more when I know something. That could be a while J/K

xrotaryguy

Oh by the way, I also cut down all those little bumps on the back side of the rotor between the friction surface and the area that the bearing preses into, because they were hitting the bolts that hold the backing plate on. I'm not sure that this was necessary. I need to get the rotor mounted up with the Rx7 backing plate in place and the spindle washer behind the inner bearing. Then we'll see if all this rotor mutilation was necessary. I hope its not. With out that metal in the center you cant put a seal in there.

trainwreck517

iTrader: (1)

Thats some great work! Thanks for the pics. Make sure to up date this once you get things going. :-D

xrotaryguy

The conversion is done! And the pedal feels as squishy as ever haha. Im pretty sure thats because I am still using the old pads which were grooved really bad. I'll get the rotors turned and the pads replaced later. Any way, here are some pics.

Here is one of the redrilled backing plate. This plate is off of an 80 Rx7. As far as I can tell, any first gen backing plate will work. The 84 85 plates have a little scoop on then for cooling though, so they may be the best ones to use. All of the holes but one are such that the backing plate can not rotate so there really hasnt been any strenght lost. AKA the caliper WILL stay put. You can see a washer just kinda hanging out on the spindle there too. Its a washer from a Subaru Spindle nut kit and its almose big enough to fit onto the spindle. I had to open it up just a little with a dremel. The Rx2 spindle is longer, from the backing plate to the threads than the Rx7 spindle so I have some washers there to make the Rx7 rotor fit. Otherwise the spindle nut runs out of threads.



Here is that Subaru washer with the inside hogged out a bit. Not much.



You'll have to use the Rx7 caliper bracket bolts as the Rx2 bolts are larger



Rotor installed. I used another washer here. It may not have been necessary. It looked like there was almost enough thread. I wanst sure so I just used the washer.



Caliper installed



45 series 13 inch Hoosiers on Panasporst installed



Unfortunately I was unable to use the inner wheel seal because of the washer being back there. To make matters worse, I can not use the dust cover either for basicly the same reason. The Rx7 rotor is just plain skinnier than the Rx2 rotor so the spindle sticks out. Since I live in Az where it almost never rains and I only auto cross the car, its not really a problem. If I lived in Oregon and I was going to daily drive the car or road race it, then I might think twice. Swapping the complete strut assy might be a better idea then.

Any way, there it is guys. If you guys are interested in doing the same thing, now you know how, and why, and why not. If you want one of those silly sleves, let me know.