Tim I don't know the spring rates for a 323, I'd expect a wagon to have much firmer springs than a sedan due to carrying capacity. I know a couple of people who have coil over upgrades in their Rx3 street cars, one in particular mentioned they were too stiff for the street.
Some extra photos of work that was carried out on the booster some weeks ago. The booster has already been installed in the car so I'm back tracking a little.
Photos of the booster reco job, carried out by Northern Brake and Clutch. The booster tested for a very minor leak, most likely wouldn't be noticed by the driver. These photos show why it's worth rebuilding old parts you buy. I could have popped it in my mates blaster and made it look pretty but that wouldn't have addressed the inner workings of the unit. These are 40 years old so chances are if it's never been rebuilt its going to be in a similar state. The case although looks bad was actually quite good after being sand blasted clean.
Pic 1, some of the old "guts" that were replaced with the new "guts" in pic 2. Part of the internal mechanism was apparently seized solid. The diaphram although was good and functioning was damaged when trying to work free the rusted parts so got a new one of those as well.
The case was sandblasted and primed, you can see the outside case is still in raw steel. The final booster and install photos can be found in one of the previous updates.
I've been talking about upgrading the front brakes recently. This has turned out to be a headache, mainly because I want to retain the originality of the car. These were off someones race car (Rx3). The calipers I've had inspected and are in quite good condition and haven't been butchered in anyway. I thought the one caliper had been shaved slightly on the inside but the engineer I'm using assures me that's not the case. It has more to do with cleaning up the original casting. The original job I had in mind was to make up a new backing template and have a laser cutter cut them out for us and that was pretty much it. It's turned out a little more involved as always.
Here I've fitted the original mount brackets that came with the setup to the strut to trial fit everything. Too my dismay neither the standard steel rims nor the Watanabe wheels were going to fit. The problem if you're cluely is that the caliper protrudes above the face of the wheel hub meaning that while other wheels may fit, the ones I want to use don't !
Some bright spark may say, easy solution I'll just use wheel spacers on the front. They'll just need to be 10 - 15mm thickness. We'll using spacers on the front
could upset the balance and handling of the car. Rx3's have a front and rear equal wheel track of 2310mm. If I add a 10 -15mm spacer the front wheels would have a wider track than the rear. The Wats have a +9.5 front offset and a +3 rear offset, this means even with the Wats the front are going to stick out further than the rear wheels. Not only that I'll be struggling to fit the front Wats on the hub with the original hub face location without running into guard clipping problems. I could space out the rear as well but the rear Wats sort of sit exactly where I want them. The task was going from one undesirable workaround to another. At that point I called it quits and spoke to several professionals who deal with suspension and brake upgrades. So I made an appointment and off I went with my boxes of bits
The engineer fabricator listened to my requirements, one of which was to retain the original front hub wheel track. He made some measurements made a few extra suggestions and then took on the task
The calipers will be changed to a single line arrangement. Generally speaking people drill holes through the piston sleeve to join the hydraulic circuits together. Apparently this can lead to difficulty bleeding the calipers, he explained another modification that is performed to do this. At that point I just said to do it, saves me the hassle and I know its been by someone who does this for a living.
The rotors that came with the calipers were in quite good condition as well, they measure 264mm in diameter and 22mm thick, vented
As far as I know these won't need to be turned down on the lathe. The replacement rotors pressure fit over the rear of the wheel hub just like the original solid rotors. Photo 2 is of the make shift caliper brackets off the race car. They'd never pass a road inspection and place the caliper were I don't want them so these are being thrown out and replaced with new engineered components, the goal is make the new brackets from a solid piece of metal that will be machined to the correct dimensions and caliper offset.
As you can see fitting good brakes over the wheels I want has turned into a headache. You can forget about using the original steel 13" rims. Due to the inner rim design there simply is no clearance for any decent brakes. To add further insult to my plans the 14 inch Wat's are a headache to fit as well. The inner Wats spoke design just doesn't provide the required clearance without some careful engineering. Other 14's may fit without problem but Wat's arent a bolt on fit in my case at least. Watanabes are quite popular in Japan, I suppose they don;t do brake upgrades over there just the cosmetic stuff.
The brake upgrade also means that I'm going to need a 14" spare because if I ever get a front flat I'll be stuck... uhhh !
Well the only way from here is obviously going to be a compromise. I've pulled the original Mazda calipers out of the bin, these will be cleaned up with new seals fitted. The pistons are well beyond their used by date (pitted) so new ones are being sourced along with hydraulic hoses. They'll be as good as new in the next update or so. With the Mazda brakes I can fit any wheels I like, with the upgrade only the 14" Wat's and larger rims will fit. Basically the compromise is I'll need to fit the original calipers when ever I want to use the standard wheels, not what I wanted but there's no other option. I can live with it, for now standard rims it is until the car is sorted. I'll post photos of the upgrade setup once it all comes back.
Moral of the story is sort all this stuff out before paint and wheel selection !
either way steelies or wats it's going to be looking tuff!! 
