Hey Guys

I'm just doing to searching and can't come up with many answers. Basically, I'm wondering how difficult it is to put an FB large axle rear end under my RX3? I know the earlier small axels are bolt it, but I have a large axle and have some other ideas that hinge on the large axle rear. Anyone done it or know what has to happen to make it work? Any info is greatly appreciated.

Thanks
Jordan

 

The fb rearend is wider.you also have to fab the mounts for the 4 link and. The watts link.you might as well just build a new one.

 

I was aking a similar question in relation to my RX2. Here's the response I got:

RX2 diff is approx. 1360mm

S1/S2 RX7 diff is approx. 1450mm

A lot of cutting and resplining involved or you would have to use front wheel drive wheels with heaps of offset.

If you are running flares then you might get away with it. You might want to look at RX4 13B or RX5 diff they are around 1410mm and the RX5 diff is disc brake.

What are you trying to achieve? Diff upgrade or brake upgrade or both?

I ended up getting a S2 RX7 LSD and getting the S3 RX7 rear calipers and the adaptor plates from REspeed. No cutting or welding required. I've done this in the past but opted for the simple option this time around. The diff is a bolt in swap. The S2 is 24 spline.
A 13B RX4 diff would be a good strong option to fit if you have more power. I'm setting up for a 12A BP.

Good luck.

 

Well I got talking with Billy from Re-speed. What I had hoped to do was use the large axle rear to use the FC rear brakes, and get the re-speed moser axles to convert the car to 5x114.3 for greater wheel selection. What I may do is get the stock RX3 axles re-drilled for 5x114.3 and just use the FB rear discs.

On another note, I cant find the tread but I want to know whats involved in swapping the whole front suspension to FB in order to use the upgrade kit (agian, from re-speed) that lets you mount the whole front hub assem. from the FC?

 

there is not enough material to drill to 5 lug.

 

Simple answer:

The S2 and S3 rear ends are the same ****. they only differ in the side spline gear as S3 came with larger axles.

The RX-3 are the same **** except the SP model has a short pinion shaft like the FB RX-7s.

I use 4.78 and 4.44 KIA gears on a S2 GSL rear end with discs from a S4 GSL plus modified driveshaft. No need to buy new discs if you have good S4 GSL diffys

 

What sort of power are you running (or going to run) in the car? S4/S5 rear brakes are overkill for most applications. Billy has the adaptor brackets to run the FB rear disc brakes. If you get the S3 you are running vented discs. Just redrill them to the 4x110 PCD.

I looked into fitting the FB front struts for my RX2 too.

Strut top mounts are different, but I'm pretty sure that a RX2 one can be made to fit the strut.

Steering arms are different too - you will have to use the RX7 ones (S1, 2 or 3). The hole spacing on the bottom of the RX7 strut is further apart than the RX2. You will have to use the S1-3 RX7 outer tie rod ends with the steering arms, as the S1 RX2 tie rod ends have a smaller taper. This is good, as the later tie rod ends are easier to get, and much stronger. Note that the RX7 steering arm is longer than the RX2 one, so this will slow your steering down a bit.

The ball joint taper in the steering arm will be too big for the RX2 ball joint. I ended up using RWD Mazda 323 lower control arms and fitted rose joints to the inside to make them adjustable. You can do the same but get a bush made up to fit inside the LCA, and still pick up on the pivot pin. In fact, you might find that the RX2 inner bush fits into the 323 LCA.

There might be other RX steering arms and / or LCA's that will work, but I haven't investigated all other options. Need RX4 steering arm that will fit the RX2 ball joint. It will also fit the RX7 strut. From memory I think you end up with +ve camber.

Not all RX4 steering arms are the same. Have fun finding one.

The RX7 struts will give your RX2 positive camber, as the tops are mounted much further inboard on the RX7's.

Another option to consider is R30 / R31 Skyline stuff. It is a direct replacement for the S3 struts (apart from maybe the strut top, but this is easier to manage). They have a thicker body, so inserts and coilover hardware is easier to find (50mm OD). Also, they have much thicker stub axles and bearings so are a lot stronger (I know people who run Skyline struts in rally RX7's because of the strength).

The DR30 and HR31 struts (Turbo import skylines) have a floating disc, and 100mm caliper spacing so that you can put any of the late model alloy 4 piston calipers on there (Skyline, 300ZX, WRX, but NOT the Mazda calipers). This gives you a massive brake upgrade. Even the stock brakes on the DR30 / HR31 struts are a big improvement over anything Mazda of that era. Best of all they have the 4x114.3 pattern, with FWD offset.

I'm not too sure about the camber with hte Skyline struts, but I think it's better than the RX7 ones. They are also shorter and allow you to lower the car more.

The other way involves a RX3 steering arm and a R100 steering tie rod end.

The RX7 strutt is slightly smaller in diameter than the RX2 at the top, So a thin sleeve must be made up so the RX2 bearing can fit. Really keen peoplle fit the RX7 bearing into a relieved RX2 hat with the aid of a spacer (Inserting whistle...)

You can then redrill the RX2 shocktower to get more neg (But thats UGLY) or redrill the RX2 struttop to get more neg. You will have to weld on a extra piece for the outer bolt.. Thus invilves a bucket of water, a Arc welder and a steady hand. ( Rubber stays in the water while you weld to keep it cool...)

I never said any of this was nice...

Or just cheat and get a K_mac or other aftermarket struttop.......

There is a diagram for making up brackets for the RX2/RX3 to FC/FD calipers with FC discs on ausrotary. You'll have to search for it. Simple machining of the RX2/RX3 hubs and the discs fit over the top.
Then, just sort out the inherent geometry issues.

 

Go to www.theracingstore.com and get the brakes there. They have single and dual piston versions and 4 and 5 lug patterns.

 

Currently running, 81-85 FB front suspension/brake swap (strut tube is also extended using RE strut tube spacer coz I dont want it too low)
RE Speed camber kit, Rear disc brake conversion using 81-85 rear caliper/rotor, RE bracket (the other RX-3s has rotary power bracket), 81-85 brake booster + 81-85 brake/clutch pedal assembly and modified GSL/GSL-SE hand brake cables.

S3 GSL 3rd member with S2 side gear (small axle) and KIA Sportage R&P (4.44 and 4.78)

I'm on limited budget (plus Im cheap) so I learned to improvise. and of course, I'm a simple man (ala lynyrd skynyrd)

 

i would've thought the rx3 and sa(maybe even fb-non se) front rotors would be bout the same.

 

Stop being a bunch of pussies and put either a Chevy 12bolt, ford 8.8" or ford 9".
The latter being the best. All the other crap will just break. Ask me how I know. If you're just going to ***** foot to the grocery store, than all of this is just a waste of time and money, just keep it stock and upgrade the brakes if it makes you feel like more of a man.

 

+1 I love my 8.8 when I had my stock rear I would go to the track and would break either axle or ring and pinion first pass. Now I can't throw enough at it lol.

 

but not everyone has $3,000 to burn for a single purpose only....10 second of fun, but oh wait, you're not there yet

I maybe the last boy scout for being very resourceful but I was able to accomplish a lot of things for less than $300 and using original mazda parts (I got extra parts so I aint worry about breaking things). so you want to race off the 91 Fwy? I'm only running 4.78, nothing special lol. Per Mark Twain, "It's not the size of the dog in the fight, it's the size of the fight in the dog."

That idiot posted things that I've already done and found to be not enough for my driving habits. SO if you want my respect, tell me something new instead of being an "internet parrot. "

 

You're not going to break anything driving to Sevenstock once a year.

 

well this is the same motor that I fucked around with for many years so it seen abused. plus been going to local runs (you cant do), been driving it to work twice on weekdays and every weekend to do errands . Giving it my regular dose of abuse (redline that bitch baby). I was hoping that it will die so I have an excuse to built a new motor but oh well.

 

SO TRUE!!! I copy that!

 

Wacky you should turbo the bitch and see how fast they start breaking lol.I say put a ford 8.8" or 9" and call it a day.yes you spend more money but it saves you the headache later.

 

Give me the parts you old fart and I'll build your motor for you. The offer still stands from like two years ago. You need a bridgeport.

 

Although I have all of the parts to go with either bridge or turbo, I'm pretty much content at this point. Thanks for the offer. I will keep you in mind (yeah, without wet dreams lol)

 

so from what im reading wacky is that. basically take a GSL diff(meaning the entire 3rd memeber) and it bolts up into the stock rx3 diff housing??? just need a new driveshaft correct?
thanks
-eddie

 

How did you guys re drilled your axles? I am building a hybrid front suspension for my Rx-3 with GSL-SE from struts with techno tout tunninb top hats for an RX-3. The rear I was going to cut a GSL-SE rear end but I ended up finding a stock Rx-3 rear end that I plan on re-drill to 4x114 and convert to disc.

 

Ford 8.8 is the way to go

91/92 ranger with v6 and towing package gets you disk brakes and 410 gears

Remove the longer axle tube, cut it down and reassemble with a second short axle. Tada , 20 mm narrower than stock. Redo the mounts and paint.

 

 

I 2nd Ford 8.8, shorten it use two short axle shafts and a sport trac lsd.

 

Hi guys- my apologies for being new to this forum and having absolutely NO clue how to navigate around, and it seems to come to a road block when trying to start a new thread.
With that being said, I am a previous owner ow 2 RX3 Coupes here in New Zealand, and sold them during my youth for penny's- which is now the cause of night terrors.

We are looking for RX3 Parts, shells, and full Cars in ANY condition. I can arrange full import requirements so you don't have to lift a finger.
I run the South Island New Zealand Branch of www.sbtjapan.com and www.betterbidding.co
So any one who wants to (genuinely) buy RX7's etc directly from Japan is welcome to contact me. I bid through Auctions Nationwide daily obviously with our staff checking cars on site. And, I travel there to purchase standard imports to New Zealand for car dealerships.

Anyways- if someone could point me in the right direction to post a classified, or on a noticeboard that would be fantastic. Really want the dreams of my very first car (Red RX3 Coupe) turned back into a reality, no matter what means.

Thanks!
Craig-