1973 929/RX4 Coupe Project
 

So far, I'm just getting ideas for the project, I purchased the car from a guy in Australia and will import it into New Zealand when I finish working offshore in a few months.

Between now and then gives me plenty of time to decide what I want to do...now that I've got the FC dialed in and running Im pretty keen just to keep this as a NA engine and to keep things as original as possible.

With 'Furb's build as some inspiration, it'll be nice to see progress of someone else's build until I get get started with mine.

The car has had all the body work done, and all the chrome is there just needs a little polish...and of course, re-assembly.

Here is a few pics of what she's like...

Engine Package Options
 

First off the list is of decisions that need to be made is the engine package, at this stage of the game I want to keep the car reasonably close to original so with this, I would prefer to run an NA block.

At home I have a Cosmo REW 13b that I was thinking to use, I've got a couple of Mazda new housings stashed away and a pair of high comp FC rotors. As far as porting goes, I was thinking along the lines of just a mild extended port to keep things nice and smooth...as it is, this will be the family sunday car once it's up and running.

The other Option would be to source an FC block but finding decent irons for these is getting difficult and then I'd have to get some housings.

Anyway, what are your thoughts on the engine setup?

One of the things that is nagging me, is the sump setup and the best way to overcome this when running the REW block in the RX4?

Nice find. That should shine up nice.

As for the engine, I'm pondering the same questions for my RX3 build.

So far, the engine is looking like it should be pretty straight forward to mount, from what I understand I should be able to use an old school 13b sump on the REW block but will have to drill and tap a couple of new holes. Will use a 12a front cover and with luck the sump will be fine.

Seeing as it's only rolling on some steel rims, I got to thinking about wheels, after hours of searching, I've comeup with a couple of ideas...

Wheel choices
 

What are your thoughts on the wheels, I've come up with a couple of options, so far I am leaning towards the gold rims...

Stud Pattern
 

Seeing as the 4x110 stud pattern sucks and the choice of wheels is very limited, I started looking into the options of redrilling discs or upgrading hubs.

From people I spoke to and things I have read, redrilling the RX4 discs is not an option, then somewhere I cam across a company call MSF Racing. Here is a link to what they can supply...

http://www.msfracingcomponents.com.a...arycomponents/

This seems to me, to be a very good option, would give me upgraded discs on both front and the ability to put discs on the rear.

That MSF site is pretty cool, I love guys that make shiz like that. Makes life so much easier and looks pretty reasonably priced as well. For engine choice what about a bridgeported NA rx8 motor with a side draft. Combine with a Long manifold or injection to give it plenty of low down torque, and am not aware of any BP MSP motors in NZ yet so would be driveable, unique, would look cool and make the right noise. :)

RX8 Block
 

I hadn't considered the RX8 block, I already have FC plates and a complete REW engine so will go with one of these. The RX8 blocks are getting cheaper now but not that keen on them when compared to the 7 blocks.

you can use RX-7 FB running gear to upgrade to 4x114.3

Renesis is an option. someone i know is working one to find out what it takes to put one in any old Mazda. he is using a RacingBeat inlet adapter plate to bolt an FC Carb manifold to the Renesis. i believe the 12a front cover fits aswell, its been a while since we talked about it.

i am using a S5 TII lump

A couple of small updates...have managed to find some wheels which has set me on a course of 4x110PCD which isn't so bad, have decided to go with FB front struts and GSL rear disc's.


https://cimg5.ibsrv.net/gimg/www.rx7...abf3f069a8.jpg


8" Front's and 10' rears.


https://cimg6.ibsrv.net/gimg/www.rx7...2ec7471d91.jpg


Needs to be lowered a little...

Here is a pic of the car that the wheels came off...hopefully I'll have a similar ride height when finished.
https://cimg9.ibsrv.net/gimg/www.rx7...ae6db67152.jpg

It seems that the only place I can find an IDA manifold for an FD block is from Racing Beat, maybe there is not enough of a market for others to produce them, I guess I'm lucky at least one company makes them!

Trying to find a DCOE manifold is another story altogether! You're probably thinking why would you want to use a sidedraft...I thought...why not!

I like the look of them for a start, I understand the IDA's have bigger fuel bowls for extended WOT but as I'm not going to be racing this car, I thought I would go with something a little different.

I was able to find the IDA and DCOE flanges on ebay so that leaves the fabrication to be done, I am assembling all the parts for this at the moment to send to a fabricators so they can make up the UIM for me, I'm keen to get this together and see how it sits.
https://cimg9.ibsrv.net/gimg/www.rx7...e79f08b2c3.jpg

those wheel look sick what are the offsets....also building an rx4 so i will keep a close eye on this thread....looks good so far.

The offsets are +13 front and rear.

It seems the best route for fabricating the upper intake manifold for the DCO was to use solid works, have a mold printed and then cast...so, it's going to cost a bit more than expected but the flow characteristics should be about as good as I'll get...
https://cimg7.ibsrv.net/gimg/www.rx7...dc71d9189a.jpg


https://cimg8.ibsrv.net/gimg/www.rx7...b0c18542ff.jpg


https://cimg9.ibsrv.net/gimg/www.rx7...2875262693.jpg

that is going to be one cool manifold....im not sure of the cost to make it but there is a company here in the states that makes one piece manifolds. they used to make them for the star mazda race series. i've had a couple and they are really nice pieces...if i remember correctly they are only $100 USD or so.........here is a pic


https://cimg9.ibsrv.net/gimg/www.rx7...240e88c443.jpg


https://cimg0.ibsrv.net/gimg/www.rx7...e7c0e7483f.jpg

here is what it looks like installed


https://cimg3.ibsrv.net/gimg/www.rx7...0d46b63d69.jpg


do you happen to know what mirrors are on the blue rx4 you have pictured?

Thats a nice looking manifold, Atkins produce a similar one but the problem I have is that finding one to suit an FD block is not easy! What is the name of the company that produced them?

Would be interested to find out if they make them for FD engines.

Will find out about the mirrors for you...

The mirrors are from an XY GT Ford Falcon...I don't think you guys in the US ever saw these on your roads...
https://cimg1.ibsrv.net/gimg/www.rx7...5b40014e83.jpg

Papsmagu...where are the engine mounts from in the last picture you posted?

the manifold will not fit the FD engine....sorry i missed that. The manifold is made for a 6 port. engine mounts are from Banzai racing. they are for the FB but they fit our cars just fine. That engine pic is from my REPU but its the same thing on the 4

thanks for the falcon pic and mirror info......you are right.....we did not get them in the US

If you're interested in those mirrors, they are available on ebay.com.au

Slight Change of direction
 

Well, I finally imported the RX4 from Australia to New Zealand, I have managed to set up home finally after working offshore for the last several years.

Anyway...here is a little update...

The change of direction...
 

After talking to a friend of mine and discussing the tune-ability of the 50DCP/SP...I've decided to go with injection.

I'm still going to retain the DCOE but I'm now gone with an EFI Hardware DCOE throttle body.

This particular unit is 52mm inlet bore tapered down to 50mm to match my manifold, with luck the slight tapering will give me some added velocity, then agin when it hits my LIM...it should increase velocity again.

It only has 2 injector bungs so the plan is to run 2 x 1300CC ID Injectors...if this doesn't work so well, I'll use the 2 injector bungs in the centre iron.

The last pic is of the engine bay so far, I've only fitted the radiator which will have to come out again shortly for the engine install.

Engine internals
 

I've had the rotating assembly sent off to be balanced, but I'm now back at sea for a couple of months so until I get home I can't post any pics.

I have an RX8 e-shaft, RX8 rotors with the apex slot machined out to 10mm depp to run conventional seals. Will be using a 12lb flywheel with an ACT pressure plate/clutch setup.

The rotors have been match weighted to within 1 gram of each other...the balancer told me they were well out on weight and took alot of work to get them within 1 gram of each other.

This will be the first time I've used RX8 rotors, so the next thing for me, is to clearance the side seals and for this, I have started to make a jig.

Fueling...
 

A quick little mock up of a surge tank I'll be running, this will have an enclosed Aeromotive Stealth pump.

This will be fitted to the inside of one of the rear wheel arch's.



A few other bits that are ready to go...

An FC gearbox that has been rebuilt and then I had it Vapourblasted, came up like new:nod:

Decided to get the manifolds, alternator housing, and a few other bits done as well.


Rear Garnish, straight out of the box...and the nose cone pretty much complete.

Wheels and brakes...
 

My brake upgrade was not as simple as I had hoped, my original plan was to run FC discs and calipers but that would have been too easy...

When I test fitted a front disc and caliper to my wheel, it was an interference fit! I have to space the disc off the wheel by about 20mm for them to clear.

I could run a 20mm spacer but not my style!

So the hunt for another option is underway, so far, Wilwood looks like the go. I also came across Aerospace brakes but to have them shipped from the US to NZ will cost a fortune!

I have been in touch with Custom Garage in Australia, Darren has been great, we are currently working on a solution for my little problem.

The other pic is a comparison of FC calipers vs. FD. Neither one wins!:(

Stolen Ideas...
 

Thanks Ferdi...got the idea for the Smiths gauges from him, they look great and will suit the finish I am after.

wow that looks really nice...well done

Engine prep
 

Engine is now prepped and ready to be assembled, I ended up using FD irons & housings, S5 NA rotors, RX8 crank and RX8 stat gears (All new). All new Mazda seals and springs.

The rotating assembly was balanced and bearings clearanced before assembly.

Using a 12lb flywheel with ACT Extreme PP and street/strip disc.

Front Brakes
 

As my original plan for using FC front brakes didn't work out I had to find another option.

As I needed to retain my 4x110pcd I did not have too many options and without changing my wheels this proved to be a not so straight forward exercise...but what is when building cars!

I ended up finding a company in Australia called custom garage, Darren was able to set me up with a set of custom calliper brackets for using with Wilwoods, this was step one.

I then took my discs and hubs into a local engineering shop to have the PCD changed on the discs's and the original RX4 hubs machined down so they could fit inside the FC discs.
When I got the hubs back and re-mounted them on the car, I was not happy, there was no easy way to securing the disc to the hub and I would have needed a hub-centric spacer machined up for certification...so, I decided to order some steel hubs from MSF Racing, again in Australia.
These hubs retain the standard offset, made of steel, not cast and have the option of 4x110 or 4x114.3. They are also supplied with a hub-centric ring for use with FC discs or don't use the ring and they will work with FD discs.

Dummy engine and gearbox mounting
 

I wanted to get the engine in the car so I could make sure everything lined up and fitted correctly, this would also give me the opportunity to fit the gearbox and sort the mounting and shifter location.

The mounting was reasonably straight forward, I was able to utilise the original gearbox mount and adapt the S5 gearbox mount to it.

Shortening of the selector took a few attempts, I shortened it by just over 100mm the first time which was not enough, second time around I had to take another 45mm off it.

The picture you see of the gearbox in the car, this was the first attempt, 45mm too long.

The picture of the gearbox end-casing, you see the final location, I had to have a second locator tab welded on and the housing shimmed so the selector shaft would move smoothly.

Engine is assembled...
 

I managed to get the engine assembled, the next part of the build is the front end wiring and ecu harness and connection.

Looking very good! I'd like to see what power this thing puts out when done. Engine is fairly similar to mine, just porting and fuel injection will be different. I thought about trading my carbs for fuel injection a few times and almost pulled the trigger on a few throttle body setups in the classifieds. Keep up the good work.

Nice man!
I'ma newish RX-4 owner so I'll be watching for more updates.

Buggy, I remember seeing your car at Deals Gap some years ago... Nice car too!

It will be back at deals gap this year again. No where near the same car it was then. Lots of upgrades done.

Wiring, fuel and suspension.
 

I have a bit of time on my hands so I thought I would do a quick update.

Have got a few things done over the last couple of months, for me, the progress is good, I am starting to see some systems being close to complete...overall, still a way to go though!

I was in debate about what to do for fueling for a ling time, I wanted something as compact as possible, I don't like to drill too many holes in the car so was reluctant to mount pumps and filters seperately...so this is my solution.

It is a Aeroflow surge-tank with an internal pump, it can accomodate dual pumps but I will only need one. To feed this tank I am using a carter LP pump. The 2 filters you can see, one is a 60 micron prefilter (Holley), the second is a 10 micron post filter (Aeromotive). This will be used to supply my 2 x ID 1300CC injectors. Am also using a Aeromotive regulator which is mounted close to the fuel rail.

The wiring harness, this took a few hours to do, this is for the ECU, all the plugs have been left off for now until it is passed through the firewall...I am contemplating a bulkhead connection which would make things cleaner and easier to remove in the future.

The struts were done through a friend of mine, they are original RX4 struts that have been shortened and the coilover platforms welded into place. These will allow me to adjust ride height without changing the spring rate.

Extractors
 

Today I received a picture of the extractors that I've had made for my car, the first set that were made were very sub standard, sourced from MSF racing in Australia...I was not happy:mad:!!! The welding was terrible, and I won't even begin to talk about the flanges...

After modifying the first set I ended up using them as a welding jig for this set, went with the v-band joins also.

Seeing the light at the end of the tunnel
 

It's been a fair while since I updated this thread, I managed to get a fair amount of the 'Big' stuff done to the car while I was at home but now I'm back to work for a while, thought it time to update.

First thing I'll go through is the diff upgrade, I was lucky enough to get a hold of a Toyota Hiace diff, the axles on these things are impressive, I'll not be breaking any thats for sure!!!

Once I got ahold of the diff, the first thing I did was strip the drum brakes off it and throw them in the bin, then it was sent to a local shop for shortening.

Once I got it back , it was sand blasted and primed...then when the temperature got about 12deg C, I put some paint on it and kept it warm with a heat gun to help it cure...

The diff head is a 4.44 LSD...I'll see how thins performs on the road, I may go up to a 4.8 ratio.

For the brakes, the axles have been redrilled to 4x110, discs being used are Nissan P11, calipers used are Nissan U13

Wilwood Bias
 

As I have changed both front and rear brakes, I thought it best to upgrade the bias valve, for this I used a Wilwood Bias Valve.

The lines were bent up for this first to determine the position where the valve would sit, then I designed the bracket to suit and had this cut using waterjet.

Once things were in place, it was welded and then painted black to look pretty...

Exhaust
 

Now that I have the diff in place, the next logical step for me was to get the exhaust sorted...and the plus being I get to hear the engine without wearing ear defenders!!!!

I ordered 2 resonators and a rear muffler from AdrenelinR in NZ, these guys deal with rotarys on a regular basis and being stainless, it suited me well, they were able to provide me with a set that should keep the noise within legal limits aswell.

Interior
 

Now that I had the exhaust in place, I thought I had better put some decent insulation in place to try and limit the amount of heat that is going to be conducted into the cabin.

I used the GT Mat product as it's cost vs. coverage was more to my liking when compared to Dynamat and it didn't have printing all over the mating.

On top of this, I am using a closed cell foam to again reduce heat and noise...this may not be shown in the pics...

Carpet was supplied by Knox Carpets in Australia.

When it shines...
 

While it had it's wheels on and I could roll it outside...I took advantage of the weather and gave her a wash...first time outside in over a year.

Nice build! Great attention to detail! Keep up the good work..
Greg

what is the intake manifold in picture 2?

LIM is an FD RacingBeat IDA manifold, the UIM is a custom made manifold, I had Brent at Dynopower do this for me, it was an investment cast.

awesome build