Re-Speed.com

iTrader: (3)

I have been a rotorhead for almost 20 years. I grew up around the Rx2's and Rx3's my father raced and got hit by the rotary bug early in life.
My first car was a 1978 Rx3 SP. It was complete with the appearance package stripes, cow plow spoiler up front, rear deck lid spoiler and rear louvers. I should have never gotten rid of that car. I traded it off to a friend of the family for my second car, a 1973 Rx2 that had been road race prepped. It should have never been put back on the street but hey I was young.
I have owned many rotor cars since then but the Repu has always escaped me. It always sat in the back of my mind that one day all circumstances would align and I would acquire one. In December of 2004 they did. Purchased off of Ebay, I found one close enough and at the right price. As it turns out I should have left it in Alabama where I found it.

My 1974 Repu had a Pinto piston motor half *** installed. The floor boards are rusted through. The fender bottoms are rusted through. The windshield is cracked. The wiring is hacked and shot. The front valance is rusted. The battery box area is rusted through. The brakes are all locked up. The interior is half there and half shot. Otherwise, it is in great shape

I have a long road ahead of me. I will try and keep you posted on my progress, or sometimes, lack there of.

Disclaimer:

First off I would like to mention that some of the things I plan to do may be sacrilegious to some. Remember, I am a long time rotorhead. I have put many pre 80's Mazda back on the roads over the years. I absolutely can not bring myself to spend to kind of money some of these NOS or used Repu parts are selling for. If I find a way to do something that fits my goals, my skill sets and my wallet, That is how I will do it. Please do not send to me about "Bastardizing a Repu". This truck is lucky I found it and pulled that piston motor out. I believe just the fact that the truck will be back on the roads is justice enough.

The Plans:


Suspension plans are to replace the leaf springs with a first generation Rx7 GSL-SE rear axle using a 4 link system. This will update the braking system and wheel bolt pattern to easier to obtain parts that will function better than before. The front will consist of custom fabricated control arms to hold the front spindles from a second generation Rx7. The benefits are the same as the rear.

Wiring will be completely replaced with a painless wiring kit. I had rx2 a year or two ago that the harness burned from the battery to the dash gauges. I rebuilt that harness and I decided I want to go all new this time around.

Engine is going to be a six port 13B I have. It will be boosted and controlled by a Megasquirt ECU. Transmission is a 5 speed from a 81 to 85 rx7. The complete drive train I will use is currently in a 1979 rx7 I occasionally drive. I will use it as a platform to get all the drive train parts completed while the chassis stuff is being done.

Fuel system will be all new parts and lines. I have not decided if I will use a fuel cell or the stock tank. Nor where it will be located.



Purchases:

So far I have picked up only a few parts.
I have picked up a 74 B1600 cab that is in pretty good shape. I will use this for the patch panels I need to fix the Repu cab. I have also picked up quite a bit or the drive train parts. The MegaSuirt ECU kit is in. I need to get a few more items and I will start work on building it. This will be one of the most challenging parts of my build for me. I have chopped parts, designed parts, manufactured parts and built many things in the past but this will be my first Fuel injected project.

I picked up some S5 Lower and Upper intakes. - The upper intake I picked up on Ebay. It is brand new and complete with the VDI system. I picked it up for $13! The lower manifold I picked up from a rx7club.com member as well as a S5 turbo and manifold.

A while back I picked up a GSL-SE complete suspension swap for my first gen. I think I have decided to put the rear end under the PU.

Progress:


The frame is completely stripped. I pressure washed the frame to remove some of the grease and grime. Once fabrication is done the frame will get a sand blasting and coating. I am tossing around the idea of wrinkle powder coating. The frame has some surface rust pits and I believe the wrinkle finish will hide it.

I decided on a ride height for the truck. I have built stanchions out of 1" Diameter steel rod that uses the body mounts in four corners to hold the frame off the ground resulting in the frame rails being horizontal to the ground at 6" ride height. This will allow me to build suspension mounts with the frame in a known spot.

The rear end choices are in the mockup stage. I have had the GSL-SE rear end under the chassis, as well as the independent from a second gen. I can not make up my mind. The choices are: 1) GSL-SE with a 4 link and Pan-Hard. 2) GSL-SE with angled top arms. 3) GLS-SE with leaf springs 4) Independent.

The solid rear axle could be done fairly easily. The chassis brackets for the front leaf eyelets and the brackets on the rear end for the stock lower arms are within .060" or each other. This means if the stock first gen lower arms were 1.5" longer and I made some bushings for the leaf spring mounts on the chassis, the rear end would bolt up. Leaving only the upper links to fabricate brackets for.

This brings me to a decision of a pan-hard bar or to angle the top links for side to side axle location. The drive shaft clearance needed would dictate the arms need to be mounted near the center of the pumpkin and angle outwards towards the front of the truck. As we all know, this arrangement enters the space where the factory gas tank is. I could move the tank where the spare tire hung underneath the bed and behind the rear end.

I could also fabricate link brackets for the rear end and run my arms forward near the chassis and use a pan-hard. This would leave room for the stock tank (slightly moved). The pan hard idea would set my roll center for the truck somewhere around the axle housing height from the ground.

Now a leaf spring setup would mean simply cutting all the brackets from the axle housing and welding on some spring pads. I could have this done and bolted up in a matter of a few hours. Seems appealing until I think about the wind up of the leaf springs under launch. Although my wife says I have begun to drive like an old lady so how much wind up would there be? I could add a top arm to the rear end on the right side and leave my tank where it is. This would eliminate the leaf spring wind up and would got together pretty simple.

Last but not least, the independent rear end. This setup would be the trickiest in my book. There is allot more fabrication involved. There would be a major amount of fixturing of the sub frame to ensure proper geometry as well.

I am going to have to ponder this a while. In the meantime I need to get the shop arrange a little bit and disassemble the cab.

DriveFast7

iTrader: (1)

Hi Bill, another option is composite leaf springs. Guys that install them say they eliminated leaf wind up and they remove their traction bars accordingly. And are laterally strong, reducing left to right movement of axel. Some guys don't even run a lateral axel locating device. Plus they're light.

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