Rebuilt Subframe Pictures Found!!

I was going through my old documents and found some old digicam photos. By old I mean October last year.

Around that time I had purchased a bunch of mini parts from Huddersfield Minispares, which consisted of brand new bushings, fully adjustable suspension, hi-lows, red dot rubber cones and some GAZ adjustable shocks. I got my subframe sandblasted and powder coated a weird berry grey that sort of looked like primer.... Hmmm don't know what I was thinking.

The subframes were completely rebuild, painting all the parts with POR15 and re-doing some of the brake lines. The rear brake master cylinders were replaced with new 5/8" ones and the rear proportioning valve was rebuild by Perth Brake Parts.

Here is a picture of the mini pre-sandblasted with some tidy Group 6 arches.

Main Belt Tensioner

The main belt tensioner was an idea I grabbed off a member on the Ausmini forums. What people had done previously was purchase a belt that would fit around the main crank and the water pump and slip it on, meaning it wasn't easy to get on or off. The pulley used by the Ausmini member Amos is from the AE92 Toyota Corolla's air con, but after calling up several wreckers who weren't interested in small business, I was informed by my friend Alan that the idler pulley from the Nissan SR20 engine was the same 4pk belt.

Once purchasing one of these from KYP in Welshpool for $15 I took it back to trial fit it. The bad news was that the pulley was definitely too big (close to 90mm) for the space I had to work with, although the AE92 Corolla used a smaller 69mm pulley. So I ended up ordering a brand new AE92 Nuline replacement pulley with bearing from Coventrys which sat perfectly in the idler bracket from the SR20. The good news was that KYP had sold me the idler pulley and whole bracket that it was attached to. I was able to cut the tensioning part off with a grinder and use that instead of recreating something else.

The next part was attaching the bracket to the block of the engine. This was simply done by using the two bolts on the back of the block where the layshaft bracket was mounted and just bolting on top of it. I did think of welding it to the layshaft bracket but it would be more convenient having them separate. After I held the pulley bracket in place with an old Glanza belt, I could line up the 3 pulleys (main crank, water pump, idler tensioner) and tack weld the brackets together.

With the bracket attached and self supporting I tested out the tensioning of the idler pulley which didn't work as well without having a belt that fit. To measure which belt would work I used a piece of string around all pulleys with the idler at its minimum to maximize the tensioning of the idler pulley. The belt I think ill be using is a 4PK0705, but I'm yet to try this as I'm working away at the moment.

This is what was created, but still needs to be cut down and properly welded.

Alternator Install & Cleaning up Subframe

Ok! So before I started the alternator I figured it was time to finish the majority of the subframe. This included properly welding the main engine mount and installing gussets or plates to give the subframe a little more strength, not that it needs it. I forget in which order these were done amongst creating the centre spars, making up the alternator brackets and remaking the front spar. You can see the end results through the pictures anyway.

Now on to the alternator. I had purchased a smaller alternator from a Daihatsu Charade G100 which is one of the smallest alternators available, producing 45A. This should suffice for my project as there isn't a lot of electrical accessories other than the motor, lights and of coarse, stereo system. I was still contemplating using the standard Glanza alternator but after holding it in the position it was going to sit, which is behind the right hand headlight, it looked a little bit big and protrusive. At least compared to the Charade alternator.

Since the pulley off the Charade alternator was a single V belt type compared to the 4PK one of the Glanza, it was simply swapped but the face of the Glanza's pulley had to be lathed down (already pre-done in the above photo). With the actual alternator bracket, I first made up the plate that would bolt onto the engine's block using the existing cast iron block bracket that used to be mounted there as a template. Some left over 20mm OD pipe was then used for the main alternator mount. I cut up some little brackets that would sit on the mounting pipe and bolt through the main alternator mounting hole, and with one of the old Glanza A/C belts I aligned the alternator up with the crank pulley. From here it was simply tack welded to the bracket.

The only option in regards to the tensioning of the alternator was to use the existing tensioning bracket from the Glanza and mount that off the main engine mount. So with a bit of messing around I created the tensioning bracket.

The last step was to purchase a belt that would suit this application. An easy way of doing this is using a piece of string and wrapping it around both pulleys, or in my case, I marked the existing belt then rolled it out onto the floor. Sure enough I drove down to SuperCheapAuto and picked up 2 belts on either end of my measurement and returned the one that didn't fit. A Bosch 4PK0875 was the perfect belt.

Centre Support Spars and Strengthening

I had a bit more time than I originally thought before I flew out next and I really wanted to nail these centre support spars. It was a lot harder of a task than it seemed to be as a lot of thinking took place. I wanted to keep the spars to look clean without any protruding joins and match the rest of the subframe so I opted for 20mm OD pipe with a 1.6mm thickness as this could be easily bent with a conduit pipe bender we had floating around a work. The thing that worried me the most was where would I have these spars mount on the rear of the subframe and to make sure that the point at which they mounted was structurally strong enough. So before I started on the centre spars I had to weld in some plates which wasn't a bad idea as it made the whole underside of the towers quite robust.

Here is what was done:

After that was complete I made up some removable brackets that the spars would be welded to so that they could be removed at any time if needed. Amongst all this the front spar I previously had was scrapped and had to be redone using different mounting brackets than previously. I used 25mm OD 2mm thick pipe for this.

Now back to the centre spars. I decided to go through the centre near the exhaust rather than around the side because of where I mounted the front brackets and I figured it may be a better spot for its intended use - restricting flex down the centre of the subframe. Getting the bends at the right angles on a singular piece of tube wouldn't be very easy so another idea was making up a few bends then welding them together. I really didn't to lose any structural strength when doing this so a mate from work handed me a piece of lathed down pipe that would fit inside the spar pipe. This made aligning the pipe ends together a cinch and also made for a better weld over the normal butt weld.

This is what was done.

So after a few hours of messing around grinding and twisting the pipes into position, started to tack welding the pipes and brackets to each other. I was almost finished doing the centre spars, all that was left was to finish the welds in the welding bay and clean up. One thing I would of done differently was doing these whilst inside the car, because I did find that my left mount spar was slightly out by 2mm due to the overheating when welding the strengthening spar. So this could of been avoided but it was as simple as the welder was in a different location. Not a big problem though as I could still mount the subframe inside the engine bay no worries, a little bit of TLC does the trick.