The turbo manifold turned out to be a huge undertaking. Due to the size of the turbo and the fact that you can’t really buy anything off the shelf to suit an FD motor and 323 build - I decided to make my own. There are various opinions on Stainless but I decided to go for Schedule 40 2” steam pipe. I managed to get a whole bag of bends and tube from the local supplier for under $100. I bought plenty of extras to fix any mistakes I might make on the way.
Two of my key considerations were 1) Keeping the runner lengths as close to the same length as possible and 2) Keeping the split pulse timing to match the turbo. I started off by mounting the base flange to the engine (I bought this - much easier than making your own) and then removing the exhaust housing from the turbo (to make it lighter to handle) and roughly suspending it from the ceiling rafters in the position that I wanted it in the engine bay. I made my own split flange for the turbo mount. Once in position I tack welded two lengths of steel between the engine flange and the turbo flange. I could now fit the runners in between flanges.
The first step was making the collector. This is the bit that joins the two runner tubes to the turbo flange. They merge at about 15 degrees and I welded a separator plate between them to keep the split pulse.
A lot of cutting and fitting took place to make up the runners - the first one is easy. I started with the runner that connected the flanges at their furthest points. All my bends and bits of pipe were mocked and held together with tape to make changes easier. The second runner is harder because to retain the same runner length you have to put an extra bend in. I basically mucked around until I had it about right. All the seams were spot welded before doing the final welds. I also used a mig welder rather than a tig. After talking to a few friends - their suggestions were that tig welds on these heavy manifolds seem to crack after a while.
The next step was making the wastegate runners and collector. Do to space restrictions it was virtually impossible to retain the same runner length for the wastegate. It’s close - and the pipes merge right on the wastegate valve.
After some final fitting and welding I wrapped the entire manifold with heat wrap and painted it with high temp VHT manifold paint. I worked on this for about 4 months to completion (on and off) and for the price it cost me (Around $250 in raw materials, a lot of grinding, cursing, welding burns and at least 100 fitment tests) I’m really happy with the outcome!




