The JWT cams were a simple installation as they merely got placed into position as we were buttoning the engine back up. Where the GTi-R causes some challenge is that the age of the car means that factory valve springs are no longer available to order. I retained and reused the original springs. The keepers that provide spacing between the valves and cams are also rare – so I have a hoard of them that I have been saving over the years from other 54C engines that I have pulled apart. As a result and with a bit of ingenuity, I was able to get the valve clearances all around 8 thousandths of an inch. Just what the Service Manual requested.
Next up was the challenge of the turbo. I have two or three factory turbo's lying around my garage. These systems are awesome. I love the way that they come on strong early and keep on going to the redline. What I do not love is that they are all well into their twenties – as they were built in the early nineties – and I have turned my car into an oil fogger when the turbo seals have blown. Initially I was thinking of a new and identical setup to the stock unit; that way there would be no issues with compatibility with my setup. Mike offered a few suggestions and, while they were fantastic, they would have resulted in some massive changes. I can see eventually changing the stock exhaust manifold, however, it really does a good job and has reasonable flow. My Weirtech downpipe is pure art and just last year I worked with Aaron (WeirTech now at Vibrant) and Will (PZ Tuning) to create a new uppipe to go with my new Vibrant intercooler. So I was not ready to set that aside and create it all over again. There has to be some restraint, right?
This is when discussions were opened with Precision Turbo and they recommended their 5128 model. This unit is an aftermarket replacement turbo, meaning that it is ready to bolt up to the manifold. I was pleasantly surprised at how well it fit into the very cramped quarters of my NX1600's engine bay. One of my two fans had to be removed. The wastegate actuator must be designed for RWD applications, as I had to modify that to enable it to fit where it had to be rather than in the middle of the third cylinder. I flipped the bracket around, just beneath the vacuum nipple you can see where we cut/bent/welded it. Then I put the original GTi-R's actuator adjustable end arm on it. Perfect fit. The next update was that I did not even try to reuse the original factory oil and coolant lines – I had stainless flex lines built to fulfil that function. These industrial quality lines are good for over 3000 pounds of pressure and extreme heat.