This car is being set up for racing use, with most of the interior stripped out, a roll cage, big brakes, and lots of power!
To keep the engine’s oil cool while it’s producing more than double its factory power, I helped install an oil cooler.
After trying a few possible locations, it was decided to mount it in the traditional position in front of the radiator. This was the best compromise of air flow, mounting strength, and working with the lengths of the pipes in the oil cooler kit.
The air conditioning condenser and plumbing was removed (also the compressor and its bracket) to make space, as well as weight reduction. Unfortunately this meant draining the coolant and taking the radiator out for access!
Here’s the oil cooler installed between the intercooler and radiator:
The oil cooler kit also came with a filter relocator, which makes changing the oil filter much easier - much appreciated by anyone who has changed the oil filter on a Silvia (or pretty much any modern car). The relocator also has fittings for oil temp and pressure gauges.
A larger aftermarket aluminium sump was also installed. It holds more oil than the standard one and has hinged baffles inside to keep the oil near the oil pump pickup during hard cornering. There was a bit of a snag with the sump install because the drain plug thread was found to be damaged.
I re-tapped the thread to a larger size and replaced the factory drain plug with an off the shelf tapered plug, which should work well and be harder to damage in future.
The next job was to swap the ECU. The car was running an older Microtech ECU which worked ok but is a bit limited in the accuracy of its tuning and tends to be affected badly by changing weather conditions, etc.
The replacement ECU is an Apexi PowerFC D-Jetro - which used a MAP (Manifold Absolute Pressure) sensor like the Microtech, rather than the factory MAF (Mass Air Flow) sensor. A MAF sensed ECU is superior in a few ways, but since the car was already set up for MAP sensor the D-Jetro version of the PowerFC was an easier option.
Swapping it over required removing the Microtech wiring loom, which had been spliced into the factory engine loom, tidying up some other wiring (fuel pump control, etc) and plugging the PowerFC into the original ECU plug.
Since MAP sensed ECUs also need an air temp sensor, this had to be added into the wiring. The PowerFC’s air temp sensor has a different thread to the Microtech one, so the fitting in the intake pipe needed to be modified.
One of the PowerFC’s nice features is a readout from the engine’s knock sensor. This can be a very handy thing to have, as it can tell you if the engine is pinging (detonating) under certain conditions. It’s not foolproof, but it’s generally worth keeping en eye on, and never worth ignoring!
When the ECU was installed we found that the knock sensor wasn’t working. Upon closer inspection I found that the plug had fallen off the sensor, and was missing the small wire clip that holds it on. Not having a clip on hand, I found a paper clip and made a new one!
A minute or so with some needle nose pliers and it looks just like a real one 
The knock sensor plug went back on and the ECU started giving the knock readout as it should!
The last job to do was to bleed the brakes because they were feeling very spongy after being upgraded to some very nice four piston AP racing calipers. Bleeding the brakes is pretty simple, as long as you have two people - but these calipers have two bleed nipples each! So, each caliper has to be bled twice, but once that was done the pedal felt nice and solid.
