Turbo charging a SR20DE
Turbo charging a naturally aspirated SR20DE is a relatively straight forward task. This writeup goes through the extra step of fitting up most of the turbo engine bolt on bits, but this is not necessary.
The method used here takes advantage of all the existing turbocharger hardware from an SR20DET.
Oil and Water Lines
The most time consuming bit is getting oil and water to the turbo. For the coolant feed, I unbolted the coolant and heater lines from under the DET inlet manifold and put them onto the DE. For the coolant drain, as well as the oil feed and drain, you have to drill the block and tap in the stock positions.
The DE block has blank oil and and water positions on it already, they just need to be drilled through and tapped. Obviously the DET and DE blocks are cast identically at the factory.
This service can be done by mobile guys - rough cost is $140. Easier than buying three different sized drill bits and thread taps to suit, and then risking stuffing it up yourself.
The oil feed is the only semi-difficult one to drill and tap, as the blank is on the exhaust side of the block but the gallery is actually all the way over on the inside of the inlet side of the block. So you have to drill quite a long way before you hit the gallery, about 140mm in total.
For the oil drain they used the large DET drain piece that screws into the very bottom of the block. The coolant drain blank surface on the block is not machined, its just a raw casting, so to ensure an adequate seal with the banjo copper washer, put some 3-bond sealant between the block and the washer.
After that you can use all of the stock lines to bolt up the turbo. The turbo manifold itself goes straight onto the DE, everything ends up in the stock DET position.
Electronics
The crank angle sensor from the DET goes straight into the DE. Simply have the motor on #1 cyl TDC on the compression stroke, line up the two white dots on the CAS shaft and slide her in. Easy as.
Use the DET throttle position sensor - NOTE - The automatic ones are different and will not plug up the manual loom.
The DET uses coil-on-plug ignition instead of a dizzy, so you have to put the coil loom from the DET onto the DE. The coil packs themselves are held down by bolts that screw into the DET rocker cover. These bolts are not really necessary, but you can drill and tap the DE rocker cover for them. Or simply use a DET rocker cover.
Injectors
If you are using the DET computer, its recommend to fit up the DET 370cc injectors. The stock DE ones (260cc) flow much less. Use the DET fuel rail as well, along with the DET fuel pressure regulator. Im not sure if the DE one would handle a positive pressure signal.
Flywheel/Clutch
The DET flywheel is about 20mm larger diameter than the DE, as is the clutch. You can use either one, but probably advised to use the DET fly and clutch where possible.