RevHard Turbo Kit Installation on the Honda Civic Si (EP3)

Begin by removing everything the kit will occupy or block. Take off the valve cover, the factory intake, and the stock exhaust manifold (header). Raise the front of the car and support it on jack stands, remove both front wheels, and take off the front bumper to expose the intercooler location. Keep both metric and SAE sockets within reach throughout the job: the car's own fasteners are metric while much of the kit hardware is SAE.

Drop the oil pan so a return bung can be added. The EP3 pan seals with Honda-bond (Ultra Flange II) liquid silicone rather than a paper gasket, so scrape the old sealant off completely and lay down fresh sealant when the pan goes back on. Have an elbow fitting welded into the pan as high up as practical, then coat the finished weld with JB Weld to seal off any pinholes.

Thread the oil return fitting into the turbocharger on the bench before the turbo ever goes on the car. Reaching that fitting from underneath once the turbo is mounted is extremely awkward and generally calls for a 14mm flex socket. This is also the moment to decide on the return plumbing: many builders replace the kit's tube-and-clamp arrangement with a dedicated return line (for example from fast-turbo.com), which is less prone to the leaks that the supplied setup can develop.

With the header and valve cover already off, lower the turbo manifold in from the top and bolt it to the cylinder head. Mount the turbocharger, wastegate, and dump tube to the manifold. If any manifold bolts will not pass cleanly through their holes, open the holes up with a grinder until the bolts seat properly.

Set the intercooler in the bumper opening and clamp it in position, then work out the charge-pipe routing linking the turbo, intercooler, and throttle body. Because the kit gives almost no guidance on pipe placement, expect to spend time trial-fitting sections before anything lines up. Mark and drill the intercooler mounting points once the piping is settled. To refit the front bumper over the intercooler, shave the back face of the bumper and trim the driver-side mud guard with scissors so both clear the piping.

Bolt the blow-off valve to the charge pipe near the intake manifold using its gasket and two bolts. Tee the valve's signal line into a manifold vacuum source, and run that line to the upper port on the valve.

Attach the two-bolt elbow return fitting to the underside of the turbo and run the return hose down to the welded bung on the oil pan. If the hose ends up crowding the turbo manifold, have the fitting re-welded to change its exit angle for better clearance.

Confirm the wastegate is bolted to the base of the turbo manifold with the dump tube fastened alongside it (its fasteners take an Allen key). Run a length of silicone vacuum hose from the nipple on the turbo to the side port of the wastegate, and leave the remaining port open to atmosphere as the vent. Because the wastegate sits upside down in this application, the open vent port ends up at the bottom once installed.

Take the oil feed from the passenger-side block port where the factory oil-pressure sending unit threads in. Install a multi-outlet takeoff adapter (such as the TunerToys dual/triple outlet, http://tunertoys.zoovy.com/product/OTODK/Oil_Take_Off__Dual_Outlet.html) so that single port can serve the stock sensor, an aftermarket oil-pressure gauge sender, and the turbo feed line together; running the gauge sender on its own braided steel line keeps it from cracking off under hard driving. Seal every block-side fitting with Teflon tape, but leave the compression feed fitting at the top of the turbo dry, as it must not be Teflon'd. Route the feed line up to the top of the turbo.

Fit the charge pipe onto the turbo compressor outlet and attach the air filter to the intake side of the turbo.

Fasten the five-bolt downpipe to the side of the turbo and wrap it in the supplied exhaust wrap to hold heat in. The downpipe mates directly to the EP3's factory catalytic converter, though many builders run a test pipe in its place instead.

Protect every line and component routed near the turbo and downpipe with heat wrap, because the radiated heat will otherwise melt them. The kit supplies a sheet of wrap; stepping up to Thermo-Tec or Full-Race gold-foil wrap provides better protection where the budget allows.

Connect the Hondata K-Pro and load a starting calibration. This build ran Siemens 630cc injectors, so load the RevHard Motoron base map and update the injector size under the parameters menu to match. Get the car professionally tuned before running any meaningful boost.

Before the very first startup, and again after every oil change, prime the oil system. Pull the 15A ECU fuse from the underhood fuse box, then crank the engine for about 30 seconds so oil circulates fully through the turbo before it can fire. This step keeps the turbo bearings from spinning up dry.