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| Home > RX-7 > Tech/Mods > Modifications > Turbo NA Guide > Prepping The Intercooler and Turbo, Upgrading The Injectors |
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The picture above represents the turbo and intercooler before cleaning and modification. They are both off of an '88 10th Anniversary (not that it really mattes). The owner blew the engine, and I purchased the turbo and cooler.
Because the TII intercooler will be front mounted, it was necessary to remove the backing plate. This plate is a thin sheet of aluminum that is used in the stock top mount location as both a heat shield and a duct. It helps duct air from the scoop, through the cooler, and out into the engine bay. In front mount form, this would almost completely block airflow to the intercooler and the radiator, so it had to go. The rivets were simply drilled out from both sides, and the backing plate removed.
Rivets on the opposite side of the intercooler to be removed.
The finished intercooler. The backing plate has been removed, and the cooler cleaned inside and out with degreaser. Interestingly enough, I burnt out a hair dryer using it to force air through the cooler to dry it out. There is a vacuum nipple which was plugged later.
Now room had to be cleared for the turbo. Because the turbine (exhaust side) housing of the turbo sits so close to the lower engine, it is impossible to retain the air control valve (ACV). So it was removed, as well as the 5th and 6th port actuators. There is simply no space. The lack of properly functioning 5th and 6th ports will result in very little effect once the engine has been turbocharged. Note that by removing the ACV, either the car will have to be run without catalytic converters, or the airpump will have to be directly connected to the converters. I have removed the air pump in these pictures to make everything more accessible, but it was reinstalled later on. The secondary throttle blades were removed to improve throttle response and make more space in the throttle body. They are completely pointless, and removing them results in quicker throttle response and a little more top end airflow.
The entire upper intake was then removed. This allowed access to the primary injectors, and all the vacuum hose (it was swapped with new silicon hose). The intake was then brought inside the house (much warmer than the garage) for modification.
The cold start is a system that injects a solution of ethylene glycol (coolant) and water into the intake to assist in cold starts. It is completely useless, doesn't work, and Mazda even issued a Technical Service Bulletin instructing dealers to remove it. This plate fits on the upper intake in place of the cold start valve and eliminates the system entirely.
This rather bad picture shows the completed upper intake. TII injectors have been installed, as well as a bolt to block off the hole left from the secondary throttle shaft. The hole was tapped, and the bolt screwed tightly in with liberal amounts of Loctite for sealing. Also note the cold start blockoff plate has been installed.
While the upper intake was removed, 550CC TII injectors were installed in place of the 460CC NA primaries. All the old vacuum hose was also replaced by silicon hose since it was convenient at the time.
The upper intake was then reinstalled.