420a Eclipse Candy Red Ported Intake Manifold with SRT-4 Injectors Installed

Here is the mockup of the Intake manifold setup. This manifold has been Dipped and sandblasted to remove oil gunk buildup that occurs from the emission system. Oil can build up for blow by on the turbo as well but my engine already has thousands of miles on it well before it ever saw a turbocharger. If you look inside of a stock 420a engine with around 100,000 miles on it or more you will see at least a 1/8 inch thick build up on the inside. In some spots it can build as thick as 1/4 inch around inlets and outlet nipple and sensors. A little buildup has minimal effect however at the buildup gets taller that the dimples and flasking on the inside of the intake the air stops tumbling inside the intake. This is a common problem with ported and polished intakes however when it does it without being ported and polished your just burning extra gas at a loss of power. Thats right you lose power at this point as there is less airflow ( like a clotted artiry, think of the grease as butter) and less fuel atomization ( the fine mist that makes a clean burn).

We are limited in alot of ways by doing a Mild Port by hand. I could smooth out the inside of this manifold with a paint mixer and sand paper or even a electric " nail file" approach. You can purchase thin electric nail files for maybe ten dollars and they are about as thick as a double a battery. Attach them to a dowl rod and you could reach most of the inside surfaces. The surfaces to pay particular attention to are the flat surfaces Directly in front of each port. Also the edges can be smoothed out some around the edges of the port. This area does not cause the air to tumble so it will not affect idle.

The part of the Intake that supports low rpm idle is the last three inches of the intake plenum. Literally from the support flange ( little dimple you see on the bottom its sitting on) to the Main flange that mounts to the head. This is the intake I have for my 420a Stage 2 Turbo Setup I am about to put into commision. The injectors are 270cc SRT-4 Style injectors. These are actually set to flow LESS . This is due to the drop in fuel pressure. The FMU will be dropped 15 psi ( maybe more if needed) to correct the difference in injector size and the FMU will be given a more aggressive Boost to pressure ratio. The car really seems to want more boost than 5 psi I have been running the last three months. I have a Turbonetics T3/T4 so only running 5 psi really is a drag. I have considered switching to a smalled T3 that could still flow 350Hp. Anyways, these injectors will flow around 550cc at 85-90 PSI from the Walbro HP 255L Fuel Pump. The pump and FMU can produce 110 PSI of pressure so 600cc + is possible with this new set. However I want to keep the pressure low arround 85psi if possible to conserve the fuel with better fuel mix.

This is a picture of one of the injectors up close. They really are not much bigger than the OEM. However they flow 90cc more at idle than the OEM ( Oem injectors idle pressure is 55 PSI, Accel injectors 45 psi or less)