‹W4A33›

In order to proper select an intake manifold you should understand everything involved. With auto cars its all about finding the perfect cylinder head combination because you want top end power as well and some low end and mid range power for stall/spoolup on the line. So your trying to find a way to have your cake and eat it as well.

There are three possible variations of cylinder heads. And basically this gets narrowed down to the intake port runner size since we are focusing on intake manifold selection and not differences in the heads. Note: 1G 6 Bolt and 1G 7 Bolt heads are exactly the same with the exception for the head bolt/stud holes being different.

Here is what a large runner intake port looks like compared to a small runner intake port.

Intakes are not cross compatible. They will technically bolt up but the ledge thats created creates turbulence in the intake port and causes issues with airflow stability, velocity, promotes fuel puddling, and will work against you.

This intake manifold is basically the Evo3 intake manifold for large runner heads. It has two separate sets of intake runners. One set is longer then the other and they feed into a single port at the cylinder head and have a divider much like you see in a cylinder head. It has an actuated set of butterflies in a set of runners. The way it works is off boost the butterflies stay closed and that keeps the air moving through one set of runners and keeps manifold air high velocity and this helps increase off boost throttle response and spool. Then once boost pressure comes on the butterflies go open to take advantage of the large volume to make horsepower. There are several ways to actuate this. You can do it the stock way, use a electronic device to work it or you can do a mechanical setup with an internal wastegate actuator. Be aware that there are stock manifolds out there that arent split runner that say Cyclone. Those are different then these 3 piece split runner cyclones. The top end powerband is slightly better then stock but not much. This manifold is good for about 7800-8000 RPM or higher depending on camshaft.

The function of this manifold is the same as the Cyclone except it is a two piece design instead of a 3 peice. It does not say Cyclone on the casting. This manifold is found in EDM Galant Dynamic-4, Galant AMG, JDM/EDM Galant GTi. They are rare items and also have actuated butterflies and split runners. These intake manifolds have a far smoother design with better shaped runners and a larger plenum volume. The top end powerband is a good bit better then the Turbo Cyclone but not much. This manifold is good for about 8000-9000 RPM or higher depending on camshaft.

Venom and Slowboy Racing Sheet metal intake manifolds are for some reason sought after. Both of these intakes are very terrible. I have back to back compared them with stock and the stock intake manifold picked up quite a but of midrange power and spool over them. Do not use these. They are seriously junk with no R&D. They are also known to crack and burst.