The main reason we set out to build this manifold is that the OEM plastic manifold will have a limitation to where it will either leak or crack under increased boost pressures. Those boost pressures may be 15 psi or 20 psi, either way plastic can only sustain a certain amount of boost before it fails.
Below you will see the intake manifold that we designed, which is very similar to the OEM look, with the following changes:
- We have removed the waffle design on the top side - Increased the volume of the inside of the manifold by 10% - Designed to withstand 100+psi
The big thing with this manifold that we saw when compared to the stock manifold was there were very minimal gains/ loses in regards to power.
Below you will see a twin turbo built motor 370z performing a run on the stock manifold in the blue line and a run on the SOHO manifold in the red line.
Boost remains very similar to the stock intake manifold and you can see the power and torque difference is similar as well. There is a slight increase in boost on the top end resulting in a very minimal loss in power, which could relate to this engine not liking the timing at that boost level.
On the other side you see that there is a slight increase in boost on the bottom end resulting in an increase in power and torque down low.
The test was conducted on the same vehicle, same dyno, and no change in the tune so that we could compare apples to apples and not apples to oranges.
In order for this intake manifold to work on the HR engine, you will need to purchase the OEM VHR lower intake manifold and OEM VHR fuel rails