Auxillary Port Valve Trouble

[NoDOHC]

Originally Posted by My5ABaby

They open when you rev your car in neutral without putting any auxiliary air into the system?

The S4 ports work fine in Neutral, it was the S5s that required the car to be in gear.

The exhaust backpressure is primarily caused by air flowing through the exhaust meeting restrictions that require a differential pressure to overcome. This backpressure is the same with the transmission in neutral at WOT as it would be with the transmission in gear at WOT.

The S5s are computer-controlled, so they do require the car to be in gear.

Originally Posted by kev41

I do have a custom and by custom I mean made by myself and my dad who is a motorcycle mechanic at the local bike shop. I was thinking about buying the RB header and presilencer will this combo create enough back pressure or do I need the whole system

Exhaust backpressure is not your friend. It does not help power, fuel economy or engine life at all. You want less backpressure. The ideal backpressure is negative (scavenging using tuned exhaust headers).

What you need is the means to make the aux ports open without having backpressure - the simple solution is the 12V air pump and the solenoid from the rats nest.
Rpm switches are easily acquired and easily installed (use the tach wire). Many people have done the 6PI that way with success.