jgrts20

OK heres a question: How do the actuators actually work and what is the concept of them? I know they run off of either back pressure or air pump. Now how do they work, I look at them and wonder hmm theres NO air hoses that even run into them just the typical one hose yet they still open at 3800rpms. hopefully this doesnt stump anyone, but take a shot at it. oh, is it even possible to run each one off an airpump? use two for both........sound stupid but I hate this 5th and 6th port bullshit.

playdeadva

theres a lot of threads about them. search around and youll find a buttload of info. but basically they just open up at high rpms to allow more flow of air. if they dont work then your high end will be horrible. and if they stay open constantly you lose low end.

jgrts20

dude im not a noob, I know how they work read the post its not the normal question. The question is how in detail do they work, the route the air take to get to them? beside I converted them to electric.

playdeadva

ohhh sorry haha i just looked at your post count. you got me stumped. im gonna go read my FSM now hahaha now you got me wondering. maybe something with the VDI also?

NZConvertible

Pressure acts on a diaphragm which pulls or pushes on a rod connected to the valve. Very simple.

So there's NO air hoses except the typical one hose...

The S4 system is very simple. A line from the exhaust tees to the two actuators so they see exhaust backpressure. Exhaust backpressure increases under load so when load gets to a certain point the actuators open the auxiliary port valves. This means they don't open necessarily at 3800rpm like everybody thinks, because they'll open later at lower load than they will at full load. The 3800rpm number probably comes from approximately when they open on a stock S4 at full throttle. As soon as you do any improvements to the exhaust, backpressure will be less so the valves open later than before. This means the better your exhaust is the less effective the stock S4 6PI system becomes.

The S5 system uses air pump pressure instead of exhaust backpressure, and that pressure is switched by a solenoid valve so that the auxiliary ports open exactly when the ECU wants them to regardless of exhaust mods. The FSM says this is at 3,850rpm. IMO this method should be adopted for any S4 with a modified exhaust, using either the stock air pump or an electric one, with a solenoid valve triggered by an adjustable rpm switch. This allows you to open the ports at the ideal point.

You wouldn't do that for the same reason you wouldn't use one engine for each rear wheel. It's unnecessary and pointless.

I think what you mean is you hate not understanding the system. Saying you hate the 6PI concept would be like saying "I hate having a broader powerband than a 4-port engine". It's a very simple system that works well at improving the engine's performance.

idsigloo

*Gives Props to NZConvertible* This kid knows his ****.

nopistons

The air "hose" that you're not seeing is a thin metal tube, with banjo bolts at each end. The tube runs from one side of the LIM to the other, carrying the exhaust back pressure to both actuators. There are internal passages which take the back pressure from the banjo bolts to each actuator. If you remove an actuator, you'll see the exit of the passageway at the mount for the actuator, next to a bolt hole.

jgrts20

thanx guys, after looking at the actuators yesturday when I took them off, I see where the air goes in and out of them. I appreciate the explaination of this and I love the 6pi system when its fully functionable, no doubt about that. Sometimes it can be a pain in the ***. Thanx again NZ and nopistons.

chris