Four cyl VIRS revisited

[cjthor]

Well I have been drivin around with my boosted b6 for almost a week now. Here is a question. I know the VIRS system is controlled my a solenoid and uses vaccuum to open the intake runner actuator. So what happens when boost hits? The system opens at about 4k and I dont really think its opening. You need vaccuum and there isnt any at 4k. Any ideas??? Should I just wire them open? Closed?

[maldo]

The VRIS system should be operational at cruising speeds when not under load. Once the system sees boost it should close as it no longer sees vacuum. It would be optimal to have it closed at all times, keeping torque up and allowing for quicker spool up of the turbo. A sudden move by the VRIS to open could cause quite a drop in torque. I guess it depends on what your goal is, try it both ways to find out what seems to work best with your setup.<p>BTW, how does it feel?

[David Coleman]

4 cylinders have VICS
6 cylinders have VRIS
VICS works on increasing runner diameter at a specific RPM by opening ONE set of valves
VRIS works by changing the length of the intake path with TWO sets of valve at SEVERAL RPM's

[cjthor]

Yup I meant VICS or whatever its called. I guess I will wire it shut and see what happens. Probably help out with torque a little and have less vac lines in my engine bay.

[boostedmx]

just disconnect the vacuum line and pinch it off. when the engine is running they are held shut by a vacuum operated shutter valve. when vacuum is lost they open(under full throttle). since more internal volume of an intake = more torque you really should try it all three ways to see which way suits your turbocharged application. could have some downfalls but could also have some benefits.

[ProtegeSTS]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by maldo:
The VRIS system should be operational at cruising speeds when not under load. Once the system sees boost it should close as it no longer sees vacuum. It would be optimal to have it closed at all times, keeping torque up and allowing for quicker spool up of the turbo. A sudden move by the VRIS to open could cause quite a drop in torque. I guess it depends on what your goal is, try it both ways to find out what seems to work best with your setup.<p>BTW, how does it feel?<hr></blockquote><p>
Ideally, you'd have time on a dyno to see when and where each setup is better. IE...on load, off load, and each of those through the rpm band. Then get some solenoids to control it.