1997 850 How VVIS works?

Post by **bmncw** » 28 Aug 2015, 02:27

Hello MVS, does anyone know how exactly VVIS features works on 850?
Thank you

Post by **abscate** » 28 Aug 2015, 03:31

I'm not sure what VVIS is Rizky, can you explain?

Post by **tryingbe** » 28 Aug 2015, 06:04

Volvo Variable Intake System, came on a few n/a 850

https://www.matthewsvolvosite.com/forums ... =5&t=30281

Post by **Ozark Lee** » 28 Aug 2015, 07:11

bmncw wrote:Hello MVS, does anyone know how exactly VVIS features works on 850?

In most cases it doesn't work at all. It had a nasty habit of getting stuck in position.

...Lee

Post by **precopster** » 28 Aug 2015, 08:32

The VVIS system is a unique dual runner intake manifold with long and short runners. It is quite a large and heavy manifold and has very large ports and the head has matching ports also.

When working properly it opens a set of butterfly valves at the entrance of the intake manifold which divert airflow to either the short or long intake path depending on engine revs. The system is built to sharply cut in.the long intake runners at 4,000rpm.

This can lead to a performance dip as the engine should be using the longer runners at earlier revs. There was a Swedish enthusiast who designed a far better system based on a gradual engine rev input and the setup was marketed worldwide for Volvo enthusiasts. Here's a video of a VVIS intake: