Iris

[Whoru465]

If the IRIS valve wasn't working (i.e., stuck in full open/closed or somewhere in between) How would you tell? Would it set off an error code? Or would the horrible performance be enough to tell? Thanks.

[oab_au]

Originally posted by Whoru465
If the IRIS valve wasn't working (i.e., stuck in full open/closed or somewhere in between) How would you tell? Would it set off an error code? Or would the horrible performance be enough to tell? Thanks.

If there was a problem in the electrics that work the valve, then it would post a code. If it was the butterfly valve stuck or mechanical not working, then no code. A solenoid valve turns on stored vacuum to pull the valve open, a spring closes it

If the IRIS valve was stuck closed, there would be good acceleration up to 4000 rpm, then the engine would run flat from there with little torque. If it was stuck open, it would be gutless below 4000 rpm, but run hard above 4000 rpm.

It is not known to give trouble, but there is allways a first. What problems are you having?

Harvey.

[Mr. Pockets]

Originally posted by oab_au
If the IRIS valve was stuck closed...the engine would run flat from there with little torque.

If it was stuck open, it would be gutless

Do you really think that the IRIS has that profound an effect on the engine's performance? I mean, I'm not saying that it doesn't do anything. I'm just curious, now, how 'gutless' it would be without the IRIS working properly.

[immortal_suby]

I suppose you could unplug the vacuum line to it and find out.

[oab_au]

Originally posted by Mr. Pockets


Do you really think that the IRIS has that profound an effect on the engine's performance? I mean, I'm not saying that it doesn't do anything. I'm just curious, now, how 'gutless' it would be without the IRIS working properly.

Hi Nick, yes mate, it is responsible for the two torque peaks that we have seen in the dyno graphs. If it was stuck open, the low speed Inertia pressure would be lost thorough the valve to the other side. Instead of building pressure in the cylinders on each side.

Stuck closed at higher rpm, the resonate inlet pipes could not induct a full cylinder of air, from one side, it needs both sides to be joined, to provide enough chamber volume to supply the air in the time available.

Harvey.

[Whoru465]

Thanks for the replies. I'm not having a problem, but I think I was trying to ask what Pockets asked. Kinda, whats the potential for a bunch of us driving around with non-functioning butterfly valves and never even knowing it?