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#1
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The infamous IRIS Valve
Is it needed? Is it beneficial to remove? Will the car run without it on the stock ECU??? Please explain to me why so many people remove it...
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#2
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Re: The infamous IRIS Valve
I dont know of anyone who has removed their IRIS valve....
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Former: 1994 Barcelona Red(x2), 1995 Brilliant Red, 1992 Liquid Silver, 1992 Ebony(x2), 1992 Pearl White (x2) Current: 2017 Ford Raptor 2017 Kawasaki KLR 1995 Guards Red Carrera 1995 Spec-ish Miata - track car 1957 CJ-5 |
#3
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Re: The infamous IRIS Valve
<<I dont know of anyone who has removed their IRIS valve....>>
+1 here. never heard of that... |
#4
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Re: The infamous IRIS Valve
What is the IRIS valve, what does it do? and what does it look like?
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1992 NZDM SVX Maroonish Red/Black ( 1st car ive owned with an cd player ) Has been retired 1989 Vortex 6 Maroon 1983 RX Silver Grey 1973 1400 GSR Yelo 2 Door Coupe awaiting Restoration |
#5
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Re: The infamous IRIS Valve
There was mention of messing with it in rally bob's build and nevin wanted me to ship my intake manifold to him without it as a core for him to send me his polished intake manifold, I've not heard back from him yet as to if he runs his without it or why he removed his
So that is why I was curious, because I'd seen it a few other places around. I'll do some searching and post some links so it'll be more clear. I'm just really confused what it is and why people are messing with it. PS: Bobby did you get my voicemail I left ya? I misplaced your paypal addy to send ya the cash for the radio cage, also still wondering if you found that visor and how much you wanted for it. let me know. |
#6
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Re: The infamous IRIS Valve
http://www.subaru-svx.net/forum/show...+Valve&page=14
I'm confused... what is it... what is it used for... and why did they remove it, and why did nevin remove his.... |
#7
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Re: The infamous IRIS Valve
I've been trying to find the part of the ECU that controls it to experiment whether there is any benefit to opening/closing it at a different rpm than stock. But I haven't managed to find it yet.
As I understand it, with the iris closed, you get more power at low rpm. With it open, you get more power at high rpm. I can't imagine it would be benefical to remove it unless you were doing other mods to the intake system.
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Subaru ECU and TCU Website 1992 Alcyone SVX Version L 1992 Alcyone SVX Version L 1994 Alcyone SVX S40-II 2004 Subaru Legacy 2.5 SE Sports Tourer 1996 Subaru Legacy 2.2 GX Wagon 1988 Subaru Justy J12 SL-II |
#8
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Re: The infamous IRIS Valve
personally I think removing it would be a bad idea...
__________________
Former: 1994 Barcelona Red(x2), 1995 Brilliant Red, 1992 Liquid Silver, 1992 Ebony(x2), 1992 Pearl White (x2) Current: 2017 Ford Raptor 2017 Kawasaki KLR 1995 Guards Red Carrera 1995 Spec-ish Miata - track car 1957 CJ-5 |
#9
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Re: The infamous IRIS Valve
I would imagine the iris is acting like a secondary valve in a carb. setup, with the iris closed you get a lean mixture at start-up (less airflow) - slowly getting more richer to compensate for increased airflow at higher road speed???
Steve (1 OF 1) |
#10
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Re: The infamous IRIS Valve
I've always thought that the opening and closing of the IRIS valve was purely driven by engine vacuum and not by a signal from the ECU. If this is, in fact, the case, then you could rig up a cable to manually open and close the valve any time you wanted to
-Bill
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Retired NASA Rocket Scientist Most famous NASA "Child" - OSIRIS-REx delivered samples from asteroid BENNU to Earth in Sept. 2023 Center Network Member #989 '92 Fully caged, 5 speed, waiting for its fully built EG33 '92 "Test Mule", 4:44 Auto, JDM 4:44 Rear Diff with Mech LSD, Tuned headers, Full one-off suspension '92(?) Laguna, 6 spd and other stuff (still at OT's place) My Locker |
#11
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Re: The infamous IRIS Valve
Bill you are partially correct. The valve is operated by a vacuum diaphram but the vacuum is controlled via a solenoid under the intake. It stores intake vacuum in the black canister under the intake w/ a check valve so that when the ECU initiates the solenoid the vacuum stored can operate the valve.
It can be rigged manually, but thats a PITA. The gains and/or losses of using it to not using it are going to be minimal. If you are running the stock ECU, there is no reason to get rid of it, just make sure it operates properly. I may fiddle with it when I am working with the hyrda on an extra output from the ECU but that is only if I am REALLY bored Tom |
#12
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Re: The infamous IRIS Valve
Quote:
Yeah, I forgot about the solenoid Help my memory here. Actuation of the solenoid causes the diaphram to open the IRIS, thus creating a single plane intake? -Bill
__________________
Retired NASA Rocket Scientist Most famous NASA "Child" - OSIRIS-REx delivered samples from asteroid BENNU to Earth in Sept. 2023 Center Network Member #989 '92 Fully caged, 5 speed, waiting for its fully built EG33 '92 "Test Mule", 4:44 Auto, JDM 4:44 Rear Diff with Mech LSD, Tuned headers, Full one-off suspension '92(?) Laguna, 6 spd and other stuff (still at OT's place) My Locker |
#13
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Re: The infamous IRIS Valve
Quote:
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#14
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Re: The infamous IRIS Valve
You'll be down on power, but you probably won't even notice it. What usually happens is that the check valve - in line with the vacuum line from the intake to the vacuum canister - cracks. Little guy is way too expensive for what it does...
-Bill
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Retired NASA Rocket Scientist Most famous NASA "Child" - OSIRIS-REx delivered samples from asteroid BENNU to Earth in Sept. 2023 Center Network Member #989 '92 Fully caged, 5 speed, waiting for its fully built EG33 '92 "Test Mule", 4:44 Auto, JDM 4:44 Rear Diff with Mech LSD, Tuned headers, Full one-off suspension '92(?) Laguna, 6 spd and other stuff (still at OT's place) My Locker |
#15
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Re: The infamous IRIS Valve
Just to be clear, I have NOT removed my IRIS valve. I removed it on a spare IM that has been polished, and I was just telling him to remove it merely to help keep down on weight (and therefore shipping cost) when I ship my polished one to him.
And no, I would see no merit in taking out the IRIS valve on one of these motors unless possibly in forced induction. It would be possible to control the opening and closing of it, but that woudl only be necessary if you were changing cams, adding headers, etc... and you would NEED a couple dynos to figure out the optimal point. The easy way to do it would just be to use an MSD window switch and then you could use whatever pills you need to open/close the valve.
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Jesus is the remedy 2015 Expedition EL Ecoboost Ebony Pearl '95 Subaru SVX LSi Home of the Bontrager Works 22mm rear sway bar!! |
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