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#1
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Question about intake modification.
I'm thinking of doing a ram air setup.
functional small scoop on the hood that feeds directly into the stock filter box? I would move the filter box upstream, placing the maf just a few inches upstream from the TB. Invert the filter box, cut a hole in the bottom, and allow the plumbing built into the hood running to the scoop to seal with it when the hood closes. I know that there are proven gains by going with some sort of ram air setup. One member reported some level of success by simply cutting a hole under the fender where the intake resonator resides. My logic is that I could get higher pressure in the manifold with a scoop. And possibly a quicker throttle response with a dramatically shortened intake length. Thoughts, suggestions? put downs? Thanks, Patrick
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Patrick 1995 Ebony Pearl. S.N. 0001 "Araby" JDM Power Mode Switch, Integrated GPS/Video Player 6Xk Miles. 1992 Teal - Sold to Mysvxrocks [SIGPIC][/SIGPIC] |
#2
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That sounds like an interesting project. Keep us informed if you do it. Many here have modified the intake box, but I don't think any one has done what you describe. Good luck.
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. Earl .... ... .... ><SVX(*> Subaru Ambassador [COLOR=”silver”]1992 Tri Color L[/COLOR] ~45K (06/91) #2430 1992 Dark Teal LS-L ~184K (05/91) #0739 1992 Claret LS-L ~196K (05/91) #0831 1992 Pearl LS-L ~103K (06/91) #1680 1992 Pearl LS-L ~151K (06/91) #2229 1992 Dark Teal LS ~150K (07/91) #3098 (parts car) 1992 White LS-L ~139K (08/92) #6913 1993 25th AE ~98K (02/93) #164 1993 25th AE ~58K (02/93) #176 1993 25th AE ~107K (02/93) #215 1993 25th AE ~162K (02/93) #223 1994 Laguna Blue Pearl LSi ~124K (1/94) #2408 1994 Laguna Blue Pearl LSi ~144K (10/93) #1484 1994 Laguna Blue Pearl LSi ~68K (10/93) #1525 1994 Barcelona Red LSi ~46K (02/94) #2624 1994 Pearl LSi ~41K (12/93) #1961 1995 Bordeaux Pearl LSi ~70K (02/95) #855 1996 Polo Green LSi ~95K (03/96) #872 1997 Bordeaux Pearl LSi ~55K (08/96) #097 2003 Brilliant Red LS1 Convertible ~29K (04/03) #8951 1999 Magnetic Red LS1 Coupe ~33K (04/99) #6420 My Email | Old Locker | New Locker | Picture of 15 of the 19 |
#3
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if i am understanding it correctly, it does sound like a good setup
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1992 Subaru SVX LS~L Ebony Pearl 1992 Dodge Stealth R/T Firestorm Red 1992 Subaru SVX LS~L Pearl White 1992 Subaru SVX LS~L Ebony Pearl JDM 6MT/DCCD 2007 Subaru Legacy Spec B. Diamond Grey Metallic |
#4
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At low speed there will be little or no ram effect, and at less than wide-open throttle any ram air-flow effect that you do achieve will be reduced. Which is, of course, what throttles are supposed to do. The price you pay is one of altering the resonant behaviour of the entire inlet tract. By making it shorter you raise the resonant frequency, which might possibly help at high engine revs, except for the fact that the IRIS valve in the inlet manifold is set up to work with the original system. Subaru claim that the IRIS valve contributes to a volumetric efficiency of over 100% for certain portions of the rev range. Once you change the inlet tract the IRIS valve will not open at the optimum time any more. Its anyone's guess whether such a change will be for the better or worse overall - but if I had to bet, I know where I'd put my money Pete. p.s. If you want higher airflow at all speeds, just take the air filter out!!!
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I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the state of Science, whatever the matter may be. Sir William Thomson Last edited by ItsPeteReally; 03-17-2007 at 01:31 AM. Reason: Inadvisable postscript |
#5
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Hi Patrick,
On the face of it I agree that the prospects may appear rosy, but apart from a possible placebo affect, you could be very unhappy at having hacked your car about. Do some reading and you will understand why. Google will find you loads of factual data. A ram charge system as coined by Chrysler, involves a different set up. The SVX is already set up so that air is drawn from a high pressure area, which is in effect what you are trying to achieve. If you would like the visual affects of a bonnet scoop, that is another aspect entirely.
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Trevor, New Zealand. As a child, on cold mornings I gladly stood in cowpats to warm my bare feet, but I detest bull$hit! |
#6
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well after a large amount of time tinkering with this stuff myself i would honestly say only modify with filters, once you start in with the intake system all hell breaks loose. as has been stated earlier in here the IRIS valve will basically cancel out and decrease the good of anything you do, beyond that... the frequencies of the resonation can REALLY suck, with mine we got the intake set up exactly where we wanted it and we saw gains, however we are now having some not so fun problems with interfiernce with the MAF and its putting the car into a limp mode and killing it all. initial curve with the IRIS off and closed we hit bigger numbers at the wheels then when it opened and drop us into a limp mode.
simply put, only go filters, possibly the inverted intake set up, but DONT move the MAF and dont change the length of the set up. that would be the personal advice i would give you in regaurds to this project. however, put a nice K&N or better pannel filter on your inverted scoop set up and i do believe you would see a reasonable and noticible gain across the board. good luck and best wishes! i hope to see some sound results and pics along the way! Chris
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98 Impreza Wago-O-Doom & Datsun Roadsters |
#7
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Yes, ram air works...
No, it won't do anything below ~25 mph (confirmed with pressure gage measurements) Yes, it will add ~5-10 hp above ~25 mph Yes, you shouldn't move the MAF or airbox (I use a GREEN filter in the stock airbox) (in use for over a year with no issues...) -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 Last edited by SVXRide; 03-17-2007 at 12:49 PM. |
#8
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Some good info in this thread. I am hoping to see how this pans out. What ItsPeteReally is saying about the IRIS valve is really interesting since I have been reading up on this the past two days.
Quote:
Could you give me more information on your findings as far as maf placement and intake tubing lenghth? I will be looking for info from you by searching but this is the first time I am reading about this. I am REALLY interested in this information. We can talk in PM since this may be unrelated to this thread. Thanks! BTW: Chris...are you referring to this intake-->
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Kevin Thomas 1997 2.2ltr Subaru Impreza Outback Sport Wagon (AWD/Auto) 13.03@100mph 1989 2.7ltr Subaru XT6 (AWD/Auto) 15.912@85.93mph 1996 3.3ltr SVX (AWD/Auto) 15.070@91.38mph ***R.I.P*** 2010 RAV4 AWD Sport (13.717 @ 99.19mph ) 2015 Honda Fit LX CVT (15.2 @ 90mph) Last edited by Myxalplyx; 03-17-2007 at 02:12 PM. |
#9
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yes sir that one would be mine. shoot me an IM if you want to talk about it more, its just easier. curly2k32007
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98 Impreza Wago-O-Doom & Datsun Roadsters |
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