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Old 04-16-2003, 05:20 AM   #1
uluv69Marines
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Default Car hesitates from stop

Hey guys got a wierd question...every since i put my weapon r intake on, my 98 rs lunges, pauses, and slowly starts to accelerate if i jump on it from a stop. if i'm rolling at 2grand, it opens right up...my mods: venom 400, random cat, borla cat-back, pro-ecm.
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Old 04-16-2003, 08:24 AM   #2
Legacy777
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that sounds like the typical bogging associated with free-flowing intakes.

I had it when I had my intake on my legacy, and several friends reported similar problems with theirs.

Solution....put stock box back on.....or look into a cobb CAI
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Old 04-16-2003, 11:46 AM   #3
Deznuts05
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yup... common problem... but this may seem like a stupid q's but did you reset your ecu?

if so you'll just have relearn how to drive the car
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Old 04-17-2003, 02:32 AM   #4
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One of the many reasons you no longer see Weapon-R intakes on Subaru's...
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Old 04-17-2003, 08:03 AM   #5
lucien2
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I'm not sure how the intake is set up on an RS, but I do know you have a Phase I DOHC like me, and it needs the torque chamber to be in the pipe line. What's happening is the chamer normally hold a reservoir of pre-filtered air for the intake plenum to use when asked for a lot of throttle, as in from a dead stop. So with the Weapon R (or JC Sports, etc) it isn't there anymore so it has to suck new air through the whole intake. It becomes momentarily starved for oxygen and bogs down. I went back to stock intake minus the snorkus after I really had a close call at an on-ramp construction zone.
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Old 04-17-2003, 09:38 AM   #6
uluv69Marines
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Default thanks

appreciate it guys...I heard something about it before. Do you think that the same thing would happen on a tubo setup without an intercooler?
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Old 04-18-2003, 01:50 AM   #7
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Quote:
Originally posted by uluv69Marines
Do you think that the same thing would happen on a tubo setup without an intercooler?
I'm not following you on this one... What do you mean?
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Old 04-18-2003, 03:32 AM   #8
uluv69Marines
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saying that engine is temporarily "starved" of oxygen, could the same thing happen on a turbo setup without an intercooler (resevoir) to hold filtered air?
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Old 04-18-2003, 06:23 PM   #9
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im pretty sure the N/A engines subaru makes need the torque box...ya know that big ugly black box right before the throttle body... to supply enough air to the engine because the intake manifold is so small it runs out of air and lacks power on the low end. or wherever you find a bog in the power band...a good intake should hold enough air to be twice the engines displacement... this manifold without the torque box is better suited for turbo boost where it never runs out of air... just an idea
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Old 04-19-2003, 02:23 AM   #10
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Quote:
Originally posted by uluv69Marines
saying that engine is temporarily "starved" of oxygen, could the same thing happen on a turbo setup without an intercooler (resevoir) to hold filtered air?
Not quite, but There have been issues with intakes on WRX's not doing anything power wise, so in that reguard the stock system (after silencer removal) works quite well unlike the N/A cars. An intercooler just keeps the air colder before it goes in the engine, as turbos get quite hot and heat the air up.
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Old 04-19-2003, 02:56 AM   #11
Eric SS
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Quote:
Originally posted by lucien2
I'm not sure how the intake is set up on an RS, but I do know you have a Phase I DOHC like me, and it needs the torque chamber to be in the pipe line. What's happening is the chamer normally hold a reservoir of pre-filtered air for the intake plenum to use when asked for a lot of throttle, as in from a dead stop. So with the Weapon R (or JC Sports, etc) it isn't there anymore so it has to suck new air through the whole intake. It becomes momentarily starved for oxygen and bogs down. I went back to stock intake minus the snorkus after I really had a close call at an on-ramp construction zone.
Bingo. Basically the engine runs out of air and very briefly (VERY briefly) wants to stall until the charge starts moving through the runners again
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