Injen or similar CAI - does it increase power? (was: need help all u pros)
01-08-2006, 10:59 PM
#1
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Car Info: 2005 WRB w/ Silver Rims
need help all u pros
ok.. can anyone that has an injen cai or a similar cai tell me if it increases or decreases hp for wrx or sti... dyno charts and detailed explanations would be very greatly appreciated
01-08-2006, 11:10 PM
#2
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Originally Posted by FujiApples
ok.. can anyone that has an injen cai or a similar cai tell me if it increases or decreases hp for wrx or sti... dyno charts and detailed explanations would be very greatly appreciated
sorry no dyno charts from end users. CAI for subaru is a mixed bag. People say it increase while others say they lose power. Even if it shows on a dyno a higher power increase. Is it really worth it?
Its more or less opinion. I honestly feel that CAI do almost nothing for turbo charged cars. Yes you should put a filter on so it will not destroy the turbine.
If you're going to spend that type of money, buy an uppipe or a downpipe. Free up some of the exiting pressurized air in the engine.
01-08-2006, 11:16 PM
#3
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lol thanks... by the way that dude was me on myspace.. that u got pissed at cuz u didnt kno who i was.. and i met u before 
... anyways... say i have a cai and a bov non recric... if i got the air to fuel tuned right.. what would my power output look like..
... anyways... say i have a cai and a bov non recric... if i got the air to fuel tuned right.. what would my power output look like..
01-08-2006, 11:22 PM
#4
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Originally Posted by FujiApples
lol thanks... by the way that dude was me on myspace.. that u got pissed at cuz u didnt kno who i was.. and i met u before ... anyways... say i have a cai and a bov non recric... if i got the air to fuel tuned right.. what would my power output look like..
... anyways... say i have a cai and a bov non recric... if i got the air to fuel tuned right.. what would my power output look like..no worries about the myspace, I only add people I really know. ask jorge it took him a couple of months.
Anyway onto your car issue. Don't worry about a tune on you're set up at the moment. Worry about a tune when you're catless, upgraded injectors. Different turbo. If you're only messing around with the simple bolt ons, it won't be worth it for a tune. You'll need a tune when the car starts to knock or hesitate
oh BTW
post you're questions here
https://www.i-club.com/forums/rife-plazapalooza-151/life-plaza-tech-corner-realz-its-free-122507/
01-08-2006, 11:25 PM
#6
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Originally Posted by LifePlaza
no worries about the myspace, I only add people I really know. ask jorge it took him a couple of months.
Anyway onto your car issue. Don't worry about a tune on you're set up at the moment. Worry about a tune when you're catless, upgraded injectors. Different turbo. If you're only messing around with the simple bolt ons, it won't be worth it for a tune. You'll need a tune when the car starts to knock or hesitate
oh BTW
post you're questions here
https://www.i-club.com/forums/showthread.php?t=122507
Anyway onto your car issue. Don't worry about a tune on you're set up at the moment. Worry about a tune when you're catless, upgraded injectors. Different turbo. If you're only messing around with the simple bolt ons, it won't be worth it for a tune. You'll need a tune when the car starts to knock or hesitate
oh BTW
post you're questions here
https://www.i-club.com/forums/showthread.php?t=122507
yep took a while. then when it happend i felt cool! lol
01-08-2006, 11:26 PM
#7
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alright dude but ill just finish up this question here.. if i get a bov with my cai... wont i lag and run crazy rich? is there a cheap way to fix this? and i dont think turbo upgrades are comin soon.. but downpipe and catback exaust maybe..
01-08-2006, 11:28 PM
#8
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and i kno i dont need the cai.. but its supposed to help at least a little.. everyone said it was better than the typhoon plus it was carb certified.. so i got the injen cai instead...
01-08-2006, 11:36 PM
#9
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Originally Posted by FujiApples
alright dude but ill just finish up this question here.. if i get a bov with my cai... wont i lag and run crazy rich? is there a cheap way to fix this? and i dont think turbo upgrades are comin soon.. but downpipe and catback exaust maybe..
an CAI or BOV will not cause lag.
A BOV to 100%atmosphere is just wasted air that could have been recycled since it's already cold and pressurized.
Niether one of these mods will decrease lag. You won't know if you're running rich untill you notice it at the tail of you're muffler. Other than that do you have a wide band o2 sensor hooked up to see what your fuel graph looks like. I'm pretty sure you're within the factory ECU specification of correction with you're current mods.
01-08-2006, 11:39 PM
#10
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doesnt bov cause car to run rich and lose power because all the air is vented out? and i dont have an 02 sensor. Can u tell me where to get one of these or anything else cheap and effective i can use to control my air/fuel ratio? cuz eddie told me when i get the bov i will definately run rich and lose power 
01-08-2006, 11:50 PM
#11
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Originally Posted by FujiApples
doesnt bov cause car to run rich and lose power because all the air is vented out? and i dont have an 02 sensor. Can u tell me where to get one of these or anything else cheap and effective i can use to control my air/fuel ratio? cuz eddie told me when i get the bov i will definately run rich and lose power
01-09-2006, 12:04 AM
#12
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well i believe you.. what will happen if i get bov with teh cai... and what can i do to maximize the efficiency cheaply... and how much power will i gain/drop?
01-09-2006, 12:12 AM
#13
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Originally Posted by FujiApples
well i believe you.. what will happen if i get bov with teh cai... and what can i do to maximize the efficiency cheaply... and how much power will i gain/drop?
you're car will make more noise. You'll think you'll have more HP gains but in reality feeling a 5-10HP is almost impossible.
Save up money for an up-pipe and a down pipe. Free up the power don't worry about gaining right now since you don't have the funds for real upgrades
01-09-2006, 10:15 AM
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Blow Off Valve FAQ
Term usage: "Blow off valves" go by several names, among them are compressor bypass valve (CBV), air by-pass valve, bypass valve (BPV), blow off valve (BOV), Diverter valve, and possibly a few others. BOV is the common and incorrect term that lumps true blow off valves and bypass valves under the same term. For the sake of correctness, this post will refer to either aftermarket BOV, aftermarket BPV or OEM BPV as these are the most correct terms.
What is the function of a blow off valve (BOV)? To release pressure from the intake tract of a turbo car when the throttle closes. It is a vacuum-actuated valve designed to releases the air to the atmosphere.
What is the function of a bypass valve (BPV)? To release pressure from the intake tract of a turbo car when the throttle closes. It is a vacuum-actuated valve designed to recirculate the air back into the intake before the turbo inlet, but after the airflow sensor.
What is the purpose of a BOV/BPV? When the throttle closes and the intake system is under pressure, the high-pressure air entering the motor will bump into the closed throttle plate, and in the absence of a BOV/BPV, a pressure wave will travel back to the turbocharger. The result is that the compressor wheel will stall (a phenomenon known as “compressor surge”) and slow down very quickly. This is hard on the bearings and decreases the turbo’s lifespan, but it also means the turbo will take longer to spin up the next time the throttle is opened.
Are aftermarket BOVs necessary with Subaru turbos? No. The OEM BPV is perfectly fine up to 20psi of boost. For applications using higher boost levels, an aftermarket BOV/BPV should be considered.
Can I mod my stock BPV to hold higher boost? Yes. This link gives detailed instructions on how to do so.
Is the STi BPV better than the WRX BPV? No. They are the same. However, the JDM STi BPV will hold more boost as it is physically different than both the USDM STi BPV and the WRX BPV. The specific PSI rating of the JDM STi BPV is unknown.
Which manufacturer is best? This topic is highly debated. There have been no reported consistent "bad" aftermarket Bovs. Obviously, there may have been bad ones sold, but not enough to report as "bad" overall.
What are the different types of aftermarket BOVs/BPVs? Different manufacturers use different methods. There are three basic types:
1. Aftermarket BPV: Similar in function to the OEM BPV where 100% of the air is recirculated.
2. Atmospheric BOV: 100% of the air is vented to the atmosphere.
3. Hybrid BOV: These depend on the manufacturer and end user settings. These can either be adjustable or manufacturer set for different percentages of atmospheric/recirculation dumping. They can also be set to work as recirculation during lower boost conditions and 100% atmospheric during higher boost conditions.
Are there any downsides to aftermarket BOVs? There have not been significant amounts of problems with BOVs. Aftermarket BOVs can and do require some light end user maintenance to keep them performing perfectly. For aftermarket hybrid BOVs that have end user defined settings, there will be an initial period of adjustment to obtain the desired recirculation/atmospheric ratio. As well, most aftermarket BOVs will require "tuning" (usually via supplied washers, a screw, or other mechanism on the BOV itself) to allow them to idle correctly and blow off at the right time.
Are there any negative effects with aftermarket BOVs? Yes. The downside of releasing the air to atmosphere is that it has already been metered by the mass air sensor, and when it blows off, the ECU will be injecting the wrong amount of fuel into the cylinders. The engine temporarily runs extremely rich, meaning too much fuel is injected into the cylinders.
This temporary rich condition isn’t usually that harmful, but it can cause bucking or hesitation on lift-throttle. If the condition is really bad, it can eventually foul spark plugs and even clog the catalytic converter as unburned fuel on the catalytic converter burns very hot, and too much of it can melt the cat.
Can my tuner or engine management tune out this rich period? No.
Where do I buy aftermarket BOVs/BPVs? Every Subaru/Import performance store sells BOVs. For purchasing, support your local economy or the I-CLUB Vendors.
How hard is it to install aftermarket BOVs/BPVs? Allow around 1 hour for install time. Professional installation, depending on your area, is around $75. This is one vehicle modification that is very simple and can be successfully accomplished by even the greenest shade tree mechanic.
How do I install BOVs/BPVs? Refer to the BOV/BPV manufacturer's instructions. For BOVs/BPVs without instructions, below is a link to one of the better known installation instructions:
scoobymods.com instructions (with photos)
Editors Note
My thanks to Dan of Mach V Motorsports for writing an excellent BOV article that provided a lot of the information contained within this FAQ. He also provided additional information that was helpful in the formulation of this FAQ.
This post was created because I wasn't able to find a good blow off valve FAQ. I came up with the text based on LOTS of searching here. Upon reading this you should have an idea of whether a blow off valve best suits your needs or not. The manufacturer is up to you.
If you find an error in this FAQ, please PM me with factual details and I will update this post. Responses such as, "I have XXX's blow off valve and it's great!" or "XXX's blow off valve broke after 1 month" are not appreciated here, that is what the Car Parts Review Forum is for.
Term usage: "Blow off valves" go by several names, among them are compressor bypass valve (CBV), air by-pass valve, bypass valve (BPV), blow off valve (BOV), Diverter valve, and possibly a few others. BOV is the common and incorrect term that lumps true blow off valves and bypass valves under the same term. For the sake of correctness, this post will refer to either aftermarket BOV, aftermarket BPV or OEM BPV as these are the most correct terms.
What is the function of a blow off valve (BOV)? To release pressure from the intake tract of a turbo car when the throttle closes. It is a vacuum-actuated valve designed to releases the air to the atmosphere.
What is the function of a bypass valve (BPV)? To release pressure from the intake tract of a turbo car when the throttle closes. It is a vacuum-actuated valve designed to recirculate the air back into the intake before the turbo inlet, but after the airflow sensor.
What is the purpose of a BOV/BPV? When the throttle closes and the intake system is under pressure, the high-pressure air entering the motor will bump into the closed throttle plate, and in the absence of a BOV/BPV, a pressure wave will travel back to the turbocharger. The result is that the compressor wheel will stall (a phenomenon known as “compressor surge”) and slow down very quickly. This is hard on the bearings and decreases the turbo’s lifespan, but it also means the turbo will take longer to spin up the next time the throttle is opened.
Are aftermarket BOVs necessary with Subaru turbos? No. The OEM BPV is perfectly fine up to 20psi of boost. For applications using higher boost levels, an aftermarket BOV/BPV should be considered.
Can I mod my stock BPV to hold higher boost? Yes. This link gives detailed instructions on how to do so.
Is the STi BPV better than the WRX BPV? No. They are the same. However, the JDM STi BPV will hold more boost as it is physically different than both the USDM STi BPV and the WRX BPV. The specific PSI rating of the JDM STi BPV is unknown.
Which manufacturer is best? This topic is highly debated. There have been no reported consistent "bad" aftermarket Bovs. Obviously, there may have been bad ones sold, but not enough to report as "bad" overall.
What are the different types of aftermarket BOVs/BPVs? Different manufacturers use different methods. There are three basic types:
1. Aftermarket BPV: Similar in function to the OEM BPV where 100% of the air is recirculated.
2. Atmospheric BOV: 100% of the air is vented to the atmosphere.
3. Hybrid BOV: These depend on the manufacturer and end user settings. These can either be adjustable or manufacturer set for different percentages of atmospheric/recirculation dumping. They can also be set to work as recirculation during lower boost conditions and 100% atmospheric during higher boost conditions.
Are there any downsides to aftermarket BOVs? There have not been significant amounts of problems with BOVs. Aftermarket BOVs can and do require some light end user maintenance to keep them performing perfectly. For aftermarket hybrid BOVs that have end user defined settings, there will be an initial period of adjustment to obtain the desired recirculation/atmospheric ratio. As well, most aftermarket BOVs will require "tuning" (usually via supplied washers, a screw, or other mechanism on the BOV itself) to allow them to idle correctly and blow off at the right time.
Are there any negative effects with aftermarket BOVs? Yes. The downside of releasing the air to atmosphere is that it has already been metered by the mass air sensor, and when it blows off, the ECU will be injecting the wrong amount of fuel into the cylinders. The engine temporarily runs extremely rich, meaning too much fuel is injected into the cylinders.
This temporary rich condition isn’t usually that harmful, but it can cause bucking or hesitation on lift-throttle. If the condition is really bad, it can eventually foul spark plugs and even clog the catalytic converter as unburned fuel on the catalytic converter burns very hot, and too much of it can melt the cat.
Can my tuner or engine management tune out this rich period? No.
Where do I buy aftermarket BOVs/BPVs? Every Subaru/Import performance store sells BOVs. For purchasing, support your local economy or the I-CLUB Vendors.
How hard is it to install aftermarket BOVs/BPVs? Allow around 1 hour for install time. Professional installation, depending on your area, is around $75. This is one vehicle modification that is very simple and can be successfully accomplished by even the greenest shade tree mechanic.
How do I install BOVs/BPVs? Refer to the BOV/BPV manufacturer's instructions. For BOVs/BPVs without instructions, below is a link to one of the better known installation instructions:
scoobymods.com instructions (with photos)
Editors Note
My thanks to Dan of Mach V Motorsports for writing an excellent BOV article that provided a lot of the information contained within this FAQ. He also provided additional information that was helpful in the formulation of this FAQ.
This post was created because I wasn't able to find a good blow off valve FAQ. I came up with the text based on LOTS of searching here. Upon reading this you should have an idea of whether a blow off valve best suits your needs or not. The manufacturer is up to you.
If you find an error in this FAQ, please PM me with factual details and I will update this post. Responses such as, "I have XXX's blow off valve and it's great!" or "XXX's blow off valve broke after 1 month" are not appreciated here, that is what the Car Parts Review Forum is for.
Last edited by kenji815; 01-09-2006 at 02:31 PM.