Subaru WRX Forums banner

1 - 13 of 13 Posts

·
Registered
Joined
·
3,474 Posts
The lower resonator should not cause issues because of the air straighteners within the MAF housing, the only issue that may arise from the lower opening may be a difference in air temps from the snorkel vs the fender which may richen the mixture from denser air readings since there are 2 different temps mixing together this may be confusing the MAF at times. At this point, you should be unplugging the negative for 2 minutes then putting it back in once the intake is installed so the car can do a re-learn. The CAI will be getting consistent air temp readings since there is now only one air flow source as opposed to 2 if you just remove the resonator.
 

·
Registered
Joined
·
333 Posts
williaty has a write up over at NASIOC where he shows that without the resonator the air vibrates past the MAF which causes the MAF to think its getting more air than it is (AT WOT ONLY). Take a look and tell me what you think:

http://forums.nasioc.com/forums/showthread.php?t=1471819

so basically josh when you floor it do you notice it running rich at the low end? kinda hard to tell now that i think about it...

btw someone just did a hybrid for 2008: http://forums.nasioc.com/forums/showthread.php?t=1655076
 

·
Registered
Joined
·
3,474 Posts
williaty has a write up over at NASIOC where he shows that without the resonator the air vibrates past the MAF which causes the MAF to think its getting more air than it is (AT WOT ONLY). Take a look and tell me what you think:
http://forums.nasioc.com/forums/showthread.php?t=1471819
so basically josh when you floor it do you notice it running rich at the low end? kinda hard to tell now that i think about it...
btw someone just did a hybrid for 2008: http://forums.nasioc.com/forums/showthread.php?t=1655076
The problem I see from that analysis from a tuning standpoint would be that this person's testing schema is in error. I would beg to see this person's graphs under a rally condition or in drift when clutch kcking and throttle blipping are in excess. Under those conditions the spikes should be all over the board as intake air velocities are constantly at stop and go. The graphs shown are most likely as a result of a standing throttle test where an initial influx of air resulting from high air flow from the SRI causes MAF voltage to spike and once air velocities become more constant the readings become more closely matched. The stock versions fail to do this because intake velocities inside the box are dramatically lowered because of the intake air tract angles within the box and resonator. This causes the initial high velocity air to slow to a point that does not spike the MAF voltage.
 

·
Registered
Joined
·
3,474 Posts
The test with just the resonator removal is also missing. Leading me to think that it is not the resonator that causes fluctuations rather than the complete open pod design of a cone filter (which for some reason he states is the same, how open pod air surface against a panel is the same is beyond me, how this conclusion comes about is also weird) and the huge amount of air that rushes in, unrestricted by the box. The added benefit of the open pod also shown with the MAF spike can also be correlated to an increase in actual throttle response between boxed and unboxed intake systems.

It runs rich in between closed and open throtle situations because the maf is far away from the throttle body. The maf has accounted for air in the intake tube so fuel is dumped, however, that air never gets in because your throttle is closed so it comes out as unburt fuel in a rich mixture in this situation.
 

·
Registered
Joined
·
1,643 Posts
williaty has a 04/05 impreza... it's a little different. the factory intake on the 08/09 models is pretty efficient... only reason to get a CAI is for the noise. you will actually LOSE power in the low RPMs.
 

·
Registered
Joined
·
1,643 Posts
you'll gain noise and smooth out the flow of air a little bit... you're basically just eliminating that accordion section
 

·
Registered
Joined
·
978 Posts
Discussion Starter #13
i mean its only from 1-1.8k full throttle so its short and rare... just wondering if you noticed anything. As for me im worried because ive got a lightwieght pulley which doesnt help vibration so im unsure if i should go SRI, CAI, or stock/SRI hybrid.
i also have a pulley its a cosmo racing one

i havent noticed anything ill regular or negative

as far as power loss i havent really noticed anything like that

its seems to be running better
 
1 - 13 of 13 Posts
Top