sudden loud vtec crossover

[Cb3vtec]

hi, i put my oem air cleaner box and cat. back on or inpection and now the vtec crossover is 10 times louder, i thought it was the other way around. does anybody know why? also the engine seems quicker general, if i put it in first gear and floor it, the tires will spin, it would not do that before..strange....

[marcusv8thunder]

Air box will never make a car louder, so i dont know there, but having the cat back in will give you more back pressure, giving you more torque down low, that may be what you are feeling.

[Cb3vtec]

hmm, the loud vtec crossover sounds like it is comming from the airbox, it really is 10 times louder than the whalepenis, as for the cat i really cant understand the big diffrence...but thanks for sharing your thoughts.

Air box will never make a car louder, so i dont know there, but having the cat back in will give you more back pressure, giving you more torque down low, that may be what you are feeling.

[wed3k]

maybe because youre choking it with the stock airbox?

[toycar]

Maybe its quiter, so its more noticeable.

Also, maybe there is a higher pressure in the intake, magnifying the sound.


Crazy idea #3, maybe the oem intake is better and Honda really does know what they r doing.

My cd5 is vtec. Well, f22b1, but still vtec.

Def faster/better throttle response with oem airbox vs short ram intake. The crossover, though suttle, makes a bigger difference(performance) and is louder with the stock box as well.


My opinion, the answer is drowned in science and has to do with the never ending arguement of flow vs pressure.

Pressure creates torque, flow equates to HP.

Same principal applies to having an exhaust that's too big for a car. No pressure from too large of exhaust equates to a terd off the line with a small performance gain at 6,000rpm's. Just like a double stacked, gutted plenum. Too much airflow isn't a good thing, and torque always suffers with a lack of pressure.

Honda outsmarted this issue with the butterfly in the intake on some models. Half the runners being open creates higher pressure at lower rpm's, for better performance. They open up when needed, but stay closed the rest of the time.

My guess, your stock airbox is actually better for the motors performance. It's not like Honda didn't think this particular issue out, and design the air box around the pressure needed to maintain the proper flow, determined by the cars natural aspiration limits.

Without changing the "flow" the stock air box is probably designed with more r&d then any aftermarket intake. The cfm of thr motor isn't going to change much, and that airbox was probably designed for optimal cfm with the given lift/duration/bore size/intake/exhaust size.

Change the port diameter, the lift/duration on the cam, the bore size, thr stroke, intake manifold/throttle body, something that effects the cfm of the motor, and maybe adding an intake will help. Until then, I bet your stock box rules all.

[Cb3vtec]

hmm, i think you are the one closest to the answare, it felt like i had a diffrent engine so much more powerful, but i cant understand that a cat and stock air box (no filter) did all that....ow well, I`m bulding the engine a bit in the spring, maybe the whalepenis is better then...

[danf20bcb7]

Maybe its quiter, so its more noticeable.

Also, maybe there is a higher pressure in the intake, magnifying the sound.


Crazy idea #3, maybe the oem intake is better and Honda really does know what they r doing.

My cd5 is vtec. Well, f22b1, but still vtec.

Def faster/better throttle response with oem airbox vs short ram intake. The crossover, though suttle, makes a bigger difference(performance) and is louder with the stock box as well.


My opinion, the answer is drowned in science and has to do with the never ending arguement of flow vs pressure.

Pressure creates torque, flow equates to HP.

Same principal applies to having an exhaust that's too big for a car. No pressure from too large of exhaust equates to a terd off the line with a small performance gain at 6,000rpm's. Just like a double stacked, gutted plenum. Too much airflow isn't a good thing, and torque always suffers with a lack of pressure.

Honda outsmarted this issue with the butterfly in the intake on some models. Half the runners being open creates higher pressure at lower rpm's, for better performance. They open up when needed, but stay closed the rest of the time.

My guess, your stock airbox is actually better for the motors performance. It's not like Honda didn't think this particular issue out, and design the air box around the pressure needed to maintain the proper flow, determined by the cars natural aspiration limits.

Without changing the "flow" the stock air box is probably designed with more r&d then any aftermarket intake. The cfm of thr motor isn't going to change much, and that airbox was probably designed for optimal cfm with the given lift/duration/bore size/intake/exhaust size.

Change the port diameter, the lift/duration on the cam, the bore size, thr stroke, intake manifold/throttle body, something that effects the cfm of the motor, and maybe adding an intake will help. Until then, I bet your stock box rules all.

idk man my cd5 wasnt havin it with the stock airbox, throttle response was sloppy as hell, that was with a new k&N filter. sounded deep tho due to big box, when i put a run of the mill ebay brand CAI its throttle response was way better.

[Cb3vtec]

strange, for me its the other way around...this is really strange...

idk man my cd5 wasnt havin it with the stock airbox, throttle response was sloppy as hell, that was with a new k&N filter. sounded deep tho due to big box, when i put a run of the mill ebay brand CAI its throttle response was way better.

[toycar]

idk man my cd5 wasnt havin it with the stock airbox, throttle response was sloppy as hell, that was with a new k&N filter. sounded deep tho due to big box, when i put a run of the mill ebay brand CAI its throttle response was way better.

Bought mine new off the lot in 1995. Maybe mine (no offense) has been better maintained?.. just a thought. For sure, short ram intake was a waste of time on my f22b1. Vtec engagement, acceleration and response is better w/oem intake, atleast from my experiences.

Not really sure why we would have different outcomes. I have no cel's, nothing wrong with the car at all. Mine is a 5spd, is yours maybe an auto?

[RustyBucket]

but i cant understand that a cat and stock air box (no filter) did all that...

You're running without an air filter? That could explain some difference in sound. If you are indeed running without an air filter... why???

[Cb3vtec]

forgot to mention this is a jdm h22a engine, no CEL, 5 speed LSD trans. It is very well maintained, no sludge in engine when i got it, good compression on all cyl, but i was thinking and i have tried the oem intake before and there was no such effect then...then it must be the cat.?

Bought mine new off the lot in 1995. Maybe mine (no offense) has been better maintained?.. just a thought. For sure, short ram intake was a waste of time on my f22b1. Vtec engagement, acceleration and response is better w/oem intake, atleast from my experiences.

Not really sure why we would have different outcomes. I have no cel's, nothing wrong with the car at all. Mine is a 5spd, is yours maybe an auto?

[Cb3vtec]

You're running without an air filter? That could explain some difference in sound. If you are indeed running without an air filter... why???

cause i was driving in snow storm and cold wether and it is clogging my filter with ice....i usually never do that.

[toycar]

forgot to mention this is a jdm h22a engine, no CEL, 5 speed LSD trans. It is very well maintained, no sludge in engine when i got it, good compression on all cyl, but i was thinking and i have tried the oem intake before and there was no such effect then...then it must be the cat.?

Yup, thats a very reasonable explanation as well.

Still has to do with air flow though. The pressure is maintained in between firing sequences better, with a cat converter in place. Torque always suffers at the loss of pressure.

[GreenMadness]

yeah no filter in a stock air box is loud as hell, esp at cross over.... thats like shoving a megaphone on your intake. Im assuming you ran a filter before, so regardless of which set up what you hearing is a case of filter vs no filter.

the more open you engine is to the world the louder said engine will be,

stock filter in a stock box is baffled and muffled well, not very open.

ram style with cone filter and no baffle box surround is somewhat open

no filter at all is really open.


* and as for the freezing, im taking it you did not run the full stock air box?

[danf20bcb7]

Bought mine new off the lot in 1995. Maybe mine (no offense) has been better maintained?.. just a thought. For sure, short ram intake was a waste of time on my f22b1. Vtec engagement, acceleration and response is better w/oem intake, atleast from my experiences.

Not really sure why we would have different outcomes. I have no cel's, nothing wrong with the car at all. Mine is a 5spd, is yours maybe an auto?

shouldnt even hear the crossover in a b1 really, hard to say mine was used with 80k on it, i never use a short ram they are wastes on these, a cai on the other hand seems to be key, but not just an ebay cai, differences in size of tubing and thickness play roles here, o and yeah i gots the 5spd as well, hell even my old auto showed same improvements, the only other iffy half decent setup ive tried is a stock airbox with k&n and no lower airbox. still seems to be more responsive, just a thought where you from and might yours be cali emmissions? im from pa and the car is as well, just wondering if it would effect in any way not doubting your experience