Air intake silencer removal

[ranchodenieve]

I have seen several discussions about the merits of removing the air intake silencer and the resonators. The snorkel on the intake silencer is certainly a serious air flow restriction and its removal is probably appropriate. The side cavity might make up for momentary air flow demands, but the snorkel is still the determining factor in air flow. I think that its removal would definitely be good for performance because doing it increases raw air flow under all conditions. It also makes life easier when pulling various other components in this area.
But, now we come to the resonators after the air filter. Many folks seem to think that they also should be removed. I have a different opinion on that based on my experience building bikes. Messing with the stock air box, other than improving flow to it often results in performance losses across the power band, but may result in higher top rev power. essentially losing tractability during normal use. Good for ultimate speed, but not daily operation in traffic. The top resonators actually have a different function in the system. They don't really increase turbulence since the air will flow directly through the tube to the engine. Rather, they provide a buffer to compensate for air pressure changes as throttle opening changes. Essentially they provide a place for air to go to as the throttle is chopped and then provide a momentary reservoir of air as the throttle opens. This keeps the fuel air mixture more stable. I think that leaving them connected should help low end performance.
Thus, I think that we shouldn't mess with the top end, but definitely remove the intake silencer before the filter. I know that this will ignite controversy. Any conflicting opinions are welcomed.
Bill W

 

[chris2523]

the throttle body is smaller than the silencer tube, so i doubt there is much to lose there.

as i understand it, the helmholtz resonators are there for pressure waves from the valves, not the throttle.
and their effectiveness is questionable on a v8 application.

 

[driller]

Performance-wise, I seriously doubt it means much either way. I believe most of the air induction design before the throttle body is all about noise reduction.

Personally, I think removal of the resonators simply helps with appearance to uncover the engine, especially after the engine cover is removed.

My thoughts on the snorkel... the design is deceptive. Yeah, it looks like the opening is 'too small' and must obviously be restrictive but it actually is an engineered diffuser inlet. The length to diameter ratio of the taper with the bell inlet opening actually enhances total flow all the while minimizing turbulence to effectively effectively 'silence' the rush of air into the intake filter assembly.

Remember the similar design of the snorkel inlet on the old circular air intakes that were atop the carburetor of old school engines? Remember how we used to flip the air intake cover over so it sounded cool?

{sarcasm} Remember how much faster the car was when you did that? {/sarcasm} :fart

It may actually flow more with the snorkel removed, but not appreciably so. But it will be noticeably louder, especially if you also remove the resonators.

 

[billcu]

My black car has the resonator removed by the PO. It's always had a different, not as responsive, throttle tip in feel than my other 94's. I've always wondered if that was the reason. I'll have to swap my spare stock tube in, to see if it makes a difference sometime.

I've read that intake resonators can improve volumetric efficiency at the target RPM and frequency, but I've also read that it doesn't do much for a v8.

 

[beerdog]

Removing the snorkel makes it much easier to work on the air suspension compressor.

 

[steve]

You will get a more aggressive engine/exhaust sound by removing it but doubtful about any performance gains. In fact it may disrupt the air flow and maybe a slight decrease in mpg or performance.

 

[ranchodenieve]

There is yet another reason to consider removing the silencer. It places the air intake very low to the ground. Basically too low for Arizona. Now, it doesn't rain much here, but when it does during monsoon season we have a unique problem. Most of our older surface streets don't have storm drains. Instead, they are vee shaped so that the water runs down the middle of the street until it gets to a wash and then runs off into the desert. In effect the street is a paved wash. Monsoons pour down rain for a short time, but the water is deep and it runs fast. It also leaves deep puddles since water does not soak in well.
Rule # 1: Never drive into a running wash. You don't really know how deep that it is and the street underneath could be washed out. They run fast enough to float your car away. This is why we have the Stupid Motorist Law. If you drive into a wash and get stuck, you get to pay for all of the fire department rescue cost and a high fine. If you make it through a closed wash, you just get the fine($500+). But even 4WDs might not make it through.
With the air silencer in place, you probably need to park until the storm is over. Without it, you just need to be careful. Be wary of puddles no matter where you live. While there is a small drain hole in the bottom of the silencer, you might consider adding additional drain holes and/or enlarging it if you decide to keep it on.
I took mine off. But, I'm not going to mess with the stuff on top of the engine.
Bill W

 

[BlackIceLSC]

...not to mention these "chambers that store air" are laid across the top of a hot engine.
from experience and track time slips, there was no change in performance WITH or WITHOUT them.

the 93's had dimples in the intake tube to create turbulence...they were done-away with for the next model year.
The inner-fender silencer can be done away with but the engine-bay intake tube needs no modification unless you like the "smooth" look.

I am going to trust with the amount of technology these cars have, and the design the 4.6 DOHC has, I am sure it was tested over and over again with many different intake designs...there's a reason the engineers made it the way they did and I am not one to pretend I can do better.