View Full Version : air silencer

06-01-2005, 02:16 AM

I have a buddy with a 01 GT. He removed the air silencer and comments on significant hp gains. I would imagine that an 03 cobra would have greater hp gains.
- Has anyone removed their air silencer, or am I the only one who hasn't installed a CAI?
- Would removing the air silencer make the air filter more supceptible to rain water?
- Dose it make any difference?
- I'm thinking about installing a regular K&N air filter in my 03 cobra...would that make any difference?

Also, I was wondering what exhaust setup is good for freeing up the extremely restricted ponies while keeping the the sound level down...you can't beat the sound of a supercharger. I like the way X-pipes sound. Is there anyway to use an X-pipe with minimal sound increase? Sorry for all the questions. Thanks in advance.


06-01-2005, 05:29 AM
I have taken mine out but did not notice any improvement ( even disconnected the battery too). The cliam is with the silencer and air filter removed you should net about 13 hp. That number will drop off a tad with the air filter in place. As for removing it, I would not worry about water in the filter all that much since it is not mounted directly in the fender well. You are not the only one who has not removed the intake tract for a CAI. I am one who has yet to do that.

As for the X-pipe, you could probably replace that and still keep the stock exhaust. In my opinion, bassani has the better part. It looks well built. That would be the one I would get. That is something else I have not replaced yet. As for the stock exhaust, that was the first thing I removed shortly after getting the car. I can still hear the supercharger whine over the exhaust especially with the windows closed.

06-02-2005, 09:32 PM
I witnessed an 11rwhp gain on a bone stock '03 cobra a few years back by removing just the silencer. I removed the silencer on my old 99 cobra (loved that car) and picked up 3 rwhp and 1 ft lb of torque. It did lean me out about .3 on the a/f across the board. Definately not anything I could feel. On an '03 cobra, I can't feel gains like that. I guess my butt dyno isn't very sensitive. The only true to life mods that I've noticed real improvements on the butt dyno are a vortech supercharger install, my 4.30 gear install, and lastly, a MAC straight shot cai for my '03 cobra. I picked up 5mph in the 1/8 mile with just that mod alone. I'm sure I'd feel a pulley install on the '03 cobra, but mine is still unpullied. And it will remain that way until I replace the eaton with an '01 cobra intake.

09-06-2005, 06:38 AM
The last time I was at the track, I decided to remove the air silencer. It was not easy without tools but I did it anyway. What I did notice was my ET's improved greatly by 1/2 second. I guess it does make a difference afterall. :D

09-06-2005, 03:12 PM

I have a buddy with a 01 GT. He removed the air silencer and comments on significant hp gains. I would imagine that an 03 cobra would have greater hp gains.
- Has anyone removed their air silencer, or am I the only one who hasn't installed a CAI?

-R Removing the snorkel on your OEM cannister will cost you 3 rwhp/tq. I didn't believe it either, put it back on & the power reappeared. My first three pulls right there.

I had read this about '03 Cobras in MM&FF in '02 , i believe, so I tested it when I put Ginger on the rollers for the first time in July '03. Jeff (of Team Ford) and I were scratching our heads...I had brought with me a K&N drop-in I already had & also a KB CAI to swap on... What worked best is the 12" K&N stuck to the end of the MAF. Go to any NMRA race & see what the big dogs run...:thumbsup:

09-08-2005, 06:57 AM
I have read in MM&FF mods for mods on the 03/04 motor on the engine dyno and they found a considerable amount of gains with it removed. However, the snorkle on the 04 did not reduce the overall diameter like the 01 did. Wheather or not the difference in my ET is due to getting used to drag racing at the track or it did actually improve performance is yet to be determined. I did manage to put it back in but cut down to size (modified) so it just enters the fenderwell to reduce drawing in heated air from engine bay.

09-12-2005, 12:01 AM
Ausie, I've only ever read gains from replacing the entire OEM air box assy. with a CAI setup. Not doubting you saw gains at the track, although that could be from many different factors. I was unable to locate the back issue that claims -3rwhp losses but I'll locate that info. Like I said, I didn't believe it either. I was even more amazed when after cooling the car down & bringing it back up to temp for the snorkel removal pull that it was down exactly by 3rwhp for peak #s.


Stang03, it is well documented that a simple CAI kit will get you 20-25rwhp. As relatively inexpensive as they are, why wouldn't you get one? If you don't get a CAI w/ filter, then yes buy a replacement K&N. I doubt it'll be significant but guaze flows better than paper anyday.

09-12-2005, 07:00 AM
I have gone through several MM&FF mags and all I could dig up on the filter removal was a net gain of 13hp (not sure what the torque gains were) but I also know that is without a filter in the air box (not a good thing to do). I also heard of report that the removal of the screen in front of the MAF will cause issues. It appears the MAF is too sensitive and needs to have the screen as a diffuser to operate properly. I would prefer the screen and filter than none since the rotors in the Eaton do not like small foriegn objects flying into them.

I am thinking of a JLT CAI kit but may settle for the RAI kit. Too bad the filter is exposed in that one. hmm, Billut flow does have a sheet metal air box for that application (seen that in the throttle body section).

I will have to wait until friday to get back onto the track again, Sunday schedule had a show posted so I would not have been able to run if I went.

09-12-2005, 06:15 PM
ausie just bought a jlt rai and with the complete kit it came with a shield which will cover the filter picture below

09-13-2005, 06:57 AM
ausie just bought a jlt rai and with the complete kit it came with a shield which will cover the filter picture below
SWEET, have you noticed much of a difference with that over the stock pipe? Also, does it hit the strut tower when you lay into it? The RAI is one thing I am considering but also the CAI as well. For ease of install, the RAI is the ticket but still debating which one to get.

09-13-2005, 11:15 AM
It actually touches the strut tower brace. I plan on putting some velcro on the pipe so it wont get scratched. I love how it sounds under the hood the intake is pulling some serious air and the supercharger damn sounds louder

09-21-2005, 06:26 AM
One thing not to do, if you do remove the snorkle just leave it off and do not cut it like I did. I did modify the rubber silencer in hopes it would work much the same way it did for the 01. Oops. Since the supercharger draws more air into the intake when compared to the N/A 01 it will actually close up (collapse) the modified silencer. Unfortunately having done so will draw in heated air from the radiator which will result in lowered performace.

Here is something of merrit in the following link.


09-22-2005, 11:32 PM
What is an air silencer, and where can it be found??

RF Cobra
09-23-2005, 12:15 AM
It is located inside the fender well. The air enters through the silencer and then into the air box in the engine bay. So if you look at Robs pictures he posted the silencer is in the fender well just to the left of where the airbox is in the picture.

It is an engineered piece of plastic/tube that helps quiet the engine exhaust and in the process restricts some of the air flow.

09-23-2005, 06:34 AM
I am not sure if it was intended to function similar to a restrictor plate that NASCAR places on the caburators but it seems to anyway. Depending on model of mustang you have the air silencer may be of a different design. From 99 on up to the 04 Cobra's the air silencer was nothing more than an extended rubber tube or snorkel and is attached to the factory air filter box which brought the openning of the air flow closer to the outside fender wall. In most cases it has a smaller inner diameter than the rest of the inlet tubing after the MAF meter which reduces the effective volume of air that can flow into the engine. Some designs like the MACH 1 and probably the GT's have a square shaped bulb extending out from the inlet tube which acts like a resonator of sorts by creating a pressure differential in the pipe to cancell out the inrush of air. With the 99 and up Cobra's (not sure about the earlier years but since the air box design seems not to have changed much propably the same thing) once the air silencer was removed, you can actually hear the air getting sucked into the engine similar to sticking your hand over a vaccum hose without closing it off, hence its function was to reduce the cabin noise of the inrush of air entering the engine. In most cases, removing it may make a difference in ET's if drag racing but mostly it will not be noticed on the street. There is a benefit in keeping it in place is that it will be drawing air from the fender well. If you remove it, it is likely that the front section of the air box will be exposed to heated engine air which will reduce the effect of removing it, however it is still better than having an exposed filter without an air box or shield.
In the newer mustang (05), they placed two restrictions on the inlet tubing. The first being the air silencer and the means of how it attaches to the air box. The second air restriction is the hydrocarbon filter which is stuffed into the inlet tube in front of the throttle plates.