Intake Silencer/Resonator 98+ Seville

jadcock · #1 (**permalink**) 02-26-07, 11:11 AM

For anyone who has removed only the intake silencer/resonator on a 98+ Seville, and left everything else in place, including the factory airbox, what did you think? The '97, even with the factory airbox, has a more "howling" punch to it at WOT. The '01 STS (and I noticed the same thing on the '04 DeVille I rented), has a flatter and more mechanical sound at WOT.

Will removing the intake resonator and plugging the hole improve the sound quality at WOT?

No, I will not consider replacing the airbox with a cone filter.

CadillacSTS2003 · #2 (**permalink**) 02-26-07, 11:16 AM

yuh it makes it louder...
obviously...

jadcock · #3 (**permalink**) 02-26-07, 01:02 PM

Thanks for the response, I guess. I didn't say I wanted it louder. I was simply asking the folks who have done it what they experienced.

And I wouldn't use the word "obviously" because some folks have told me that it didn't change the tone or the volume of the intake noise. Just trying to get some varying experiences.

ilovemysportycadilla · #4 (**permalink**) 02-26-07, 01:05 PM

I'll tell you what sounds awesome, may be a little too loud for you. Before the 2001 STS I bought, I had a 1996, and I put flowmaster delta 40 series mufflers on it, it sounded amazing. Very similar to a late model mustang GT. If you are into that kind of thing, it is well worth the money!

submariner409 · #5 (**permalink**) 02-26-07, 07:06 PM

I may be wrong, but, could the engineering studies that created this intake air system have shown that there was a need to damp out a pulse or two in the pipe which would occur at sudden WOT or gear change airflow patterns? The "resonator" holds a significant air volume......looks like a couple of quarts' worth......and is very close to the MAF/IT sensor. Just a thought. (Whazzat got to do with Flowmasters ???)

danbuc · #6 (**permalink**) 02-26-07, 07:16 PM

The only real purpose the resonance chamber serves is to quiet induction noise under high load conditions. The whine you year from the intake system at WOT is what's reduced by the chamber. Some people don't like to hear any noise from the vehicle, while some people love that howling induction whine you get from a non-silenced intake system. I removed mine simply to make it easier to check the trans fluid and replace the air filter. It's up to you really whether or not you want to pull it. Removing it does not positively, or negatively affect vehicle performance, so it's either for ease of maintenance, or just for that extra bit of sound. Either way, it's easy to remove, and you can plug the hole with just about anything. Some people use a plastic cap, I used a rubber plug used to seal PVC pipe.

jadcock · #7 (**permalink**) 02-26-07, 08:24 PM

Thanks guys. Those were useful comments.

submariner409, that's an interesting thought regarding the intake damping. If it is the case, I would tend to think it to be very minor, since none of the older Northstars had that resonator. Actually, looking at the differences between the engine packaging on the '01 vs. the '97, I'd say they probably would have put a resonator on the '97, but there's really no room over there.

danbuc, being able to check the trans fluid would be a great plus. Did you notice any improvement on the sound quality after removing yours? Or was it just about a wash either way? I like the idea of removing mine just to be able to check the trans fluid without taking the durn thing apart!

caddydaddy · #8 (**permalink**) 02-26-07, 10:07 PM

I removed the silencer on my 2000 STS a long time ago! I don't really notice any difference in engine noise, other than the Corsa cat-back I installed!

It is nice to not have to take the whole intake hose off to check the trans fluid too.

Ur7x · #9 (**permalink**) 02-26-07, 11:07 PM

I'm sure the factory put that chunk of plastic there for a reason. Beats me what that might be...I removed mine almost a year ago... just because checking the tranny oil was such a PIA...

I speak from first hand experience. There is no change in engine noise. Zero, Nada Zilch. This goes for idle, WOT, light load, heavy load, etc.

Also no benefit in performance either.

For the record, I'm running a bone stock exhaust system.

The only change I have ever made to the car that increased the interior noise in my car was the new Michelin Pilots I had mounted last spring. While they did solve my vibration problem... They are somewhat noisy tires.

jadcock · #10 (**permalink**) 02-27-07, 07:36 AM

Thanks again guys. I had heard that before about the noise (that the resonator doesn't seem to do ANYTHING). Oh well. I think I will remove it and plug the pipe, as I'd rather not have to undergo a 15 minute procedure to simply check the trans fluid every now and again.

danbuc · #11 (**permalink**) 02-27-07, 11:03 PM

Quote:

Originally Posted by caddydaddy

I removed the silencer on my 2000 STS a long time ago! I don't really notice any difference in engine noise, other than the Corsa cat-back I installed!

It is nice to not have to take the whole intake hose off to check the trans fluid too.

Haha..yeah, with the Corsa, it does make it extremely difficult to tell small difference in noise like that. I removed it well after I had the Corsa installed, so at WOT I couldn't really hear much engine noise before or after I pulled it off.

treddekopp · #12 (**permalink**) 07-31-07, 06:04 PM

There is definately a sound difference on my 2000 SLS. I noticed a slight increase in accelerating after I removed both the "U" shaped box below the filter airbox and removed the top resonator (capped off). I noticed an immediate difference in sound only after I removed the top resonator. I noticed very little difference in "sound" when only removing the box below the filter intake. I was hoping for an increase in gas milage though. Nothing.

Cadillacboy · #13 (**permalink**) 07-31-07, 06:20 PM

Your comments urges me to remove it soon lol

submariner409 · #14 (**permalink**) 07-31-07, 07:10 PM

After all the posts concerning the "butt plug", here goes, again. Pick up a 2" rubber plumbing cap with s/s clamp at your local Home Depot or Lowes or hardware store. Remove the corrugated pipe from between the MAF and throttlebody (resonator first..). Trial fit the pipe plug flush into the resonator hole, open side down, and make a few felt tip marker lines inside the pipe where the plug skirt hangs into the air stream. Pull the plug and, with a pair of tin snips or heavy scissors, trim away the interfering curves from your marks. (Measure twice, cut once......). When the fit looks clear, reference mark the plug and pipe on the top, pull the plug, install the pipe in its proper orientation, clean the plug and inside of the pipe hole with alcohol (not rubbing alcohol because that has glycerin in it....lubricant....) and smear a film of black assembly RTV on the plug and hole and fit them together. Put the hose clamp on the outside, flush with the top edge, and just barely snug it up....too tight and you'll squash the plug job. Let it cure overnight.