Exhaust Silencers - good/bad?

My Borla exhaust is getting to me, a little too loud, a little too much drone. I was looking into adding one of these simple exhaust tip silencers that you insert into your exhaust tip. Something like this:

I think you just drill a hole or two in your tip and slide this doohicky inside and attach via screws. Anyone have any experience with these types of silencers? I really don't feel like dumping money on a new exhaust while mine is perfectly functional if not a little annoying to my aging ears.

I have never seen one of those, so no specific help from me but you don't need a whole new exhaust, just add a "resonator." I've known a lot of folks that had great results killing the drone by simply adding a glass pack before the muffler.

• Lee

A lot of motorcycle mufflers from the aftermarket offer that sort of quieting "spud". I've never used one but I believe they insert on the inlet side of the muffler and not the outlet.

There was a pretty extensive thread about this here maybe 2 months ago, with ideas including rolled tips, resonator tips, resonators, small glass packs, and other options being shared.

Reminds me of a plug of sorts .... I hear they work. Never tried them. Maybe look it up on youtube. I'm sure some shiny happy person has a full video on them.

HKS exhausts come with silencers like that. They do a little, and mount on the outlet.

I too suggest just having a resonator added. Will work better to quiet the exhaust, and give it a much better tone.

Try to set limits. Nothing too big.

EDIT: I recognize the photoshopping was horrible, and I do not take credit for it.

why would you put a bigger free flowing exhaust on a car and then choke it back down with a small outlet like that?

resonators are the way to go..

novaderrik wrote: why would you put a bigger free flowing exhaust on a car and then choke it back down with a small outlet like that? resonators are the way to go..

On the HKS I have its the same I.D. as the pipe through the muffler..Doesn't hurt performance...

I had a Megan (ebay) exhaust on my rallyx beater SE-R. It was very annoyingly loud. I bought one of the pictured "silencers" the day after installing the exhaust.

Like Mr. Truckster said, the ID is maintained through the silencer and I didn't notice any drop in performance. The exhaust was still louder than stock, but much more pleasant with the silencer.

I've used and made that type. They work well at knocking down the high pitched crack sounds. They will not do as much for the deeper heavier frequencies.

You don't need to strangle flow by going really small, like that example does. Just a little bit of an internal lip does a fine job.

Those are pretty effective on bikes in my experience, but there has always been a fairly notable hit to performance at the top of the rev range in the ones I've used. They install at the outlet, just like that. On the street bikes I leave them in all the time, but for race stuff I usually pull the inserts out. I don't need the power necessarily (dirt bikes) but it makes a surprisingly big difference in how the bike feels/how willing it is to rev. I assume the impact on a car might be similar, but these bikes all run open loop so it's possible I'm just feeling things run rich when they're plugged up where a closed loop system can correct for it.

In reply to gearheadE30 :

The outlet does not need to be the same ID as the front of the exhaust, since the exhaust cools off on the way there, reducing its volume.

I have used a 1 7/8" exhaust tip to cut drone on a 200hp rotary with no perceptible or measurable loss of performance.

The gent that rebuilt the evo on here used one to pass inspection.

I put them into the Borla kit I had on the Tiburon. OMG it helped so much. took out about 70% of the drone and brought the dB down to something manageable. I drilled a single hole in each tip (dual mufflers) for the set screw. To help even more I used steel wool behind the silencer to help absorb more of the sound. 

bobzilla said:

I put them into the Borla kit I had on the Tiburon. OMG it helped so much. took out about 70% of the drone and brought the dB down to something manageable. I drilled a single hole in each tip (dual mufflers) for the set screw. To help even more I used steel wool behind the silencer to help absorb more of the sound. 

What specifically did you buy?  My Focus ST has a Ford Performance (AKA Borla) exhaust and it drones quite a bit at highway speeds.  I'd love to drop it down a bit.

In reply to TVR Scott :

I measured the inside diameter of the outlet and found the closest I could find on eBay or Amazon. 
 

https://a.co/d/2pCiq9X

MASO 2X 60mm Universal Motorcycle Exhaust Silencer Motorbike Muffler Can Insert Baffle Silencer Black

In reply to bobzilla :

Oh, I go way cheaper than that... I measure the ID of the exhaust, then get the smallest exhaust adaptor that fits inside.

So say I have a 2.5" OD tailpipe.  That is 2 3/8" ID, a 2 1/4 ID pipe will be a slip fit.  So I get an adaptor that is the smallest I can find to 2 1/4.  I hammer it in backwards and secure with two zip screws, or maybe a tack of weld.