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-   -   car HATES exhaust silencer (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/car-hates-exhaust-silencer-664437/)

K-Tune 06-21-07 06:58 PM

car HATES exhaust silencer
 
decided to try the silencer in my apexi N1 muffler, and it did indeed quiet it down..however there's a DRASTIC drop in performance that i wasn't expecting.

is this common on our cars? its much slower to rev, lower boost, slower boost, and it sounds like a damn whistle tip (woowoo)

also it seems like the car is trying to blow the thing out of the tailpipe, i can feel the exhaust standing a good 5 feet behind my car while it idles :[

beginning to wonder if this is worth a 15-20db drop :\

SpeedOfLife 06-21-07 07:04 PM

It's a natural thing to lose performance when you impede exhaust flow, especially with a turbo model...

As far as how common your experience is? I don't know personally, but unless people are causing problems for you about the noise, just take it off...

phoenix7 06-21-07 07:52 PM

i believe I read somewhere on this forum about some guy who blew his motor when he used the silencer on his TII

boostin13b 06-21-07 07:55 PM

To put it simply, try shitting out of a straw and see how well that goes for ya, kinda the same concept for your car only on a more drastic note.

If you look at the size of the outlet on the silencer versus even the stock exhaust, it's a lot smaller. I'm guessing you have the single N1 so that's only one small outlet, not 2 like the stock setup. You shouldn't hurt the car just driving nice and easy, but I could see some major backpressure building up because of that.

FRFC3S 06-21-07 09:28 PM

How do you get it out? I have the same exhaust but I bought it like that and I can't get it off, lol. You can DEFINETLY feel the rotary exhaust pulse from like 6-8ft away on my car.

Trybal 06-21-07 09:37 PM

they are hard to get out if you don't have the tool. Take some pliers and grab the inside lip, and pull hard on the bottom, then the top, then thebottom.. It gets alittle crooked and jams so you gotta go back and forth

classicauto 06-21-07 09:40 PM


Originally Posted by FBDrifter
car HATES exhaust silencer

I hate it when people jam a big plug up my ass too!! :lol:

HAI-TEK7 06-21-07 09:50 PM

Yeah, take it out. If you worry about noise run a resonator. i had the dual N1 set up on my 3rd gen w/silencers; and it actually cracked the welds on the muffler, both of them from the pressure build up.

They be ok, if you just baby it around and dont get on it.

I used a hammer to get them out. hold the head and stick the handle in and wiggle back and forth untill it works it way out.

NJGreenBudd 06-21-07 09:57 PM

i can't believe i haven't taken those things out of my TII yet, but it's really freaking loud w/o them and I am still babying the new motor but I think I'm gonna have to yank em tomorrow.

NZConvertible 06-22-07 03:20 AM


Originally Posted by FBDrifter (Post 7066791)
decided to try the silencer in my apexi N1 muffler, and it did indeed quiet it down..however there's a DRASTIC drop in performance that i wasn't expecting.

How could you not expect that? Look at the size if the hole the exhaust is now trying to get through. Why do you think there was such an increase in performance with the aftermarket exhaust (sans silencer) compared to the stock one? I'm sure you understand why that happened, so how can you not understand it going in the other direction?


also it seems like the car is trying to blow the thing out of the tailpipe, i can feel the exhaust standing a good 5 feet behind my car while it idles
It's trying to squeeze out a tiny hole, which increases it velocity dramatically.


beginning to wonder if this is worth a 15-20db drop :\
Of course not. It's a cheap, nasty way to make a loud exhaust quiet. A properly engineered street exhaust can reduce noise to acceptable levels without using excessive restriction, but you'll have to pay more for it (e.g. RB).


Originally Posted by phoenix7 (Post 7066974)
i believe I read somewhere on this forum about some guy who blew his motor when he used the silencer on his TII

The silencer would've had nothing to do with it. If increasing backpressure popped engines, explain how they worked with a stock exhaust...

rxguru 06-22-07 01:04 PM

You can use a slide hammer with a spring loaded ceiling anchor in the end of it to get it out. But keep your magnet on a stick handy in case the anchor breaks off in your muffler!

SureShift 06-22-07 05:31 PM


Originally Posted by FBDrifter (Post 7066791)
also it seems like the car is trying to blow the thing out of the tailpipe, i can feel the exhaust standing a good 5 feet behind my car while it idles :[ :\

for a more real life example, it's kinda like when you're watering the lawn with a hose, and you put your thumb over the tip to make it shoot further... it also feels like the water comes out faster. the same sort of theory applies to other stuff like hydraulic lifts and whatnot

phoenix7 06-22-07 05:42 PM


Originally Posted by NZConvertible (Post 7068036)
The silencer would've had nothing to do with it. If increasing backpressure popped engines, explain how they worked with a stock exhaust...

OOH, OOH, here's my attempt at your response:

uniform pipe diameter all the way through? instead of 3" from the turbo back but at the last 2" is pipe the diameter decreases to 1"? I honestly :dunno:.

I just had to mention what was posted on this forum LONG AGO, just in case it really WAS caused by the silencer. I never put the silencer when I had my open exhaust JUST in case the guy was right. Maybe you can help get rid of that myth right here, right now.

NZConvertible 06-22-07 07:40 PM


Originally Posted by phoenix7 (Post 7070242)
uniform pipe diameter all the way through?

Wouldn't make any difference to the engine.


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