3" muffler ?s

[nined2tsi]

I found a 3" Dynomax muffler straight through design for $60 at Summit. If I put a full 3" turbo back wo/cat exhaust on, do you think it would be too loud? Im asking because im on a budget and im gonna start on the project prolly next week. I want something that is a little lower in pitch. Im building it from scratch downpipe and all. Any info would be appreciated plus any mig welding tips, thanks

 

[jbillakdsm]

I wouldn't go with a Dynomax muffler. I've had them on a couple of cars and they all sucked ass. I would say spend the extra money and look for a Magnaflow or even an APexi. The other part of the equation is that if you are going to a full 3", have you ported anything else on your car like the exhaust manifold? If you leave everything else stock you may run into boost problems. I would say get the intake side of things done first and then change your exhaust. Besides, if you aren't turning the car into a hardcore racer, a 2.5" mandrel bent will do just fine.

As far as sound goes, as soon as you take the cat off, a full 3" will make a lot more noise, but 1gs seem to keep that low end rumble till way up in the revs. My last suggestion is that whatever you do, PUT IN A FLEX SECTION! I built a DP at home without one and no matter what I did, the damn thing would shake the bolts loose. Crawling under your car every 300 miles to tighten stuff gets old REAL quick.

 

[nined2tsi]

I just got the flex section in yesterday. I dont have anything ported yet but I am going to get prolly a ported 2g mani and evo O2 housing. I think Im gonna stay with the 3" cause all my friends with dsms tell me too and thats what they have running real good numbers. What do you mean run into boost problems? Why do the dynomax mufflers suck? Too loud? Nasty sound? Just wondering, thanks

 

[Grizzly Racing]

why do you say the dynomax sucks?

i've had no problems with it and it sounds good to me

also... if you order that muffer from summit, they currently have a $20 mail in rebate..... so that makes the muffler $39. cant argue about that!!

 

[P8ntBalla]

i have a dynomax on my 3 inch turbo back, its not loud at all. i dont have a cat or any resonators, just straight thru piping with a dynaflow muffler. sounds like a 6 cyl

 

[BoostinAWD]

I am also using one, just make sure you stick some sort of a tip in it. Without one it is loud as hell..

Don't ask why I can't explain it, but just running the muffler alone at the end doesnt work very well and it looks like ass.

 

[2gTurboS]

Just wondering what you guys do with your second O2 sensor when you build your own exhaust, I am running an open downpipe 2.5"-3" style right now( just tried it tonight very very loud plan on putting muffler on the end of the dp) and the second sensor sees nothing, I think the car is confused because doesnt it compare what it sees in the first and the second sensors to make sure the cat is working? I have yet to get a for sure response to this so will someone please shed some light on the situation that has done this.Later Corey

 

[P8ntBalla]

from what i understand the only thing that removing the second O2 sensor does is give you a constant cel. as for putting a muffler on the dp, i wouldnt recommend it. cops look for cars without mufflers and if your car sounds louder than stock and they dont see a muffler they will pull you over. a friend of mine had a civic with a fully built turbocharged jspec b18 engine, and he had a custom made resonated pipe that let out right in front of the front tire. it was pretty damn loud and he didnt wanna get pulled ove rso he hung a muffler connected to nothing and never had a problem.

 

[jbillakdsm]

Dynomax, suck IMO b/c they all eventually have flow problems. The internals have this wonderful tendency to shake loose after a while. Something with the amount of vibration that imports put out. Magnaflow mufflers are built for the abuse that we normally put on our cars. Granted you will spend more money, but the look and endurance are worth it in the end. As far as boost problems, check on the page for exhaust problems forums and there are a coulple things written about it and I think they are better written than anything I could do.

 

[2gTurboS]

Is it normal for any kind of fluid to come out of the downpipe when you run it open ? also yes I know it will throw the CEL but what does the ecu do.Does it change anything or is it just a reminder light.I dont want my car dumping a bunch of extra fuel or pulling timing or engaging bcs..(yeah I know these wont happen,maybe the fuel thing but they are examples of what the ecu can do)..if the second O2 isnt neccessary can someone please elaborate why.Thansk Corey

 

[P8ntBalla]

i havent noticed any difference except the better low end power. im pretty sure its just there to help the mechanic help diagnose a problem and or let whoever would want to know that there is no cat on the car.

 

[Grizzly Racing]

there IS a way to fake out the ECU....... and you wont get the check engine light

heres a link to where they discussed it.... hope it helps!!

http://www.dsmtalk.com/forums/showt...=25&highlight=check engine light&pagenumber=1

 

[nined2tsi]

anybody have real good prices on 3" magnaflow mufflers? my budget keeps getting smaller so i think im gonna have to go with the dynomax if i cant find a great deal on a magnaflow or alike muffler.

 

[Grizzly Racing]

i've had a 2.5" magnaflow in the past....... the inside of the muffler is actually 2.25". the inner part is smaller then the inlet/outlet pipe.....

i know on my dynomax 3" the inner part is actually bigger then the inlet/outlet pipe......

so IMO the dynomax flows more. and the magnaflow is quieter.

 

[nined2tsi]

Thats why I was wanting the magnaflow, heard its quieter. Any other cheap mufflers that arent as loud as the dynomax?

 

[candela]

Wow you guys think the magnaflow is quiet???
I have the extreme 3" turbo back with o2 eliminator....which come with magnaflow mufflers 3" in and out! I think this thing is too loud for my taste, Im not really one to complain or let alone buy another exhaust cause I cant handle the noise, but this is definetly one loud exhaust IMO. I also have just a 3" test pipe as well, so that probably account for some of the loudness too. Dont get me wrong it sounds good, just really loud thats all

 

[Grizzly Racing]

on my brothers car we ran a muffler in place of the cat and then a muffler in its regular location..... this made it a lot quiter too..

the muffler in place of cat gives the nice appearance of a cat...

but regardless of magnaflow/dynomax ......... they are both too daym loud when you use 3"........

if you want it quiet then you'll probably need to get a 2.5"

 

[P8ntBalla]

i have a 3 inch magnaflow and it isnt loud at all. it sounds reallly deep.

 

[candela]

Yes mine is very deep as well, actually its really fuggin deep. Its just that its still too loud to me. I like a nice quite exhaust where you can listen to the motor and not just hear the turbo and exhaust like mine.

 

[mike9146]

www.roadraceengineering.com for a good price on Magnaflow. FWIW,
my car is 99-100 db at idle, measuring from 2' behind the muffler with my trusty 'Shack db meter. This is 3' TB with Magnaflow 3" in/dual 2.25" out. No tip, no cat, etc.

Mike C.

 

[nined2tsi]

With the 3" exhaust. What do you guys think about this...If i put a 3" resonator in place of the cat and then put the 3" dynomax muffler on. How loud do you think it would be? Deep sound? or just loud? I dont want a really deep annoying sound but just loud would be ok.