BluEVOIX

iTrader: (69)

I was going to make the same exhaust again with double magnaflow mufflers until I stumbled on to this:





Its a 3" straight flow through muffler with a exhaust pressure activated valve. My current setup is Cobb DP, Buschur HFC and Buschur catback with magnaflow rear muffler. I'm going to install this in place of the rear magnaflow and take note of the results. Then soon after I will make another center magnalfow muffler to replace the cat.

This technically is a 3" straight flow through system. So hopefully it turns out with great results!!!


I just bought placed an order and hopefully it does not have any back orders, but according to Jegs it ships Monday.

I'll update post 2 as the project progresses... Maybe I should have color coded my little builds like FP turbos

BluEVOIX

iTrader: (69)

Update:
-Old version rattled, new revised version has the issue fixed.
-Stock cam has no issues, but cars equiped with cams that have very heavy lope may experience thumping rattle of the valve bursting open and closing. The smoother the idle with cams the less likely of having issues.

Here are some pictures:


As you can see, the revision is made with the short half of the valve having more clearance from rubbing on the inner tube, which caused the rattle.
[IMG][/IMG]




My current exhaust system is: Cobb Downpipe, Buschur HFC, Buschur catback with Magnaflow muffler. All I did for now is, I removed the magnaflow muffler and slipped this over the buschur Intermediate pipe to test out. It has an offset enterense and center exit. So you can adjust how aggressive of an exit curve you want for the rear tip. Here are my impressions!!!!!


STOCK QUIET exhaust!!!!!!!!!

This is exactly what I was looking for. If an exhaust system is just 1 db louder than stock than I am not happy. Just to give you an idea of how quiet it is since every one's opinion of quiet is not the same!!

Idling it is quiet. The valve inside is closed through out the idle and some reving, it opens all the way if applied a lot of throttle input at a stand still. The RPM's and A/f ratio were unchanged.

At idle and holding cruising speed the car seems like its not even on. Driving during the acceleration part as long as your not boosting its very very quiet as well, and can be compared to running a 3" downpipe, testpipe with the stock catback (for those that ran that setup). I like the cruising absolute silence and I enjoyed hearing my tires on the pavement and turbo spool/whistle.

WOT and harder acceleration (boosting) it does open up but still a lot quieter than when having a magnaflow muffler at the rear. Kind of interesting, but I'm guessing the valve divides the exhaust sound and when it travels over it cancels its self slightly???

Video update:
I used a digi camera to make the video so the audio quality kind of sucks. However for a closer feel of the sound tone, lower all your bass, and tone settings on your pc speakers for a more accurate feel. The muffler pretty much takes away all of the bass from the exhaust note. Also note that I have the blox lower front engine mount which adds in some engine bay vibration and motor noises.

I know its too dark to see anything, but I tried to make the clip as quickly as I could.


Start up and idling. Sounds like a tractor but its mostly because of the digi cam I used which sucks in picking up audio. The actual sound loudness of the exhaust standing behind is similar to running stock catback with 3" testpipe and 3" downipe.




Driving around. Most of the sound is noises from the engine bay and not the exhaust. Listen to how dead silent it is when just cruising. Also notice when I accelerate you can hear the transmission gear, FP HTA green turbo whistle and the road/tire noise. Try to compare random car keys rattling, shifter changing noises to give you an idea of how quiet it is that you can actually hear those things. Best match in sound would be during acceleration = similar to 3"dp testpipe and stock catback. During cruise complete bone stock.
http://www.youtube.com/watch?v=sZ4DTKTtff0



WOT with driver side window open
http://www.youtube.com/watch?v=76KESzFTSnE


WOT with windows closed
http://www.youtube.com/watch?v=bXb-uvwSBbg

3gEclipseTurbo

iTrader: (12)

This is old technology, a company from australia i beleive, has made mufflers with a valve like this for years..

BluEVOIX

iTrader: (69)

That is the Varex Xforce muffler and they are not exactly the same.

The Varex Xforce muffler is electronically activated to open/close with a remote control. Just like an electronic dump. The Dynomax VT muffler valve pushes open with the rising exhaust flow.

I personally dislike having to open and close valves electronically. I mostly prefer a boost activated actuator or something like this. So this is another option where I can just press the pedal and have everything happen on its own.

94AWDcoupe

iTrader: (125)

actually the factory mufflers are like this. except they are not straight through when valve is open. but the valve does swing out of way. this muffler looks like a throttle plate thats still in flow path? this is a nice find. this muffler should work well.

3gEclipseTurbo

iTrader: (12)

http://www.xforce.com.au/cars/view_car/29 thats their website for more info and sound clips.

3gEclipseTurbo

iTrader: (12)

Ya but what if you want to go wot on the street? It will attract attension where the varex wont. Idk i dont like either personal.

BluEVOIX

iTrader: (69)

Hence why its still a muffler with packing and perforated tube in the back half. Also I'm going to add a muffler in the center to just like my old setup.

https://www.evolutionm.net/forums/ev...t-exhaust.html

With my old setup it was very quiet. When I was getting my car road tuned, my tuner thought my motor shut off every time I popped it in neutral after pull. But as quiet as it was, it was not as quiet as stock.

The point of this setup is to be as close to stock quiet as possible during normal driving off boost. But if I go WOT in the street it will still be a pretty quiet WOT pull similar to the double magnaflow setup.

True but only for the VIII muffler. The IX muffler does not have the flapper inside.

You are correct it acts similar to a throttle plate. But since electronic cut out dumps dont get affected by the plates in performance, I dont think this will either. At least for the amount of power the majority of the people run.

94AWDcoupe

iTrader: (125)

which one did you get? the up to 4.0CI or the over?
I am thinking since the muffler section is cut in half this will be louder at WOT compared to the standard one..

BluEVOIX

iTrader: (69)

http://www.jegs.com/i/Dynomax/289/17957/10002/-1

Dynomax #289-17957
# VT Muffler Offset Inlet Diameter: 3"
# Center Outlet Diameter: 3"
# Shell Diameter: 4.5" x 9.75"
# Overall Length: 19"
# Shell Length: 14"

17957 - Dynomax VT Mufflers Details

Single Muffler Exhaust Systems - Over 4.0L (244cid)

Steve93Talon

iTrader: (5)

I think the C6 Vettes use something like this. Corsa also makes the RSC muffler (reflective sound cancellation) that APR uses in their cat-backs. You might be interested in them.

http://www.goapr.com/products/apr_exhaust_20tfsi.html

i've read your threads, I just got done replacing my JIC Ti cat-back which was unbearably loud (came with the car). I ended up going with a Magnaflow 16660 cat-back which comes with a nice size oval muffler. I then added an 18" resonator and 3" flange (came with a step-down). I also have a resonated testpipe. The car is significantly quieter than before and it makes driving much more enjoyable, but I'm always open to making it even quieter if it doesn't compromise power or cost a fortune. Looking forward to your results.

BluEVOIX

iTrader: (69)

Yes the C6 uses something similar so do Ferrari's and some BMW's as well. That's where I got the idea but I was never able to fab anything because I dont have a welding machine.

I've seen the Corsa a long while back. But after researching there are a lot of people who are not happy because it still droned.

Right now I'm a little concerned if the muffler I got would be best for our motors. There are 2 versions under 4.0L and over 4.0L displacement. I'm wondering if the 2 different mufflers are for WOT cracking pressure reasons or for idling and normal driving reasons. Hopefully its just for WOT because Turbo pressure can easily flip it open like a V8 .

94AWDcoupe

iTrader: (125)

I think you choose correct one. I smoke 5.0s on a regular basis
r little 2.0s flow more like 6.0

wizzo 8

iTrader: (35)

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cij911

iTrader: (14)

BluEvo - Awesome thread start once again....I was at a performance shop just yesterday looking at the Dynomax. According to the owner it was the quietest he had tested (Magnaflow, Borla, etc.), but he felt it was more restrictive. I was not comfortable with his 'data' and left.

The question I have is for a ~450 whp car, what does a 3" std. setup (like my Megan Racing) gain over the stock ? For a while now I felt most of the gains reported in people's post was replacing the catalytic converter with a test pipe. I love driving my car, but just hate the drone and wish it were more quiet. As such I keep coming back to the idea of just putting the stock cat back on and keeping the 3" dp and HFC. Thoughts ??

I guess after I get my car finally tuned (new injectors and turbo), I could swap the exhausts and post VDR plots....