Project Valve Technology Muffler
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Joined: Oct 2007
Posts: 90
Likes: 0
From: az
Seems like a very complex muffler with the valve that swings open if it breaks and sticks closed yikes mucho back pressure. If your into quiet then this seems great Im just totally not into quiet and with a turbo car you want the least amount of backpressure possible. But I guess a stealthy sniper like evo could be really cool too. Pull up to a light sounding like a prius leave the light like a ferocious Evo 9 with a fp black!
I wonder whether Jegs has cleared out there stock of the ones with the defective valves? I really want to try this, especially if I can just do a quick slip off/slip on with my current Buschur Magnaflow axleback. Anyone called Dynomax about the rattle?
Well it is louder at WOT compared to normal driving. BUT if comparing to the magnaflow muffler, it is quieter at WOT as well !! Its strange but true at least in my car and in cabin pov. But if its quieter in cabin than its quieter outside as well.
It doesnt make sense why because it has less muffler packing area (only have of the wide body section). I am gonna assume the valve is splitting the exhaust sound pulse and as it travels over and joins, the waves cancel some of themselves off. Off course its not stock quiet when WOT, but its impressively on the quieter side.
Base = Dynomax VT muffler
Comparison = Magnaflow Muffler
Done same day however I started WOT at slightly different RPMS. Also there was a little knock only 1-2 counts slightly different rpm ranges on both runs. Not a real dyno but something for now with the VDR.
It doesnt make sense why because it has less muffler packing area (only have of the wide body section). I am gonna assume the valve is splitting the exhaust sound pulse and as it travels over and joins, the waves cancel some of themselves off. Off course its not stock quiet when WOT, but its impressively on the quieter side.
Base = Dynomax VT muffler
Comparison = Magnaflow Muffler
Done same day however I started WOT at slightly different RPMS. Also there was a little knock only 1-2 counts slightly different rpm ranges on both runs. Not a real dyno but something for now with the VDR.
it's probably quieter due to it being a new muffler. i remember when i got my JunB.L catback it was fairly quiet (deep tone) but still louder than stock obvisously. now it seems like it has become a bit louder. probably due to the mess inside the muffler buring off or something lol
i'm defintely looking into this. just need to see if i can sell the JunB.L lol
Last edited by vmrevo9; Jun 9, 2010 at 11:41 AM.
Got a nice Hobart 140a Handler MIG today. Never used. Just need to find a 75/25 bottle.
Maybe I'll beat that MAP guy to sound vids....
Maybe I'll beat that MAP guy to sound vids....
Just returned from getting this muffler installed.
my findings.
positives:, coast down volume, clutch in idle speed, <30 load: nice, very quiet
cruise, less than 70 load: Ok, as good or better than previous can muffler with silencer (1.5")
idle, inside: pretty good, a nice improvement, (relative to stock,- no idea)
Let me say first, before commenting on the negatives, I have large-ish cams, which may be affecting the baffle negatively. ie the pulses may be stronger than a car that idles smoothly.
I bought the over 4 liter muffler, the larger of the choices.
negatives:, wow what a disappointment, the rattle at idle is embarrassing.
possible fixes:, a bit of weight added to the baffle plate lower edge might hold the baffle down better at idle*. I could see the baffle fluttering at idle, which says to me the baffle isn't weighted properly(at least for a bigger cam-ed car). Plus, if it isn't operating as designed at idle it is unnecessarily "loose" throughout the low power range. However the problem rattle is only evident at idle.
* getting a weight permanently attached to the baffle might be difficult
my findings.
positives:, coast down volume, clutch in idle speed, <30 load: nice, very quiet
cruise, less than 70 load: Ok, as good or better than previous can muffler with silencer (1.5")
idle, inside: pretty good, a nice improvement, (relative to stock,- no idea)
Let me say first, before commenting on the negatives, I have large-ish cams, which may be affecting the baffle negatively. ie the pulses may be stronger than a car that idles smoothly.
I bought the over 4 liter muffler, the larger of the choices.
negatives:, wow what a disappointment, the rattle at idle is embarrassing.
possible fixes:, a bit of weight added to the baffle plate lower edge might hold the baffle down better at idle*. I could see the baffle fluttering at idle, which says to me the baffle isn't weighted properly(at least for a bigger cam-ed car). Plus, if it isn't operating as designed at idle it is unnecessarily "loose" throughout the low power range. However the problem rattle is only evident at idle.
* getting a weight permanently attached to the baffle might be difficult