I am about to go from a recirculated tubular O2 housing (external waste gate) to a atmospheric dumped external waste gated O2 housing. keeping my 3" SS Megan DP, and putting stock exhaust on after it. And where the first resonator bolts up, I am going to install a Y pipe and electronic cut out.

So this beast will can go from quiet to LOUD at will



I have 1 question / real concern though. Anyone think the full 3" would outflow the cutout setup described above? I mean which do you think would flow the best?

I am changing to the described system above, because the Megan catback has a poor fit and no matter what I do with the hangers it always vibrates around 3,000 rpm making a HORRIBLE sound that makes my ears want to bleed, and my car sound like crap. (and it's otherwise far from it). But I still have flow in mind, and otherwise like the current setup. So if someone thinks the full 3" is better than the cutout combo I might work with it a little longer. But if this is what you think, please explain why. I want to hear the reasoning behind your opinion.


Thanks!

Do it! You'll love having the quiet stock catback on there, and the added bonus of having a stock looking exhaust, too. Put the cutout in the DP if you can, before the exhaust necks down to the stock catback, and that will be the best setup. Since you have an atm dump o2 it may not make a huge difference in overall performance to move the cutout to the DP, but it can't hurt. I imagine spoolup would be quicker with it in the DP, though.

I have a recirc'd tubular o2 into the same DP you have, with a 3" cutout welded into the curve before the flex section, and then the stock catback is bolted on behind all that. It basically dumps out a foot below the turbo, and I hit full spool 1Krpm sooner with it open vs. through the catback.

Just finished my cutout setup... mine dumps right under the rear subframe and with the windows open i can smell the exhaust a bit when I floor it(open cutout). its the best mod ive ever done... heres a pic of it ... ill do a write up on it when I get a chance... super quiet out the stock exhaust... ground shaking out the cutout!!!!!!!!!


I have been through a greddy EVO II catback, Dejon 2.5 inch catback with magnaflow and a 3" catback with 2 resonators and a magnaflow 3" muffler... My opinions is Cut Out all the way! low noise, stereo sounds better, no resonating, cruise on the highway for hours without wanting to put a drill through your ear, sleeper look if you like that and very reasonably priced http://cgi.ebay.com/ebaymotors/Stai...r_Truck_Parts_Accessories?hash=item20af6a4e97

Cool, glad to hear it since I swapped with a guy last night. Traded him my Megan catback for his stock cat back (with CAT) and $100, then sold him the first resonator to him for $40, and sold his friend a ralliart oil cap and 255lph fuel pump for $30 So I walked away with $170 and a stock catback.

Now I just have to get a Y pipe and the cutout and I will be ready to mount it. I fired it up for a moment with the open down pipe just to piss off everyone that lives around me . I have never heard it with open DP. And HOLY CRAP, ok it's not as "loud" as I was expecting, but it was way deeper than I was expecting. Sounded wicked as as fast as it revs (12lb flywheel) and open DP . I will be putting my cutout where the test pipe would go however. Yes the turn down to go back under the car on the DP is likely the optimal place, but that would require there to be a good welder around here, and more effort and expense for likely negligible difference.

I think I might spray the OEM muffler with some black high heat paint and try to polish up the OEM tips a little more before I mount it. Hell I might just take it to the shop on post and use one of there air brushes on it and spray the whole thing (steel wire brush)

I have seen more and more people using this setup. Any linked info you have as well as a how-to will be quite beneficial. I need a new exhaust and I would love to try this.

Well, I have not tried to bolt it up yet, since it's cold and windy outside. But it shouldn't be but a 20min job. The most difficult part will be the Y pipe. My car with the Megan DP needs a 16" long Y pipe. which is not actually a Y so much as a stright piece with a 45* coming off of it. then it's just 3 bolts, nuts and a gasket + the cutout.

On top of that, I am waiting on the springs for my Tial MVS. Taking it from 20psi set of springs down to 14.5. Then I will take off the turbo, put the DEI turbo blanket I got on it, swap out the tubular O2 housing I have on it now, for the atmospheric dump one, (after a new 02 Sensor and wrapping it in header wrap), by then I should have the Y pipe and ready to mount the exhaust.






The only problem I have encountered, is that most off the shelf cutout's are only 10" long and I need a 16, so I am just going to purchase two 2bolt 3" flanges and take a off the shelf unit to an exhaust shop and have them weld some pipe on to make it longer and then the flanges will be welded to it when everything else is mounted so nothing gets clocked wrong .

posted.... http://www.dsmtuners.com/forums/articles-intake-exhaust/363787-3-flow-go-stock-show-slow.html

ive had this same idea too. i went an bought a cheap ebay 3 inch down pipe, then i had bought the QTP 3 inch cutout, had that welded into the dp. this thing eliminates my cat so it welded it where the cat would have been. when i go to bolt it up. the dam 3 inch, is bigger than my stock exhaust flange. im like . what to do. people telling me to get a 3 inch catback to make it fit. that defeats the purpose. so my idea is to get a 3 inch flange weld some pipe in it. then it goes down to my stock pipe. hope it works

I have a straight 3" turbo back. I noticed no changes between an open 3"dp, straight exhaust 3", and a straight 3" with an n1 muffler.

i'm running open dp 3in feels can't even remember how my turbs would spool b4

I now realize my answer can not be obtained without taking pressure readings at the DP, comparing both setups.