sleeperlqx

iTrader: (3)

my mods so far are:

VMAX 6.0HO engine
AIRAID MIT
PCM4less street tune


thats all^^^^ and it runs like a monster. That said Ive purchased a restalled Yank tt3200 rpm stall converter, and have plans to get the truck retuned for the bigger stall asap.

Now planing my future exhaust, as my next mod I need to proceed with. I have stumbled on quite a few questions.

do i need cat converters? will I loose power with them vs without them? I was told the ls type cats are already high flow.

as im on a tight budget i had a idea, but did not know how bright it was....

LPP longtube headers with offroad wye is what i really want down deep. But after stumbling upon cheaper LT headers, I may go the cheaper route with some ebay LT headers.

Custom wye after the collectors via exhaust shop; reuse both my cat converters OR eliminate them; all this while reusing my current muffler, and dumping right after it. Pipe sizing I will use can be bigger, but must tapper to fit the stock pieces, cats, muffler.

Stock cats have about 150k miles on them, which is why i may want to eliminate them, but if its not killing power, i rather reuse the stock cats, to have a clean oder smell. If thats a nono, then i rather use no cats all together.

I like the truck quiet. thus was thinking lt headers, with stock muffler, dumped. Or 1 big aftermarket magnaflow or something. Also with my new stall rpms will be higher alot, i dont really need the loudness attention

SlvySS

no you dont need cats. youll just have to get retuned to get the two back sensors deleted. as far as piping go somewhere around 2.5 to 3 no smaller or no bigger. should be a decent sound, you might want to pick up a bigger magnaflow but its up to you, if your dumping it it wont cost much to replace mufflers after.

sleeperlqx

iTrader: (3)

so no cats, with the ls motors and the afr set the odor is less, or will it still stink like **** in my garage? ok here goes my plans if cash permits b4 the tune.

LPP long tube headers
LPP off road wye pipe no cats 3"
into a 3" mangnaflow single in/out; prob 28 or 30" the biggest one they make.
dumped right after the muffler.

i know that should sound awesome, but i want it quiet as well... so I may even have to add a 2nd magnaflow muffler, of a shorter length, single in/out as well.

I want performance, but I want quietness....

gs7793

iTrader: (8)

yeah if your gonna run headers into an ORY into a 1 in 1 out magnaflow i would run 3" exhaust, nothing bigger. and i dont think it'll smell all that bad....but that should sound great, im sure it'll be quiet at cruise and have a nice rumble at WOT

sleeperlqx

iTrader: (3)

sounds like what I want... I cant wait... I just will take my time and do the exhaust the right way, little more cash, but better in the long run, then get another retune... not going to try and rush it all to get it tune together... but stall will be in this week, with retune.

TXsilverado

iTrader: (19)

get the texas speed 1 7/8 headers. anything bigger than a 5.3 will benifit from them.

blown 04

iTrader: (1)

Hey sleeperlqx sounds like were working on the same things, I have been wondering what to do with my 06 v-maxx as far as exhaust. Like you i want it quiet, I have dynatech headers and catted y-pipe from my old 5.3 but the y-pipe is only 2.5 not sure if that would be wise to do on the 6.0 I might sell the dynas and a set of lpps myself.

LS1TRUCKGUY

iTrader: (7)

depending on where you live, you might run into problems getting it inspected without cats. a 28" or 30" magnaflow will be dead quiet. like stock kinda quiet. A 22" magnaflow will have just a small amount of sound to it, but still sound almost stock, just to let you know...

sleeperlqx

iTrader: (3)

well fellas I did it, got the Yank3200, now got the LPP longtubes with ORY and all pieces are welded nicely already, including the flanges. So it looks like Ill have both in together for a retune at the same time after all! Ill get some pics soon, but I had plans to mount the ORY to my stock muffler, and dump it right after at a 45* turn. I think that would be quiet and still get semi loud, but I know Ill be leaving a few hp on the table without a free flowing muffler. But I want pure quietness, but I dont want to not fully let the mods shine.

So a question arises how much hp can a muffler really gain? vs stock? I did a search and seen only 2% dyno proven. Then I read magnaflow claims like 12hp 19tq on my same engine.... using the 15838 catback only... Im thinking inflated.

But I dont want to tune with the stock muffler, then switch out to a magnaflow or corsa later, and have to retune? I mean 15hp is a good bit difference. Or will I be fine on my tune once I tune the Longtubes?

LS1TRUCKGUY, I would prob be looking at a magnaflow, and a stock sounding one. I actually got my eyes on a 30" from summit. Its the biggest magnaflow, and it has si 3" and dual 2.5" out, so Ill just dump the 2 outs I was thinking. it 36" overall length!!


also here is a chart of the magnaflow catback on my same engine. 04 SS 6.0 liter. 15838 is the part number. I was thinking since Im dumping my gains should yeild even higher. But I want to use the biggest size magnaflow XL in the future.

01WS6/tamu

iTrader: (36)

On newer LS trucks changing the muffler is a decision primarily made for sound. Stock they technically flow damm good for most applications that are going to be daily driven.