After five different single pipe configurations in both 2.5 and 3-inch diameter I threw my hands up and asked the board for advice on an exhuast. The suggestion was a 2.25-inch diameter with magnaflow X. Finally found a shop that actually listens and does nice mandrel bends so got it done and over the weekend was traveling around so now already have about 600 miles on it. At first I was actually suprised that it wasn't that loud (4x9x14-inch Magna's) but the sound was awesome (I was a bit afraid it would be super loud with the 14-inch muffs and almost went with 18-inch but that would have been a mistake). After a few hundred though it has notched up a few db and the sound is fabulous. My friends were giving me a little chit the way it sounded before but when I fired this up they were like....oh ok, now it's sweet. While louder, I still don't think it's a super "loud" system until pouring the coal to it but even for myself who didn't really want too loud, the sound it so sweet I love what I hear now. I dumped mine and it's basically totally hidden with no tips. As far as performance, this is the first exhaust set up I've had that I feel gives across the board performance. I wish I had done this before the Troyer dyno b/c I know I gained but whatever. When on highway, the tip in throttle is stronger immediately and the mid rpm pull is also noticeably better. Interesting to me was that my AF1 is now almost silent (no it's not the exhaust drowning it out). I used to hear the AF1 at even low and mid throttle but now I only hear it when under basically full throttle. Anyway, this set up was only about $150 more than the single pipe systems I had before and about 5x better and for those in south Fla considering, I was real happy with the work Exhaust Depot (right near Outdoor World) did. Too bad I made so many mistakes along the way. Thanks again to OpenclassPro11, Kevin24, MGDFan, and Mike Troyer.

p.s. Just to top off getting this done, I got into a race with about a 2-3 y/o Duramax Chevy on Saturday and didn't like the way the guy approached it b/c he was trying to be sneaky. Long story short as possible he tried me on the highway but realized that wasn't gonna happen so then we are staged at the light after getting off. He would not role the window down but kept looking at me and I was asking and gesturing if he wanted to race based on the highway try.....still the freak just looked so I get a call on the cell. By the time the light turns I was into my convo and forgot about it but the dude hammers it. We had a double turn and about in the middle I was like f that let's see what this thing will do. Once I'd rounded the turn and nailed it my front bumper was ~5-8 feet off his rear and he was already on it......perfect. We were at ~20 mph at that point and from there to ~80 or so I steadily caught and passed him until his front was about 1.5 truck lengths off my rear. Basically a pretty good whipping considering the two pigs in the race. The best part was as I drove by him my exhaust was just screaming and he looked so helpless haha......he of course turned off as expected. I'm sure to go buy a programmer so I'll just smile if I see him again.

 

That looks great man. Duramax's are dogs on the highway but they can be a hassle from a stop. My buddy's 03 can't hang with my 4.2 until about 95 when the governer kicks in.

 

nice job and writeup-phil

 

how about some sound clips
i have been on the fence for a while on what to run on my 07
thanks

 

That looks real good Blackdawg and nice write up Yours is pretty much identicle to mine where it's dumped. Like i said mine took all of 1,000-2,000 miles before it really was broke in and the sound stayed the same. If you think it sounds good now give it a little more time. It should continue to get even more throaty and deaper as it breaks in. It should sound completely bad a$$ and you should get a ton of compliments

Glad ya like it and no problem for the help!!!!
Kevin

also you gotta love the sound at start up and full throttle huh??

 

Yea it's definitely getting louder. I didn't notice this much change in sound with my other (larger) mufflers. I would be more inclined to go loud with this set up because the sound is so sweet, nothing annoying, so I don't mind the increase. And btw it sounds mean as hell but not too loud towing at about 2,750 rpm on the highway (~65mph in 3rd). Really wish I'd done this from the get.

07, I don't have a way to record a sound clip. I tried listening to tons of them on YouTube and several exhaust websites and it's just hard for the average Joe with average equipment to capture the sound it seems. I'll see if one of my friends has one and play around with it to try and get something though. Not sure what you are looking for but the performance of this set up is proven (just ask some of the guys on this thread as well as Mike Troyer). As far as sound I can tell you that with these 4x9x14's it's quiet enough that you can roll up to a formal event downtown without the ladies being embarrassed to step out........but loud enough to impress your buddies and if you're not easy on it, wake up the neighbors at 3 am.

Kevin, yea I think Duramaxboy got to love some of that full throttle sound too. Haha that still makes me laugh, actually I bet he can't get that sound out of his head. Your's must sound awesome with the 4-inch rounds.

 

do you have the model numbers for the mufflers and x pipe

 

same exhaust here
10790 x-pipe-2.25"
14335 mufflers-2.25"
-phil

 

do you have a sound clip of yours?

 

Just wonderd if you lost any lowend torque with this setup because I wasa wanting to do this setup with my 05 but want to keep my torque and maggie rep said I would lose a lot with that setup?

 

What made you go with 2.25? The stock system is 2.5, correct? Is the stock 2.25 from the collectors to the Y and then increases to 2.5 from the Y back out the tail? I guess if that's the case what you did made sense, you effectively kept the same diameter from collectors out the back. I as well would like something like this with an X, some true duals, but am concerned about losing low end torque. Strange that Maggie Rep would be the one saying you'd lose torque, when Mags are known for retaining the torque on their kits. If you loose enough torque with that setup, it may be better to go with super44's...

 

nope i gained tq every where-in fact my tq band broadened and was very flat -phil

 

trust me on this-unless you are supercharging go 2.25"- my van weighs almost 9000lbs fully loaded down -if i didn't gain tq on this setup i would have had the stock exhaust back on in an heartbeat- in this case i speak from experience unlike the magnaflow rep speaking on his opinion-phil

 

I went dual 2.25-inch b/c I don't have anywhere near 500 hp at the flywheel which would warrant dual 2.5-inch. I can't explain it correctly but there's fine line with getting low backpressure (big pipes) and high exhaust gas velocity (small pipes) and it seems especially important on n/a gas engines. The stock system is dual 2.5 into and single 2.5 and hard to correlate to a dual set up. If you go with 2.5-inch dual and you aren't blown or extremely modified internally my understanding is the torque curve is moved up a few hundred rpm. As mentioned I've had single 2.5 and single 3-inch and now dual X piped 2.25-inch and I have no comparison dyno #'s between them unfortunately but the dual 2.25-inch X pipe is the only one that impressed me from a performance standpoint and no there is no perceptable loss of low end torque at all and I'd bet a dyno would show increase across the board. I've had 5 or 6 different set ups so like OpenClass if this wasn't perfect it would be off my truck.

 

Good to know. Did you both have shops do mandrel bends for this set up, or are they normal compression bends? I am very interested in this set up, but am not sure if the reputable shop near me does mandrel bends. If I hack the system off at the y and use the 2.25" x pipe with dual 14" rounds and exit the side lightning style, how would I decrease from the stock 2.5 pipe to the aftermarket 2.25 x pipe? do they make reducers for that application? Will I be happy with the sound and perfomance? I was considering Maggie kit 16616, si/do 2.5" with the 18" muffler, but have heard alot of people say it is too tame. I don't want annoying or obnoxious loud, but I want good sound (not too loud when normally cruising, but enough to show it's got ***** when I get on it), and good performance out of it with no losses. If my shop only does normal compression bends would they be acceptable for this setup, or does it really require the mandrel bends for true gains? The only real bends should be the two coming out the side in front of the rear, and maybe some very small bends to align everything. Thanks for all the help guys.