My New Exhaust

[Petri317]

Hello all. I recently purchased and installed a Dynomax exhaust system for my truck. I thought I would share some observations regarding the system for those interested. Pics and a sound clip will follow;

It sounds mean now. It's got that big block sound. Some like that, others do not. I personally think it sounds awesome. I had an exhaust shop weld the system after I installed it because the clamps provided leaked. Also, my muffler hanger was a different design than most trucks(apparently ). you should be ok if your truck has a dual rubber isolator system, as the dynomax kit comes with a 4" clamp/hanger bracket. I had the muffler shop fab up a bracket. The truck sounds only slightly louder while cruising with the windows up. It is definitely louder on hard acceleration, and you can hear it with the windows down. I paid $365 from summit plus $60 to the muffler shop for the hanger and welding the system up. The system has a two piece y pipe that goes to 3"(smoother than the stock one, no kinks), a 3" midpipe, then uses an adapter to 4". The muffler is a 4" in/out flow-thru design, and the tailpipe is also 4". That is topped off with a 5" chrome tip. The system is great if you like an aggressive sound, but it is loud! Not straight-pipe loud, and not obnoxious (in my opinion), but not quiet. For the price, you could probably have an exhaust shop fab something up, or cobble something together, but I like the (relative) ease of install, and sound provided. Plus, nobody else that I know of has tried it, so I figured, "why not?"

Now all I need to do is put in new injectors, a remanned IP, and I'm set(unless anybody has a spare $1800 for a Hypermax turbo for me.

 

[funnyman06]

Cant wait for the sound clips, no one here i know has any of their 4 inch on an NA, im looking at doing a home made kit, 4 inch tail pipe from napa and maybe a 4 inch magnaflow muffler. Im looking for a mean sound, i get very jealous of al my friends cummins with strait pipes, sound like semi trucks, but ill take the big block sound. How is it at idle, does it have a nice diesel sound to it?

 

[Optikalillushun]

ill be waiting for sound bites! im thinking of going this route, especially since it is all 4" which will be great for a future turbo. also, i was going to eliminate the muffler if i did it.

i have re-built G code injectors i bought from pensacola diesel. they sell on ebay but i called and had them send me a set...total was $129 shipped to my door.

 

[Petri317]

At Idle, from the tailpipe it has a big-block purr, which is vastly superior to the constipated sound I was getting from the stock exhaust. So no "diesel" sound from the tailpipe, but you can of course hear the engine idling.

Optikalillushun, notice a big difference with the G codes? I definitely need to change my injectors; I've got some B's and some BB's kind of mix and matched.

 

[Optikalillushun]

i did feel a difference over stock which were original. with my 35" tires and stock 3.55:1 gearing i gained a few mph going up the same hills from before and it seemed to have more throttle response. id say it was 60% new injectors and 40% power increase from the G codes. maybe 5 hp but it pulls harder now.

 

[LCAM-01XA]

Petri, so if I read you right, your Y-pipe is 3" from the manifolds down to the single part, and then after the merge you have an adapter bringing it up to 4" for the midpipe, muffler, and tail, correct? I'd really wanna see some pictures of that, in particular of the Y-pipe and the di-so merge...

 

[Petri317]

Actually, the pipes that form a y are 2.5" (like the factory) till the intersection, at which point the pipe becomes 3". This is the same setup I had with an Autojet y-pipe on a previous truck. The Y-pipe has clean, unkinked bends and should flow better than the stock pipe. I laid them side to side for comparison and measured outside diameter.

The y-pipe then connects to a 3" piece of pipe, which then connects into a 3"-4" adapter that connects to the 4" muffler. sorry for the confusion. All of these adapters are clamped in place, which is why I recommend having them welded to prevent leakage.

 

[h2odrx]

Petri, so if I read you right, your Y-pipe is 3" from the manifolds down to the single part, and then after the merge you have an adapter bringing it up to 4" for the midpipe, muffler, and tail, correct? I'd really wanna see some pictures of that, in particular of the Y-pipe and the di-so merge...

Yes me too!!!

 

[Petri317]

Looking at the layout, one could build a homemade setup with an Autojet Y-pipe, a 3-4" adapter and get a similar setup, if not a little more efficient. I went with this kit because I don't have the welding/fab skill and the time to create a system, and I wanted to try this system. I've noticed a good seat-of-the-pants gain over stock, and I love the sound! My 2 cents.

 

[Petri317]

A pic of the system. Note;summit says the intermediate pipe is 4". It is not. It is 3" and then an adapter goes to 4" at the muffler.

 

[funnyman06]

how does it look on the truck? does the 5 inch tip look to big?

 

[Petri317]

The tailpipe is a little close to the rear tire, but I think the tip looks fine. Tuesday I will have pics and hopefully video/sound.

 

[LCAM-01XA]

Actually, the pipes that form a y are 2.5" (like the factory) till the intersection, at which point the pipe becomes 3". This is the same setup I had with an Autojet y-pipe on a previous truck. The Y-pipe has clean, unkinked bends and should flow better than the stock pipe. I laid them side to side for comparison and measured outside diameter.

That's a bit odd, as my y-pipe sure looks like 2" diameter, tis 2.5" from the merge on, yes, but the individual pipes ain't nothing even close to that! I run a straight pipe all the way to the back, so that takes care of the flow compared to the stock setup, but still...

 

[Petri317]

I guess I retract my "like the factory" statement. In any case, I can tell you, the Dynomax y-pipe is DEFINITELY better than the stock one.

 

[zpd307]

so napa sells 4 inch tailpipes? i am assuming they sell 4 inch straight pipe also.