Dynomax Ultra Flo System

[SnoKing]

Has anyone installed the Dynomax Ultra Flo System 4" exhaust? This is a cat back system. Well new trucks don't have a cat, but you get the point. My kid can get me a deal on the kit. Snow King

 

[JHansen]

I have it!

Part # 19335 for the kit-comes with a Dynomax Ultra Flo muffler, 4" mandrel bent tailpipe, nice chrome tip and all the necessary OEM-style hangers and clamps. It replaces from the resonator back-I went to the local exhaust place before I started the install and got a piece of 4" pipe and a 4"-3" adapter to change that out too. Everything fit pretty good-although it's tight around the spare with that big pipe-tight enough that I don't think a 285 would wedge in there (my 265 almost touches). I also spaced the front muffler bracket out away from the frame for muffler clearance-the OEM one has a clearance dent that the Dynomax doesn't. It may have cleared anyway-but I wanted to make sure.



As for tone I don't really have anything to compare it with-there's a couple guys close to me that have the BD kit but I haven't had a chance to listen to their trucks. It's deeper but by no means obnoxious. And the turbo whistles in the pipe just like a Class 8 truck! I do have some resonance in the cab between 2000 and 2200 rpm similar to what others have reported with different exhaust systems-still working on that. Either it's gotten quieter or I've gotten used to it.



Jason

 

[SnoKing]

Have you thought about putting the resonator back on to see if it helps with the resonance in the cab? What about mileage increases, EGT or noticable power increases? I can get this kit for around $160. Snow King

 

[JHansen]

Naw putting the resonator back on really isn't an option right now anyways. From the research I've done on here it doesn't seem to make a difference-some guys without a resonator get away with no drone, some guys with it get it. Different trucks maybe have a different resonant frequency for the cab? I dunno... . I'm going to add some Dynamat or equivalent to the rear cab wall per other's experiences first. I'm leery of wrapping the system with high-heat blanket as others have also done just for the fact we see snow pretty much 6 months out of the year-I think road salt would get trapped under the blanket and make short work of the system. May still add a piece of flex pipe in the headpipe to see if that fixes it too-apparently that's been successful in some cases as well. That'll be my last resort though.



I never really noticed that much of a power increase (I have an EZ and the silencer ring/intake snorkel pulled as well)-hard to tell really by the seat of my pants. Pretty sure throttle response got better though-but I have no way of quantitavely measuring it. EGT's drop faster at cooldown-again though I didn't have my pyro installed to pull a load before the exhaust went on. Empty driving though it may have made 25-30 degrees F difference. Again I never noticed any mileage increases, although my job entails a ton of start-and-stop driving which really isn't spectacular for mileage. Hoping to get a chance in the next couple weeks to take a highway trip to get some mileage figures to compare to what I got when the truck was new...



Interestingly enough when I requested info from Dynomax about this system before I ordered they stated "a minimum of 12 hp gain, 25 foot pounds of torque increase and 100 degree drop in temperature when towing". This from a tech advisor who returned my e-mail.



If you can get it for $160 I'd go for it! Mine was close to $500 CDN-for me it was still cheaper than the alternatives. Sorry I can't come up with any better hard-and-fast numbers for you though... there is at least 1 more guy on here that has the same system-hopefully he'll chime in with his experiences. Believe his username here is RBallard? He's on the DiRT mailing list which I'm also part of-I believe he even has a . wav file of the exhaust in action. How 'bout it Bob?



Jason