TheBigGrabowsky

Does the Dynomax system fit a standard cab truck?

I'm probably the minority here, but I want to retain the V4 function. I'm averaging 19.5 mpg right now and most of that is due to keeping it in V4 as often as possible.

Borla uses airflow simulation software to design their exhausts. You are only speculating as to what the small bypass tube is doing. The only way to mimic the Borla correctly would be to use the exact same tube diameters, lengths, muffler type and size, etc. If someone could measure the following on their Borla I will be the guinea pig: 1. Tubing size (including bypass) 2. Flapper size (stock 5.3 or 6.2 version? ) 3. Muffler length, width and height.

You know, I'm a little irked with the exhaust systems on our trucks. GM really made it difficult to make a nice sounding system. It looks like our only options are the GM/Borla exhaust for $1300, but which is not really much louder than stock (so I hear) or a custom setup which will cause the truck to drone in V4 mode. That's lame. Using a tuned flapper to phase cancel the V4 exhaust pulses was pretty ingenious for the stock setup, but once you change the back pressure the flapper will not "flap" at the proper resonance and will basically become a noise maker. Borla seems to be the only ones who figured out how to replicate the flapper on a less restrictive exhaust and unless your local exhaust guy is a fluids engineer, you're not likely going to find a better solution.

Has anyone just removed the factory muffler, but left the flapper in place? I see people saying if you leave the flapper in it will sound stock, but I have a hard time believing that a loose fitting metal flap can do the job of a factory muffler just as well. I'm pretty close to just doing a muffler delete and leaving everything else stock. Makes the most sense to me if it gives me a nice growl when on the throttle, but keeps the V4 chopper to a minimum.

I hope you guys are certain those nails aren't going to fall out. If that mod gets really popular and those nails aren't in there solid then we're going to have an epidemic of nails in tires. Personally I'd just pay an exhaust shop $40 to cut out the flap. Even with it open it disrupts the airflow and creates unnecessary back pressure. This engine has to push through tiny exhaust manifolds, then 3 cats, a flapper and a muffler. Let that baby breath!

I'm doing the exact same setup on my black 2015 Sierra. Only thing is unless I find someone selling the Carbon wheels used, I'll be buying copies...which I hope are as good a fit. The 3/5 drop and those tires look perfect...exactly the look I'm going for, however I know those tires would rub on a 4/6 drop, so do they rub on your 3/5?