Hey H2CANE. What color Hummer do you have?

Aftermarket exhaust versus custom exhaust. I do not see the difference between the two outside of price. They put different mufflers up so I could hear each one and they could talk to me about performance, back pressure and sound. So in the end I have a custom fabricated exhaust system full welds, reenforced hangers and a sweet sounding exhaust system. Aftermarket online for one I can clamp on and the left pipe goes under the air system and not bended for under by the body was 600-1000. Custom was only 490.00

 

SHADOW_____When I bought my Corsa first cat back for a 2004 GMC pickup, here is what I found. Nearly all of the cat back systems use mandrel tube benders, meaning the full diameter of the tubing is maintained throughout the entire radius of the bend. CNC mandrel benders run about $250K. Muffler shops use tube benders, which decrease/crimp the diameter of the tubing in the bends. The crimp can be seen as the small ripples of metal inside the curve of the bend. Also, all cat back systems are computer/CAD designed for flow, back pressure and sound. Either way, if you like the results and the sound then you got what you paid for.

 

Also, be advised that Man1nboat and myself are at altitude over a mile high. So what we do with our vehicles will be different than someone at sea level. Now there is also a conversion chart that most custom exhaust shops use that can show you the differences with certain setups for fuel economy. Unless you are running at 3500 rpms or more no matter the exhaust setup, cold air intake flow, and re-tuning your brain it does not change much at all since not many of us drive around at over 3500 rpms. After my custom exhaust I did notice a 1 MPG increase on the digital dash but you have to understand that there is better hand designed systems that will yield more gains. For instance a cross over pipe (x pipe) prior to going into the aftermarket muffler to provide slight more back pressure. I would go the route of speaking to a custom muffler shop and talking with them. They have the conversion book and can look up the other specs as well for retuning the brain and types of intakes that work best. I will post pics of my exhaust as well as a short video for sound. No "drone" sound that I have heard others speak of inside the cab. But then again, I do have a high end Audio Visual system inside. I will jsut take pics of EVERYTHING and post them. New rims and tires going on today. The new Dropstar offroad deep dish rims with fuel offroad 35 series tires. I got them all for 100 and my stock wheels and tires on trade.

Will post tonight.

 

Hey Shadow... Did you go to a shop for the wheel/tire trade? I am thinking black rims here.. Looking forward to the pics! We should hook up sometime.

Richard

 

Man1nboat, I see you used the Magnaflow 12909. That muffler features 3.5" inlet and 3.5" outlet. My understanding from another thread is that the H2 pipes pinch to 3" for the EOM muffler then back to 3.5" after. So did you get the whole 3" section cut out? I saw someone else used Magnaflow 12589 which is the same muffler but with 3" inlet and outlet.

Thanks!!

 

I am 3.5 all the way through...