The exhaust system on my truck consists of The Other Guys headers, factory cats re-piped to 3", a 2.5" balance pipe, and a pair of magnaflow 3" in/out 5x11x22" mufflers.
I have run this system with dumps right off the back of the mufflers before the rear axle. That sounded clean and smooth, but VERY loud. Resonance, believe it or not even with an SUV, was not bad.
I have also run it with 3" tailpipes exiting in the stock location through a pair of 4" Stainless tips. This was quieter but resonated. It somehow also added raspiness to the exhaust. I didn't like the way it sounded outside with the pipes on so I would run it with just the dumps even though I hated the loudness.

I figures out at some point that the closer the pipe exist is to a muffler the less resonance and rasp the system will have. It has to do with echo and harmonics of the tubes themselves. I've also grown tired of exhaust sound and the way tips look. I like symmetry in a vehicle and both exits on one side bothered me a bit. Tips are just too blingy for me any more. I wanted to run them out the back, but not Yosemite Sam style. I think trucks with pipes sticking straight out the back look like a wheel barrow. I wanted something tucked up under the rear quarters with turndowns. Those needed to be snubbed bologna-cut for a factory look and as inconspicuous as possible.

The mufflers added to the tailpipes are Magnaflow 3"in/out 4" round by 14" long stainless units. I am using them to cancel out the harmonics.

This is what I ended up with:


Since both pipes must run under the passenger side like a pickup due to fuel tank location, I figured the best way to balance over-all length was to cross the banks over behind the mufflers:


The final result, eye level: (Sorry for the darkness, it's been a long day.)


Ground level view: (I wanted symmetry and think I got it.)


For the piping, mandrel bends from Summit along with flanges and gaskets were used. The turndowns are just more mandrel bends but carefully templated and cut to get the desired look. The hangers are the factory steel-encapsulated rubber types ordered from GM Parts. To make the hanger hooks I used 1/2" barstock from Lowes bent as needed with MAP Gas. The finish welded pipes are coated in Rustoleum Cold-Galvanizing compound (93% Vinc) and topcoated with black barbeque paint.

Sound volume has been drastically reduced. Exhaust tone is even lower now. The rasp is gone and it's never sounded more smooth and even. I've been on a quest for a long time to find a quiet good-flowing combination and have finally got something I'm happy with.

Here's a video:
http://bertok.us/pics/new-tailpipes.mpg

If you have an SUV and need a massive free-flowing system that you don't want too loud, this might work for you too.

 

your hoe is sick man. love it

 

what kind of times are you running?

 

I honestly don't know. We were set to go on January 14th, before the dragstrip at CA Speedway got tore up, and it RAINED. Now they're moving it to the other side of the complex. It'll be a while before it reopens.
Judging by the types of vehicles I can keep outrun and keep up with, I'd say it's mid 13's. It badly needs more displacement. I've reached the limit of the factory shortblock.

 

your Whipple wounds sick

 

The exhaust and the whipple sounds damn good!! Off topic but where did you get that 130MPH cluster from?

 

Looks killer man, that's hard work doing it on your back

 

Thanks,
The Cluster face is from a 1998 Police Package Tahoe. The electronics are from a 2000 Tahoe Limited. The Police electronics are incompatible with the standard-issue PCM signaling, so combining the two and then calibrating for the scale was my best option and has worked out well.

 

I thought the police package tahoe for that body style (RPO Z56) was only 99' and 00'? The cluster is part number 16265075 and one dealer still shows one available. Connel Chevrolet in Costa Mesa California. I've done this swap for the 100 to the 130mph speedo in a few trucks. At one time i had 3 of these clusters still brand new in the box. As long as you provide power to terminal number 2 to the cluster connector everything should work fine. If you try to do a plug and play without putting power to that the tach and speedo won't work.


For the topic at hand, nice job James. Your setup kinda reminds me of the b-bodies how they came out with a slight turndown from the resonators. Looks like alot of cutting and welding to get them where you wanted. Good job.

 

Wow, excellent information. Thanks!
It says on the back of the PCB "'98 Police", but you're right. If I recall, I vin'd a '99 to get it.