[quote=IlikeHummers][quote=HUM GOOD]I ran a catback Borla set up......also borla short headers. The sounds is very quiet on the highway and screams when you step into it. I went to a friends shop and install it on his lift. Time was about 2.3 hours. Very simple. The performance wasn't much...just sounds badass. After K&N cold intake, Granatelli MAF sensor, & Granatelli power tune - now it doesnt only sound mean, it is mean.
Thanks for the info looks like a nice exhaust system. Is there a lot of drone in the cabin? or is it pretty mellow at crusing? Also is the Granitelli tune similar to superchips or hypertech? I was looking at the Zoomers exhaust because it's a true dual system with an X-pipe. I heard them at my dealer and I really liked the sound. Has anybody got this set-up?
Linky:
http://www.zoomersexhaust.com/truck_...ack_hummer.asp
Can you get system with headers and catbacks? If you are just buying a dual exhaust system You could most likely have a performance exhaust shop make duals for less using 2 Flowmasters set side by side on edge running on right side where factory is. Run 3" to mufflers and 2 1/2" going out and over axle. I run the loudest flowmaster mufflers which are super 40's and it sounds like it will eat everything alive at idle. But, i had exhaust tips run in stock location all the way out the back but tucked up high pointing slightly down like factory so the heavy reverb goes on out back instead of coming inside which will turn your insides to jelly. Flowmaster has regular 40's and then quieter 50's. As long as i drive around normal it has a really deep sound which is hard to hear with the other 2 mufflers unless windows are cracked but, heard inside with windows up on super 40's and sounds just right to me, like old muscle car days. When you romp on it just a little everyone looks.
If You are wanting catback system spend the money on Dynatech long tube headers with catbacks all stainless steel. Then have shop install them and do the above suggested exhaust setup out the back instead of a premade that will most likely be clamped and leak later. With the hand built unit it will be welded and not likely to vibrate loose and rattle. The long tube header will help your lowend. You have the increased air flow now but, will do little good if you do not do something to get the exhaust away from engine.
If you are wondering if you need aftermarket catbacks ask your exhaust shop to torch a hole in pipe just in front of catbacks from factory and he should have a gauge and tube that he can stick in the whole and start engine and read back pressure from factory catbacks. You should be able to call maker of what ever catback you would like to buy and ask them for the number their unit reads on back pressure in front of their cats. Keep in mind the numbers need to be apples to apples and oranges to oranges. Number should be either from both cats reading with stock exhaust manifolds or both with same brand headers. Long tube headers will read differently than short tube headers.
For tuning just get a handheld tuner. It will tune and change speedo to match any tire change. You can tune to use different octane.
If You want a granitelli MAF make sure You get one already cold air calibrated or you will be wasting your money. I have my engine loaded up and still use factory MAF. It does just fine and that is checking it with laptop tuning software. It has enough range and sensitivity to work with system until You start going over 5 or 6 lbs. of boost. Then you have to use 2 bar density software which just let's you remove MAF and tell computer the air flow you want it to think it is getting as a MAF is not made to read with boost once it starts getting over 5 to 7 lbs. When i'm running a 10 lb. boost pulley the MAF is just going nuts so it requires a more special tuning software and then 3 bar density when we push boost to 18 lbs. and especially if we go to 20 lbs. of boost.
Any questions PM me. What i'm working on to get many people to understand not this forum in particular as many already know this but, do not change things without knowing in what order to do it and for what reason you should do it for. Having a stock system and adding a Granitelli MAF will not do much. I know because I tried it and learned a good number of years ago with My screaming 99 Silverado that You have to spend the hard earned dollars on the right stuff for the right reason.
One of the first things You should get is a handheld programmer to add power that stock system will handle but, mainly You can adjust shift points and firmness on tranny. You can adjust speedo if You decide to go with bigger tires or raise the redline limiter on tach. It is the tool that will give You the most use and then the next thing like exhaust will benefit from already having tuner in Your pocket.
Good Luck!!
TAZ