2004 6.0 NV4500 Tahoe

[Dantheman1540]

View attachment 345155


Do you have any sections of your exhaust that are relatively long and straight, like parallel to the driveshaft, in front of the axle? Most J-pipes come off the main pipe and immediately turn 90° and run parallel to the pipe. Makes for a much tighter package and less turns. Turns alter the tuning frequency since the wave is slowed and slightly altered with every degree of turn.

Right after the Gibson but before the 4" v band and over axle pipe I think I could fit one and have it make a direct 90* then head straight back to the front of the truck. I was specifically targeting the 1,500 rpm range with this pipe so I didn't expect any help above that range. In fact i think it's probably 2 inches longer than needed which explains why at 1,350ish it's dead silent. Gonna run the math in a bit and see what I need to kill the 140hz range at 2k.

Biggest issue I had doing this was that hole saws are my nemesis and I broke all 3 pilot bits before I got anywhere with the hole in the 4" exhaust. Ended up cutting a octagon with a cutoff wheel then used a small grinder wheel to round it out and a hand file to clean up the last bit. If I do another one I may try 2" and get a smaller hole saw or even a giant 2"drill bit which I may have already.

 

[Dantheman1540]

So to target the 2,100 rpm range at 360* exhaust temp which is what I measure before but could be slightly higher right there coming out of the Gibson, I come up with about a 29" pipe. I'll probably measure what I have left of the 3" and if its close Ill do it nd see how it goes.

 

[Dantheman1540]

Got crackin on the second j pipe, targetting 28" I had to use a bunch of pieces from the old dual 3" over axle pipes and it was difficult to get any long straight pieces. Welds were decent still and I remember to turn the gas off this time

 

[pwtr02ss]

Welds looking great!

 

[Dantheman1540]

Welds looking great!

Thanks this stuff is easy, I still want to switch to the .030 wire instead of the .035 I'm running now. Super pumped to start some evening welding classes in Aug, I want to learn TIG so bad!

 

[OR VietVet]

Gobs of years ago I had a friend that knew a guy that was supposedly so good with TIG That he could weld aluminum foil together. I never met the guy or saw his work but there was a couple other guys I knew that said they saw it and he was that good. I just don't know if I bought it. Just like fishing stories where the fish gets bigger with each story, we were bench racing and that may have had something to do with it.

 

[randeez]

Thanks this stuff is easy, I still want to switch to the .030 wire instead of the .035 I'm running now. Super pumped to start some evening welding classes in Aug, I want to learn TIG so bad!

you need to hurry up and learn, so you can teach me

 

[Dantheman1540]

Gobs of years ago I had a friend that knew a guy that was supposedly so good with TIG That he could weld aluminum foil together. I never met the guy or saw his work but there was a couple other guys I knew that said they saw it and he was that good. I just don't know if I bought it. Just like fishing stories where the fish gets bigger with each story, we were bench racing and that may have had something to do with it.

My neighbor can legitimately weld beer cans together I've watched him it's impressive, IDK about aluminum foil that sounds extra fishy to me. I mostly want to learn TIG so I can do more precise and cleaner welds. I feel MIG or at least my skill level with this budget machine cannot make perfectly clean welds that don't glob up. Its very enjoyable to take scraps of metal and make them into something, at least to me it is.

 

[Dantheman1540]

you need to hurry up and learn, so you can teach me

Trade TIG tips for rides in the Denali

 

[George B]

Right after the Gibson but before the 4" v band and over axle pipe I think I could fit one and have it make a direct 90* then head straight back to the front of the truck. I was specifically targeting the 1,500 rpm range with this pipe so I didn't expect any help above that range. In fact i think it's probably 2 inches longer than needed which explains why at 1,350ish it's dead silent. Gonna run the math in a bit and see what I need to kill the 140hz range at 2k.

Biggest issue I had doing this was that hole saws are my nemesis and I broke all 3 pilot bits before I got anywhere with the hole in the 4" exhaust. Ended up cutting a octagon with a cutoff wheel then used a small grinder wheel to round it out and a hand file to clean up the last bit. If I do another one I may try 2" and get a smaller hole saw or even a giant 2"drill bit which I may have already.

Regarding the hole saw. Drill your pilot with a standard drill first. Then you can use a piece of cutoff 1/4” bolt or round bar as a pilot.