Header+Exhaust HP?

Gooseslayer717 · September 9, 2019

I was looking for information on long tube headers. I have a 2011 1500 Sierra 5.3l Flex Fuel with the trailer package with increased intake. I have a tune i can use through Lew and cant decide on getting Long Tube headers or not and if it would be worth the hassle.

My Truck is a daily driver and i use it on the highway a lot. I dont want to lose torque but would like to get some decent numbers and feel like the stock headers and exhaust are restrictive.

Does anyone know the performance difference for just having a exhaust compared to having exhaust and headers?

Also would want to keep it below 1400$ total.

When removing header bolts is it common to have bolts break?

Jglew82 · September 9, 2019

In my opinion, it's not worth the cost if you are keeping it a reasonable DD. You can hang a high performance exhaust on your truck with the stock manifolds and have similar results. Also, longtubes CAN cause some tuning issues with O2 sensor latency, and also increased IAT's. Factory manifolds may not be the most attractive, but they flow pretty nice, keep the heat and noise down, and keep your O2's at their factory locations.

And yes, the bolts have a tendency to break on these.

CamGTP · September 10, 2019

Nice headers with cat converters also cost a lot of dough too. None of the cheaper headers come with cats and you want to keep those if you like your hearing. No cats will make the exhaust rasp without some sort of aftermarket resonator or j-pipe welded into to cancel out the noise.

The stock cat-back isn't really a restriction either when the engine is stock, because all the aftermarket system run the same size pipe. 3in OD for a cat-back is about as common as it gets. Do for the sound and make it how you want it.

Gooseslayer717 · September 10, 2019

So i plan on going with just exhaust then.

What are some mufflers that flow best?
Do i want a 2" dual exhuast. 2.25"? I would like to keep similar to torque/horsepower ration.

CamGTP · September 10, 2019

Put it this way, don't go smaller in diameter if it's going be a single exit exhaust. A 3in muffler will do what is needed. Pick your sound choice, I prefer the non chambered mufflers, so nothing flowmaster.

If you went dual exhaust after the muffler, then if both pipes are equal or greater than the diameter of the single pipe, it's going be be fine. Like dual 2.5in exhaust.