Exhaust

6 LITERS OF HOW YOU DOIN · September 19, 2002

I'm not new to the board I was formally BDBWTE but because of this awesome forum it won't accept my password. Ahh oh well I'll get over it. Anyway I straight Piped my 6.0L and I love the sound and the top end performance. Then I hooked the truck to our 30' Cornpro Goose. With a the tare weight of the trailer being 5,600lbs. and the additon of a 4810 Posi Trac the truck was killing it's self to pull it. I pulled the same exact setup before the straight pipe and it did fine so. Okay I know the truck is over loaded and I don't need a lecture of pulling to much I wanted to know if that straight piping your truck de-nutts it at low-end torque and if so what is the best muffler to retain the low-end torque. Thanks for your time.

6 LITERS OF HOW YOU DOIN · September 26, 2002

Thanks guys for all of the kick ass wisdom you have to offer! I just can't thank you enough just tell me where you live and I'll mail you a check for your time! Thanks again!!!

Shaners · September 26, 2002

There is no doubt that straight pipes will move the torque curve to the higher RPM's. I think that is pretty common on these Vortec engines. Backpressure creates the lowend torque, so you weren't imagining anything when you said your truck wasn't pulling the weight as well as it did before.

Maybe a Flowmaster 40 series would help restore some of the lost/moved power, and still keep some of the rumble you love.

MarkD · September 26, 2002

I have heard good things from Magnaflow, but haven't heard or had one on our trucks. A friend has one on a '93 Mustang and it sounds SWEET!

This thread really has me thinking...Why change the exhaust on a Vortec engine? Sound improvement only???

CMNTMXR81 · September 26, 2002

I have heard good things from Magnaflow, but haven't heard or had one on our trucks. A friend has one on a '93 Mustang and it sounds SWEET!

This thread really has me thinking...Why change the exhaust on a Vortec engine? Sound improvement only???

Sound is a biggy, but so is power. When choosing a performance exhaust 1 must make some decisions.

1) How loud do I want it.

2) Where do I want my power to be made

3) Do I want to sacrafice power elsewhere.

Why change from the stock system you ask? Cause the stock system is so restrictive it's rediculous. Take a straw and bend it up 10 different directions and try blowing through it. Chances are it's fairly difficult if not downright hard. Now blow through the straw straight. Big difference huh?

Same can be said about an engine. An engine is nothing more than an elaborate air pump. By uncorking intake and exhaust restrictions, you allow the engine to breath more efficiently, which in turn increases the engine's ability to make more power. The mufflers themselves don't add power.

With that in mind, removing the stock 7, 8, 9+ chamber "muffler of death" as I call them to a two chamber or straight through design, will exponentially allow the engine to breath better, especially in conjunction with opening up the intake system allowing the engine to make more power.

In some cases, such as the LS1's, where all out power is more important then torque numbers, running straight pipes or straight through systems is highly preferable to a 2 or 3 chamber muffler. No resistance, sheer volumetric efficiency allowing the engine to breath at it's maximum therefore allowing maximum HP.

In the case of LS1, Vortec style engines, where torque is a more favored part of the equation, going with a two chamber muffler may be preferrable as that slight backpressure provided by the additional chambering helps keep/improve the torque number while at the same time increasing HP over the stock sytem because of the free flow allowed by less chambering. Essentially it's a more balanced setup.

So there is benefit to replacing the stock mufflers....they ARE a big bottleneck and are too quiet.

MarkD · September 27, 2002

I guess what I am looking for is NO LOSS OF LOW END TORQUE. In a truck, a vehicle that will be used for towing, I would think that the backpressure created by the muffler would support low end torque.

6 LITERS OF HOW YOU DOIN · September 27, 2002

Seriously thanks you guys that offered your opinions I really do appreciate it. I don't mean to sound like a kid that pops off but I do speak my mine and I respect others that do the same. I realize also that I have some growing up to do but I still like being young.

I put a 40 series on the HD two days ago and it made a night and day difference in low end torque. But I also noticed declining gas mileage on the highway and less punch when at highway speeds. Over I recommend going with a muffler unless you just want to be loud. Straight she was very loud and rattled you and the truck at any speed above 50mph. with straights you will be noticed. ttyl