Question about exhaust.

[Jackpine]

Nice post, Cody! Everyone can ignore my final comment about exhaust mods only changing your wallet! :o

- Jack

[cleatus12r]

Oh, and I wanted to add that YOU DO NEED SOME SORT OF EXHAUST SYSTEM.

Some folks think that open headers are awesome (and sound good ) but they really hurt performance until the exhaust pulses are often enough (read: high RPM) that there is no atmospheric pressure reversion into the collector or primary tubes.

An exhaust system CAN be too short and it CAN be too free-flowing. Don't get my original post wrong....I re-read it and can see where it might sound like I condone huge pipe that's only six inches long.

Unfortunately, tuning the exhaust is very difficult to do. To do it right, both pipes on a "v" type engine would have to be the exact same length and that's tough when both pipes run down one side of the truck. They should have equal bends (both angle and length) and we know that is impossible. There's always a compromise.

Jack, you're right, most aftermarket exhaust systems or custom exhausts are only for asthetics and sound....let's face it, if it doesn't sound bad-***, it probably isn't. Besides, factory exhaust is not visually pleasing. No disrespect meant to your last comment.

On edit:
The most disheartening thing I see when it comes to exhaust is the pipes people will have installed at an "exhaust shop". As a diagnostic rule, the new Chevy trucks are designed FROM THE FACTORY to have a backpressure to not exceed .5 PSI (one half of a PSI) of backpressure at full load redline. That is VERY LOW. It would be hard to beat that with ANY custom job. The factory pipes on the 2500/3500HD trucks with the 6.0L or 8.1L gassers are 3" and they go into a dual inlet/dual outlet muffler then "Y" into a 3.5" tailpipe that has nice, smooth bends over the rear axle. These people have the dual 3" Inlet/Outlet muffler removed and have two 2.5" pipes/mufflers welded in with tight non-mandrel bent pipe twisting all over the rear axle to avoid the spare tire. Under certain conditions, the backpressure in the pipes will actually cause a passive EGR effect (reversion back into the combustion chamber) and set misfire codes. UGH.

The exhaust from reputable companies (that our vendors sell) are good in the flow department and usually sound really good. Power wise.....maybe a little. But they do look nice with a polished stainless tip!

[Jackpine]

Cody, no offense taken at all! I was, as usual, being my normal opinionated self and making a broad, sweeping statement that could not possibly be right in all respects. You pointed out holes in it (in a very diplomatic way, I might add) while at the same time supporting other parts of what I said - you just said them better!

Exhaust mods were really a big thing back when I was young. And, you had to be careful with them. You run into many of the same problems I was concerned about in intake mods. Airflow engineering, especially in ducts, is a VERY tricky, poorly understood, science!

- Jack

[88Racing]

Two questions you should ask yourself:

1) How much noise am I or everyone in the truck going/willing to put up with?

2) Are you going to pull any trailors?

Fords are supposed to have quiet steel? On a real long trip the sound may get to you. Especially if your married. "I told you it was going to be to loud"

The trailer question is that it depends what type.
Straight out the back are good with flat beds and most of the time with "V" and round noses.
I would not recomend them when pulling flat nose type trailers such as campers. The sound echos back at the cab.

I recomend some system with side discarge then you don't have to worry about the above.

Lars

[88Racing]

Forgot to add this in.

How long are you keeping the truck?

I only ask that because up here up where I live some of the galv steel kits rot out in 3 to 5 years due to road salt. So I went with with stainless did not want to spend the money again. But it is easily justified if the truck needs a new look again.

Lars

[04FX4]

I am married and dont want loud. I also pull a Travel trailer. I think I will get a magniflow SI/SO.

[88Racing]

I have partial hearing loss and even when I put my first Gibson on si/do under the bumper it got to me after 90 miles of travel of a 450 mile trip. I was pulling a uhaul tandom cargo. The good thing the drone put the kids to sleep the bad thing was the ringing in my ears. After that took it off sold it to a buddy. Replaced it with si/do same side 2 outlets in stock location. Was alot better after that, wife was happier too! Noticed after I got married their opinion counts for a whole lot more.

Lars