Twisted exhaust pipe--hurting power?

This is on my 4.2 V6 F150. It doesn't have a ton of power to begin with, so I'm wondering: is this costing me power, and if so, enough to make it worth replacing?

Depends on the power level you are extracting.

Power loss will increase proportionally to how far you press down the accelerator.

Really bad if you are towing.

Makes sense. 

What about mileage? I admit I was hoping for more a bit more than 14-15 mpg, especially with an electric fan, but maybe I was just optimistic.

I'm going with "You need to fix that." 

Don’t you remember the Engine Master? series on YouTube on the Westech Dyno when Freiburger smashed the E36 M3 out of a set of headers with a hammer.  The result?  More power.

A 401 CJ said:

Don’t you remember the Engine Master? series on YouTube on the Westech Dyno when Freiburger smashed the E36 M3 out of a set of headers with a hammer.  The result?  More power.

Agreed.  However, those pipes were each about the size of the one shown here.  I would cut it out and fix it.  I would also lobe to know how the hell that happened.

Will said:

Makes sense. 

What about mileage? I admit I was hoping for more a bit more than 14-15 mpg, especially with an electric fan, but maybe I was just optimistic.

Best I could ever get from mine was 16, and that was really being nice to it.

As far as the pipe is concerned, I wouldn't fix it.  You're only making just under 200 hp.  You'd have to do much worse to it to get it to really kill power.

The thing is, the only time that would ever affect power is WOT at redline, and how many times do you actually do that?

That's in a radius, where it is also reduced diameter, and you can tell it is not only kinked on top, but also on the opposite side, where it can't be readily seen in the photo.

I would replace it.

Best i can tell this is where it comes down after going over the axle? The cheap-ass in me says cut it off just before the axle and clamp a turn down on the pipe and be done.

I would fix it. I bet its necked down pretty small. 

Run the numbers.   How much will it cost to fix it vs. how much do you predict  you'll gain in fuel efficiency?

My guess is that it won't be worth it.  Even if you somehow gained 1 MPG from it, let's say you spend $30 in some new pipe, and then it takes you 2 hours to repair it.  By the time you drive 30,000 miles, you'll be just breaking even on gas savings vs. time+money outlay.   The numbers get worse if you spend more (time/money) to fix it, better if you spend less.

Now, one of the biggest things that improve MPG is psychology, so there may be enough placebo affect in play that if you replace it you'll be easier on the start/stop that you gain 2 mpg.   In that case, you're breaking even @ 15,000 miles driven.

I would fix it just because it bugged me and I would constantly be thinking about what effect it had if I didn't, ROI be damned.

A 401 CJ said:

Don’t you remember the Engine Master? series on YouTube on the Westech Dyno when Freiburger smashed the E36 M3 out of a set of headers with a hammer.  The result?  More power.

But on the flip side of the coin there was that episode of Roadkill where the kinked tailpipe caused their '50-something GMC pickup to overheat and spit out oil because the exhaust couldn't get out

TheRX7Project said:

A 401 CJ said:

Don’t you remember the Engine Master? series on YouTube on the Westech Dyno when Freiburger smashed the E36 M3 out of a set of headers with a hammer.  The result?  More power.

But on the flip side of the coin there was that episode of Roadkill where the kinked tailpipe caused their '50-something GMC pickup to overheat and spit out oil because the exhaust couldn't get out

A dented header pipe (high speed, low volume flow)is a little different than a kinked tailpipe (low speed, high volume flow). If it's an appreciable kink, I'd consider fixing it. 

Also, it probably happened because someone backed the tailpipe into something. 

snailmont5oh said:

 appreciable kink

Funny, that's the name of my punk/ska Pixies cover band...