Centexguy

I've read through nearly every thread on here and all I've found is vendors claiming theirs adds power and using their charts. I don't trust vendors dynos. I'm looking for individuals who have done any sort of testing on a dyno or a track with an aftermarket cat back. I know the downpipes free up power and have seen a few members report 2 tenths gain in the 1/4. But nothing with cat backs. I'm just having a hard time swallowing that a cat back with a straight through muffler (like our factory one) has THAT much better flow. Especially since our cat back's are what, 2 3/4" and have 1 bend in them from the factory.

I'm debating on how to finish my exhaust off now (offroad down pipes, stock resonator, no muffler) and unless I can find some actual data showing a catback behind an aftermarket downpipe actually gained power, I think I'm going to put my stock muffler back on and be done with it. It'll be nice and quiet but the turbos will still sing and it will still flow very nicely.

RockhoundF150

Better downpipe and removing the cats is your best bet, in most cases, unless there is some wild bend after the cat. Just my experience in the past with turbos.

Centexguy

Got the cats taken care of. Just need the cat back and I'm really struggling with dropping the coin on one if its just for noise and there is no power gain. My experience with turbo charged diesels is the same. The stock exhausts with a straight through muffler will flow more than enough air for 600hp so the 4-5" systems are a waste of time and money.

HoustonRider

the cat-backs USED to be about the flow and the mandrel bends (and the diameter of the pipe) when OEM pipes were choked down and the bends had big kinks in em. not so much anymore. With the mufflers flowing like they do, I don't see how any cat back could be noticeable.

klumb15

https://www.f150forum.com/f70/new-of...59311/index28/
Post #275

https://www.f150forum.com/f70/ecoboo...62637/index51/
Post #507

It's 6 to one and a half dozen to the other.

I noticed a little bit with mine but it could just be the placebo effect. I plan on selling my catback in the spring in exchange for some downpipes mated to the stock catback.

Centexguy

Did either of those tests have aftermarket down pipes? I think vtechkiller does but can't remember. Maybe he'll chime in.

curtk69

agrees x 10
the big three bean counters have obviously noticed how many people want more power and better sound and get it anyways from aftermarket, and thus factory exhaust and stereo systems have improved fantastically in last decade to the point some vehicles cant really be improved for more power, just sound.
.

if you really want more power from your exhaust, you probly need to do a complete tuned system starting with long tube headers, hi flow cats and flow through mufflers , properly sized mandrel bent pipes for optimum tq/hp all topped off with dyno tuned a/f ratios for the computer.
this mite end up costing 2-3000 but then youd know for sure you got what you paid for instead of just hit n miss and actually a lower peak tq in favor of slightly more peak high rpm hp.

Centexguy

When I'm running 9s and spinning 8000rpm I'll look into that haha

jcain

They'd be the shortest long tube headers, known to man, on an ecoboost truck......

02reaper

iTrader: (2)

I think the 2 biggest kinks in the f150 system are the small y-pipe, and the 2.5" pipe coming into and going out of the resonator. Other than those 2 things, the system ain't bad.