So I took the plunge and ordered a MPT SCT. I also ordered 2x94136 High Flow Cats (one of mine is gone). I wonder with true duals and the new cats what kind of gains I would see. Whatever the case Im sure that it will run better than it does now.

 

Hi & congrats!

Wellsir, if yer existing cat was plugged, it'll run a LOT better e'en wiffout a 'grammer

True duals ... er not much there I'm afraid ... and if not sized correctly you could be losing low-end grunt.

99% of the gains you will feel will be as a direct result of the custom calibrations.

You are gonna datalog, right?


MGD

 

True duals? Bupkis. No tangible gains to be had there. You might think there is because it'll sound faster, but it's a placebo effect. However, you may notice a slight decrease in torque if yer true dual pipes be too big arayound. 2.25" be plenty. No bigger'n 2.5".

High flow cats? You may be able to notice a slight differ'nce yonder, but it'd be just that - slight.

Far and away, the most tangible gains you will realize will come from the tunes. Ye di'nt 'splain whut kindly veehickel ye gots, but I'll assume from yer info that it's a 2005 with the 5.4? If so, seems like I recollect seeing "after" dyno charts on the MPT tunes for the 3v 5.4 where the increase in HP was ~ 25 and aboot 35 more ft lbs of torque? Maybe a feller with actual experience with MPT's 5.4 3v tunes can confirm?

Did you ask Mike at MPT what you could expect in the way of gains when you ordered yer custom tunes?

Either way, you'll like what you hear with the exhaust, but you'll like what you feel with the tunes! Neither of those are bad things!

 

Wow! Do great minds thank alahk, er whut? Looky lahk we's a-typin' tha same thang at tha same time!

 

The exhaust was already on my truck when I bought it. I was thinking about about changing it anyway but that will have to be later now lol. Yeah I will be datalogging

 

MGD

______________________________

 

I didn't notice much from long tubes, no cats, and custom tunes. BUT your truck will run much better and sound great now

 

So what is the best exhaust setup. I guess I read wrong in thinking it was the true dual.

 

Simple. If you want to retain yer low-end grunt, stay stock. The stock system is all stainless and mandrel bent (mostly). The huge muffler internal volume both keeps it quiet with no drone and preserves torque.

One other alternative:

"In fact, I did some dyno-testing on my '05 F-150HD, stock pipes with a 2.5-inch straight thru muffler added vs a full 3-inch cat back. The muffler change gave 3/4 the performance gain of the full system for about a third the cost. Stick a nice tip on the stock tailpipe for window dressing and you get a great performance/dollar ratio."

Above excerpted from this thread: https://www.f150online.com/forums/ex...ep-single.html ---- Post # 14

Anything else you do may hurt perf, may be louder, may sound like crap (e.g Fartmaster), may drone, WILL be more expensive - a combination of any/all of these is entirely possible - and in the case of POS Fartmasters, be entirely true on all counts

Save yer money - noise pollution added by punks wif fartcans (or Fartmasters, or No mufflers) is disrespectful of others, anti-social, rude, punkish and Soooo 20th Century. Time to grow up, kids.

[ It's almost as bad as running NO cats at ALL, which, aside from being Federally illegal, regardless if you have local e-testing/inspections or not - is the penultimate act of stupidity and ignorance as it offers NO perf improvement and can actually Hurt perf by taking needed heat out of the exhaust system (heat promotes scavenging - yes, really. Dint know that? Shame on you) ].

MGD

 

See yeah thats the thing, the folks that had this truck before more kind of butchered. Here take a look at these pics.

 

Sorry for the crap pics, it was pretty cold when I took them.

 

Hi.

So - looks like 2.5" pipe all the way (?) with no crossover of any type (not good) and chambered mufflers - either Flows or knockoffs (also not good).

Y'know what sir, this is gonna be a chunk o' change to reconfigure whichever way you go next, so I gotta ask - does it sound and perform okay by you?

If so - just run what you have and pullstart the ol' piggybank, while you take yer time and do some exhaustive ( pun intended) research on exhaust alternatives, while accumulating funds.

The very best is all mandrel-bent stainless ( 2.25" fer the best low-end grunt), Dynatech longtubes, highflows, X-pipe and Borla (or Maggie ovals: cheaper). This is gonna use up 1.5-2k depending on the shop, yer location, any deals, etc. Just as a reference.

The alternative and much cheaper route is to partiallyl restore the 2-into-one config; Maggie y-pipe after the cats, into an intermediate pipe, into a 2.5" Maggie oval SI/SO ( or SI/DO ) and exit as you prefer (refer to Jim Allen's post above ). Tailor muffler length to suit yer sound preference - longer being quieter.

Bear in mind - these are my thoughts - exhaust preferences are a VERY personal thing - and can sometimes acquire near-religious fanaticsm and incur somewhat *cough**cough* "vigorous "debate

Hence the entreaty to do ye due-diligence research - as long as that takes. Yall want to try and nail it right, the first time.

MGD

 

Yeah thats what I figured you were gonna say. Right now it does ok but it sounds like complete crap when you rev it up. Idling its fine. I guess what I can do is just get the HFC's installed see if that helps and then do a 2.5"in/3"out y pipe to a 3" intermediate pipe to a 3" SI/DO and be done with it. I didnt realize how bad it was until I got up under there and looked.

 

I really wouldn't go about changing a bunch of things looking for performance. It's quite difficult to notice a few horsepower on a 5k pound truck. If you're gonna do it, do it for the sound, and just hope there's some performance there as an extra.

 

Welp I got my HFCs and the canned tune installed this weekend. Quite a large difference in sound and performance. The truck is much easier to drive now and the throttle response is leaps and bounds better than what is was. I will say that I am interested in seeing how much of a difference MPT is going to make with their race tune that I requested. It should be interesting.