[jonrjen]

4" vs 2 x 2.5" Exhaust for flow, performance, sound which is the better way 2 go?

OK, been reading a lot of post on aftermarket exhaust. Seems that the preferred purchases have been with a 4" exhaust pipe and larger tips.

There also seems to be some discussion of drone, which can be somewhat corrected or lessened with the use of a tip end baffle which will also give you back some of the loss of back pressure and lower end torque.

So my question is, which would be the better route to go with an aftermarket exhaust? With a 4" or dual 2 1/2" pipes. Would the duals maybe result in less possibility of drone? Would you still have that loss of lower RPM TQ? Would a side exit with both duals at the same exit point sound better than dual exhaust that exit with one pipe on each side of the rear of the truck?

I don't want a import performance sound, but I am also aware that I'm not going to get the V8 rumble from a V6 turbo or not.

Any and all feedback is more than welcome and greatly appreciated.

 

[m361]

I have the 4" Flo-pro catback setup. IMO the ecoboost just doesn't sound good loud and the drone was bad, so I added the Twister resonator. I also added the AFE stage 2 CAI. I haven't dyno'd my setup so I can't say what the numbers are, but it definitely feels like an improvement in performance. The resonator cut down the drone so I am happy with that. I should have my SCT tuner next week so I am looking forward to that upgrade.

I went with this setup mainly because it was affordable. I am one that never likes to pay full retail for anything, so I just shopped around for deals. I was able to get the stainless Flo-pro exhaust for $346 shipped ($379 retail), and the stainless Twister resonator for $88. I found my AFE CAI on craigslist new for $200 ($450 retail). The SCT tuner I got on ebay used for $260 ($379 retail). Total $894 for the everything ($1296 retail). Just gotta be patient and determined.

Best part is I was able to easily install all of these upgrades myself with very limited automotive knowledge which also saved a lot of $.

 

[jonrjen]

I was looking at the Gibson dual exhaust myself. It is an aluminum setup but in TX I don't worry about it not being stainless. However it is offered in both dual pipes exiting at the factory exit point or straight back and exits under the rear bumper one pipe on each side.

I guess part of my thinking it that most aftermarket exhaust are 3.5 or 4". Where as the Gibson is 2.5" but with being duals that would equate to 5". However there maybe a downside in the fact that with being smaller exit pipes it may raise the pitch of the exhaust. I guess worse case would be that I'm out $349 and a couple of hours installation time?

 

[jared]

I was looking at the Gibson dual exhaust myself. It is an aluminum setup but in TX I don't worry about it not being stainless. However it is offered in both dual pipes exiting at the factory exit point or straight back and exits under the rear bumper one pipe on each side.

I guess part of my thinking it that most aftermarket exhaust are 3.5 or 4". Where as the Gibson is 2.5" but with being duals that would equate to 5". However there maybe a downside in the fact that with being smaller exit pipes it may raise the pitch of the exhaust. I guess worse case would be that I'm out $349 and a couple of hours installation time?

2 2.5" pipes would be close to a single 3.5" I think a 4" is way to big for the kind of power these trucks are puti g down. For an otherwise ztock trucka single 3 would be more than adequate. A single 3 would support somewhere around 500 hp and 3.5 would do at least 700.

 

[jonrjen]

Thank you. Sound wise any idea which would have the better sound..rear exit vs. dual side rear quarter panel exit?

The website does make mention that the rear duals are not recommended for trailer towing due to the air flow between the rear of the truck and the front of the trailer (I assume that they are talking more travel trailer style trailer) could result in exhaust being pushed back toward the rear of the truck cab and enter the car through vent holes.

Where as this problem would not exist with the side exit exhaust.

I have no expectations of towing a travel trailer with my truck as I purchased it to be towed behind our motor coach.

Performance and sound are more of a concern in by book.

 

[jared]

Infront of the axle would eliminate several feet of pipe and 180º of bends. However it would be noticably louder Inside the cab. Both exiting on one side would sound better.

 

[13'TwinScrew]

I have the solo performance Mach-X dual...I also tow. I have not seen, heard, smelled, etc. any issues with the side exit set-up. I get compliments all the time on the looks with the dual tips. I also get a ton of compliments on the sound. Does it sound like a V6, nope. Does it sound like a V8, nope. It sounds like an ecoboost with a lower idle tone and distinct turbo whistle.

 

[jonrjen]

I have the solo performance Mach-X dual...I also tow. I have not seen, heard, smelled, etc. any issues with the side exit set-up. I get compliments all the time on the looks with the dual tips. I also get a ton of compliments on the sound. Does it sound like a V6, nope. Does it sound like a V8, nope. It sounds like an ecoboost with a lower idle tone and distinct turbo whistle.

I pulled up a sound clip of your exhaust, I must say that it is one of the better exhaust that I have heard.

Thank you for your reply,

 

[13'TwinScrew]

Thank you, I need to get a newer one up. It's been on now about 3K miles and sounds even better to me. It's deeper and even more mellow. I also am tuned now and it sounds great, I can hear the turbos under light throttle and exhaust at the same time.

 

[FordFan]

2 2.5" pipes would be close to a single 3.5" I think a 4" is way to big for the kind of power these trucks are puti g down. For an otherwise ztock trucka single 3 would be more than adequate. A single 3 would support somewhere around 500 hp and 3.5 would do at least 700.

4" is not too big for this truck. You got to remember this is not a natural aspired engine, it got to exhaust large volumes of air like a diesel engine.

 

[13'TwinScrew]

Until extra upgrades become available Full-race has some pretty convincing dyno's that say that 3" is optimal. That's not saying gains aren't made with 4"...just depends on WHERE you want to make them (up in the rpms, or lower in them).

A lot of guys running Down Pipes are showing some good track numbers and definitely making power (at 99 MPH runs). But there is a point where you can hurt power in the RPM's you might want it.

 

[AKSilverboost]

I am currently looking at the aFe Mach Force 4" exhaust. It has a great tone and will work well with the other aFe parts that I am looking at. And it won't hurt the bank account too much to get either.

 

[SkiSmuggs]

The Full-Race 3" catback is better quality than OEM, can be ordered with or without a resonator and kicks butt.
Ford F-150 EcoBoost 3" Cat-Back Exhaust System - Full-Race.com

EcoBoost - Full-Race.com