Magnaflow versus Flowmaster ~ Showdown on the Dyno

Figures.

 

that afr is not ideal, but hey you'll have good mpg till you melt the bottom end. lol what octane are you using?

 

Good. I was hoping not. Kink bends are no bueno :/

Those AFR's are horrible. Wow. Exact opposite of the 1GR OEM tune. (Really rich)

 

Yeah, except that's only at WOT under full load. All I run is just regular 87 octane pump gas with no additives. It's a work truck so the gas pedal never makes it to the floor except on the dyno. However, I am going to look into some kind of simple MAF control that will richen up the mixture, possibly the URD or something similar to it. That would yield some better dyno numbers.


Greg

 

Yeah, I know. My exhaust system is mandrel bent. I found the only guy in the area with a mandrel bender. He's highly skilled and did a beautiful job bending compound angles to get the pipe out the rear bumper. Even though it was a close fit, there's absolutely no banging bumping squeaking or rattling.

It is... and I'm going to do something to resolve it.


Greg

 

It's a testament to how well the stock exhaust is designed. The chambered stock muffler performs as good as a straight through Magnaflow. I'm just happy that I didn't do anything to lose the good low end torque.

This test does answer the question of an aftermarket muffler on a 2.7. You'll get better sound, but not better performance.


Greg

 

Depending on your definition of "better"

How does it sound? I know youtube vids don't really capture the depth so I try not to judge by them.

 

The Magnaflow does sound better than the stock muffler which makes almost no sound at all. This vid is pretty close to the real sound... very mellow, no rice, and no cabin drone. You can only hear more exhaust sound inside if you open all the windows.

https://www.youtube.com/watch?v=e2X9wPQE2Zw

Now I'm curious to see how the Flowmaster sounds and performs on the dyno. It gets installed this coming Wednesday. When its in, I'll post some vids of the sound.


Greg

 

That does sound good.

 

Knowing nothing about MAF and how A/F ratio, I just did some reading up on it and found that normal driving is closed loop where oxygen sensor feedback constantly adjusts the fuel trim. So in normal driving, nothing is going to get damaged.

It's only in wide open throttle that the engine operates in open loop where the O2 sensor is ignored and the factory set fuel map takes over which is lean because of my intake and exhaust mods. Since that happens so seldom and is of such a short duration, the only affect is that the engine makes less power at WOT.

So I don't think I need to do anything about it unless it's just to get some better dyno numbers. My OBDII scanner indicates that nothing is out of norm on the fuel trims and there were no pending codes triggered by the WOT dyno runs, so all is well.

If I'm wrong about this, please don't hesitate to explain as I only know just the little I've read so far.

Greg

 

You'd be surprised how often your engine goes into open loop.
Pick up an Ultragauge and watch it run for a while.

You are in open loop on cold start until the engine is up to 180 or so... I'm still in open loop in the morning when I'm accelerating up the onramp.
You are in open loop well below WOT... it's all about engine load. I'm not sure exactly where because I don't have a load display configured, but I'll see it kick into open loop when climbing a grade from time to time.
You are in open loop during deceleration when the throttle is closed and the engine is below around 2200.

During decel it's not a big deal... I'm pretty sure the kick to OL on decel is so the ECU doesn't register a fault during injector shutdown... and you aren't under load anyways.
But for cold starts and high load conditions, that is the last time you want the mixture to be running lean.
I'd throw a MAF calibrator on there ASAP after seeing that dyno run.

 

I agree with Rich.................. Its repeated many times about open loop/WOT like they are 1 and the same.

The truck is in open loop WELL before WOT and is load dependent, not pedal/plate dependant........... I see open loop often, and trust me if I only seen it at WOT, Id have no tires in a days work

jeebus those numbers (AFR) are spooky............ have a baseline dyno?

I swear I read n/a 4.0's hitting 10:1 even............. Im unsure about you I4 guys tho.

 

10:1 is really fat, especially in today's environment. I've seen bone-stock Harleys running 18:1... it's no wonder they pop and run hot when the owners add pipes. I tweaked the tune on my Vulcan to add about 5% more fuel than the stock tune when the throttle is at less than 10% and the RPM is above idle to prevent popping on decel.

 

hence the "my fender is black" "soot all over my bumper" "soot on tip" threads.

Even with all my parts, I still bury 10:1
Im hoping to lean it up with the smaller pulley someday

 

Subbed

 

Since I have an adjustable FPR, and my AEM wideband only reads as rich as 10:1, I couldn't tell how much richer it was actually running. I lowered the fuel pressure lower than stock (43.5 psi). Now at WOT in the high, it stays in the area just above 10:1, around 10.3:1, and runs much better. It stays in the 11's until about 4k, then richens mod til redline. A nice mechanical improvement, but not enough change to make it have a CEL, for fuel trims being off to far.

 

When the engine is warming up the mixture is metered rich like the choke on a carburetor, that's why it's open loop, so I don't believe that's a problem.

What the dyno doesn't show is the A/F at loaded engine/partial throttle conditions. Next dyno test I'll do a run at partial throttle just to see what's going on. I don't want to jump and buy a bunch of expensive stuff until I'm absolutely sure that I need it.

Exactly. Decel A/F can't be a problem because the butterfly is closed. And when DFCO kicks in above 1,400 rpm the A/F is infinity/zero with a negative engine load.


Greg

 

Good convo in here.

I haz 4 kink bends in my pipe aft my muffler which is the same 22 inch mag you've got. Will be changing that when URD/Gadget releases the 12+ urd headers

what it looks like now... Great high clearance tho!

 

can't wait to see the Flowmaster. I always loved them back when I had hot rod cars..

 

Same here...
The Flowmaster goes on this coming Wednesday. I'll take some videos. It'll be pretty tame sounding as it's a 50 series Delta Flow on a full exhaust system. But I am curious how it will sound in combination with a long tube header.

I'll likely run it for at least a week, and then dyno test it to see of there's any difference. The Magnaflow dynoed so close to the stock muffler, I'm guessing that the Flowmaster will do the same. If each muffler can only make a difference of 3 horsepower on a 370 horsepower Mustang, it's likely to be less than 1 horsepower on a little 2.7!

The fun part about this is finding out.

So many people badmouth Flowmasters, so I want to see for myself if there's any real world performance and sound difference. I believe that most of the problems arise from making poor choices on which model muffler to use for each application. And also to answer the complaint that they don't flow like straight through mufflers on a flow bench pumping air through them. The flaw in flow testing is that the air is constant fan forced and not pulsed exhaust from an engine so there is no scavenging effect taking place inside the Flowmaster muffler... which is what it is specifically tuned to do. Defeat the scavenging and of course it's not going to flow like a straight through. (duh)

I watched all of the Flowmaster youtube videos, and nearly everyone with 4 bangers runs 40's (a bad choice, they're NOT recommended for 4 cyls, or even 6's) which are pretty damned loud. Because of this, the 4 banger videos sound absolutely dreadful. Or if the video is of a 50, it's a single in/dual out. On a 4 cylinder that setup sounds raggedy because there's just not enough exhaust there flowing through the two large tail pipes.


Greg