Magnaflow versus Flowmaster ~ Showdown on the Dyno

No offense, but try to use complete sentences when answering posts . I don't understand what you mean by no it's not, but I'm guessing your saying that dyno chart is not as advertised. Could you enlighten me then if you have some pertinent information, thanks in advance. I've read your build thread a few times and that's one fast MILF wagon jks, honestly kudo's brother, I bet most people don't expect your numbers when you hit the track!

 

I don't believe he has forced induction.

 

Sorry thats the "summer cold" talking. The dyno chart is of pulls from my truck, which is N/A not boosted. Also it was on a heavier and smaller wheel and tire set.

 

Thanks. I'll have to see if I notice a difference, I'm ordering the URD y-pipe later this week.

 

Got my old flowmaster setup put on the new truck, and took the advice from here & from flowmaster to replace my 2inch dump pipe with a longer pipe (12inch). It severely reduced the drone inside my truck. And love the "new sound" haha


Old dump pipe, I'll post the new piping tomorrow

 

port and polish? ramp and throat?

Isn't equal length the main advantage to headers? It ensures the exhaust pulses from each cylinder are equally spaced, which is better for exhaust flow and scavenging.

Yep, I was told a length of tailpipe is needed to smooth the flow after the muffler and maintain exhaust gas velocity. Again, better for scavenging.

 

The longer the pipe, the better the sound.

 

Oooh... I like gun talk.

You're absolutely right.

The time it takes for the pulses to travel to the ends of the header runners and to be reflected back to the engine exhaust ports is a resonant frequency. So the longer the runners are, the longer the distance for the pulses to travel. The longer the distance, the lower the resonant frequency. And the lower the frequency, the lower rpms get the scavenging affect.

Besides making the exhaust quieter, that added length of pipe also helps to prevent reversion, which is the tendency for outside air to get sucked back into the muffler instead of that same suction acting on the exhaust to pull it out (scavenging).


Greg

 

It depends on the engine.

Traditionally, for a 4-banger, the Tri-Y design was better for bottom end torque because the cylinders were paired on the first two "Y" segments as equal length, then those segments joined together at a distance where the out of phase cylinders aided in scavenging the in-phase cylinders.

LCE used to make a very well respected Tri-Y for the 22RE.

Purely equal length is ideal for high RPM operation.

 

My experience with the LCE long tube header was different.

On the dyno, it lowered my torque peak by 650 rpms from the stock peak of 3,800 rpms down to 3,150 rpms.

In contrast, on the dyno the short tube Doug Thorley tri-Y header raised the torque peak from the stock peak 3,800 rpms up to 3,900 rpms.

I would agree that an even longer tube tri Y header like the old LCE 22R would lower the torque peak more.

Here's a pic of a real long tube Doug Thorley Tri Y for the 22R...




Man, I'd love to have something like this on my truck.


Greg





Greg

 

Not sure where you are seeing a loss in torque? Maybe the starting point of the graph perhaps? If that is the case, then it is simply that they starting the pull at slightly different RPMs. Correct me if I am wrong in my interpretation of your understanding.

If you follow both the hp and the TQ curves, you can see a definitive split where the HP and TQ stay more level with the Y-pipe. Whereas the curves of the OEM y-pipe fall. At the end of the pull, there is a huge difference of gain between the two y-pipes. Hard to tell on my phone, but close to ~30 ft-lbs gained and ~20 whp. That is significant.

 

Ask Gadget. I have a very strong hunch that he will say that his MAF controller will be able to do some closed loop tuning as well.

 

I saw the very slight loss in torque (~1% loss) when I looked at the max torque numbers on the top of his graph. The way it looks to me is that the torque curve is shifted towards the lower RPM's which to honest is where I want my power. I agree the y-pipe curve is overall better which is why I'll be ordering one as soon as I have the cash for it.

Again, I could be wrong, I also looked at the curve on a phone. I wish they could tabulate the results. That makes more sense to me than a curve but to each his own.

BTW Torspd I finally had a chance to read your entire build thread on a very long tip. You've almost tempted me to find a spare block and modify the piss out of it. I have a fiance though and I think if I spend that much time with my truck she won't be my fiance anymore . God speed good sir.

 

Just from looking at the URD without a dyno chart...




...I'd guess that it would enhance the torque.

The collector is moved further away from the engine making the two runners longer similar to making the longer runners on a tri Y header which makes for a lower resonant frequency. So the enhanced scavenging effect would occur at lower rpms.

Greg

 

Hey, Tor... will the URD MAF controller and a plug and play harness work on my 2.7 to correct the open loop lean condition? If it does help I'll be happy to get one then I'll have something else to dyno.


Greg

 

Not Mark, but yes it can. Now, problem is you will need a good AF sensor to monitor it to create the MAF cali maps, unless Gadget has a good map for your mods already.

Also on the question about closed loop correction and the MAF Cali. According to Gadget, the Cali can help in closed loop if your air intake is causing any induced MAF sensor error. How much this is though is unclear to me.

 

Actually, the biggest feature for me of the URD y pipe is that it is not flattened to fit the 4x4 drive train. The URD and Stock in your picture are 2wd versions and I'll be ordering the slightly different 4x4 version. On 4x4 Tacomas the stock has two flattened, and very restrictive looking, bends to get one side of the y pipe to fit around the transfer case and transmission assembly. The way figure it I am losing power on those 3 cylinders due to excessive back pressure on a supercharged motor and also not getting an even flow from both pipes. Those two things are probably robbing me of at least 5% of my HP and Torque I should be making me thinks.

BTW thanks for being great about me asking this question in the middle of your thread. I apologize if I've lead us off topic.

 

There's nothing to apologize for, dog...
I'm totally fascinated with everything about exhaust flow design, so this is right up my alley.

Greg

 

What you mean port and polish? And ramp and throat?

And I didn't think it mattered but it definitely has

 

Here's the deal with fluid flow (air,exhaust, etc)... When you're talking high velocity low density air, such as that coming out of an engine, the change in piping size would need to be more significant than a few creases from bends. From my fluid dynamics class, I could truly go back through my old notes and give you definitive % changes cause of size, but that's a lot of math and it's summer haha but if you're truly worried, instead of buying the headers, had a muffler shop piece together a minimum crease y pipe from the headers out. That way can not only avoid creases but also instead of the ypipe having so many bends, you can have 2 separate exhausts. Maybe have the left headers flow down and then out the left side and the right flow down and out the right, no conjunction or anything. Cause my knowledge of superchargers/turbos is you want 0 restriction and the best flow