longarm
Car sold back to original owners
Interesting test using Magnaflow mufflers.
below 3200 the smaller pipe is better... other than that on a 620 horse motor the 3" is as close to open headers as can be while the 2.5" killed 20hp. no real surprise there..
why don't they try it on a 350-400 horse motor? that would be more the regular guy type of power..
Those 2.5 inch Magnaflows seem very quiet. I think I want a pair. My chambered Jeg's can get tiring on the highway.
Two things come to mind with your statement.Why wasn't the jetting changed when the 2.5" system was showing rich. The engine appeared to like the open header A/F ratio. Kind of invalidates any comparison.
Hey Ho Whoa whoa whoa hey! Stop screamin at me.This isn't about me... IT'S ABOUT THE DATA THEY PRODUCED WHICH HAS A HUGE FLAW IN IT.
Get it! Carry on.
All this "Rich vs not rich" aside.
I'm curious how much of those losses they would have gained back with a H or X pipe.
An interesting episode for sure. Especially how little power loss there was with how long of pipe they had.
If you're ever wondering what exhaust to run on your setup. Consult this chart.
View attachment 1714936830
For the full maths, go here: http://www.exhaustvideos.com/faq/how-to-calculate-muffler-size-pipe-diameter/
It explains it all. But in short. A certain amount of horsepower flows a certain CFM. And a certain CFM requires a certain pipe size. Not really as complicated as it seems. I am going 3 inch on my setup. It's a lot. My 340 is really only going to put out 420ish horsepower. But I will be running nitrous. And with that I can definitely hit close to 600. Not to mention I will be doing head and cam work this winter and should end up in the 475 area N/A. 2-3/4 pipe being difficult to find I went 3 inch. Am I worried about torque loss down low? Not really. I'm going with an H pipe setup which should help balance things out. Going from manifolds and 2-1/4 to full length headers and 3 inch exhaust should make a serious improvement in my power. I'm curious to see what it does.
I don't know where this chart comes from, but if take 2 CFM per HP.
I can tell you most of these rule of thumb charts are wrong, and they err way on the small side.
Look at carbs. For DECADES people thought a dominator was too big for everything. Now they are on everything. The charts were always wrong. I don't put much into the above chart either.
One day, I'm going to retire and just do dyno testing. Just because.are you guys convinced these tests are legit?
The last one showed a 335 hp 383 with a cam,headers and intake change increasing the output by 145 hp?
..and the stock 340 test with XE268 cam,headers and intake change putting out 391hp?
One day, I'm going to retire and just do dyno testing. Just because.