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+--- Thread: Straight piping a N/A engine? (/showthread.php?tid=3019)
Straight piping a N/A engine? - Purplecomputer - 10-10-2011
hey i know this has good results with turbo and you are letting all the air freely flow without restrictions but is the same true for a N/A engine?
RE: Straight piping a N/A engine? - waz - 10-10-2011
For a small block Chevy (5.3L) N/A, you would lose some torque on the very low end, not very noticeable. The increase in top end usually offsets it pretty well. (The only reason I use the SCB for an example is because I have some experience with them.)
Different sizes and makes of engines, port layout, valve sizes, manifold/header design, pipe diameter, pipe routing, and a bunch of other stuff that doesn't pop into my head right now will all make your results vary.
RE: Straight piping a N/A engine? - Purplecomputer - 10-10-2011
(10-10-2011, 11:24 AM)waz For a small block Chevy (5.3L) N/A, you would lose some torque on the very low end, not very noticeable. The increase in top end usually offsets it pretty well. (The only reason I use the SCB for an example is because I have some experience with them.)
Different sizes and makes of engines, port layout, valve sizes, manifold/header design, pipe diameter, pipe routing, and a bunch of other stuff that doesn't pop into my head right now will all make your results vary.
I was actually asking about straight pipping on a mercedes N/A diesel engine like my 616. I know that doing such on a gasser would make you lose power.
RE: Straight piping a N/A engine? - JB3 - 10-10-2011
I felt zero difference in performance when I did it to my 240. Sound difference was not hugely different, there was a nice increase in note during certain RPMS and loads that were gratifying.
Idle gave the car a nice rumble noise to it. Heres mine with a straight pipe-
I just put in pipe in place of the mufflers, did not go up in size
http://www.youtube.com/watch?v=1rZD0xarUEI
RE: Straight piping a N/A engine? - carlitosgy6 - 10-10-2011
the real purpose of running a straight pipe in a turbo is for better turbo spooling,my truck have a 3 inch pipe from the turbo,its quiet,if you do this on a n/a,i don't think you will feel any improvements,but if you make it bigger the power its going to be worst
RE: Straight piping a N/A engine? - Purplecomputer - 10-11-2011
good info guys. I though it would have been the opposite for diesel engines, well i guess with turbos only.
RE: Straight piping a N/A engine? - iheartboost - 10-11-2011
im quite certian its still the same dynamic as a gas engine thats n/a its not about back pressure or any garbage like that. its about how much flow there is.
if its too much you loose torque too little you choke up at the top end. ideally figure out what you need to flow. and stiaght pipe that back all the way if you like the sound if not add a muffler and/or resonator.
RE: Straight piping a N/A engine? - ronnie - 10-12-2011
ideally you would exhaust into a vacuum. Of course this is not going to happen. Your exhaust system if designed right will try to pull the exhaust from the engine. Tuned headers may well be of value, and a good muffler like flowmaster. The idea is to have each exhaust pulse "pull" the next one along. A straight pipe offers low resistance, but does nothing to enhance cylinder evacuation. So far I have put my efforts into ip adjustments, and intake manifold. Did just enlarge the burn holes in the pc's, nice gain there.
RE: Straight piping a N/A engine? - carlitosgy6 - 10-13-2011
(10-11-2011, 10:07 PM)iheartboost im quite certian its still the same dynamic as a gas engine thats n/a its not about back pressure or any garbage like that. its about how much flow there is.ronnie cant explain better!!!!thats the point,evacuation of the cylinders by scavenging removing spent gases and pulling new air just before the piston begin the intake stroke,in the overlap period,and yes om617 has some overlap to do this,this scavenging isky called it in their 50's cams the fifth cycle, thats one of the most important parts of the ecuation of a racing engine or a daily use one,and this cool incoming air charge that goes directly to the exhaust port cools the ex valve
if its too much you loose torque too little you choke up at the top end. ideally figure out what you need to flow. and stiaght pipe that back all the way if you like the sound if not add a muffler and/or resonator.
RE: Straight piping a N/A engine? - iheartboost - 10-13-2011
yea lol i dident want to get into exhaust scavenging lol. i was content with. dont make the tubes to big lol
RE: Straight piping a N/A engine? - yankneck696 - 10-13-2011
I almost thought of patenting a self scavenging exhaust system a couple decades ago...
Having an eductor system (like my old gold dredge) would lend a negative pressure at the exhaust.
Here's the idea: Using scoops on the vehicle that taper down (increasing velocity) to a widened area on the exhaust will produce a low pressure area to draw the exhaust gasses out...
Use your imagination...
Ed
RE: Straight piping a N/A engine? - dieselboy - 10-14-2011
It will sound horrible on a n/a 4cyl diesel. My 240d sounded like a bosozoku car.
RE: Straight piping a N/A engine? - ronnie - 10-14-2011
for now I still have the original exhaust manifold, stock down pipe then enlarged to 2.25" back to a muffler from a 300. No resonator. This was a hurry up exhaust as the stock pieces fell off on the highway, so made up an exhaust from stuff laying around the shop. This is louder then the original but not to noisy. I may well make a set of headers, just not high on the priority list at the moment. I did do a tuned intake, and it did make a nice differance.
RE: Straight piping a N/A engine? - lgreeley83 - 03-12-2012
my 2 pennies. I put 3" straight pipe on my 240 from manifold to rear. I drove around for 10 minutes and knew the noise was gonna get me a ticket. Nice sound until you drove it. Rediculously loud. I went right back to the mexico muffler by me and paid 40 to have a muffle put in.
RE: Straight piping a N/A engine? - Simpler=Better - 03-12-2012
I heard of someone taking a set of chevy long tube headers and adapting them to a 250, apparently it almost lined right up.
RE: Straight piping a N/A engine? - Ducos - 03-12-2012
I straight piped my 190d 2.0. Sounded AWESOME with a bullet "Japs" muffler at the end =) think it was 2" piping
Sounded like a more Man'ly supra. for real :-)
RE: Straight piping a N/A engine? - Alastair E - 03-13-2012
Wont make much performance difference --if any at all!--It will SOUND different, Thats for sure...
Only way to make more power, is add more fuel. --But without more air (Turbo) there's a limit as to how much you'll get before huge smoke, high EGT's damage etc...
Approx 3/4 (Three-quarter) turn on the 'M' pump max fuel screw will give a slightly higher power without TOO much extra smoke...
RE: Straight piping a N/A engine? - winmutt - 03-15-2012
(03-13-2012, 05:39 AM)Alastair E Wont make much performance difference --if any at all!--It will SOUND different, Thats for sure...
Only way to make more power, is add more fuel. --But without more air (Turbo) there's a limit as to how much you'll get before huge smoke, high EGT's damage etc...
Approx 3/4 (Three-quarter) turn on the 'M' pump max fuel screw will give a slightly higher power without TOO much extra smoke...
There is no danger of high EGT on the NA.s I second the 1/2-3/4 turn. Don't expect miracles.