Hey today i got a straight pipe put on my car from the cat back was wondering how much power that would free up from the 2 ton stock muffler (not really but it was freakin heavy....)
wont be much. like Darkstars said. 3 or 4
Im a Xbox 360 fanboy...and damn proud of it!!
Wouldn't backpressure become an issue?
www.kronosperformance.com / 732-742-8837
^^^ I dont see how it would, what do ya meen?
1997 Sunfire
WAI
pacesetter header
Underdrive pulley = STILL SLOW.
50 shot of NX
Excidium wrote:-5 hp @ 2400 rpm
+2 hp @ 6500 rpm
exactly. absence of backpressure kills your low end torque.
I was a retard, and now I'm permanently banned.
SO a straight pipe would kill the own end torque, but a bent pipe (shape of stock) would increase it?
Quote:
exactly. absence of backpressure kills your low end torque.
Lol i thought NJHK meant a problem with too much backpressure.......sorry.
1997 Sunfire
WAI
pacesetter header
Underdrive pulley = STILL SLOW.
50 shot of NX
SO you are running no muffler now? I bet its loud and nasty. How big is the pipe? Without a full exhaust, you are not going to gain much.
2012 HD VRSCF
2010 Ford Explorer
2006 Ford Ranger
2004 Chevy Cavalier
The pipe is stock size and its comeing out almost stock location its bent and coming out the left side of my rear finder as for noise...i always thought it sounded pretty cool..but to each his own.Yeah you can feel the low end los but you can also feel it pull alittle bit better around 5000 and 6000.
With a stock size pipe, you have do nothing but made noise. I doubt you made anything.
2012 HD VRSCF
2010 Ford Explorer
2006 Ford Ranger
2004 Chevy Cavalier
my low end is @!#$ i got a 2.5 cat back, not my idea the guy i bought the car from had it on there
PAKIPOWER wrote:my low end is @!#$ i got a 2.5 cat back, not my idea the guy i bought the car from had it on there
that would make sense. you need 2.25"
I was a retard, and now I'm permanently banned.
Spotabee Racing (The Fake Z24) wrote:PAKIPOWER wrote:my low end is @!#$ i got a 2.5 cat back, not my idea the guy i bought the car from had it on there
that would make sense. you need 2.25"
Unless he intends to boost.
http://members.rankmyride.com/djtorello
u don't want back pressure u never want back pressure there is only three motors that need it n.a diesel because it needs the heat for proper combustion, a two stroke , and old V-twins on a Harley because the combustion chamber are so poorly designed the air / fuel mixture slips right through the combustion chamber and u get power curves that look like that crack in your windshield the word is velocity the goal with a exhaust is to achieve proper velocity and bigger is not always better your motor is a air pump it will pump out the same amount of exhaust whether u have a 1'' pipe or a 10'' pipe the only differents between the two pipes is how fast the exhaust will move through the pipe (the velocity ) if the pipe is to big when the exhaust pulse comes out of the combustion chamber its not big enough to fill the over-sized exhaust causing it to move very slow down the pipe than it starts to cool down and contract taking up even less room when that happens u loose all your scavenging (the vacuum created behind each pulse that helps pull the next one out ) but on the other hand u don't want to be to small because than the exhaust has to move very fast to get the same job done (its like a garden hose the same amount of water comes out whether your thumb is on the end or wide open the only thing that changes is the velocity ) if the pipe is to small the engine is starting to use power that would have normally pushed the car down the road to push the exhaust out not counting the contamination in the combustion chambers from the exhaust being forced out of the chamber instead of having a vacuum waiting on the other side of the exhaust valve ready to pull it out (scavenging) so the best set up would be to build an exhaust with the proper size pipe on a j-body that is daily driven and has bolt ons 2.1/4 is lots even 2'' gm engineers aren't dumb the reason they put a 2'' on is they know for most of the cars life its going to see ideal to around 3000RPM and for everyday use thats great your not going to be at 6000 every were u go but were the engineers stop is with the mufflers and cats they are made with no performance in mind the goal is meet a emissions standard and or db standard thats it so don't necessarily make it bigger just make it flow better cat backs in 99% of the cases only make noise thats it the gains are minimal the cat is the problem. ideally you would want the exhaust to be the proper diameter with nothing impeding the flow and nothing soaking up the energy of the exhaust (like a sound absorbing muffler ) a strait pipe would be ideal but this is excluding good mufflers that help savaging like a flowmaster or a borla xr1 that helps savaging and soaks up negative harmonics and keeps them from reverberating back up the exhaust pipe and into the valve train. and i know in the real world u have to have a muffler so when choosing i will make it easy because there is only two to choose from a absorption muffler (a muffler that soaks the sound up with packing) when picking one of these just make sure its the right pipe diameter for your application and that u can see right though it and that the sides are smooth no scoops fins exc. or the only other choice a deflection muffler again make sure its the right pipe diameter and it has the least amount of chambers u can live with (the less chambers the loader it is ) and make sure its a flowmaster they are the only one that use this technology properly the rest are just hacks and i know what your thinking a flowmaster won't flow as good as a muffler i can see through and thats not the case its just different technology but i think thats for a different post i better stop before everyone falls asleep i didn't plan to go on this long hope this helps so to wrap up i don't want to see the word "back pressure used ever again.
its even longer when u post it. sorry
LEVI wrote:u don't want back pressure u never want back pressure there is only three motors that need it n.a diesel because it needs the heat for proper combustion, a two stroke , and old V-twins on a Harley because the combustion chamber are so poorly designed the air / fuel mixture slips right through the combustion chamber and u get power curves that look like that crack in your windshield the word is velocity the goal with a exhaust is to achieve proper velocity and bigger is not always better your motor is a air pump it will pump out the same amount of exhaust whether u have a 1'' pipe or a 10'' pipe the only differents between the two pipes is how fast the exhaust will move through the pipe (the velocity ) if the pipe is to big when the exhaust pulse comes out of the combustion chamber its not big enough to fill the over-sized exhaust causing it to move very slow down the pipe than it starts to cool down and contract taking up even less room when that happens u loose all your scavenging (the vacuum created behind each pulse that helps pull the next one out ) but on the other hand u don't want to be to small because than the exhaust has to move very fast to get the same job done (its like a garden hose the same amount of water comes out whether your thumb is on the end or wide open the only thing that changes is the velocity ) if the pipe is to small the engine is starting to use power that would have normally pushed the car down the road to push the exhaust out not counting the contamination in the combustion chambers from the exhaust being forced out of the chamber instead of having a vacuum waiting on the other side of the exhaust valve ready to pull it out (scavenging) so the best set up would be to build an exhaust with the proper size pipe on a j-body that is daily driven and has bolt ons 2.1/4 is lots even 2'' gm engineers aren't dumb the reason they put a 2'' on is they know for most of the cars life its going to see ideal to around 3000RPM and for everyday use thats great your not going to be at 6000 every were u go but were the engineers stop is with the mufflers and cats they are made with no performance in mind the goal is meet a emissions standard and or db standard thats it so don't necessarily make it bigger just make it flow better cat backs in 99% of the cases only make noise thats it the gains are minimal the cat is the problem. ideally you would want the exhaust to be the proper diameter with nothing impeding the flow and nothing soaking up the energy of the exhaust (like a sound absorbing muffler ) a strait pipe would be ideal but this is excluding good mufflers that help savaging like a flowmaster or a borla xr1 that helps savaging and soaks up negative harmonics and keeps them from reverberating back up the exhaust pipe and into the valve train. and i know in the real world u have to have a muffler so when choosing i will make it easy because there is only two to choose from a absorption muffler (a muffler that soaks the sound up with packing) when picking one of these just make sure its the right pipe diameter for your application and that u can see right though it and that the sides are smooth no scoops fins exc. or the only other choice a deflection muffler again make sure its the right pipe diameter and it has the least amount of chambers u can live with (the less chambers the loader it is ) and make sure its a flowmaster they are the only one that use this technology properly the rest are just hacks and i know what your thinking a flowmaster won't flow as good as a muffler i can see through and thats not the case its just different technology but i think thats for a different post i better stop before everyone falls asleep i didn't plan to go on this long hope this helps so to wrap up i don't want to see the word "back pressure used ever again.
i'm sorry I didn't really read all your post, I saw the first line and just clicked the quote button. If you are naturally aspirated, YOU NEED SOME BACKPRESSURE IN YOUR EXHAUST STREAM TO HAVE ANY AMOUNT OF LOW END TORQUE WHATSOEVER.
I was a retard, and now I'm permanently banned.
Glenn Janosko wrote:i always thought it sounded pretty cool..but to each his own.
Very true, but have you listened to it outside the car? Especially with someone else driving it? It may sound good inside the car, but like FireFighter stated, it is probably loud and nasty when you are driving around. I have heard several J's with straight exhaust and they sound really nice at idle, but are just plain nasty about 2000 RPMs.
As for the debate on backpressure. This has been argued over and over and over and over again on here. Until someone puts their car on the dyno with a before and after we can't settle this other than each person's own theory.
My girlfriend's Cavy is running straight pipe since the muffler fell the hell off, and it runs AND sounds like SHHHHHHHHH, so um, yeah. Not worth having on accident, definitely not worth doing on purpose.
"Silly cluth, glazing is for donuts!"
Mr Clean wrote:My girlfriend's Cavy is running straight pipe since the muffler fell the hell off, and it runs AND sounds like SHHHHHHHHH, so um, yeah. Not worth having on accident, definitely not worth doing on purpose.
if the muffler fell off, and it still has a cat, that's not straight pipe. straight piping would refer to no catalyst, no muffler.
I was a retard, and now I'm permanently banned.
Spotabee Racing (The Fake Z24) wrote:Mr Clean wrote:My girlfriend's Cavy is running straight pipe since the muffler fell the hell off, and it runs AND sounds like SHHHHHHHHH, so um, yeah. Not worth having on accident, definitely not worth doing on purpose.
if the muffler fell off, and it still has a cat, that's not straight pipe. straight piping would refer to no catalyst, no muffler.
LOL. Samantics... You know, Spotabee, I like you, but damn. Bustin me up like that. And I thought you and me got along! :-) But you're right, tho. Catalytic converters do keep it from being a straight pipe. But it still sounds like a bad idea. Cat or no cat. Bad. Very bad.
"Silly cluth, glazing is for donuts!"
But then again, the original post mentioned a straight pipe from the cat back so this whole conversation was in vain. Damn samantics.
"Silly cluth, glazing is for donuts!"
if your using the turm "backpressure" that means u just don't get it. when its put in text and u just won't read it thats an entirely different problem so i give up.
Im so confused.....Oh well i guess when it comes down to it if you like it then you like it...so do it..if you dont then...dont...thanks for it anyway guys...
