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RoadRage · 10-15-2002, 10:49 AM

Is it good to have a little back pressure in the exhust system of a NA engine. I know with turbo you don't want back pressure so the turbo can spool faster, but what about NA. Pro's and Con's anyone?

lsvtec · 10-15-2002, 11:11 AM

Back pressure = bad. The back pressure myth is BS. It is all about exit velocity. You want the exhaust gasses to exit the cylinder as fast as possible to create a vaccuum.

pissedoffsol · 10-15-2002, 12:01 PM

IMO, 0 is bad. a little is good- stock, sucks.

chet · 10-15-2002, 12:59 PM

i wouldn't go so far as to say its a "myth." yes, a more freeflowing header and exhaust is great, but why doesn't every aftermarket exhaust come in 3 inch trim diameter. its because too much flow can change the combustion cycle by creating too much flow. this will lead to reduced power in lower rpm's.

as is the case with most applications, a compromise is best. stock exhausts are designed for the consumer wanting a quiet, yet efficient design that serves its purpose well.

knowledge · 10-17-2002, 05:56 AM

I believe you need a little backpressure for the valves. They will float like hell with zero backpressure.

lsvtec · 10-17-2002, 10:47 AM

Why would they float at 0 back pressure? That doesn't make any physical sense. Technically 0 back pressure is not possible, there will always be some resistance to the flow or gases out of your engine.

E_SolSi · 10-17-2002, 11:04 AM

unless you were running your car in a vaccum there would be some kind of resistance just from the ambient air pressure

and speaking of "back pressure"... damn B 2 years!!! thats gotta suck

lsvtec · 10-17-2002, 11:17 AM

That's what I said.

pissedoffsol · 10-17-2002, 11:41 AM

Quote:

Originally posted by E_SolSi@Oct 17 2002, 11:04 AM
unless you were running your car in a vaccum there would be some kind of resistance just from the ambient air pressure

and speaking of "back pressure"... damn B 2 years!!! thats gotta suck

i wouldn't know what sucking is like anymore either

lol

lsvtec · 10-17-2002, 11:54 AM

We need to start a get Brian laid fund.

knowledge · 10-18-2002, 06:01 AM

lmao! Dont go to Reno to get a hooker! I tried this past weekend for my brother inlaw and it was $500. Better off renting a video B.

10-15-2002, 10:49 AM	#1
RoadRage Member Join Date: Sep 2002 Posts: 38 iTrader: 0 / 0% Rep Power: 15	Is it good to have a little back pressure in the exhust system of a NA engine. I know with turbo you don't want back pressure so the turbo can spool faster, but what about NA. Pro's and Con's anyone? __________________ Juiced LS.............mmmm

10-15-2002, 11:11 AM	#2
lsvtec GNU/Linux Evangelist Join Date: Sep 2002 Location: Greater Portland, OR Posts: 5,497 iTrader: 0 / 0% Ride: The Cheapest Road Bicycle I could get Rep Power: 69	Back pressure = bad. The back pressure myth is BS. It is all about exit velocity. You want the exhaust gasses to exit the cylinder as fast as possible to create a vaccuum. __________________ v3sw7+9Chw6ln3pr7Ock4ma9w3TXm3l7GDF i7Ce6+8t4MNb8Oen6g6RAOa26s5MRp6 hackerkey.com

10-15-2002, 12:59 PM	#4
chet Senior Member Join Date: Sep 2002 Location: st petersburg, florida Posts: 888 iTrader: 0 / 0% Rep Power: 23	i wouldn't go so far as to say its a "myth." yes, a more freeflowing header and exhaust is great, but why doesn't every aftermarket exhaust come in 3 inch trim diameter. its because too much flow can change the combustion cycle by creating too much flow. this will lead to reduced power in lower rpm's. as is the case with most applications, a compromise is best. stock exhausts are designed for the consumer wanting a quiet, yet efficient design that serves its purpose well. __________________ <a href=\'http://www.geocities.com/coker_boy/honda.html\' target=\'_blank\'>The Green Machine</a>

10-17-2002, 05:56 AM	#5
knowledge Senior Member Join Date: Sep 2002 Location: Beale AFB, CA Posts: 1,410 iTrader: 0 / 0% Rep Power: 29	I believe you need a little backpressure for the valves. They will float like hell with zero backpressure. __________________ The C5 is strong with this one........

10-17-2002, 10:47 AM	#6
lsvtec GNU/Linux Evangelist Join Date: Sep 2002 Location: Greater Portland, OR Posts: 5,497 iTrader: 0 / 0% Ride: The Cheapest Road Bicycle I could get Rep Power: 69	Why would they float at 0 back pressure? That doesn't make any physical sense. Technically 0 back pressure is not possible, there will always be some resistance to the flow or gases out of your engine. __________________ v3sw7+9Chw6ln3pr7Ock4ma9w3TXm3l7GDF i7Ce6+8t4MNb8Oen6g6RAOa26s5MRp6 hackerkey.com


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10-15-2002, 12:01 PM	#3
pissedoffsol RETIRED Join Date: Sep 2002 Location: Retirement Home Age: 29 Posts: 49,951 iTrader: 2 / 100% Ride: Electric Scooter Blog Entries: 1 Rep Power: 531	IMO, 0 is bad. a little is good- stock, sucks.

10-17-2002, 11:17 AM	#8
lsvtec GNU/Linux Evangelist Join Date: Sep 2002 Location: Greater Portland, OR Posts: 5,497 iTrader: 0 / 0% Ride: The Cheapest Road Bicycle I could get Rep Power: 69	That's what I said. __________________ v3sw7+9Chw6ln3pr7Ock4ma9w3TXm3l7GDF i7Ce6+8t4MNb8Oen6g6RAOa26s5MRp6 hackerkey.com

10-17-2002, 11:54 AM	#10
lsvtec GNU/Linux Evangelist Join Date: Sep 2002 Location: Greater Portland, OR Posts: 5,497 iTrader: 0 / 0% Ride: The Cheapest Road Bicycle I could get Rep Power: 69	We need to start a get Brian laid fund. __________________ v3sw7+9Chw6ln3pr7Ock4ma9w3TXm3l7GDF i7Ce6+8t4MNb8Oen6g6RAOa26s5MRp6 hackerkey.com

10-18-2002, 06:01 AM	#11
knowledge Senior Member Join Date: Sep 2002 Location: Beale AFB, CA Posts: 1,410 iTrader: 0 / 0% Rep Power: 29	lmao! Dont go to Reno to get a hooker! I tried this past weekend for my brother inlaw and it was $500. Better off renting a video B. __________________ The C5 is strong with this one........

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