honda civic headers
Senior Member
Joined: Apr 2005
Posts: 2,448
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RE: honda civic headers
So back pressure is for torque?
Im not sure but I think you gain less torque with NOS then with a SC?
Again I still would like to know why my car needs back pressure. What does the back pressure actually do to help my car. The way I understand back pressure it would only make sense that it is bad and not good. How could anything putting resistance on the exhaust, which you want out of the way as quickly as possible, make more power. It just seems so contradictive to me. please explain, I truthfully would love to know.
Im not sure but I think you gain less torque with NOS then with a SC?
Again I still would like to know why my car needs back pressure. What does the back pressure actually do to help my car. The way I understand back pressure it would only make sense that it is bad and not good. How could anything putting resistance on the exhaust, which you want out of the way as quickly as possible, make more power. It just seems so contradictive to me. please explain, I truthfully would love to know.
Joined: Jul 2005
Posts: 427
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RE: honda civic headers
Backpressure is a good thing all cars need it, if u didnt have it u would mess up the internals of ur motor. Backpressure is only used in the beginning for takeoff, y u think u see so many civics so loud and there not going anywhere all u hear is noise. cuz the exhaust is to freely. and y u think when u buy a high performance exhaust system it comes with the cat and the resonator and it garentees u 10- 15 extra hp.
it's hard to explain backpressure but your exhaust have to be alil restricted to run clean and smooth, not noise u hear from blocks away and it's a lil civic going like 20mph. Those kinda of cars are all show no go
it's hard to explain backpressure but your exhaust have to be alil restricted to run clean and smooth, not noise u hear from blocks away and it's a lil civic going like 20mph. Those kinda of cars are all show no go
HCF Member
Joined: Jun 2004
Posts: 7,699
RE: honda civic headers
holy crap. im sorry, but i have to butt in again. you havent actually explained HOW it helps power. saying that "it would mess up the internals of ur motor" or "backpressure is only used in the beginning for takeoff" doesnt EXPLAIN anything. and when you see those civics with loud exhausts that dont go anywhere, thats because they have little tiny stock engines, and a crappy welded on muffler. chances are, most of those civics you see that are really loud and slow, have a cat and a bunch of stock crush bent exhaust piping.
and when you buy a high performance exhaust system, it has a resonator because a lot of people dont want that horrid loud noise you get from not having one. and most performance exhaust systems do NOT come with a cat. in fact, i cant think of one that does. and even if you were to buy a real high-flow cat, not a wanna-be cat thats actually a resonator, its to REDUCE backpressure over the stock cat.
and no. no, its really not hard to explain backpressure. its bad. period. do a little homework before you continue to make an *** of yourself. first impressions last a long time.
and when you buy a high performance exhaust system, it has a resonator because a lot of people dont want that horrid loud noise you get from not having one. and most performance exhaust systems do NOT come with a cat. in fact, i cant think of one that does. and even if you were to buy a real high-flow cat, not a wanna-be cat thats actually a resonator, its to REDUCE backpressure over the stock cat.
it's hard to explain backpressure but your exhaust have to be alil restricted to run clean and smooth,
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Joined: May 2005
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RE: honda civic headers
and y u think when u buy a high performance exhaust system it comes with the cat and the resonator and it garentees u 10- 15 extra hp
it's hard to explain backpressure
Senior Member
Joined: Apr 2005
Posts: 2,448
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RE: honda civic headers
Im welding up my exhaust tip tommorrow at work. Ill take pics and write up a DIY. How much more backpressure could you get then 100%. Ill keep you updated.
In my SI, I had no cat, Greddy header, Greddy Evo exhaust. It was fairly quite when I took off but did take off fairly quickly if I do say so myself.
Am still waiting on why you need backpressure. It doesnt make sense to me that it would help your engine run cleaner, if less exhaust can leave the cylinder, it would actually be running dirtier. Right? I still would very much like to be proved wrong. If someone can give me a reasonable explanation on why the engine needs back pressure I will switch sides on this argument and call eveyone, even Sacicons, an idiot. I am the type of person that needs to understand everything before I belive it though.
In my SI, I had no cat, Greddy header, Greddy Evo exhaust. It was fairly quite when I took off but did take off fairly quickly if I do say so myself.
Am still waiting on why you need backpressure. It doesnt make sense to me that it would help your engine run cleaner, if less exhaust can leave the cylinder, it would actually be running dirtier. Right? I still would very much like to be proved wrong. If someone can give me a reasonable explanation on why the engine needs back pressure I will switch sides on this argument and call eveyone, even Sacicons, an idiot. I am the type of person that needs to understand everything before I belive it though.
Joined: Jul 2005
Posts: 427
From:
RE: honda civic headers
I like they way u guys think u kno what ya'll talkin about. just read understand and learn ok. "THis is for SAC and STREET SNIPER"
read this artical and if it's not good enough show me a diff one.
http://member.rivernet.com.au/btaylo...onvertors.html
read this artical and if it's not good enough show me a diff one.
if you want top end, then the less restriction the better, but some is needed
for maximum torque. This relates to intake systems also.
for maximum torque. This relates to intake systems also.
HCF Member
Joined: May 2005
Posts: 3,313
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RE: honda civic headers
Yeah, I read that article. It's really more like a Q&A forum, but the highlights are...
But then he says...
Even your "expert" has no facts, figures, dynos, or anything to back up his need for backpressure.
He went on to explain that backpressure is also needed in the intake system also to maximize the low and top end which is why some sophisticated systems have dual runners.
I believe that the term "backpressure" in his explanation is being interchanged for "effective resonance." Correct me if I am wrong Sac, but intakes and headers (headers specifically) are "tuned" like an organ pipe. Exhaust pulses at different rpm ranges create different resonating frequencies. A finely tuned header or intake can utilize these frequencies to maximize the intake or exhaust velocity. Have you ever seen a giant organ with all of the different pipes? Each pipe is tuned for a different resonating frequency and therefore has different physical characteristics to carry those frequencies; fat, short pipes for the low notes and tall, thin pipes for the higher notes and so on. You couldn't use just one size pipe to play an organ just like your header can't maximally utilize the effective resonance of every rpm's exhaust pulse.
My point is that it's not lack of restriction or "backpressure" that is causing a loss in low end torque, it's the different resonance, because most quality exhausts are tuned to be most effective when your engine is really singing... in the higher rpm's. You could just as easily tune an exhaust with little or no backpressure to retain the low end and give nothing on the top end.
Low end torque needs a certain amount of backpressure to give maximum torque where the cam comes on
I've never heard numbers on the decrease in torque by doing this.
He went on to explain that backpressure is also needed in the intake system also to maximize the low and top end which is why some sophisticated systems have dual runners.
I believe that the term "backpressure" in his explanation is being interchanged for "effective resonance." Correct me if I am wrong Sac, but intakes and headers (headers specifically) are "tuned" like an organ pipe. Exhaust pulses at different rpm ranges create different resonating frequencies. A finely tuned header or intake can utilize these frequencies to maximize the intake or exhaust velocity. Have you ever seen a giant organ with all of the different pipes? Each pipe is tuned for a different resonating frequency and therefore has different physical characteristics to carry those frequencies; fat, short pipes for the low notes and tall, thin pipes for the higher notes and so on. You couldn't use just one size pipe to play an organ just like your header can't maximally utilize the effective resonance of every rpm's exhaust pulse.
My point is that it's not lack of restriction or "backpressure" that is causing a loss in low end torque, it's the different resonance, because most quality exhausts are tuned to be most effective when your engine is really singing... in the higher rpm's. You could just as easily tune an exhaust with little or no backpressure to retain the low end and give nothing on the top end.
