| Exhaust from start to finish - Click HERE for Original Thread |
| Darkrid3r |
I have seen lots of tail pipes out there, some just a simple cat back or muffler.
Im fairly new at car performance mods but does it not make sence to go right from the motor to the back of the car with a custom exhaust system?
Whats the point in unrestricting your muffler if your cat is just causing restriction? besides the fact that its a requirement in Canada :D
Is it worth just changin the muffler? I think its all look and sound but I could be wrong.
What is reasonable to spend to do a job right? 2,000?
Dark |
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| redbaron303 |
I personally ran a cat back on my previous car, with a "bigger muffler" but it wasn't that useful!
I now run 3 inch piping from my turbo straight out the ass of my car, no cats or muffler this time.... and it's a lot better, IMO!
'I personally think its better to do FULL exhaust because you're right with having the restriction w/out doing the full job. |
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| Spike7ss |
I too have 3 inch on my shev, once i got the cat and the restricted muffler out, there was a HUGE difference in sound and torque, but that is on a v-8 4x4 pick up. ive heard that smaller cars need the cat for back pressure or something?
:bigthumbup: |
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| ManHunter |
Just changing the muffler won't do anything for performance. You need to do the whole exhaust. And you can get whole exhaust systems for less than 2000$.
I have the Greddy power extreme on my car and I am quite happy with it.
MH |
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| redbaron303 |
I think racing beat for rotary cars is about $2k by the time you've got it shipped and installed (full system) but I haven't heard of any exhaust costing near that much otherwise.... unless you buy BIG names like HK$ haha!
Besides what vehicle are you plannin on doing the exhaust to, I don't think you want full 3 inch exhaust w/no muffler/cat on a civic that has no other mods, i've heard that cuts your torque down on an already torqueless car!?! Remember mufflers help keep it quiet, I just fear my "noise" tickets this year... haha! |
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| Darkrid3r |
I would do the exhaust on a Mazda P5 2002.
Not sure what I want though, sound or performance. I guess as you reduce restriction you get more noize :D
Dark |
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| GTS Jeff |
| u are totally right. |
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| THEONE |
| If you don't have a Turbo you need some back pressure! ;) |
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| THEONE |
Quiet doesn't have to mean restrictive!! ;)
Have you seen the white regal that runs low 8's you can't even hear it! |
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| redbaron303 |
quote:
Originally posted by THEONE@Mar 9 2003, 07:16 PM
Quiet doesn't have to mean restrictive!! ;)
Have you seen the white regal that runs low 8's you can't even hear it!
That car is insane... I wonder what exhaust setup he has on that car... I've also heard that turbos somehow help keep the car quieter than an all motor ride :) Seems that way from my experience as well.... Does anyone know what that white regal is running for exhaust setup and/or why its so quiet! |
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| THEONE |
| The answer to your question would be 4 flowmaster mufflers! :bigthumbup: |
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| redbaron303 |
| 4Flowmasters? Dual exhaust meaning two per side or? That's in interesting setup, but obviously it works! |
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| CanadianR |
[QUOTE]I guess as you reduce restriction you get more noize
That is not true, you can have a free flowing exhaust that is still about as quiet as stock.
[QUOTE] If you don't have a Turbo you need some back pressure!
That is also untrue. That is a myth created by muscle car fans and oldschool guys. In modern small-displacement engines you do not want ANY backpressure. Trust me, I've been doing alot of research on this as i am considering purchasing a new header/highflow cat/exhaust, all the experts say that you don't want any backpressure in an exhaust system on a smaller engine.
Sorry i don't know how to quote properly!!
As far as the exhaust goes, you probably won't get much more power from it even if you get a well-made, properly sized exhaust unless you are able to add an intake and a header. It's all about being able to get more air into the engine and efficienlty pull the spent gases out of the engine that will makeyou more power. If you are just purchasing for the sound then i guess just find out what someone else has that sounds good to you. But if you are also interested in performance then i think you should get as much info as you can before purchasing. Try checking some Mazda-specific web boards to see what brands are available and what people think of them. You really need to decide what your ultimate goals in the long run for the car are before you buy the exhaust. Are you planning on alot of mods ie. cams or nitrous or turbo etc or are you planning on just basic bolt-ons? I ask because depending on how much power you plan on making and whether you're going FI or not makes a difference in the diameter of exhaust piping youn will need. I will just assume you are going with basic bolt-ons (if you are planning more let me know) so a 2.25" diameter exhaust is what you will need. 3" is only good for a turbocharged car or extremely powerful NA car. The thing to make sure is that it is 2.25" the whole length of the car. You should also get a high-flow cat with a 2.25" inner diameter to go with the exhaust. Many aftermarket exhausts also have a bottleneck where the cat is connected to the exhaust so you need to check for that. The exhaust won't get you alot of power but you will get more when you get a good header and intake. As far as noise goes the more resonators you add in the exhaust the quiter it will be and the design of the muffler has alot to do with the loudness of the exhaust. If you need more info or want to learn more let me know. I'll be happy to provide more information if you would like it. |
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| ManHunter |
quote:
Originally posted by CanadianR@Mar 10 2003, 11:21 AM
ifdljkfdlj
What's that? Are you having a problem? Should we call 911?
MH |
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| THEONE |
| Yeh you dont need back pressure! You want back pressure if you want any low end torque which those motors don't have much of stock! :wacko: :wtf: |
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| BlueTurboEGG |
Well, here is my take on the backpressure issue.
When My NX was without turbo, I installed headers, intake and exhaust.
I had a full 2" exhaust no cat with 2" muffler. Pretty peppy, good offline torque, the press into seat feeling sorta fell off after 6K on the tach.
When I moved upto a full 2.5" with a 2.5" muffler. Still peppy, lost ALOT of offline torque, but this time the motor kept pulling right to the fuel cut.
You don't get something without losing somewhere else.
Personally, I like all the power being at the top (but not like a VTEC motor) that way boggin' around town is easy, and power is a blip of the throttle away.
Depends on how you like your ride to go. |
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| CanadianR |
| Backpressure being useful is a myth that oldschool domestic guys started a long time ago. The theory does have some merits with older engines, BUT that is based on an engine which goes by the slow burn theory. Modern japanese engines are constructed to take advantage of the fast burn theory, using high engine speeds and scavenging to promote effiecient removal of spent gases. You will not get any gains by adding a restrictive exhaust that causes backpressure in these engines. In fact the best header builders ie: guys who build headers and exhaust for Formula three etc. actually build the header/exhaust in such a way as the line up the exhaust pulses and actually effectively pull the exhaust out, promoting even more exhaust scavenging. Bottom line, if you want performance yopu don't want backpressure. |
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| WookeysRX7 |
| Canadian R, you are wrong in a sence that all back pressure is bad. In high school we had a drag car that had a 454 in bored out and all that shiznit. We put like a foot and a half no even of pipe after the headers so that there will be a vacum like reaction which is also called backpressure to have the exhaust come out at a faster rate. We dynoed the engine with the collectors on and then ran it when them off and noticed a 25HP difference. Mind you we had like 600 some odd HP but still! :bigthumbup: |
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| GTS Jeff |
quote:
Originally posted by CanadianR@Mar 11 2003, 01:17 PM
Backpressure being useful is a myth that oldschool domestic guys started a long time ago. The theory does have some merits with older engines, BUT that is based on an engine which goes by the slow burn theory. Modern japanese engines are constructed to take advantage of the fast burn theory, using high engine speeds and scavenging to promote effiecient removal of spent gases. You will not get any gains by adding a restrictive exhaust that causes backpressure in these engines. In fact the best header builders ie: guys who build headers and exhaust for Formula three etc. actually build the header/exhaust in such a way as the line up the exhaust pulses and actually effectively pull the exhaust out, promoting even more exhaust scavenging. Bottom line, if you want performance yopu don't want backpressure.
ure partially right. backpressure IS useless at high rpms. but what about lower rpms? u need a smaller diameter exhaust to make sure the gases dont get turbulent at lower speeds/rpms |
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| CanadianR |
quote:
Originally posted by WookeysRX7@Mar 11 2003, 01:23 PM
Canadian R, you are wrong in a sence that all back pressure is bad. In high school we had a drag car that had a 454 in bored out and all that shiznit.
You are talking about an older engine which was built using slow-burn theory. Didn't you read through my post? I stated that there was some merit to having backpressure in the oldschool engines. However, you are not comparing apples to apples, as i am talking about a modern, Japanese small-displacement engine which relies on the fast-burn theory. Sorry if i sounded like i meant that backpressure is bad in ALL engines, i just meant in any modern engines. |
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| CanadianR |
quote:
Originally posted by Jeff TYPE R@Mar 11 2003, 06:34 PM
ure partially right. backpressure IS useless at high rpms. but what about lower rpms? u need a smaller diameter exhaust to make sure the gases dont get turbulent at lower speeds/rpms
No, i'm completely right. You need to size the exhaust so as to have the best compromise between low and high rpm. If you use too small diameter exhaust you're going to get backpressure and performance will be alright at low rpms but will definately be resricted at mid and high rpms. On the other hand, if you use too large a diameter exhaust you are going to lose exaust velocity and have noticeable losses everywhere except maybe at very high rpm's. The bottom line is, you need a properly sized exhaust sysyem built for the kind of power your car makes that will be the best for all rpm ranges, and that exhaust will be free-flowing and not cause any backpressure. Again i'm not talking about old pushrod technology engines, just modern japanese ebgines. By the way, Darkrider, what are your power goals for this car? |
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| GTS Jeff |
quote:
Originally posted by CanadianR@Mar 12 2003, 11:01 AM
quote:
Originally posted by Jeff TYPE R@Mar 11 2003, 06:34 PM
ure partially right. backpressure IS useless at high rpms. but what about lower rpms? u need a smaller diameter exhaust to make sure the gases dont get turbulent at lower speeds/rpms
No, i'm completely right. You need to size the exhaust so as to have the best compromise between low and high rpm. If you use too small diameter exhaust you're going to get backpressure and performance will be alright at low rpms but will definately be resricted at mid and high rpms. On the other hand, if you use too large a diameter exhaust you are going to lose exaust velocity and have noticeable losses everywhere except maybe at very high rpm's. The bottom line is, you need a properly sized exhaust sysyem built for the kind of power your car makes that will be the best for all rpm ranges, and that exhaust will be free-flowing and not cause any backpressure. Again i'm not talking about old pushrod technology engines, just modern japanese ebgines. By the way, Darkrider, what are your power goals for this car?
uhh yea u just restated what i said. |
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| CanadianR |
quote:
Originally posted by Jeff TYPE R@Mar 12 2003, 03:25 PM
uhh yea u just restated what i said.
I didn't restate what you said. You said that you needed a smaller diameter exhaust to ensure good lowrange. I said that you need something properly sized so that its not so large as to only make power at peak rpms and not so small as to cause backpressure at higher rpms and choke off power, there is a difference between what i said and what you said.A properly sized exhaust won't give you maximum power all the way through the rpm's, rather it is a compromise with the exhaust most efficiently working where the car makes its peak tourque, but still working fairly well at other engine speeds. |
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