Exhaust Cam VS Intake Cam
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Exhaust Cam VS Intake Cam
Based on what I've read (please correct me if I'm wrong, that's the point of this thread), intake cams produce more power on lower RPMs and exhaust cams produce more power at higher RPMs, is that correct? I read descriptions on both and they both say,"add power throughout the entire powerband" but they must actually be different. What's on your opinion on a N/A car? Obviously (based on if I'm right), in Hondas, higher RPM is better, anything after 5000rpm, right? I want to build a K20A2 N/A and want a good cam to start things off with.
This is a website that I looked at, it also has a diagram if you scroll to the bottom: http://auto.howstuffworks.com/camshaft.htm
Any help would be appreciated
This is a website that I looked at, it also has a diagram if you scroll to the bottom: http://auto.howstuffworks.com/camshaft.htm
Any help would be appreciated
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Joined: Oct 2007
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From: Oregon City, OR, USA
Re: Exhaust Cam VS Intake Cam
I think you need to spend a little more time researching; your k20a2 is a dual overhead cam, so you don't have the same limitations in cam design as a conventional SOHC as shown in that article.
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From: b00sting my D16s, SoWis, USA
Re: Exhaust Cam VS Intake Cam
Actually, typical "large" intake cams have the ability to kill more low-end power than "large" exhaust cams. They tend to open sooner and close later, meaning you create a pressure wave up the intake runner before you should for low rpm (early opening), and push some air out of the cylinder since the valve is still open as the piston comes back up.
A weak exhaust cam profile will mainly restrict high-end because air doesn't like to go past a certain speed, at which point it chokes. Add lift and duration, and you raise that point far up he rpm band - to the point the port is the choke point. This is why someone might say an exhaust cam is for top-end.
The only way I can figure you're thinking how you are, is how cam timing crap like VVT-i or the "i" in i-vtec advances the intake cam (increasing overlap). Generally, you would retard both to shift power towards redline, and advance to shift it towards idle. In this case, more overlap is better than overall cam timing.
A weak exhaust cam profile will mainly restrict high-end because air doesn't like to go past a certain speed, at which point it chokes. Add lift and duration, and you raise that point far up he rpm band - to the point the port is the choke point. This is why someone might say an exhaust cam is for top-end.
The only way I can figure you're thinking how you are, is how cam timing crap like VVT-i or the "i" in i-vtec advances the intake cam (increasing overlap). Generally, you would retard both to shift power towards redline, and advance to shift it towards idle. In this case, more overlap is better than overall cam timing.
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From: Manhattan, New York
Re: Exhaust Cam VS Intake Cam
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Thread Starter
Honda-Tech Member
Joined: Jun 2005
Posts: 7,051
Likes: 0
From: Manhattan, New York
Re: Exhaust Cam VS Intake Cam
Actually, typical "large" intake cams have the ability to kill more low-end power than "large" exhaust cams. They tend to open sooner and close later, meaning you create a pressure wave up the intake runner before you should for low rpm (early opening), and push some air out of the cylinder since the valve is still open as the piston comes back up.
A weak exhaust cam profile will mainly restrict high-end because air doesn't like to go past a certain speed, at which point it chokes. Add lift and duration, and you raise that point far up he rpm band - to the point the port is the choke point. This is why someone might say an exhaust cam is for top-end.
The only way I can figure you're thinking how you are, is how cam timing crap like VVT-i or the "i" in i-vtec advances the intake cam (increasing overlap). Generally, you would retard both to shift power towards redline, and advance to shift it towards idle. In this case, more overlap is better than overall cam timing.
A weak exhaust cam profile will mainly restrict high-end because air doesn't like to go past a certain speed, at which point it chokes. Add lift and duration, and you raise that point far up he rpm band - to the point the port is the choke point. This is why someone might say an exhaust cam is for top-end.
The only way I can figure you're thinking how you are, is how cam timing crap like VVT-i or the "i" in i-vtec advances the intake cam (increasing overlap). Generally, you would retard both to shift power towards redline, and advance to shift it towards idle. In this case, more overlap is better than overall cam timing.
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