Port timing (with a focus on exhaust timing)
Thread Starter
Senior Member
Joined: Nov 2003
Posts: 295
Likes: 6
From: Mich. USA
Port timing (with a focus on exhaust timing)
Question: What provides better results (low mid-range or peak) early opening or late closing exhaust porting?
Discuss
Graphical representation coming soon!
Discuss
Graphical representation coming soon!
Thread Starter
Senior Member
Joined: Nov 2003
Posts: 295
Likes: 6
From: Mich. USA
Graphs aren't beautiful and they have absolutely nothing to do with actual flow ability but they are get the point across and they are big. I am almost color blind and I can make them out so no complaints, make your own damn graphs if you don't like it!!!!
Exhaust timing (4 and 6 port 13B graphs overlap)
http://img412.imageshack.us/img412/3348/exhaustwn7.jpg
Intake timing
http://img259.imageshack.us/img259/5750/intakezx8.jpg
Exhaust timing (4 and 6 port 13B graphs overlap)
http://img412.imageshack.us/img412/3348/exhaustwn7.jpg
Intake timing
http://img259.imageshack.us/img259/5750/intakezx8.jpg
I need a new user title
Joined: Oct 2005
Posts: 2,646
Likes: 1
From: Yaizu, Japan
As I understand it...
Late opening, late closing exhaust ports (like the GSL-SE) should provide the best low-end. For high-end you basically want the biggest ports you can get (early opening, late closing).
Late opening, late closing exhaust ports (like the GSL-SE) should provide the best low-end. For high-end you basically want the biggest ports you can get (early opening, late closing).
Junior Member
Joined: Jan 2007
Posts: 26
Likes: 0
From: Arizona
Can someone please tell me:
1) in the chart above, the "IO" column gives the e-shaft angular position when the intake port just begins to open. Right?
2) if the answer to (1) is "yes", then how many additional degrees of e-shaft rotation later is the intake port fully open?
I'm playing around with some intake runner length calculations, and I need to know when the port is fully open.
Cheers,
Bug
1) in the chart above, the "IO" column gives the e-shaft angular position when the intake port just begins to open. Right?
2) if the answer to (1) is "yes", then how many additional degrees of e-shaft rotation later is the intake port fully open?
I'm playing around with some intake runner length calculations, and I need to know when the port is fully open.
Cheers,
Bug
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