Choice of Cam??
Choice of Cam??
i tried engine tech forum and no one seems to be able to answer what i'm asking so im going to try here...
i plan on doing cams soon and need to decide which duration to go with 272 280 and so on. What i'm trying to find out is what the durations do. why go with a 272 rather than 280? why do a 272 on intake and 280 on exhaust (2 different durations instead of a matching pair)? if im understanding correct more lift the more exhaust or intake the valve will allow to enter the chamber or exit to the exhaust. if thats correct then im half way...... what i want to know is why go with one rather than the other. pro and cons whatever just please help me understand so i can make a good choice......
i plan on doing cams soon and need to decide which duration to go with 272 280 and so on. What i'm trying to find out is what the durations do. why go with a 272 rather than 280? why do a 272 on intake and 280 on exhaust (2 different durations instead of a matching pair)? if im understanding correct more lift the more exhaust or intake the valve will allow to enter the chamber or exit to the exhaust. if thats correct then im half way...... what i want to know is why go with one rather than the other. pro and cons whatever just please help me understand so i can make a good choice......
Newbie
Joined: Jun 2004
Posts: 49
Likes: 0
From: Miami Lakes
How I understand it, though I might be a bit off is:
272s are great for stock turbo and depending on cam manufacturer they wont require a sprint kit, good idle, minimum issues.
280s for larger turbos then stock to maximize their efficiency, might have idle issues or cold start issues, require stricter ecu management, considered race application only.
The reasoning behind the 272/280 setups for the 9 is based on the MIVEC controlled exhaust cam (evo 9 has 1 exhaust and 10 has both ext/int) allowing really good gains while maintaining good idle and street drive ability.
Hope that helps. Im sure you can find a ton more information on the forums through searching, broaden your search area beyond the tech guides.
272s are great for stock turbo and depending on cam manufacturer they wont require a sprint kit, good idle, minimum issues.
280s for larger turbos then stock to maximize their efficiency, might have idle issues or cold start issues, require stricter ecu management, considered race application only.
The reasoning behind the 272/280 setups for the 9 is based on the MIVEC controlled exhaust cam (evo 9 has 1 exhaust and 10 has both ext/int) allowing really good gains while maintaining good idle and street drive ability.
Hope that helps. Im sure you can find a ton more information on the forums through searching, broaden your search area beyond the tech guides.
Yup, as soon as you list your mods most of us can tell you at least what duration to get. Chances are some GSC S1s would be wonderful for you though. I had a set for my Evo, decided to sell it right before I put them on.
well i have a buschur mail in flash, intake, turbo back exhaust with high flow cat, walbro, upper ic pipe, mini battery, and thats about it..... i'm still trying to learn so i was thinking of doing the cams and maybe an intercooler and lower ic pipe before messing with the turbo
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Id say get a set of 272's with springs and retainers for better idle and higher rev capabilities than have who ever installs these throw in that boost controller set to 23psi and get it reflashed. But thats just what I would do.
Its going to take a little more then a paragraph to get all the considerations for a cam. In addition to all of the above...the bigger the cam number the higher in the rmps the power band goes..( no this doesnt mean red line moves up). Do yourself a favor visit some cam manufacturer websites, buy a book, so you really get a grasp of things..too big a cam with mismatched components is a real mess. everyone has an opinion--so asking the masses will get you a variety of answers all with conditions...
Evolved Member
Joined: May 2007
Posts: 884
Likes: 0
From: W SUNSET & PCH
one thing that im vVERY suprised nobody touched on is lift. duration is when thing but lift is a whole nother topic.
for example a HKS 280 duration cam has a low lift for such a high duration. this is ideal for adding as much air as possible with out going ridiculously aggressive on duration. so if you plan on running allot of race fuel (more than ounce a month) than this is something you should research more.
for doing staggered setups, 272 intake and 280 exhaust (or vice versa) is to have a more controlled amount of air for your setup. ideally you want to get as much air into the motor as possible but at the same time we have a turbo. so you can argue the point that you want as much air as possible going out to spool the turbo.
but as meck said, buy a book or two. visit manufactures websites to get all the schematics of the cam. duration, lift, etc, etc,
for example a HKS 280 duration cam has a low lift for such a high duration. this is ideal for adding as much air as possible with out going ridiculously aggressive on duration. so if you plan on running allot of race fuel (more than ounce a month) than this is something you should research more.
for doing staggered setups, 272 intake and 280 exhaust (or vice versa) is to have a more controlled amount of air for your setup. ideally you want to get as much air into the motor as possible but at the same time we have a turbo. so you can argue the point that you want as much air as possible going out to spool the turbo.
but as meck said, buy a book or two. visit manufactures websites to get all the schematics of the cam. duration, lift, etc, etc,
