Cam Lsa... ?
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From: St. Paul MN
Cam Lsa... ?
Ok, I know this is a question that will make the experts shake their head, but I am fairly ignorant when it comes to internals. I know I want to add a cam. The exact size, not sure. Not extreme, but not completely tame.
but my question is, I know the 112 lsa is more recommended for manuals, and 114 lsa for autos. I have an '06 auto, but really want the rough idle of the 112 lsa. Is there any other way to achieve this? or is it possible to have a 112 lsa efficiently work in my auto?
ps... will be getting LG Lt's, catted X-pipe and corsa prior to cam
If this has been beat to death, I apologize, I didnt find it in search. Thank you for the help guys.
but my question is, I know the 112 lsa is more recommended for manuals, and 114 lsa for autos. I have an '06 auto, but really want the rough idle of the 112 lsa. Is there any other way to achieve this? or is it possible to have a 112 lsa efficiently work in my auto?
ps... will be getting LG Lt's, catted X-pipe and corsa prior to cam
If this has been beat to death, I apologize, I didnt find it in search. Thank you for the help guys.
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112lsa or 114lsa alone will not let you know how the cam will idle.
Cam overlap comes from intake/exhaust duration and LSA to determine how the car will idle.
((Intake + Exhaust) / 4 - LSA) * 2
More overlap = more aggressive idle
Cam overlap comes from intake/exhaust duration and LSA to determine how the car will idle.
((Intake + Exhaust) / 4 - LSA) * 2
More overlap = more aggressive idle
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Well a lower LSA will have a choppier idle than a higher LSA if all else is equal with the cam, sure.
That doesn't mean, however, that you can't have a 114lsa idle rougher than a 111lsa
A 228/232 114lsa (2 degrees overlap) will idle harder than a 220/220 111lsa (-2 degrees overlap)
LSA is just a factor in the equation.
In an A6 you can run low LSA and big duration, it just takes more skilled tuning.
The cam going in my car is a 238/242 110lsa (20 degrees overlap). It's going to be VERY rough though.
That doesn't mean, however, that you can't have a 114lsa idle rougher than a 111lsa
A 228/232 114lsa (2 degrees overlap) will idle harder than a 220/220 111lsa (-2 degrees overlap)
LSA is just a factor in the equation.
In an A6 you can run low LSA and big duration, it just takes more skilled tuning.
The cam going in my car is a 238/242 110lsa (20 degrees overlap). It's going to be VERY rough though.
Last edited by FloydSummerOf68; Sep 14, 2011 at 05:09 PM.
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From: St. Paul MN
Well a lower LSA will have a choppier idle than a higher LSA if all else is equal with the cam, sure.
That doesn't mean, however, that you can't have a 114lsa idle rougher than a 111lsa
A 228/232 114lsa (2 degrees overlap) will idle harder than a 220/220 111lsa (-2 degrees overlap)
LSA is just a factor in the equation.
In an A6 you can run low LSA and big duration, it just takes more skilled tuning.
The cam going in my car is a 238/242 110lsa (20 degrees overlap). It's going to be VERY rough though.
That doesn't mean, however, that you can't have a 114lsa idle rougher than a 111lsa
A 228/232 114lsa (2 degrees overlap) will idle harder than a 220/220 111lsa (-2 degrees overlap)
LSA is just a factor in the equation.
In an A6 you can run low LSA and big duration, it just takes more skilled tuning.
The cam going in my car is a 238/242 110lsa (20 degrees overlap). It's going to be VERY rough though.
so the higher duration is more of a factor in the choppy, throaty sound?
if so, how do you measure duration?
(understanding that this is a whole new topic, but if can be answered somwhat easily, I would appreciate it)
Last edited by Italiano24; Sep 15, 2011 at 10:13 AM.
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A lower idle speed makes any cam choppy. If all you want is a good idle lope, lower the idle RPM until you get the sound you want. Also lowering the ignition timing advance makes it shake more.
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Also, if anyone is able to chime in on my previous duration question
Thank you
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Based upon the above questions, my suggestion is get your cam from whomever is going to do your tune (yes, you will need to modify the engine computer settings) and tell them what you want to achieve. That way you'll get a cam that will achieve your lumpy idle and be able to be tuned to meet the rest of your driving goals. I think DRM is in your neck of the woods and would be a good place to check out.
Increasing duration increases overlap and overlap is a significant factor in idle quality.
Duration is measured as the time the valve is being lifted. Advertised duration is when the valve is just starting to be lifted. It is common to quote cam specs at .05 lift, and that is the lift used in the duration numbers you see quoted.
so the higher duration is more of a factor in the choppy, throaty sound?
if so, how do you measure duration?
if so, how do you measure duration?
Duration is measured as the time the valve is being lifted. Advertised duration is when the valve is just starting to be lifted. It is common to quote cam specs at .05 lift, and that is the lift used in the duration numbers you see quoted.
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I also have an automatic..I just got KOOKS headers, & plan on a cam..
I told Cartek I need a cam to work with my stock converter, but pull hard over 3000 rpm.. (I don;t give a S$%T about a "choppy" idle, I'm not out to impress anyone, I WANT PERFORMANCE the hell with how it sounds at idle.... I want it to "PULL" strong between 3000 - 65000 RPM...
I'm sure I could get a cam to sound like a Top Fuel car, but run line a Honda Civic... (Not what I want)
When I get the # on the cam that will give me PERFORMANCE not SOUND I'll post it here...
Just curious how many of you guys prefer a shi%%y running car that sounds bas azz.. or who would prefer a mild sounding idle, but a cam that PULLS HARD between 3000 - 6000 rpm... JMO
I told Cartek I need a cam to work with my stock converter, but pull hard over 3000 rpm.. (I don;t give a S$%T about a "choppy" idle, I'm not out to impress anyone, I WANT PERFORMANCE the hell with how it sounds at idle.... I want it to "PULL" strong between 3000 - 65000 RPM...
I'm sure I could get a cam to sound like a Top Fuel car, but run line a Honda Civic... (Not what I want)
When I get the # on the cam that will give me PERFORMANCE not SOUND I'll post it here...
Just curious how many of you guys prefer a shi%%y running car that sounds bas azz.. or who would prefer a mild sounding idle, but a cam that PULLS HARD between 3000 - 6000 rpm... JMO
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Joined: Apr 2009
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From: St. Paul MN
I also have an automatic..I just got KOOKS headers, & plan on a cam..
I told Cartek I need a cam to work with my stock converter, but pull hard over 3000 rpm.. (I don;t give a S$%T about a "choppy" idle, I'm not out to impress anyone, I WANT PERFORMANCE the hell with how it sounds at idle.... I want it to "PULL" strong between 3000 - 65000 RPM...
I'm sure I could get a cam to sound like a Top Fuel car, but run line a Honda Civic... (Not what I want)
When I get the # on the cam that will give me PERFORMANCE not SOUND I'll post it here...
Just curious how many of you guys prefer a shi%%y running car that sounds bas azz.. or who would prefer a mild sounding idle, but a cam that PULLS HARD between 3000 - 6000 rpm... JMO
I told Cartek I need a cam to work with my stock converter, but pull hard over 3000 rpm.. (I don;t give a S$%T about a "choppy" idle, I'm not out to impress anyone, I WANT PERFORMANCE the hell with how it sounds at idle.... I want it to "PULL" strong between 3000 - 65000 RPM...
I'm sure I could get a cam to sound like a Top Fuel car, but run line a Honda Civic... (Not what I want)
When I get the # on the cam that will give me PERFORMANCE not SOUND I'll post it here...
Just curious how many of you guys prefer a shi%%y running car that sounds bas azz.. or who would prefer a mild sounding idle, but a cam that PULLS HARD between 3000 - 6000 rpm... JMO
Hey I'm glad you chimed in... I must have missed the part where I said I want a choppy idle "AND NO PERFORMANCE TO COME FROM MY CAM WHATSOEVER... I JUST WANT TO IMPRESS PEOPLE THROUGH THE MAGIC OF SOUND ALONE." I would have missed it if you wouldn't have brought it to my attention.
The addition of LT's, X-pipe and Corsa means I want my car to run shi%%y, you pegged me
Last edited by Italiano24; Sep 15, 2011 at 08:59 PM.
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