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Old 09-30-2008, 12:56 AM
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Default Have you noticed...

...that cam manufacturers have been using a 115 LSA on their truck oriented cams? At least Comp and Vinci have. (I'm assuming that Crane has a truck grind too since Vinci does...)

Here's Comp's XTreme Truck grinds:

206/212 .513/.520 115
212/216 .520/.524 115
208/212 .554/.558 115

...and the Vinci "Trucker":

216/224 ..551/.551 115

I'm assuming it has to do with the big broad torque curve associated with the wider LSA, and the torque that's needed to get a heavy *** truck moving...and keep it moving.

Anyone care to elaborate?
Old 09-30-2008, 01:34 AM
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just from my little research, I think a lower lsa (i.e. 112) is better. It gives more torque under the curve in our useable range. I don't think we spin high enough to take advantage of the extra power up top of the higher lsa cams.
Old 10-01-2008, 11:02 AM
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I guess that nobody else has noticed lol
Old 10-01-2008, 12:46 PM
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I'm sure you know this, but it is worth repeating.
Generally the wider the LSA, the broader the torque curve will be.
And the narrower the LSA, the more peaky the curve will be.
I betcha that they are thinking about trucks needing the torque at the very bottom of the scale to get heavy loads going.
It is harder to get a load moving from a stop than it is to accelerate once moving.

Maybe they are also thinking that trucks are heavier than cars especially when loaded. Heavier vehicles need better brakes and braking pressure is built off vacuum. A wider LSA will show more engine vacuum.
Old 10-01-2008, 01:38 PM
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Originally Posted by AdioSS
I'm sure you know this, but it is worth repeating.
Generally the wider the LSA, the broader the torque curve will be.
And the narrower the LSA, the more peaky the curve will be.
I betcha that they are thinking about trucks needing the torque at the very bottom of the scale to get heavy loads going.
It is harder to get a load moving from a stop than it is to accelerate once moving.

Maybe they are also thinking that trucks are heavier than cars especially when loaded. Heavier vehicles need better brakes and braking pressure is built off vacuum. A wider LSA will show more engine vacuum.
This was my thinking exactly, except for the brake booster/engine vacuum part, didn't think of that.
Old 10-01-2008, 01:43 PM
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My cam has a 121 LSA.
Old 10-01-2008, 01:47 PM
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Originally Posted by KySilverado
My cam has a 121 LSA.
Dag um thats a hell of a number. I love my 114 LSA but I'm thinking as soon as I get the chance I'm getting a much milder truck cam that is good for everyday driving and towing with stock drive-train components. Plus I want to see if my fuel milage will increase a little.
Old 10-01-2008, 01:49 PM
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Originally Posted by KySilverado
My cam has a 121 LSA.
WTF do you have in there?
Old 10-01-2008, 01:53 PM
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Originally Posted by AdioSS
WTF do you have in there?
Lingenfelter design. GT7

LS1-GT7 208 / 230 .554" / .546" 1.7 ratio 121 LSA
Old 10-01-2008, 02:52 PM
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Originally Posted by KySilverado
Lingenfelter design. GT7

LS1-GT7 208 / 230 .554" / .546" 1.7 ratio 121 LSA
I wanna hear an idle clip of that thing



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