Have you noticed...
Sep 30, 2008 | 12:56 AM
#1
Thread Starter
PT's Slowest Truck
iTrader: (19)
Joined: Apr 2004
Posts: 17,863
Likes: 2
From: Hackensack, NJ
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?
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?
Sep 30, 2008 | 01:34 AM
#2
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.
Oct 1, 2008 | 12:46 PM
#4
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.
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.
Oct 1, 2008 | 01:38 PM
#5
Thread Starter
PT's Slowest Truck
iTrader: (19)
Joined: Apr 2004
Posts: 17,863
Likes: 2
From: Hackensack, NJ
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.
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.
Oct 1, 2008 | 01:47 PM
#7
TECH Apprentice
Joined: Jan 2007
Posts: 353
Likes: 0
From: Perry FL
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.
