Effects of Change in LSA discussion
#21
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Another thing. We typically lean torward the wide lsa's on this board for our applications for 4 reasons.
1- 110 lsa and less, computers don't like them. They can and have been tuned and ran but it is a battle to get them tuned just right. The idle and off idle transitions change constantly and the powerband is much more noticable rather than a smooth transition of more equal combustion efficiency across the rpm range.
2- In a lot of cases, people on this board run some form of FI or Nitrous. Neither of them like anything less than 112* lsa on a street engine.
3- Our trucks are heavy and, in most cases, have small cubic inches. Those two together are going to need all the help they can get to help get a heavier vehicle rolling.
4- Most of us still use our trucks for a daily driver and still use them as a truck to haul and tow. Putting a cam in that will increase higher rpm power, although will make it faster, will sacrifice the low end tq for everyday usability.
1- 110 lsa and less, computers don't like them. They can and have been tuned and ran but it is a battle to get them tuned just right. The idle and off idle transitions change constantly and the powerband is much more noticable rather than a smooth transition of more equal combustion efficiency across the rpm range.
2- In a lot of cases, people on this board run some form of FI or Nitrous. Neither of them like anything less than 112* lsa on a street engine.
3- Our trucks are heavy and, in most cases, have small cubic inches. Those two together are going to need all the help they can get to help get a heavier vehicle rolling.
4- Most of us still use our trucks for a daily driver and still use them as a truck to haul and tow. Putting a cam in that will increase higher rpm power, although will make it faster, will sacrifice the low end tq for everyday usability.
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Next week we'll be putting in my Dart 225's and Comp Cam. The cam #'s are 224/230, 581-588, 114. My thinking was that with these heads and cam I might lose a little on the bottom end but with the Radix and 4.56 gears it probably wouldn't make a huge difference in narrowing the range and with these heads and the 114 the upper range should be improved significantly. Is my thinking correct?
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Originally Posted by JimS
Next week we'll be putting in my Dart 225's and Comp Cam. The cam #'s are 224/230, 581-588, 114. My thinking was that with these heads and cam I might lose a little on the bottom end but with the Radix and 4.56 gears it probably wouldn't make a huge difference in narrowing the range and with these heads and the 114 the upper range should be improved significantly. Is my thinking correct?
Your truck is going to be a beast with that combo .
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Bringin' out some results... Just to show where I'm coming from.
My Pop's '03 Z06 - Bone stock w/ the 204/218-118.5LSA cam
Notice the 'lack' of torque below 3800 RPM.
Single Pattern 221 cam? One of the MTI grinds. 112LSA vs. 114LSA
112 takes the victury throughout the midrange.
224/224-110LSA/106ICL... Comp X-E grind. Check out the torque.
Shaun Perry profile... Put in a 347ci Mustang. Same EFI intake restrictions as us, applying the same rules. 246/240 110LSA/111.5ICL... Retarded the cam. Broad and Flat torque curve.
Just some results that I have saved up... I have some dynos I may host that shows the negative effects of advancing a cam in one of these motors.
... But I may save it before I get called a dyno racer.
My Pop's '03 Z06 - Bone stock w/ the 204/218-118.5LSA cam
Notice the 'lack' of torque below 3800 RPM.
Single Pattern 221 cam? One of the MTI grinds. 112LSA vs. 114LSA
112 takes the victury throughout the midrange.
224/224-110LSA/106ICL... Comp X-E grind. Check out the torque.
Shaun Perry profile... Put in a 347ci Mustang. Same EFI intake restrictions as us, applying the same rules. 246/240 110LSA/111.5ICL... Retarded the cam. Broad and Flat torque curve.
Just some results that I have saved up... I have some dynos I may host that shows the negative effects of advancing a cam in one of these motors.
... But I may save it before I get called a dyno racer.
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Originally Posted by mjhoward
.
Your truck is going to be a beast with that combo .
Your truck is going to be a beast with that combo .
Sorry to interrupt the dialouge with my personal stuff. Thanks for your interpretation of my combination. Now back to your regularly scheduled programming.......
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Originally Posted by Sport Side
Bringin' out some results... Just to show where I'm coming from.
My Pop's '03 Z06 - Bone stock w/ the 204/218-118.5LSA cam
Notice the 'lack' of torque below 3800 RPM.
Single Pattern 221 cam? One of the MTI grinds. 112LSA vs. 114LSA
112 takes the victury throughout the midrange.
224/224-110LSA/106ICL... Comp X-E grind. Check out the torque.
Shaun Perry profile... Put in a 347ci Mustang. Same EFI intake restrictions as us, applying the same rules. 246/240 110LSA/111.5ICL... Retarded the cam. Broad and Flat torque curve.
Just some results that I have saved up... I have some dynos I may host that shows the negative effects of advancing a cam in one of these motors.
... But I may save it before I get called a dyno racer.
My Pop's '03 Z06 - Bone stock w/ the 204/218-118.5LSA cam
Notice the 'lack' of torque below 3800 RPM.
Single Pattern 221 cam? One of the MTI grinds. 112LSA vs. 114LSA
112 takes the victury throughout the midrange.
224/224-110LSA/106ICL... Comp X-E grind. Check out the torque.
Shaun Perry profile... Put in a 347ci Mustang. Same EFI intake restrictions as us, applying the same rules. 246/240 110LSA/111.5ICL... Retarded the cam. Broad and Flat torque curve.
Just some results that I have saved up... I have some dynos I may host that shows the negative effects of advancing a cam in one of these motors.
... But I may save it before I get called a dyno racer.
As I stated before, there are too many variables to make a general statement like "the tighter the LSA the lower the cam comes in". My sole purpose of this thread is to keep people from saying that when it isn't true.
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Yeah, we are on the same track... This whole time when you described "bringing in the power sooner" I had assumed you were hinting towards the midrange torque and how 'soon' the torque curve, really just KICKS in.
The wide LSA is great for drivability in the Z. Idles like stock... Easy idle tuning exc. But, as you can see from the dyno, the midrange torque takes its toll in how quickly it builds up.
But anyways... Cool! Good talkin.
The wide LSA is great for drivability in the Z. Idles like stock... Easy idle tuning exc. But, as you can see from the dyno, the midrange torque takes its toll in how quickly it builds up.
But anyways... Cool! Good talkin.
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