110 LSA on highway ?
02-28-2007, 11:06 AM
#22
This thread made my brain hurt. I think it made like, 25 baby seals die and baby Jesus cry like 15 times.
You're all talking about LSA as if it wasn't a realative measurment. You should be talking about overlap. LSA is only a factor in calculating the overlap.
You can figure overlap with this equation: Intake duration plus Exaust duration, divided by 4, minus LSA, times 2.
For instance, a 226/236 110 LSA GMPP ASA cam has 11* of overlap. The TRex, a well known racing cam from Thunder Racing, has 25* of overlap. The TR224 cam on a 112 LSA, basically the standard by which all street cams are measured, has no overlap (0*).
Copied and pasted from the cam FAQ:
You're all talking about LSA as if it wasn't a realative measurment. You should be talking about overlap. LSA is only a factor in calculating the overlap.
You can figure overlap with this equation: Intake duration plus Exaust duration, divided by 4, minus LSA, times 2.
For instance, a 226/236 110 LSA GMPP ASA cam has 11* of overlap. The TRex, a well known racing cam from Thunder Racing, has 25* of overlap. The TR224 cam on a 112 LSA, basically the standard by which all street cams are measured, has no overlap (0*).
Copied and pasted from the cam FAQ:
Originally Posted by jrp
- LSA is defined as spread in camshaft degrees between the intake centerline and the exhaust centerline.
- Overlap is the number of crankshaft degrees that both the intake and exhaust valves are open as the cylinder transitions through the end of the exhaust stroke and into the intake stroke
- Bigger duration cams will have more overlap then a smaller duration cam even if both are on the same LSA.
- The key to making overlap work is maximizing the power in the rpm band where you want it.
- Long overlap periods work best for high-rpm power. For the street, a long overlap period combined with long-duration profiles combine to kill low-speed torque
- Reducing overlap on a long-duration cam will often increase midrange torque at the expense of peak power, but if the average torque improves, that’s probably a change worth making.
- Many enthusiasts purchase a camshaft strictly on the basis of how it sounds. A cam with generous overlap creates that distinctive choppy idle that just sounds cool.
- Overlap is the number of crankshaft degrees that both the intake and exhaust valves are open as the cylinder transitions through the end of the exhaust stroke and into the intake stroke
- Bigger duration cams will have more overlap then a smaller duration cam even if both are on the same LSA.
- The key to making overlap work is maximizing the power in the rpm band where you want it.
- Long overlap periods work best for high-rpm power. For the street, a long overlap period combined with long-duration profiles combine to kill low-speed torque
- Reducing overlap on a long-duration cam will often increase midrange torque at the expense of peak power, but if the average torque improves, that’s probably a change worth making.
- Many enthusiasts purchase a camshaft strictly on the basis of how it sounds. A cam with generous overlap creates that distinctive choppy idle that just sounds cool.
03-01-2007, 08:14 AM
#23
TECH Senior Member
Originally Posted by Sharpe
This thread made my brain hurt. I think it made like, 25 baby seals die and baby Jesus cry like 15 times.
You're all talking about LSA as if it wasn't a realative measurment. You should be talking about overlap. LSA is only a factor in calculating the overlap.
You're all talking about LSA as if it wasn't a realative measurment. You should be talking about overlap. LSA is only a factor in calculating the overlap.
You can figure overlap with this equation: Intake duration plus Exaust duration, divided by 4, minus LSA, times 2.
For instance, a 226/236 110 LSA GMPP ASA cam has 11* of overlap
The TRex, a well known racing cam from Thunder Racing, has 25* of overlap. The TR224 cam on a 112 LSA, basically the standard by which all street cams are measured, has no overlap (0*).
Copied and pasted from the cam FAQ:
Copied and pasted from the cam FAQ:
03-01-2007, 11:56 AM
#25
TECH Senior Member
Originally Posted by Sharpe
Really? How so? Am I just doing the math wrong or is there another factor? (Not that there's much difference for rough figures used to quickly compare cams, but...)
03-01-2007, 12:31 PM
#27
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Originally Posted by LS1T/A4
So my cam 224/228 .590/.590 113 will have no overlap.
(224+228)/2-2(113)=0
Will it still sound like the car is "cammed"?
~J
(224+228)/2-2(113)=0
Will it still sound like the car is "cammed"?
~J
03-01-2007, 05:15 PM
#28
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I have an M6 running a 110 with 3.23 gears. I've got a little bit of bucking, but that is due to my tune being off. (Vacuum leak that has since been resolved. ) I wouldn't worry about it. 
03-01-2007, 05:59 PM
#29
Originally Posted by Mssingkid
I have an M6 running a 110 with 3.23 gears. I've got a little bit of bucking, but that is due to my tune being off. (Vacuum leak that has since been resolved. ) I wouldn't worry about it.
03-01-2007, 11:16 PM
#30
Originally Posted by LS1T/A4
So my cam 224/228 .590/.590 113 will have no overlap.
(224+228)/2-2(113)=0
Will it still sound like the car is "cammed"?
~J
(224+228)/2-2(113)=0
Will it still sound like the car is "cammed"?
~J
I think it will sound just like a TR224 112 cam, which, by the way, I love. Visit www.ls1sounds.com for samples. If it doesn't have enough lope sound for you, lower the idle. I googled "LS1 stock cam duration lift LSA" and got this for a 98 C5: 202/210 .472/.479 117
That would be -1.5 degrees of overlap, if I did the math right.
Keep in mind that all this is just for rough, simplified guidelines, and I got my info just by searching and reading others' posts who know way more than me (like PREDATOR-Z, even if I was right and he was wrong, Naaaa!
) on this forum. I'm not trying to pass myself off as PatG or anything, just trying to help out. Sorry my first post was kind of pissy. I just five minutes earlier fond out that the damn government cant afford to give me a Pell grant, though I live on my own and make $9.5/hr... Looks like my life will never get any better, I'll never make more money, and worst of all, my time slip will never get any lower.
03-02-2007, 07:06 AM
#31
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Originally Posted by bww3588
im hoping you have automatic gears because you once had an automatic in that car and not because you put them there by choice. i bet 6th gear is worthless unless your doing 70.
Yea, the car was an AUTO, thats why i still have the 3.23's back there(Still debated on 3.90's or 4.11's for my 12bolt). It's not as bad as i thought it was going to be, but yes 6th is worthless unless i'm going like 75. It gets great gas mileage
