Power transfer - motor to wheels
12-02-2013, 10:49 AM
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Power transfer - motor to wheels Does anyone have a guesstimate as to what improvement, either in percentage or HP gain, that you have seen or would expect to see when going from stock C5 LS1 clutch to a McLeod RST? I had one guy say he experienced a 30 hp improvement on the power his motor got to the wheels when going from stock LS7 clutch to a RXT due to decreased weight. That's about a 5% gain. I believe this was with stock flywheel.
Any guesses going from C5 LS1 clutch to RST? I guess getting her on the dyno is the best way to find out...
Any guesses going from C5 LS1 clutch to RST? I guess getting her on the dyno is the best way to find out...
12-02-2013, 11:06 AM
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If you receive any "HP gain" it will only be when motor
RPM is changing quickly, and you'd have to constrain
your period-of-interest to within a single gear - the
momentum put to the clutch / flywheel is taken back
out across the next gear change.
Squint too close at a dyno curve and you can convince
yourself of a lot of things, that don't really mean Jack
in real life.
RPM is changing quickly, and you'd have to constrain
your period-of-interest to within a single gear - the
momentum put to the clutch / flywheel is taken back
out across the next gear change.
Squint too close at a dyno curve and you can convince
yourself of a lot of things, that don't really mean Jack
in real life.
12-02-2013, 11:33 AM
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If you receive any "HP gain" it will only be when motor
RPM is changing quickly, and you'd have to constrain
your period-of-interest to within a single gear - the
momentum put to the clutch / flywheel is taken back
out across the next gear change.
Squint too close at a dyno curve and you can convince
yourself of a lot of things, that don't really mean Jack
in real life.
RPM is changing quickly, and you'd have to constrain
your period-of-interest to within a single gear - the
momentum put to the clutch / flywheel is taken back
out across the next gear change.
Squint too close at a dyno curve and you can convince
yourself of a lot of things, that don't really mean Jack
in real life.
12-03-2013, 09:08 AM
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If you receive any "HP gain" it will only be when motor
RPM is changing quickly, and you'd have to constrain
your period-of-interest to within a single gear - the
momentum put to the clutch / flywheel is taken back
out across the next gear change.
Squint too close at a dyno curve and you can convince
yourself of a lot of things, that don't really mean Jack
in real life.
RPM is changing quickly, and you'd have to constrain
your period-of-interest to within a single gear - the
momentum put to the clutch / flywheel is taken back
out across the next gear change.
Squint too close at a dyno curve and you can convince
yourself of a lot of things, that don't really mean Jack
in real life.
12-03-2013, 01:15 PM
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I was thinking the same thing, that or "hp gain" from lighter fly wheel/new clutch setup. I want a 30+hp gain from a clutch. then i would be on the numbers I'd like to see from that alone.
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12-03-2013, 01:18 PM
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I would think the who told me that, being a speed shop guy, would've mentioned if the clutch was slipping. Anyway, possibly a little of that. It was a heavy LS7 clutch though that was being upgraded from.
12-03-2013, 01:20 PM
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I thought about going with a lighter flywheel but my car is primarily a street car so I didn't want the harsher engagement.
12-03-2013, 09:10 PM
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To clarify, I fully expected that was some sort of exceptional result (if even true) but it does make sense that with the lighter clutch there would be some drivetrain improvement. I was curious if anyone else had done this same upgrade or if anyone had enough experience to venture a guess as to resulting gain at the wheels from this upgrade. I figured a 1-3% gain would be reasonable just based on the typical range of HP percentage lost from flywheel to the ground.
12-03-2013, 10:14 PM
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You will be able to use the power you have alot better with a lightwheight. Power output stays the same you wont see any gains on a dyno from a flywheel but you will sure as hell see it on the street.
12-03-2013, 10:22 PM
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To clarify, I fully expected that was some sort of exceptional result (if even true) but it does make sense that with the lighter clutch there would be some drivetrain improvement. I was curious if anyone else had done this same upgrade or if anyone had enough experience to venture a guess as to resulting gain at the wheels from this upgrade. I figured a 1-3% gain would be reasonable just based on the typical range of HP percentage lost from flywheel to the ground.
12-03-2013, 10:35 PM
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Right, freeing up the power that is already there but the dyno would measure the street value not the flywheel value, so wouldn't it show up on the dyno?
12-03-2013, 11:31 PM
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I believe that you would see little to no peak HP gain. However, if you consider the definition of power as being the rate of doing work, then you sould see an increase in power at the wheels as the car accelerates. I believe in a dyno pull, this would manifest itself as a steeper increase in the power curve and more area under the curve, but virtually the same peak HP as the motor lays over at the HP peak.
Since a quarter mile pass is a series of dyno pulls in each gear, I believe the lighter flywheel would result in a quicker ET with trap speed being virtually the same as before. This is assuming the car is geared to reach HP peak in the traps....... I would also think that if the car pulls hard through the traps, then you would get some increase in trap speed too.
Might be wrong, but it makes sense to me. Would love to see back to back passes on the 1/4 mile dyno to see what really happens.
My experience is based on an old alcohol injected dragster that would lay over at 159 mph. It would not go any faster in high gear no matter how hard we ran it in low. When the motor laid over in high gear, it became a real turd.
12-04-2013, 07:32 AM
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I've been thinking about this for the last 24 hours or so. I will state that I am not an expert....
I believe that you would see little to no peak HP gain. However, if you consider the definition of power as being the rate of doing work, then you sould see an increase in power at the wheels as the car accelerates. I believe in a dyno pull, this would manifest itself as a steeper increase in the power curve and more area under the curve, but virtually the same peak HP as the motor lays over at the HP peak.
Since a quarter mile pass is a series of dyno pulls in each gear, I believe the lighter flywheel would result in a quicker ET with trap speed being virtually the same as before. This is assuming the car is geared to reach HP peak in the traps....... I would also think that if the car pulls hard through the traps, then you would get some increase in trap speed too.
Might be wrong, but it makes sense to me. Would love to see back to back passes on the 1/4 mile dyno to see what really happens.
My experience is based on an old alcohol injected dragster that would lay over at 159 mph. It would not go any faster in high gear no matter how hard we ran it in low. When the motor laid over in high gear, it became a real turd.
I believe that you would see little to no peak HP gain. However, if you consider the definition of power as being the rate of doing work, then you sould see an increase in power at the wheels as the car accelerates. I believe in a dyno pull, this would manifest itself as a steeper increase in the power curve and more area under the curve, but virtually the same peak HP as the motor lays over at the HP peak.
Since a quarter mile pass is a series of dyno pulls in each gear, I believe the lighter flywheel would result in a quicker ET with trap speed being virtually the same as before. This is assuming the car is geared to reach HP peak in the traps....... I would also think that if the car pulls hard through the traps, then you would get some increase in trap speed too.
Might be wrong, but it makes sense to me. Would love to see back to back passes on the 1/4 mile dyno to see what really happens.
My experience is based on an old alcohol injected dragster that would lay over at 159 mph. It would not go any faster in high gear no matter how hard we ran it in low. When the motor laid over in high gear, it became a real turd.
12-04-2013, 08:45 AM
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I started searching and here are a couple sites i found with good info
http://www.uucmotorwerks.com/flywhee...heel_works.htm
http://forums.nicoclub.com/does-a-li...p-t398381.html
http://www.uucmotorwerks.com/flywhee...heel_works.htm
http://forums.nicoclub.com/does-a-li...p-t398381.html
