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WHATEVER
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In looking at all the dyno sheets the motor stops making power at 9000rpm, why is that? If the rev limit is moved to 10,000 will it continue to build HP?
 

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DTHDOC said:
In looking at all the dyno sheets the motor stops making power at 9000rpm, why is that?
That's where the rev limiter kicks in.
 

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DTHDOC said:
In looking at all the dyno sheets the motor stops making power at 9000rpm, why is that? If the rev limit is moved to 10,000 will it continue to build HP?
Your cam choice will dictate the powerband of an engine. The stock cams begin to keel over around 86-8700rpm. Get something with more duration and you will raise the powerband up and beyond 9000rpm, further if you really want but you loose streetability then.
 

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Wet Blanket
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o2man98 said:
Your cam choice will dictate the powerband of an engine. The stock cams begin to keel over around 86-8700rpm. Get something with more duration and you will raise the powerband up and beyond 9000rpm, further if you really want but you loose streetability then.
I think it also depends on the color of powerband you are running. :stilpoke:
 

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myvrodrocks
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With increased RPM you also need stiffer springs so that the valve will actually close. If you can imagine the cam turning so fast that it throws the valve open and then actually looses contact with the valve...that is called valve float. then the piston comes up so fast and tries to compress the air/fuel and the valve is still open and the mixture is pushed back out the opening and power is lost. there is a fine line between max power and where it falls off. Over-reving an engine can be dangerous because if the piston goes faster than the valve closes, then they could contact and bend or break..
 

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Color me Gone
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If the power drops like a rock you know it hit the rev limiter. If it starts to fall off a little slower you know it ran out of camshaft. I think the guys with the destroyers that have over .500 lift cams are running them to 11k and still making power but with stock cams your going to peak between 8500 and 9000 IMHO. As others mentioned you also need better springs as you start turning the engines faster so the valves don't float. I know with the turbo and Nicks map my redline is set at 9,500 and mine pulls strong to the point it shuts off the fuel.
 

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'04 1300
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Max said:
If the power drops like a rock you know it hit the rev limiter. If it starts to fall off a little slower you know it ran out of camshaft. I think the guys with the destroyers that have over .500 lift cams are running them to 11k and still making power but with stock cams your going to peak between 8500 and 9000 IMHO. As others mentioned you also need better springs as you start turning the engines faster so the valves don't float. I know with the turbo and Nicks map my redline is set at 9,500 and mine pulls strong to the point it shuts off the fuel.
Are you using the stock heads/valves/springs to 9500?
 

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Color me Gone
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sburke91 said:
Are you using the stock heads/valves/springs to 9500?
Yes, currently. I am however building an engine now just to turn the boost up that will be using stock springs but different cams and SE heads. With the turbo though the lift won't be much more then stock just reduced duration to take advantage of the forced induction.
 

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surely there are curves out there from people with an SERT who have raised the limiter enough to show when power is dropping off? How far can you raise the limiter with an SERT? I don't have one and am curious.
 

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Dilligaf
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It's looking like this thread is going to thin out the heard of v-rods on the street.:stilpoke:
 

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DTHDOC said:
In looking at all the dyno sheets the motor stops making power at 9000rpm, why is that? If the rev limit is moved to 10,000 will it continue to build HP?
stock power peak is in before 9000 . unless you cam it and increase airflow that is the way it is.
 

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kerryw said:
surely there are curves out there from people with an SERT who have raised the limiter enough to show when power is dropping off? How far can you raise the limiter with an SERT? I don't have one and am curious.
you can raise the rpm limit high enough to put the rods out. (11000 plus.)
 
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