horse power gains

[bulldog0369]

I have a 2005 Monte Carlo SS, I plan on changing the factory pulley with a 3.25" pulley, how much HP will I gain with this swap?

 

[old-git]

Try this:

Boost (psi) = (PR x 14.7 x V / C/2 ) - 14.7 - I

PR is pulley ratio, crank pulley diameter divided by drive pulley diameter.

14.7 is the pressure of the air we live in, we don't live in a vacuum, we live in 14.7 psi.

V is the volume of your blower for one rotation.

C is capacity of the engine in cc
C/2 is C divided by 2 - because for one rotation, a four stroke engine is only half way through a complete cycle. When the piston is up the top and starts going down, air and fuel go in, then it gets to the bottom and goes back up and compresses the mixture. That's one rotation. Then the spark plug ignites the mixture and it starts to go down again, it gets to the bottom and then goes back up again pushing the burnt mixture out the exhaust valve and returns to the top to start over again. That's two rotations.

I (capital "i") is an allowance for boost lost due to valve overlap. All engines have valve overlap; the intake valve opens before the exhaust valve closes - the incoming fresh air and fuel pushes out the last of the burnt exhaust gases.. The allowance is around 5% boost lost for every 10 degrees of overlap.

 

[TCJBOLDIE]

Am constantly reminded of how little I know when the O-G punches out tech details like this ^^^^^

 

[T9 man]

Greetings bulldog0369 and a Warm Welcome to our TorqueCars Forum my Friend!

Good to have you along with us

 

[davalav]

Am constantly reminded of how little I know when the O-G punches out tech details like this ^^^^^

I know... I feel a superior when I get all technical with friends! Then I read one of OG's comments I feel very stupid.


Stop being so smart!

 

[old-git]

Sorry, I will shut up :-(

 

[T9 man]

 

[TCJBOLDIE]

Sorry, I will shut up :-(

That has as much chance of happening as King Canute s attempt to stop the tides

 

[old-git]

True However, King Canute didn't try to stop the tide. He was simply showing his subjects that he wasn't a god

 

[HDi fun]

Bad move by Canute. It's better to be feared than to be loved in a lofty position such as that occupied by the aforementioned.

And we all know that fear of the unknown is the greatest fear of all.

 

[Andrewchou]

Try this:

Boost (psi) = (PR x 14.7 x V / C/2 ) - 14.7 - I

PR is pulley ratio, crank pulley diameter divided by drive pulley diameter.

14.7 is the pressure of the air we live in, we don't live in a vacuum, we live in 14.7 psi.

V is the volume of your blower for one rotation.

C is capacity of the engine in cc
C/2 is C divided by 2 - because for one rotation, a four stroke engine is only half way through a complete cycle. When the piston is up the top and starts going down, air and fuel go in, then it gets to the bottom and goes back up and compresses the mixture. That's one rotation. Then the spark plug ignites the mixture and it starts to go down again, it gets to the bottom and then goes back up again pushing the burnt mixture out the exhaust valve and returns to the top to start over again. That's two rotations.

I (capital "i") is an allowance for boost lost due to valve overlap. All engines have valve overlap; the intake valve opens before the exhaust valve closes - the incoming fresh air and fuel pushes out the last of the burnt exhaust gases.. The allowance is around 5% boost lost for every 10 degrees of overlap.

awesome formulae!:bigsmile: