i was wondering how we can output 271hp from the 2L engine and boost peaking to 19psi?
i need technical data and even equations or calculations if needed!
i dont need thoughts and opinions, i need sharp data plz!

 

You're in WAY over your head. There's no 'simple' equation. It would take pages to just list all the variables, not even mentioning the equations.

There's a reason people use $10k software to predict this stuff.

 

Uhh 19 is stock PSI. MBC, Turboback and a Flash will get you 271 easy

 

i didnt get u?
the evo is 271hp stock y to do all modifications!

 

Because people want more power.

 

He meant 271 wheel horsepower not crank. Stock Evo 8 are 270 hp at the crank and around 245 hp at the wheels.

 

am replying on a prev quote, that no need to do mods to achieve 271hp!!

obv. we need to mod. to gain more power!

 

so we cant have a brief and logical way to analyse the 271HP?

 

I think this guy is looking for actual equations to explain the physics behind the 4G63 power output. It actually shouldnt be too hard to calculate the relationship between boost pressure, displacement, and hp. I might have to bust out my thermo book and refresh my memory on this stuff (been a few years).

 

^+100000

 

Well, no... there is no way to calculate 271hp in an easy way. There are many variables.

Flow Dynamics of EVERY component.
Thermal efficiency of the combustion process
Friction Losses
Windage
Parasidic drag.

You can definately calculate an "ideal" engine model, with as was said before pages and pages of data. But it would be so far off from the reality, that it's worthless. This is why engineers improve engine design over years. They design a basic structure to perform well, and through testing, testing and MORE testing, they refine it. If it could all be done before with computer modeling, they would plop out a 100% efficient engine in the begining and be done with it.

 

I'll see what I can dig up as well.

 

I am sorry, I spoke too soon. I just found this book on my shelf:

"The internal combustion engine in theory and practice" It's 782 pages of equations, calculations and theorys published by the MIT press.

That should be one of about twenty books you will need to properly calculate the horsepower of this engine

 

wow!!
u know am really interested to see also that at 0.8 bar what hp evo output!
i think when we know how these hp are output then we can manipulate with different variable to c the difference!
very interesting subject : ) !

 

Like I said

Or, you can pay a license fee to Ricardo to use their software. Of course, your engine model is only as good as your input data.

Well, you can do a very simplistic, ballpark, calculation. First of all, the Evo doesn't make 271hp at 19psi as the boost tapers. So it's actually at about 17.5psi which equals 2.22 bar absolute (assuming 1 atm ambient). 0.8 bar boost equals ~1.81 absolute.

so 1.81/2.22 = .815, .815 * 271hp = ~221hp. There ya go. Overly simplified, but gives you a general idea.