Based on torque figures for the 951 engine.

Has anybody done a calculation of this sort for any engine?

Any comments are appretiated.

 

For a stock 951 engine,close to 1010 psi.

 

Really? That sounds high, but I am just comparing to graphs of unknown engines that I have..

 

Yeah,that's what I get when calculating the peak cylinder pressure...It wasn't BMEP you were looking for?

 

No, I am ordering a spark plug combustion pressure sensor, and the options are 0-100bar or 0-200 bar range. By your numbers, it sounds like the 0-200 bar may be necessary for use on heavily modified engines.

Would you mind posting the method of calculation? I know it must be pretty complicated, and I have been looking through books with no luck.

 

100 bar = 1480 psi

 

I figured that part out myself ... but for a higher boost engine it is going to be more, say I am working on an engine that makes 600 hp , then the peak pressure is likely to be over 100 bar if stock really reaches 1010 psi.

 

yep :-)

 

hmm reminds me of the idea - to calculate knock - from inside the combustion chamber. wonder what happens on a linear graph if you take a run from 0/1bar to 1/2 WOT. and then deliberately induce a slight knock doing the same test. I am sure you would be able to detect the knock. Now that would make the knock detection issues a thing of the past.

 

Except for the cost involved..... OEMs and race teams do this anyway, just not reasonable or necessary yet for the average car.

 

You'll need the 200 Bar one... If you boost enough to get to 600 hp,even very well tuned,you'll be at the other side of 2000 psi,altough barely...if you don't tune it that optimum,but run race fuel to compensate,the 200 Bar one just barely makes it... 2450-2720 psi,depending on tune.

Unfortunately,I cannot give you the formula to calculate it,I have software that does that for me.