[revetec]

Originally Posted by hightower99

I believe you are misunderstanding what I said. Say you have a 2L engine and it produces 200HP (149kW) at 8000RPM, this means it is producing 131.3lbs-ft. of torque (178Nm) at 8000RPM. The calculated BMEP is then: 4*p*178Nm/0.002(m^3)= 1118.4kPa BMEP. Now the only ways to change that figure are: change dispacement or change the torque. As long as it is a 2L engine producing 131.3lbs-ft. (178Nm) of torque then the BMEP is always going to be 1118.4kPa. However the output (I am assuming you mean power?) can be pretty much anything depending on RPM. If you want a lower BMEP for any given output then you need to rev higher, which is not good for efficiency. If you are talking about avg. cyl. pressure vs. torque then that is mechanical efficiency.

So what happens to the BMEP at partial throttle?
Torque decreases and the BMEP decreases.
Look, you are still talking about BMEP at wide open throttle.

The BMEP shows how efficient combustion and the mechanical efficiency of the engine but what it doesn't show is the amount of fuel you are using to achieve it.

This is why BSFC is the real figure to measure efficiency. It actually shows how much fuel per kW-h you are making. This is Efficiency! You can have an engine that produces high BMEP but at what fuel cost.

Originally Posted by hightower99

I loath how you try to simplify/generalize everything. I told you what the average RPM is for me and why. Accept it.

So the way you drive and the conditions you drive under are in line with an average driver worldwide? Guess what hightower99, not one car company is going to tailor make an engine to drive under your specific driving conditions, rather than an average consumer's driving conditions and requirements and the characteristics of the vehicle the engine is planned to be fitted to.

Generalization is a way of making a product suit the majority of consumers and I'm not going to accept the way you drive as a point of testing or development. You will have to accept the above.

Originally Posted by hightower99

I think you misread what I posted again. I said the info I see on the net is usually WOT BSFC figures. Therefore to make a fair comparison I would have to use WOT figures for your engine.

I talked to Orbital and the best BSFC figure is created around 75% manifold load. Go do your homework and quote from a reputable source and let us know where it came from. If you can't do this then stop posting your opinions and start posting some facts you can back up.

I have the luxury of going through independent testing, and you have not. The usual tests are at several RPM and manifold load points determined by the European Drive cycle (NEDC99). The main tested spots are 2 and 3 bar manifold loadings as this is the most common figure driven through in the NEDC99. Most efficiency occurs around the 4.5 bar manifold loading and around 2,000rpm.

Originally Posted by hightower99

I can already cruise at 100km/h at about 1900-2000RPM but that is a moot point because I rarely cruise at 100km/h. I either cruise at about 80-85km/h or 115-120km/h and even then I cannot maintain a stable cruise for very long (because of how the road system is designed in Denmark). Personally I think my final drive is abit high.

I'm sorry your road system doesn't allow you to cruise at 100kph for extended periods of time. Denmark doesn't seem to be a good region to quote as an average of the world does it?

Originally Posted by hightower99

Well think about that for a moment. You have to maintain the engine at 2000RPM and 450kPa load (the only point where you have proved high efficency) which means that the engine can only make about 86Nm of torque which at 2000RPM means you are only making about 18kW of power. Now knowing that the current market for 18kW generators is around the price range of 3700-4700USD and normally use air or watercooled 1L V-twin engines. Do you think you can price your 2.4L revetec generator competetively? Keep in mind that your engine is barely making 18kW at that point when normally 18kW generators need engines that produce 22-24kW

How about we get a 18kW generator engine and stick it in your car for you to drive. What do we achieve from even contemplating this?

If we were to build a generator for a landfill emission project the engine is far more cost than what you have quoted. Anyways I can expect us to be competitive in price on an engine and the savings on generating more power with the same amount of fuel would pay for any increase in initial cost if there was, not to mention the carbon credits gained from such a application.