Quote:
Originally Posted by LostCause
I'd find your engine's BSFC and accelerate to cruising speed as quickly as possible staying in that rpm range. It is important to stay closed loop, though.
Accelerating quickly cuts down on pumping losses by opening the throttle plate. High rpm's create a lot of friction, so it is important to keep engine speed low. Essentially, you are trying to drive with a lot of load.
SVOboy's website has a section on the topic that covers it well. Accelerate quickly, shift early, cruise slow. Use whatever gear pattern allows you to do so.
- LostCause |
I mostly agree with your post but would like to make the following comment in regards to friction.
I was reading some SAE papers today (again!!), and as I was educating myself on friction modifiers I found out the difference between cruising at 1250 rpm vs 2500 rpm is roughly a 10% increase in engine friction. Chances are you are much closer to the BSFC island at 2500 rpm with the added friction load. Is that movement towards the BSFC island worth it? It depends of what the BFSC map for your engine look like.
Those maps should come with the owner manual
(sorry I'm just really mad I can't find one for my engine)