B16A Plonked, What's next?

[hattech-v]

to clock ur timing using rsm is not accurate but still can help.

 

[shiroitenshi]

peak hp doesn't occur at peak torque. peak hp occurs just before the hp curve drop. peak torque is where engine acceleration is the greatest. that's where engine efficiency is the highest.

torque is proportionate to air flow. as long as hp increases with regard to RPM, there will be air flow in & out. after peak torque, air will flow lesser as RPM increases. the torque curve indicates air flow pattern. as RPM goes up towards redline, engine efficiency will drop tremendously. this is the region where HP will stop rising. the engine will be having difficulty to breath.

Hmm.. that's right.. it doesn't occur at peak torque (I think the my dyno sheet made it pretty much clear on that.. after all, that's the actual reason I paid money to dyno a stock engine.. hehehe.).. the hp is calculated per rpm points as can be seen on the dyno chart.

Actually I don't think airflow lessens after after RPM increases, since the inertia of the air still counts for something.. more like it has reached the maximum flow capacity, hence the engine is starting to feel the resistance of having to pump that air in and out (e.g. It want's to pump in and out more than XXX amount of air+fuel volume at XXX rpm, but the exhaust only allows pushing out of XXX volume, asuuming the intake isn't a factor, so the bottleneck starts) hence we generate less power past that flow limit. That's why our exhaust pipes must be sized right, in order to alleviate that breathing problem. I simply don't get how airflow can be starting to lessen when the engine is still trying to pump air in.. I could be missing something there.. but I'm just not noticing it. Ditto for the intakes as well.

Still cam durations and opening and closing timings affect that as well, so Sturgeon's law apply on the above as well.. :P

However, I can't seem to get rid of a niggling feeling that I've been taught that peak hp is measured through the peak torque numbers.. Now that you've mentioned it.. I might have gotten it wrong. I'll get back to you on that one. Let me recheck what I've learnt.