Quote:
Originally Posted by RICE RACING
EGR as you state does NOT produce power or heat, it is the inverse to that as you are limiting the amount of oxygen and therefore fuel in each chamber so "ultimate heat" and power go down not up.... it's a temp control thing and emissions thing not a power thing.
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We should note, that cooled EGR actualy can work as water injection I.e. controling of end-gas temperature - autoignition chemistry.
Quote:
Originally Posted by RICE RACING
Same applies to water temperature.
Running a rotary at 90 deg C+ reduces HC, it also reduces power (proven fact).
It does not matter if its a Aixro go cart rotary or a Mazda R26B 4 rotor these engines all and in between make MAXIMUM power from 65 deg C to 75 deg C.
The key is density increase in aspirated volume, and the correlation to reduced knock events is directly proportional to the lowering of HEAT (in the air, the block etc) not increasing it........ though through the effect of combusting more stuff we do get higher end heat in the chamber..... there is no lack of heat in any rotary engine as I listed above. What there is a lack of is control of the end heat and where it is put into and this is why water injection is the #1 rotary engine modification when looking boosted applications.
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Very true. Its balance between higher volumetric efficiency at lower temperatures of block and intake system and slightly lower frictional losses at higher temperatures and vica versa.
It seems that most people consider <100°C as success, during cruising
Many people are forgetting that water isn't only knock suppressant, but also total loss internal coolant, and honestly, how many RX-7's can run at full power for any significant length of time? Why bother with expensive engine modifications when all what is needed is a bit of water?
As far as end-gas behaviour goes, it would be interesting what direct injection of water to the trailing side of rotor face during final phase of compression could do with knock, but I must partially agree with lowering of overall EGR rate as partially burned hydrocarbons are unstable combustion species prone to autoignition and consequent detonation.