ECU hacks
12-20-17, 07:51 PM
#1
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ECU hacks
I wonder if anybody has figured out how to hack the ECU. Two hacks that I think would be nice for the 300h.
1) The car already recognizes the key fob when it gets near and turns on the interior lights. Should be an easy hack to get it to unlock the doors when the key is close by a la Tesla. And lock them when the key goes away.
2) The 300h has an Atkinson cycle engine which gives high efficiency but has poor horsepower and torque. It would be good to modify the ECU so that in SPORT mode the Variable Valve timing system would change the timing so that the engine would run the Otto cycle instead. That would be the same as all other non hybrid cars. This would give an instant boost of 30 hp or so, and much higher torque. Toyota's Atkinson cycle engines just use slightly different valve timing, otherwise they are the same as their Otto cycles. This timing can be changed because it already is variable by the VVT system. That would take the anemia away from the 300h in the sport mode when the traction battery has run down but still achieve the efficiency in NORMAL and ECO modes.
Do we have any good hackers in this board?
1) The car already recognizes the key fob when it gets near and turns on the interior lights. Should be an easy hack to get it to unlock the doors when the key is close by a la Tesla. And lock them when the key goes away.
2) The 300h has an Atkinson cycle engine which gives high efficiency but has poor horsepower and torque. It would be good to modify the ECU so that in SPORT mode the Variable Valve timing system would change the timing so that the engine would run the Otto cycle instead. That would be the same as all other non hybrid cars. This would give an instant boost of 30 hp or so, and much higher torque. Toyota's Atkinson cycle engines just use slightly different valve timing, otherwise they are the same as their Otto cycles. This timing can be changed because it already is variable by the VVT system. That would take the anemia away from the 300h in the sport mode when the traction battery has run down but still achieve the efficiency in NORMAL and ECO modes.
Do we have any good hackers in this board?
12-21-17, 01:35 PM
#2
Would love to this, if only I can get my hands on a 300h. But it won't be that easy. Modern Otto cycle engines come close to behaving like an Atkinson cycle engine using Variable Valve Timing. This feature is actually used for quicker warm-up to reduce emissions at startup when the rpm is high. It is certainly feasible to make engines with different camshafts and multiple injection (port and direct) that are capable of working in both Otto and Atkinson cycles. That would result in both higher fuel efficiency and higher engine power output when required.
No doubt that Atkinson cycle engine is thermodynamically more efficient but it comes at a cost. Atkinson cycle engine has idling speed of 1200 to 1800 rpm. Its output at lower rpm is poor but that is compensated by electric motor in a hybrid vehicle. That is why Atkinson cycle engine is usually paired with CVT to optimize power output. It is my understanding that Atkinson cycle in Lexus engines hold intake valve up to the middle of compression stroke and at the same time next firing cylinder intake valve is also opened, and air-fuel mixture that is pushed out of one is directed into another cylinder, which reduces pumping losses. Balancing these timing issues between Otto and Atkinson cycles would be tricky.
No doubt that Atkinson cycle engine is thermodynamically more efficient but it comes at a cost. Atkinson cycle engine has idling speed of 1200 to 1800 rpm. Its output at lower rpm is poor but that is compensated by electric motor in a hybrid vehicle. That is why Atkinson cycle engine is usually paired with CVT to optimize power output. It is my understanding that Atkinson cycle in Lexus engines hold intake valve up to the middle of compression stroke and at the same time next firing cylinder intake valve is also opened, and air-fuel mixture that is pushed out of one is directed into another cylinder, which reduces pumping losses. Balancing these timing issues between Otto and Atkinson cycles would be tricky.
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