Why don't LPG Falcons run higher compression?
This is one question I've had since the dedicated LPG Falcon was released.
Correct me if I'm wrong. Normal ULP has a RON of something like 91, and PULP is supposed to have a RON or 96 or so, with Optimax at 98 or something. I know the RON values vary per-bowser, but those are the claimed numbers.
I vaguely remember that LPG has a RON of 104 or 105. Which means, you can run a much higher compression ratio on LPG. Despite the fact that LPG has a lower specific impulse than fuel, when you factor up the compression ratio, I was under the impression that you could squeeze a little bit more power out of LPG.
The reason dual-fuel engines run poor on LPG is because the timing and compression need to be retarded/reduced so that standard fuel doesn't detonate. And thus the lower specific impulse of LPG kills you. I had thought, however, that a dedicated LPG engine would give you a clean slate again.
I have often wondered if a computer-controlled turbo on a dual-fuel car would be a good idea - run low-boost on Petrol and Higher boost on LPG.