The opinions and viewpoints expressed by users of Offroad-Express Forums are wholly their own and not necessarily those of Offroad-Express.
https://www.offroadexpress.kiwi:443/Forums/
https://www.offroadexpress.kiwi:443/Forums/viewtopic.php?t=21657
KiwiBacon wrote:
Lpg fumigation leads to people tripling the engines torque by doing sfa.
How much boost depends on what torque your engine is already putting out and how good your fuel and intercooling is.
If you could get 280Nm from your 4.5, then you need to increase the air density by 1000/280 = 3.57 times.
To get 3.57 times the air density with a 60% efficient turbo and 60% effective intercooler you need about 58psi boost. But at that your intake temps will be about 130C.
70% effective intercooler would only need 52psi and your intake temps would be down around 100C.
With engine mods to handle the torque and reduce the compression ratio until you've got it working. Those reduce the engines efficiency enough that you need more boost or a better intercooler. The better your intercooler is the less boost you need.
