04-12-2014, 01:37 PM
You can run a tiny bit more rail pressure to get better fuel economy, but obviously there's a point when the power required to drive the pump overcomes the gain in fuel economy, and also it will wear the pump faster. So when making a map with the 1800 bar fuel pressure sensor and R70 pump I don't make much of a change during part load conditions, what I do do is to increase fuel pressure at the higher revs and full load to reduce injection duration and hence smoke and EGT. Even with an R70 pump there comes a point on stage 3 tunes where the pump can't keep up with both the fuel flow and pressure, however this does usually depend on the condition of the pump.
I set up a stage 1 with high fuel pressure on Poodle's car, it ended up with 130 BHP but for the extra money I wouldn't say it's worth it for 5 BHP. Quite interesting though as the Siemens SID801 system runs 1500 bar fuel pressure from the factory, these can go to 130 BHP on a stage 1 with no smoke easily. This shows that the extra fuel pressure makes a difference on the injection duration.
I set up a stage 1 with high fuel pressure on Poodle's car, it ended up with 130 BHP but for the extra money I wouldn't say it's worth it for 5 BHP. Quite interesting though as the Siemens SID801 system runs 1500 bar fuel pressure from the factory, these can go to 130 BHP on a stage 1 with no smoke easily. This shows that the extra fuel pressure makes a difference on the injection duration.
