Re: 2.4 JTD Boost levels.
standard jtd not mapped is 1.2/1.3 overboost down to 1.0/1.1 normal, varies under driving conditions, load etc.
I run a 3bar map sensor, couldn't get the 3.5 to work as the base voltage is 1v rather than 2v on idle which the ecu needs to see.
the 3 bar sensor will measure up to 2bar, pushing it at 2.1bar, the other 1 bar is atmospheric as pud says.
the 3 bar senor is fitted a sstandard to 16v and 20v and can be retro fitted to 8 or 10v motors.
I run 1.5 bar low revs rising to 1.8/1.9 at high revs, dialled in above 2500rpm, this is to keep the torque line linear so it does not rip apart the box and clutch.
The clutch seems to take 400nm at the wheels (don't know what that would be at fly, 440nm?) but has a hard time with 313lb/ft at low revs (at wheels)
I have the GT2256 turbo as fitted to the 140/150.
It can provide 1.9bar flat out at max rpm. may not last long but great power and fun.
pulling huge 'spike' torque low down is not good for the clutch or box, limit it low down and bring it in high up.
Mine is still an ongoing project, awaiting 76mm intake as 80mm is too big, then play agaon with the maps.