Friends, Yesterday have installed Grimmspeed MBC on Punto 75 HP at Bay 6. MBC is set to 21 psi. Initially, we wanted to find the stock Boost Pressure. Found it to be 18psi. Increased the psi with multiple runs with each turn click which increases 1/4 psi per click. The turbo was responding nicely with no smoke or harshness. Max increase now set to 21psi. The stock Wastegate is actually set to 1.5bar = 21.76psi. Now the turbo boost is linear across the power band and its real tight which holds the spool pretty well. Below are the pics which gives more info. --- Double Post Merged, Sep 20, 2015 --- Below are some of the points answered by tuner. 1) Impact on Turbo by using MBC due to change of atmospheric pressure at various places- There will definitely be impact on the Turbo as we increase the boost pressure. The MBCs are installed in 3 Swifts & 2 Ritz which uses the same MJD engine. Those are running at 22-24psi with the remap and MBC. Each of these are run close to 25-40000 kms with remap+MBC. No turbo failure yet. And engines have responded well in varying altitudes. These cars are driven to places like Ooty/Kodai/Munnar/Himachal/Leh/Spiti/Manali and beaches. As per the drivers, they felt the cars responded better in Mumbai/low pressure areas and was more powerful compared to weathers in Bangalore. But its always better to keep the boost to 1.5 bar and not more just to play safe. 2) Impact on Timing Chain/Pistons/Injectors- MBCs are used only to control the turbo push within the torque power band. Its on the drive shaft and will have less impact to these if kept within the limits of 1.5bar. Moreover, the impact on Turbo is more than the actual components. 3) Full Boost Part Throttle- This should not be experienced if using MBCs. This is bad for turbo and early failure is guaranteed. 4) Overboost- If the boost pressure is not controlled within the turbo limit, car will throw the Overboost CEL error. And turbo probably will melt. EGT should not hit beyond 1650. This throws car to limp mode where the car can be driven within 2000rpm. 5) WGDT and Boost Tables- No way to change these tables in ECU for 75BHP. Thats the reason MBCs are used to control them appropriately when all the limiters are moved up the graph. There is definitely increase in Power even if the increase is around 3psi from stock. As we drive, we feel the difference during WOT surges within the power band. Surprising of all is Swift/Ritz DDiS are responding very well compared to Fiat MJD with the MBC. Have heard few not so good reviews of Prosport/Perrin MBCs. Grimmspeed or Hallman Pro are good for use. Fiat MJD uses KKK Turbo.