My lower pulled arrived today from Mina. I have done the Euro toys upper (along with complete cooling system refresh and new plugs) and am looking forward to also doing the Bosch pump and an aluminum intercooler. I'm going with the Euro toys tune which I believe is Viezu's.

While I have some limited understanding of the differences between the Denso and Bosch ECU's I am curious how boost is regulated on the older cars where it's mechanical actuation.

While I know our options for measuring boost on our cars is is limited and the location of the factory sensor is not an ideal location, I see most users utilize Torque. I know that some people are reporting back significant increases in boost after both pulleys but I believe these are all newer cars with Bosch ECU and electronic boost pressure regulation. I have read stories from different owners not reporting increased boost pressure on the earlier cars while having both pulleys done.

I am curious how maximum boost will be increased on my 2011.

 

It's pretty much mechanical. There's a vacuum actuator with two inputs - one input above the throttle, one input below the throttle. The more diffrence (zero pressure below the throttle, high vacuum above the throttle) the more bypass plate is closed. Once a PCM detects a too high boost - it will just close the throttle to leave a boost in a destined values.
If there's no boost increase after a pulley(s) then it's a wrong tune with stock boost limiters values.

 

Key is in proper ECU programming whenever you go past factory boost or upping power levels. Otherwise ECU no matter Bosch or Denso, will work it's magic and keep peak boost near stock set levels. Pm me Can help you out, fb.me/alphajagtuning, have set 1/4mi record on 5.0sc Denso so far at 11.2 1/4mi and have fastest 1/8 mi and 0-60 so far on 5.0 Supercharged Jaguar XJ with Bosch ECU..