▁and ▁load ▁ranges ▁to ▁deliver ▁ ▁at ▁ 2 0 0 0 ▁r pm , ▁while ▁the ▁secondary ▁tur bo ▁joins ▁in ▁above ▁ 4 0 0 0 – 4 5 0 0 ▁r pm . ▁With ▁both ▁tur bos ▁boost ing , ▁a ▁ ▁tor que ▁peak ▁arriv es ▁at ▁ 4 8 0 0 ▁r pm ▁and ▁maximum ▁power ▁() ▁is ▁seen ▁at ▁ 6 0 0 0 ▁r pm . ▁Note ▁that ▁Japanese - market ▁B 4 s ▁– ▁running ▁on ▁ 1 0 0 - oct ane ▁fuel ▁– ▁are ▁r ated ▁at ▁. ▁ ▁The ▁primary ▁tur bo ▁( located ▁at ▁the ▁left ▁rear ▁of ▁the ▁engine ) ▁del ivers ▁boost ▁in ▁the ▁low ▁r pm ▁and ▁load ▁range , ▁while ▁the ▁secondary ▁tur bo ▁comes ▁in ▁to ▁aid ▁mid - to - high ▁range ▁breath ing . ▁During ▁the ▁primary ▁tur bo ▁stage , ▁boost ▁pressure ▁is ▁controlled ▁by ▁a ▁conventional ▁arrangement ▁of ▁an ▁EC U - control led ▁duty - cycle ▁sol en oid ▁and ▁an ▁internal ▁waste gate . ▁ ▁The ▁secondary ▁tur bo ▁remains ▁in oper ative ▁during ▁this ▁stage , ▁as ▁a ▁separate ▁exhaust ▁control ▁val ve ▁( s itu ated ▁on ▁the ▁right ▁side ▁of ▁the ▁engine ) ▁remains ▁closed . ▁This ▁val ve ▁prevents ▁exhaust ▁g ass es ▁entering ▁the ▁secondary ▁tur bine . ▁ ▁During ▁the ▁ 4 0 0 0 – 4 5 0 0 ▁r pm ▁trans itional ▁stage , ▁however , ▁the ▁exhaust ▁control ▁val ve ▁is