Sorry Guys... Pretty late to the party. Just got a RX7 abit over a year, recently got the power FC and the Apexi Boost controller installed.

My question is, do I have to turn sequential turbo function off for it to work? I have search everywhere without a definite answer or I have overlooked. Sorry.

With sequential turned on, first turbo works beautifully up until transition at 4.5-5K, boost would drop to 0.2x 0.3 bar.

With it off, it's not as hard as a sudden drop. I head hissing sound might have a leak somewhere... So sequential have to be off?

 

You want that on since you have the sequential turbo system. That turns on or off the system that runs all the solenoids for the sequential control. You would turn that off if you had a single turbo.

It sounds like you have the typical no boost on the second turbo problem. There are a zillion threads on this, read up and do some testing.

Dale