IPD says their ECU backs off the boost before shifting to reduce

the load on the transmission (automatic, of course). That

strikes me as a good idea. They have been supplying Volvo

ECUs for a long time and could probably directly address your

questions.

They seem to have very good customer service, too (see the

thread "Not happy with IPD torque bushing", below, where IPD

staff have left comments here along with their phone numbers).

This counts for a lot in my book.

By the way, I think IPDs numbers are with the exhaust upgrade.

You probably need to drop 10HP off their numbers to compare

(unless PES also says their numbers are with an upgraded exhaust).

I think torque is more important so check those numbers, too.