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Old 10-27-2005, 04:33 PM   #17
Scooby Specialist
Member#: 88322
Join Date: Jun 2005
Chapter/Region: MWSOC
Location: Indianapolis, IN
2009 BMW 135i


I'm not familiar with the ProfecB, but I would say you would want to do this mod if you are using an aftermarket boost controller if the kit does not come with its own solenoid. If the kit does come with the solenoid and it is a 3-port, you can probably install it the same way. I'd still follow the instructions with your kit, though.

The polarity of duty cycle is the same. Energized is to build boost, at rest is to lower boost and/or run wastegate spring pressure. The basic mechanics are the same, but your duty cycles or map values may not need to be as high as a bleed-type setup.

I finished tuning my boost map. I ended up about -50 across the RPM range. I'm going to try moving boost gain down a notch at a time. Right now at 53 I have no spike if I roll-in to boost. I can notice in my logs that boost build slows down a lot right about 14psi, then slowly works its way up to my midrange target of 17.5, so I'm pretty sure I can tweak a lower boost gain and improve response more without spike.

So far I'd say it is still a tad more responsive, but I definitely can build boost at lower RPM in higher gears. I can hit 1bar in 4th gear at 2800rpm if I punch it at 2000rpm. I think I can even hit 16 psi at about 2600rpm in 6th gear if I want. I found out that I needed to retune my 80% load site at 2250-3000. Never hit it before!

Off the top of my head, I seem to remember someone saying the Perrin unit is a Grainger part. Pop "grainger" into search.
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Freon is offline   Reply With Quote