Product review - Greddy Profec B-Spec II Boost Controller

The Greddy Profec B-spec II is a small and relatively inexpensive boost controller and can be bought for as little as US$300. I bought mine from Boost Solutions when they were on special for US$299.

The unit is either black or blue in colour and is about 8cm wide, 8cm deep and 2cm high. This small size allows the unit to be conveniently fitted almost anywhere. On the left of the unit are two small chrome push buttons one above the other. The top button switches between two presets and by holding the button in for two seconds turns the unit off (or on). The lower button (mode) cycles through the configuration screens. In the centre is the LCD display screen and on the right a larger knob which can be turned to change settings and pressed to make the setting stick.

Some of the features are:

Monitors real time boost pressure.

Two preset settings (low and high or track and street etc) which is activated by a single button press.

An audible warning when exceeding a set boost.

A limiter to lower the boost to a safe pressure when the warning is sounded.

A peak boost readout and a last boost readout.

Boost can be read in kPa (kilo pascals) or PSI (pounds per square inch). By default the unit is set to kPa.

Will boost up to 43PSI

I won’t cover the installation as it is straightforward and can be done in about two hours with simple hand tools. The installation is similar to many other controllers and is adequately covered in tech articles on the net. As with many other controllers the kit only comes with enough hoses, clamps, tees etc for a single turbo car, so you will need to get some more bits and pieces.

When the unit is turned on it automatically goes into the real time boost monitoring mode. This is difficult to read accurately as with most digital readouts as it leaps around a bit, so an analogue gauge is recommended as well.

Turning the knob on the right allows you to SET BOOST. BEWARE, this is the percentage duty cycle of the solenoid (where 0 = base boost, 100=wastegate limit) not PSI. Pressing the set button (the one you just turned) locks this number in. The display will then return to the boost monitoring display.

Pressing the mode button (left lower) will cycle through the other settings. The next setting is the GAIN, this is a percentage and adjusts the boost consistency (wastegate sensitivity). Setting the gain too high will cause spikes and too low the boost will increase with RPM.

The next setting is START BOOST. Setting this as close as possible to your SET BOOST without spiking will allow the quickest spool up of the turbos. Getting this right makes for a very responsive car. This setting unlike the last two is in PSI (or kPa) which I find a little weird. I would have thought it more sensible to have the SET BOOST in pressure rather than percentage measurements as well.

The next push of the mode button gets you to the WARNING setting. This is the boost in PSI (kPA) that the alarm sounds. This is a red display rather than the pleasant blue of the others. I wonder why?

The next is the limiter and allows a percentage of your boost setting between 0 (limiter off) and 100 (base boost). This is also a red display.

Pushing the mode button once more gets you into the PEAK BOOST display which holds the last boost peak even if power is removed from the unit.

The next push of the mode button takes you to screen that lets you turn the last boost feature on or off. Funny thing here is I don’t know where to look to see the last boost. If anyone else has this unit perhaps they could enlighten me.

The manual is not very clear but is usable. One thing to note is that they consistently make the mistake of calling the MODE button the SET button.

All in all I think the unit is good value. It may not have all the fancy features of other units but it does what it is supposed to do fairly cheaply. You will love the throttle response of your car when you get it adjusted correctly.