Product Name:  
BOV Kompact EM VR25  
BOV Kompact EM VR25 (7th Gen Nissan Z)  
Product Description:  
Product Number:  
Document Version:  
V1.00 Rev A  
Turbosmart accepts no responsibility whatsoever for incorrect installation of this product which is potentially hazardous and can cause serious  
engine damage or personal injury.  
The EM series BOV is designed for use as a factory replacement for a turbocharger that utilises an electronic diverter valve, this valve can be  
used on other applications if there is a control signal to actuate the BOV.  
Ensure the engine is cold prior to installation.  
- Turbosmart recommends that your Blow off valve (BOV) is fitted by an appropriately qualified technician.  
Please check that the following items have been provided in your EM Series BOV packaging  
Turbosmart EM Series BOV  
Allen Bolts (M6 Cap Screws)  
Turbosmart Sticker  
Main units  
Allen bolts for mounting BOVS  
Figure 1 - Kit Contents  
Allen Key Set Metric  
Basic Socket set  
Torx Bits  
Turbosmart has developed a unique “plug and play” diverter valve (or bypass valve) upgrade for your vehicle that is currently equipped  
with an electronic diverter valve. While we have developed this unit to be as simple as possible for you to install, we have not  
compromised on performance. This unit will not leak under elevated boost pressures and will still provide you with rapid response  
ensuring that all the OEM calibration strategies are not interfered with, providing you with maximum boost performance while the  
advanced strategies of the OEM’s are retained.  
The EM series BOV is available in two configurations, Dual Port and Plumb Back. The functionality of the BOV is still the same, there  
is no performance difference between the two units, it is a personal preference if the user wishes to utilise a classic vent to atmosphere  
sound or revert all bypass gasses back into the inlet tract of the turbocharger.  
As the valve is completely controlled by the factory engine control unit, the factory diverter valve is almost silent, due to our  
construction, it is possible that your EM series will be much more audible. By being able to hear the unit actuate, occasionally the  
valve may be opening for a few seconds under the following events such as traction control, cruise control management, rapid  
gearchanges and varying throttle position changes, these are all coded as part of the torque management software in the OEM engine  
control unit, there is no adjustment available over these functions via our product. By hearing these events, it is not abnormal, it is  
completely normal for the EM series BOV to be considered “very active” as it is protecting your turbocharger from surge events or  
bypassing air for torque management purposes.  
Figure 2 - EM Series BOV Overview  
Identify diverter valve location.  
On the model designation, 7th Generation Nissan Z (RZ34) the  
Diverter valves are located on the compressor housing outlet  
pipe. The RHD variant car passenger side is located up higher  
and easier in the engine bay than the driver’s side, which is  
located a little lower in the engine bay closer in line with the  
chassis rail.  
Pictured the two 10mm on the RHS airboxes. These are the  
mirrored on the LHS airboxes and must be removed as well.  
Allow for the engine to cool down.  
If the diverter valve cannot be located, seek assistance from your  
local specialist.  
It may be required to remove auxiliary components to  
access the diverter valve, ensure you consult your local  
specialist or a service manual for correct disassembly  
Removing OEM Airboxes  
The two Airboxes need to be removed from the car to allow for  
adequate movement. They are held on with two 10mm bolts for  
each side, attached to the front radiator support of the car. With  
the bolts removed the intake hoses are quick release  
components that need the retaining clip to be removed to allow  
for them to release the airbox from the car  
These clips are what retain the airbox to the inlet pipe for the  
turbo cool air feed. To release the three points of contact must  
be pulled in these directions. Technically the dotted line should  
release all of them if pulled lightly in that direction.  
The Air Flow meter wiring will also need to be unclipped to allow  
the boxes to be completely removed. This is easily removed from  
the airbox.  
It may not be necessary to remove the engine undertray  
panel however it enables access if it is possible to work  
underneath the vehicle.  
Removing the OEM Front Engine Cover  
Unclip the electronic connector by pulling the grey locking tab  
back and then pushing down.  
The front engine cover is held on with 1 x 5mm Allen key . This  
is lightly held on and needs a small amount of force to unlock it  
from its rubber bush. Pulled in an upwards in the location of the  
This can now be removed from the car and put in a safe place  
until reassembly.  
Once removed store the diverter valve and hardware in a safe  
Removing the RHS Divertor Valve  
The OEM divertor valve is located near the shock tower. It is  
located as seen below in the outlined circle. There are 3 x Torx  
bolts holding the divertor valve on. It may be required to remove  
some auxiliary brackets, wiring and components to allow for  
easier access of each bolt. Beware of dropping these bolts  
Fitting RHS EM Series BOV  
Take 3 of the M6 bolts supplied of the 6 to fit the RHS EM BOV.  
Use an M5 Allen key to fit these bolts. The electronic connector  
can now be plugged into the car. Although polarity isn’t important  
you do need to hear a positive click to ensure that the connector  
is locked in.  
Fitting LHS EM Series BOV  
Removing LHS EM Series BOV  
The Electronic gate must be rotated 90 degrees to allow fitment,  
this has an adjustable nut on the actuator rod. It is important to  
only move the actuator anti clockwise and only 90 degrees. The  
Electronic gate is held on with 4 x 4mm Allen key bolts.  
Removing the Left-hand side is similar with the airboxes already  
removed. The Airbox Retaining clip must be released as  
previously explained.  
We need to remove the PCV pipe to allow for movement around  
the turbo inlet area. There is a clip that holds the wiring in that  
will need to be removed to allow movement.  
Take the three remaining M6 bolts to fit the LHS EM BOV. Use  
an M5 Allen key to fit these bolts. The electronic connector can  
now be plugged into the car. Although polarity isn’t important you  
do need to hear a positive click to ensure that the connector is  
locked in.  
With the wastegate clocked we need to move the loom down  
slightly to accommodate for the change of position. There is  
tape holding two bits of the conduit together than can be  
removed as well as cable tie clips that can release the loom and  
allow for move movement. Ensure that adequate strain relief is  
available to the wastegate plug to ensure no issue at the  
Here is the BOVs location, it is near the inlet of the turbo. We  
need to remove the 3 x Torx T30 on the BOV as well as the  
electrical connector.  
Unclip the electronic connector by pulling the grey locking tab  
back and then pushing down. The electronic actuator also can  
be unplugged there is no locking tab on it.  
Refitting Removed Components  
Once the Turbosmart EM has been fitted correctly to the car, we  
can refit the parts that have been removed or unplugged  
including hoses or electrical components.  
We need to refit the Airboxes, an audible click must be heard  
when reconnecting the car airboxes to the car. As well as the 4 x  
0mm bolts that hold the airboxes on.  
Remove Your EM series BOV.  
Install New Electronic Actuator into your  
EM series BOV.  
Remove the electronic plug from the EM series BOV and  
loosen the hose clamps on the inlet and recirculation hoses.  
Remove the BOV from the vehicle.  
Ensure the O-rings on your new actuator are correctly seated  
in the grooves before installation. Also take not to damage the  
O Rings on burrs/threads during assembly.  
Cosmetic engine covers may be required to be removed  
prior to the assembly being visible.  
The turbocharger assembly may require the vehicle to be  
raised on a hoist or jacked up and secured using vehicle  
jack stands. Ensure your safety is not compromised.  
Remove Electronic Actuator from your EM  
series BOV.  
Using an 11mm open end wrench in the flat sides of the  
solenoid, undo the actuator in an anti-clockwise direction  
when viewed from the end. Ensure the wrench is placed on  
Failure to ensure O-rings are seated correctly may lead to  
cutting of an O-Ring and unexpected results from the EM  
series BOV.  
Slowly insert the new actuator while turning in a clockwise  
direction to avoid tearing the O-rings.  
Ensure the cavity is free from debris using avoiding shifting dirt  
into the passages.  
Tighten the new solenoid into the EM series BOV ensuring the  
wrench is on the metallic portion of the solenoid.  
Tightening the solenoid on the plastic cover may result in  
unrepairable damage to the solenoid.  
It is important that any issues are resolved before heavy driving.  
BOV not actuating - Confirm electrical signal plug is connected appropriately, as the plugs are new, some force may be  
required to click the plug into place. The car will experience heavy surge if not actuating.  
Valve is staying open Confirm the valve has O-rings as they may have been dropped or lost during installation.  
Boost pressure loss or lower than before - Confirm the valve has O-rings as they may have been dropped or lost during  
Failing the above, submit a technical request to with information of your engine configuration and  
photos of installation.