Sunday, October 22, 2017

How to control VCT (VVT) using DIYPNP

VVT (VCT) Control using DIYPNP ?? No way ! well yes :) Just keep reading

Any one who considered a VVT (BP6D) engine swap had to answer the VVT question (Mazda calls it VCT), How I'll control it ? New ECU ? VVT Tuner ? Leave it disabled ?

Well, you can go either way but if you have a DIYPNP installed already you can use it to control VVT.

You need to wire the VVT solenoid to the ECU location, on the board you need to use ALED or WLED outputs, wire the output you choose to the external pins.

You need to supply 12v and GND(ALED/WLED) in order to control VVT.

After all is wired we want to configure it.

One little explanation before we actually do, "Real" VVT control consist of a 3D table the utilize LOAD, RPM and duty cycle.

Like so : (Taken from MS3 Basic)


The idea is to apply smooth transit in and out of full VVT camshaft advance.
On the DIYPNP we do not have this kind of table/control BUT we can enjoy the VVT nonetheless !
Our control will consist of a on/off trigger.

My VVT tests on the dyno show a performance gain from very low rpm (<2000) upto 5500~.
For the best tune you need to enable VVT at around 2000rpm and disable it at 5500~, in order to do that we configure the WLED/ALED output as follow:


Just keep the "On" trigger away from your stop and go speed.

Very noticeable improvement ! Enjoy !