What is needed to run a VPC

Merlin Beerens · 07-26-2002, 07:30 AM

just wondering, what I will need to run a VPC, are ECU changes NECESSARY? I 've heard some guys get driveability issues with this thing.

jdmawd · 07-26-2002, 07:38 AM

the ecu can remain stock. its a good idea to have a gcc or S-afc to make more refined fuel adjustments. the vpc will only make very small fuel changes and will not make rpm spacific changes which are needed for REAL tuning. the largest benifit of the vpc is that it 1 removes 100% of the intake restrictions before the turbo. and 2 it converts you're mass air systam to a speed density system thus you will not loose counts under high boost high flow situations.

BatmanGSX · 08-02-2002, 01:04 AM

You can actually run a VPC with no other mods to the car, it will work fine (if you set it up and tune it properly). If you have 550s you need a 550 chip, if you have 660s you need either a 660 chip (which people have issues with) or a 550 chip with an AFC. In any case I reccomend an AFC or GCC with the VPC. But probably the AFC. You wire it up like this:

sensors > VPC > AFC > ECU

This is because the VPC is a good fuel computer on its own, no need to fool it with an AFC, and also the AFC works much better in airflow mode than pressure mode. So you let the VPC read its sensors, do its thing, then take that signal and mod it before it gets to the ECU.