Vnt help

[Chairchild]

when it comes to VNT control - the 3 options you have (in order of preference) are:

1) full electronic control - most commonly via an arduino. Requires a TPS, and MAP sensor as a minimum for any form of refinement.

2) set the vanes at a reasonable mid-point, then control boost with an external wastegate.

3) fit a boost actuator on, and suffer with all the drawbacks that brings



My Dissertation at uni was on a mechanical vnt controller - the same turbo controlled by a wastegate gave better power. I used a Saab GT1752, and fitted a Saab GT1849v hotside for the vnt version (GT18 turbine exducer was the same diameter, which meant it still worked as intended with the GT17 turbine wheel).


Blue = ran with no turbo
red = plain wastegate setup
green = the best the mechanical vnt control setup could muster

No intercooler was used, and the adaptor setup leaked like mad, hence the rather naff peak power, I will admit




But tbh... the power graph speaks for itself. It was toss