Sneaky Pete

Hello first post here,

New to the forum please bare with me,
I am in the process of turboing a 2 liter Kubota diesel tractor with a VNT15 variable vane turbocharger. I have most things sorted in my head but the control of the vanes eludes me, I am very familiar with the system and how it works but I would like to add this to the tractor that has NO vacuum system or ECM to control boost.

Can you help me think of a way to control boost with an aftermarket or maybe 12 volt linear actuator? How about a servo from a model airplane? I know sounds stupid.

I like compact, simple is best, non vacuum would be great. I have seen some of the mechanical systems people have made but there is not much room under the hood of this machine for extra springs and cables.

The stroke of the original actuator is about 13mm.

Thanks, Pete

Matt Cramer

Are the vanes electronically or mechanically operated?

Sneaky Pete

Mechanically via a vacuum canister. Turbo is off VW TDI ALH engine. It matches my needs. Unfortunately these is no ECM to control the vacuum solenoid or any vacuum system onboard the machine so I either start from scratch adding an ECM and vacuum system of find an electric linear actuator that might work with a standalone unit.

It's a big undertaking on a new tractor, I want to do it right the first time and not overly complicate things. Reliability is a must.

Thanks, Pete

Matt Cramer

You could try a mechanical boost control, treating it like a conventional wastegate, and see if that gets you anywhere.

farmerz24

registered here just for you.

so i added this turbo to a 650cc motorcycle.

what i did was reversed the stock vnt solenoid so now the vanes are closed with no boost/vaccum applied to the actuator.

i then tapped the opposite side of the solenoid can with a barb so that i could pressurize the opposite side of the diaphram. what this did was allow the vanes to open and vent boost once it reached around 9 psi. works well.

to add more boost, simply run an air regulator inline from boost pressure to the opposite side of the can (to the stock nipple on the top of the can)

for each psi the regulator allows to the top of the can, 1 more psi boost should be achieved.

try that. simple. mechanical. no vaccum source needed.

Sneaky Pete

I ran across this interesting engine swap. Same turbo I have and it looks very simple. This is a new tractor and I won't compromise reliability or operational ability. Still considering a new turbo from the same Kubota engine series with a wastegate, Either one is around $700 dollars. I love the simplicity of a not using electronics.
I really appreciate the help I can do the install easy enough it's engineering the control device that eludes me. The tractor has a crank sensor, TPS sensor already for the transmission ECU I could tap into IF I could figure out an electronic way to control boost simply via stand alone controller.

farmerz24 you reversed the solenoid or the VNT actuator? Also thanks for joining.

Thanks! Pete

New simple twist on mechanical VNT control