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View Full Version : VNTs and EFI


Woznaldo
06-10-2013, 07:57
For those of you that have managed to get an EFI setup running well with a VNT Turbo, can you please post up your experiences, hurdles and fixes.

In the past it was thought that it would be near impossible to do, but I think I am right in saying that a few within the club have done just that.

The reason for the enquiry is that I have a VNT sitting in the garage and I'm already going EFI. I'll get the EFI running with the std turbo first, but would like to try the bigger VNT while it's just sat there.

Woz
Os8472
06-10-2013, 08:41
The big problem I had was boost control, with the OE actuator in place the boost wouldn't sit below 25psi at best.

In the end I used an external wastegate to control the boost and a normal 7psi actuator to control the vanes on the vnt, worked well in the end
James5
06-10-2013, 12:14
Anyone tried to use one of the vnt electronic actuators I am sure a standalone unit can control it
Woznaldo
06-10-2013, 12:29
Anyone tried to use one of the vnt electronic actuators I am sure a standalone unit can control it

I have had the same thought, that by using an electronic actuator controlled by the ECU the boost can be controlled a lot better than just dumping boost via a boost sensing actuator?
GTphil
06-10-2013, 19:42
The perfect combination really, well mapped it should help break gearboxes :)
Adey aka Ewok
06-10-2013, 21:34
Has anyone tried adjusting the vnt stop as well as the actuator to keep it in control?
James5
06-10-2013, 23:01
talking about VNT's I just remembered philr5t's Actuator setup is very different to any other I have seen you might want to take a look his.

http://www.rtoc.org/boards/member.php?u=1075
Woznaldo
07-10-2013, 05:58
talking about VNT's I just remembered philr5t's Actuator setup is very different to any other I have seen you might want to take a look his.

http://www.rtoc.org/boards/member.php?u=1075

I had a quick flick through Phils build thread, but can't find any detail on the actuator setup other than it being a Big Jim setup? I would love to know what's different.

Here's the build thread: http://www.rtoc.org/boards/showthread.php?8048-bringing-my-5-back-from-the-dead

An epic build!
Woznaldo
24-07-2017, 12:57
I'd be really keen to find out how Phil's actuator setup worked with the VNT. In the build thread it talks about the actuator pulling the vanes closed, but I don't know much more than this?
Ian S
25-07-2017, 14:24
IIRC, Jim reversed the connections using a big actuator, Forge T3, etc., so the 'rear' had the pressure. I guess he must have moved the spring to the 'front'. He also fed some pressure to the front, or something. Had a hose going to both rear and front similar to Renault, but I don't know why.
Matty
25-07-2017, 22:21
Ive got a VNT in at the moment, just making an actuator setup for one. Will post some pics tomorrow. :agree:

I've been told that short vacuum/pressure runs between the scroll and actuator help keep the boost under control better as there is less delay.