Holset HE351VE VGT Turbo (NO 56K)

[Aero]

No problem.

The last sentence? "More pressure closes the VGT down, as a failsafe to prevent overspeeding during an air supply failure."? On the HE431v with the pneumatic actuator. It actually works the opposite of a traditional wastegate actuator. It requires pressure to close the VGT rack thereby increasing boost pressure. They do it that way to prevent a turbo from grenading if the actuator looses pressure for any reason. Pump failure etc. IIRC it takes somewhere around 60psi to fully move the actuator.

Pictures of the linkage on the back of a Garrett VNT design.
http://www.vgturbos.50megs.com/photo4.html
An animation of the VGT parts. Notice most are in the oil/water cooled area.
http://www.holset.co.uk/files/2_5_1_5-VGT.php

[ababkin]

Ah, i get it: vanes need to fully open in the event of failure to reduce the exhaust speed over the turbine and therefore reduce boost.

thanks for elaborating
Alex

[Fred]

This innovative approach ensures a high level of durability and reliability, essential for commercial diesel applications.

Hey, that's what I said :-)

Thanks for the links!

[Aero]

Warmup mode with the VGT closed down.
http://youtube.com/watch?v=7VK4-v0I7Ak

[Fred]

Wow, so, if I understand that video correctly, it is spooling up at idle?? Cool! :-)

[ababkin]

Wow, so, if I understand that video correctly, it is spooling up at idle?? Cool!

cool indeed. Anyone can put my worries about EGTs with this thing to rest? (know of anyone running it successfully on a gas engine?)

Alex

[Aero]

I should find out in the next month or two.

[Fred]

Awesome :-) I look forward to it!

[Aero]

So I got to start and drive the new setup for the first time today. All I can say is wow.
The setup.
8.3:1 7 bolt 2.4.
stock 2g head, cams, intake.
Stock ex manifold with homemade adapter.
HE351VE VGT turbo.
~50% E85
No intercooler at the moment
Megasquirt 2 Extra 2.01
Running on a basemap generated by the computer, so rich it makes my eyes water, ignition timing is low and may be off, need to borrow a timing light.
8" of 3" pipe after the turbo to get the exhaust out of the engine bay

To start off the VGT rack is closed all the way. I have a 14b actuator on it, with no boost source. Relying on my right foot and the boost cut in the MS for safety.

Sounds like a freaking jet, the only noise is the turbine whine, I am driving around with no hood.
Its been a few months since I got to drive it, but cabin exhaust noise is less than the 2.5" dp and 3" test pipe back greddy evo style full exhaust.

This is in 5th gear. Positive boost comes in at 1900 ~2psi 2500-2600 12psi 2900 - 15 psi. Didn't hear any surging whatsoever. It spools quick enough to blow off revving in neutral.

I obviously need to get the control worked out to get it to open the rack when its needed, still haven't gotten a chance to work on that yet.
My LC1 isn't working right so I've got to figure that out, borrow a timing light and tie up a few loose ends so I can dial the tune in a bit and get some more logs.

[Aero]

The next day.


The 351v is supposed to open all the way to 25cm, I wish I had used some clay before I mounted it to calculate nozzle area with it all the way closed.

I hooked up the wastegate actuator connected to the VGT rack to a boost source last night. This is a stock 14b actuator with no boost controller. It has enough travel to open the rack all the way. Its what an 11psi actuator? The exhaust pressure forces it open at 7-8 lbs and slows spool slightly. Even with the rack open all the way via the actuator , the boost starts climbing as RPM rises. 12psi occurs at 3900 and 24 psi at 4400. Going to try a ball/spring boost controller on it and see if I can keep the earlier spool. Otherwise I may try wiring up the MS boost control.
I'm glad I included the 38mm wastegate into my manifold adapter though obviously its going to be required. I need a stiffer spring than the 4 psi one in it though so I can use it.

It sounds sort of like an electric cutout opening, or wastegate dump opening when the VGT rack opens up although it still isn't as loud. I think the vanes quiet it down quite a bit.