VNT/VGT mechanical vacuum control
VNT/VGT mechanical vacuum control
Hi
Is this setup still up do date and how is the last year experience of it?
Is the vacuum site connected to the vacuum pump? (not transmission site)
Is the vacuum pump on Mercedes diesels as mine OM603 constant vacuum? or does it variable with rpm?
Thinking of trying this setup and will be grateful for all the help I can get.
Do anybody know if there is any electronic VGT control close or workin allready?
Regards Atli
Hi Atli,
still no progress over here...
I also prefer the electronic actuator. I ordered a LED dimmer that has a poti to manage the PWM output. Important here: 140 Hz.
The dimmer cost me 7 EUR incl. shipping.
Then it needs a PID unit with an analogue output to replace the dimmer and it could work, so my ideas as a non electronic.
There is a guy on VW TDI forum with a nearly complete solution but he is very busy and can not give a schedule for a "plug and play" sell-able solution.
I failed with my mechanical set up because the vac is too weak in sense of flow. Boost comes fast and acts the vanes but then the vac is too slow to move the vanes for rebuild boost. Have to admit that it made some fun driving with this set up (but only to be the clown on the street).
It was like boost-no boost, boost-no boost,...
The last thing I will try is to link the vanes directly to the pedal in an adjustable way regarding movement, then push back the vane lever with up coming boost. The pedal linkage is spring loaded to the vane lever so the boost actuator can push the lever back although the pedal is depressed. Could work but also might end up in the scrap bin.
Tom
(11-13-2010, 07:03 AM)Atli Is this setup still up do date and how is the last year experience of it?Yep, I enjoy the hell out of it. The only thing I've done is fine tune the boost pressures of each stage and adjusted the timing of how much throttle until the second stage comes in. As the balls seated in and started sealing better the pressures drifted upwards 2-3psi.
Quote:Is the vacuum site connected to the vacuum pump?Yes. It is connected to the first nipple of the main line and shares with the shutoff circuit (it would also share with the door locks and CC, if they still existed). I also drilled out the orifice at the main line nipple to 1/16", not sure how small it was before. The second nipple (closest to the check valve) is for the transmission alone.
Quote:Is the vacuum pump on Mercedes diesels as mine OM603 constant vacuum? or does it variable with rpm?MB's vacuum pumps always work to pull maximum vacuum. At my altitude that works out to 15"Hg but sea level that can be as high as 22"Hg.
Quote:Do anybody know if there is any electronic VGT control close or workin allready?Only functional one I'm aware of requires a CAN equipped vehicle to operate.
Quote:I failed with my mechanical set up because the vac is too weak in sense of flow. Boost comes fast and acts the vanes but then the vac is too slow to move the vanes for rebuild boost. Have to admit that it made some fun driving with this set up (but only to be the clown on the street).Mine doesn't do that, it goes to boost and stays there. The only real variance is at low loads where it will run between 3-5psi, which my water injection system depends on to cut off water flow during deceleration.
It was like boost-no boost, boost-no boost,...
Quote:The last thing I will try is to link the vanes directly to the pedal in an adjustable way regarding movement, then push back the vane lever with up coming boost. The pedal linkage is spring loaded to the vane lever so the boost actuator can push the lever back although the pedal is depressed. Could work but also might end up in the scrap bin.That method has been popular in the VW world. I don't like it though, it doesn't have any way to limit/vary boost pressure with engine load/throttle. Throttle movement only changes how quickly the turbo spools up to maximum boost (and the actuator pushes against the throttle force).
(11-13-2010, 07:03 AM)Atli Is this setup still up do date and how is the last year experience of it?Yep, I enjoy the hell out of it. The only thing I've done is fine tune the boost pressures of each stage and adjusted the timing of how much throttle until the second stage comes in. As the balls seated in and started sealing better the pressures drifted upwards 2-3psi.
Quote:Is the vacuum site connected to the vacuum pump?Yes. It is connected to the first nipple of the main line and shares with the shutoff circuit (it would also share with the door locks and CC, if they still existed). I also drilled out the orifice at the main line nipple to 1/16", not sure how small it was before. The second nipple (closest to the check valve) is for the transmission alone.
Quote:Is the vacuum pump on Mercedes diesels as mine OM603 constant vacuum? or does it variable with rpm?MB's vacuum pumps always work to pull maximum vacuum. At my altitude that works out to 15"Hg but sea level that can be as high as 22"Hg.
Quote:Do anybody know if there is any electronic VGT control close or workin allready?Only functional one I'm aware of requires a CAN equipped vehicle to operate.
Quote:I failed with my mechanical set up because the vac is too weak in sense of flow. Boost comes fast and acts the vanes but then the vac is too slow to move the vanes for rebuild boost. Have to admit that it made some fun driving with this set up (but only to be the clown on the street).Mine doesn't do that, it goes to boost and stays there. The only real variance is at low loads where it will run between 3-5psi, which my water injection system depends on to cut off water flow during deceleration.
It was like boost-no boost, boost-no boost,...
Quote:The last thing I will try is to link the vanes directly to the pedal in an adjustable way regarding movement, then push back the vane lever with up coming boost. The pedal linkage is spring loaded to the vane lever so the boost actuator can push the lever back although the pedal is depressed. Could work but also might end up in the scrap bin.That method has been popular in the VW world. I don't like it though, it doesn't have any way to limit/vary boost pressure with engine load/throttle. Throttle movement only changes how quickly the turbo spools up to maximum boost (and the actuator pushes against the throttle force).
(11-16-2010, 05:57 AM)Jambo What is the orange unit in the breather line? Can you give some details.
Bump for MTUpower.
(11-16-2010, 05:57 AM)Jambo What is the orange unit in the breather line? Can you give some details.
I added an exhaust brake function.
All it consists of is an emissions valve from a 90's Volvo. Its wired to the output of the brake switch to activate. It blocks the 1st and 2snd stage boost valves to make the turbo put out up to 16psi boost during deceleration, good for around about 30psi backpressure at 4500rpm and 10psi at 2000rpm.
Air output from the valves enters the top (coil end) of the solenoid. Non-energized, the flow is unobstructed between the ports. Energized, the flow is completely blocked (capped end).
The only thing left to be added is a relay to automatically disable the water injection during braking. This will also allow me to set the 1st stage injection a few psi lower since it will no longer be tied to low boost for it to shutoff during deceleration.
Does it sound any different during deceleration.
The exhaust quiets down a bit and the turbo whistles pretty decent. It surges some under 2000rpm, but at that speed it won't damage anything.
Does the whistle sound like it would be under full load.
(02-15-2011, 11:27 PM)ForcedInduction :Lightbulb:
Fuel pressure regulator.
(02-15-2011, 11:27 PM)ForcedInduction :Lightbulb:
Fuel pressure regulator.
(03-19-2011, 11:56 AM)George3soccer Does the whistle sound like it would be under full load.
(03-19-2011, 11:56 AM)George3soccer Does the whistle sound like it would be under full load.
I have been slowly evolving my valve design - the goal was to get it to pop from 0 to 15 psi with an actuator movement of 1-7/8" so that it can be directly connected to the cruise control cam.
I got the basic system working with plumbing parts but it was sticky. I started to worry about that. If it's going to be attached to the throttle linkage, it better be smooth and durable. So I've been iterating to get it hiccup free.
first picture is of the assembly mounted on the valve cover. from that, I found that the lateral forces on the actuator rod was a big problem
so I decided to replace the long carriage bolt I was using with a precision ejector pin. That was way better but would still bind because the bearing surface wasn't long enough. So I then added a slide block as you can see. now it's really smooth and doesn't bind with moderate side pressure. I also decided to use the dawes valve - I drilled out part of the casing so that the long spring could pass into it - this was really so I could make use of some precise parts using my not-so-precise tools. The whole thing has been a fun exercise in managing errors and of careful assembly. the whole thing would be fairly cheap except that for every piece I'm using, I also bought 4 or more other sizes of that thing before I got it right.
(shown with the first plumbing version)