Ford Power Stroke Nation banner

1 - 20 of 67 Posts

·
IM OUT!!!
Joined
·
4,548 Posts
This is here for all to see, read and to give informative info. This will also be followed with some installation pics both current and old. Mike (bigrpower) let me take a couple pics of his set up with the precision wastegate, thanks Mike!
Once again all questions and input are welcome.

Inside the wastegate is a diaphragm which creates a seal, and a spring which holds the wastegate closed. Spring rates vary depending on the amount of boost you want to run, typically they are given in a "bar" value for example 1 bar would be 14.7psi. This would mean that in order to open the wastegate you would need to excerpt a greater pressure than the 14.7psi spring holding the wastegate closed. In order for the wastegate to work you must have the compressor reference port hooked up to the compressor side of the turbo, if you don't have this vacuum line attached than the boost pressure will not be limited to the set spring pressure; it will build unlimited boost pressure until your engine is destroyed.

Normally pressure from a spooling turbo pushes against the diaphragm (though the vacuum line attached to the compressor reference port) which in turn pushes against the wastegate spring. When the pressure from the spooling turbo exceeds the spring pressure the wastegate's plunger opens releasing the excess pressure through the dump tube into the exhaust after the turbo or to open atmosphere. Typically, if you use the wastegate to control your boost levels you will experience a decrease in power and spool times. Why? Although the spring fully opens at its set spring pressure it tends to begin opening before reaching the set spring pressure. This "pre-opening" leaks boost pressure through the dump tube before max boost pressure is reached resulting in a decrease in power mostly toward the top end. This can be corrected by using a boost controller.

In order to run a manual boost controller we need to tee off of the vacuum line which runs from the turbo compressor housing to the compressor reference port. The manual boost controller works using a spring and check ball, by screwing the adjusting screw into the boost controller you put more pressure on the spring which reduces the amount of airflow through the boost controller and into the boost controller port. Less airflow means less pressure will be assisting the spring to keep the wastegate plunger shut. The pressure in the vacuum line going to the compressor reference port will equal the pressure the turbo is producing. A boost controller will allow you to direct some of that pressure to the top of the wastegate diaphragm creating two opposable forces. By adjusting the spring pressure of the boost controller you can vary the amount of boost that the turbo will make before opening the wastegate's plunger. If you want to run a higher boost level than the wastegate spring allows you will need a boost controller.


The manual boost controller is a very simple device that can help you make more power from your turbo setup. Here are three additional things to keep in mind about wastegates:

Without a line running from the compressor housing to the wastegate's compressor reference port boost pressures will keep increasing forever. This will quickly destroy your engine!

Run a wastegate as close to the desired boost pressure as possible this will help the boost controller handle the pressure better.

You can't reduce your desired boost pressure lower than the spring rate.

Moderator Edit: (note this is for Elites wastgate kit only, other kits may contain different springs and may alter adjustments and proceedures) After the wastegate is installed, you should have the boost reference line from the intake or CFM elbow running to the inlet side of your manual controller. From the controler the line will run to the port on the SIDE of the wastegate. You will have one other line on top of the wastegate, that is just a vent to atmosphere, put the end of that in a clean dry place.

Set up: Easiest way to monitor drive pressure vs boost pressure is to set up your dashdaq, or livewire, to read MAP (absolute) and EBP, Both of these readings will already have atmospheric pressure (11.7-14.8 depending on altitude and ambient temp) calculated into the gauge reading. This way when you are reading data logs, or glancing at your gauges during a run you dont have to figure in atmospheric pressure on the boost side, this should speed things up as well as make it a bit more accurate. Turning the wastegate clockwise will increase the pressure to the port on the side of the wastegate, thus opening the wastegate valve earlier, and dropping back pressure. Turning counterclockwise will lower boost to the gate, and thus increase back pressure
SO
Clockwise= lower back pressure
Counterclockwise= higher back pressure

I beleive elite calls for an initial adjustment of like 2 or 2.5 turns in clock wise.

You want to try and get the boost and back pressure within about 10 psi of each other, more or less is ok depending on your liking for spool up or back pressure.


:ford:
 

Attachments

·
IM OUT!!!
Joined
·
4,548 Posts
Discussion Starter #2
Here are a few pics of Mikes (bigrpower) wastegate set up from elite...

1)is where the 90* fitting was placed for a boost or vaccum referance. in this case it is the tube that runs out of the high pressure turbo.

2)the first line runs to the boost regulator. the side it should be running to is the "IN" side, which hooks up to the turbo or wherever you have it for your boost.

3)is the "OUT" part of the boost regulator which runs to the wastegate

4)in this case the line was ran to the top of the wastegate and vented out the bottom

sorry for the pics of the wastegate, i couldnt get the camera in there and his engine was hot.
 

Attachments

·
NOT AT THE TABLE CARLOS
Joined
·
232 Posts
Nice Post. This information is priceless because so far the tuning of these trucks via the wastegate has been very confusing. I have just a couple of observations in relation to this post.

Inside the wastegate is a diaphragm which creates a seal,
In testing my set up, which is the same as Mikes (Precision Turbo), I have noticed that the bottom of the wastegate is NOT sealed and actually leaks boost. Now, I have not been able to see if this is consistnet in all wastegates or only mine. Which would indicate a faulty wastegate.

Perhaps if Josh gets another wastegate he can test this prior to install. This test needs to be done with a compressor and about 25-30 psi of shop air to the bottom/side of the wastegate. Mine would not hold pressure.

The top on the other hand WILL hold pressure.

(though the vacuum line attached to the compressor reference port) which in turn pushes against the wastegate spring.
BFT I would edit the post and not call the boost reference line a vacuum line, Unless that is what it is and vacuum is actually pulling the wastegate open. I understood it but a noob might get confused and become internally confilcted when calling it a vacuum boost line. Quite possible I am conflicted. Please keep all gender jokes to your self. I had to jump on that phrase before someone else did (Dzchey21)

I do have a couple of questions though.

Does this mean I should block off the EGR cooler plate




Then tap my "U" shaped pipe between my turbos and plumb it like Mike's set up. My only hesitation is...... The "U" shaped pipe between turbos, is that a BOOST location or a VACUUM reference. It would seem to me that this is a boost reference and being between the turbos NOT an accurate one.

Boy, my instructions from Elite were WAY off in left field if this is the case. My intake track is going to look like swiss cheese with holes and plugs all over the place.
 

·
Registered
Joined
·
750 Posts
The "U" shaped pipe between the turbos has boost from the small turbo and vacuum from the VGT. I would not take a boost reference from there. I would take one from an IC pipe instead. I was told by Elite to hook into the boost reference port and vent the boost controller port to atmosphere. I have installed an electronic boost controller and don't have to guess anymore. Using both ports makes more sense to me, but I followed instructions and it seemed to work.
 

·
The Diesel Cartel
Joined
·
1,111 Posts
We really needed something like this to start getting facts out there.

Here some light I can shed on the situation.

1. I feel that the best place to get Boost Reference is from the cold side intercooler pipe, or from the intake elbow. I chose the intake elbow because I didnt have a bung or a way to weld to the intercooler pipe and its pretty thin and wouldnt thread very well.
2. The block off plate will not give you a boost reference because when the EGR is turned off the valve is closed and not letting any air pass through.
a. I know EvilTwins "rigged" his valve open but im sure thats just a temporary fix and I think it would be best to tap somewhere else and block the plate. I got a 1/8" NPT plug and plugged the plate.
3. Anyone who has an aftermarket cold side pipe should already have bungs welded into it and then you can use that for a nice clean place to get boost from.
4. When routing the boost lines be sure to keep clear of hot and or moving parts. The one moving part to be especially careful of is the Turbo Actuator arm. If this get s caught up or is not allowed to move freely then your turbo is not going to function correctly.

This is all that I know so far. I am working on a plan to get up to Rudys Diesel and have them swap out the wastegate for me on Monday. I am hoping they can do this without taking the cab off and that they can help me get tuned correctly as well. Its over 800 miles from South Florida to North Carolina where they are located and im pretty sure my truck is running well enough to make it there. I feel they are one of the most knowledgable shops in the country when it comes to this stuff and it will give me a little peace of mind to know that it has been done right and the truck is going to be reliable again.
 

·
NOT AT THE TABLE CARLOS
Joined
·
232 Posts
If you are running your hose to the top of the wastegate you NEED VACCUM to open the wastegate. If there is boost on that port it will hold the wastegate closed. I am certain that the wastegate will not open on back pressure alone. Without some help in the form of boost at the bottom/side or vaccum at the top the valve will stay closed.
 

·
The Diesel Cartel
Joined
·
1,111 Posts
Mine definatly was opening on backpressure alone but I think we can all safely say my wastegate is no good.

I also dont think there is a proper way to make vacuum on a diesel engine....so running boost to the side port to assist in opening must be the proper way to do it.
 

·
NOT AT THE TABLE CARLOS
Joined
·
232 Posts
I do remember Mike submitting a back pressure/ablolute boost pressure log that appeared to be in good relation to each other and was working properly. So there has to be something to his setup despite our conclusions that the top port is not to be used due to lack of vaccum.

The way mine is plumbed my backpressure will not go over 60-65 psi as it shouldn't. BUT, the relationship between my back pressure and my absolute boost bressure up to that point is not maintaining the 1:1 or 5 to 10 psi higher that we are striving for.
 

·
IM OUT!!!
Joined
·
4,548 Posts
Discussion Starter #9
as far as tapping for a boost source, there are a few ways of doing it. you get a more accurate reading after the IC since that is where you see the drop of pressure.


edit: the pics of mikes wastegate set up were done by elite and from what i know, work very well! he hasnt messed with the regulator yet as it drives really well. im sure there are some power he can squeeze out by slight adjustment.
 

·
WWDD
Joined
·
10,531 Posts
Hey great idea im going to make this a sticky thanks for all the great info and feedback guys... you are what makes this site great.
 

·
Registered
Joined
·
268 Posts
This might be a dump questions. As I dont have a ton of experience with external gates and diesel. But I do have alot of time with them on Turbo 2 stroke snowmobiles. What we use is the exhuast drive pressure to open the gate up. Since it sounds like you are still using the vanes on the turbo to control boost, And your just using the wastegate to reduce drive pressure once in the higher end of boost why couldnt you just set your gate to open at 65psi off of drive pressure. That way its not boost realated. I could be thinking about this wrong and it just a idea, but it works really good on our turbo snowmobiles. Of course our drive pressure is is usally 1:1 and I'm building .6psi of boost at idle.

Mike
 

·
NOT AT THE TABLE CARLOS
Joined
·
232 Posts
I will post up a couple of log files so we can validate our setups. Hopefully someone that has a set up that works can chime in and help us get this right.
 

·
WWDD
Joined
·
10,531 Posts
This might be a dump questions. As I dont have a ton of experience with external gates and diesel. But I do have alot of time with them on Turbo 2 stroke snowmobiles. What we use is the exhuast drive pressure to open the gate up. Since it sounds like you are still using the vanes on the turbo to control boost, And your just using the wastegate to reduce drive pressure once in the higher end of boost why couldnt you just set your gate to open at 65psi off of drive pressure. That way its not boost realated. I could be thinking about this wrong and it just a idea, but it works really good on our turbo snowmobiles. Of course our drive pressure is is usally 1:1 and I'm building .6psi of boost at idle.

Mike
Yeah which is generally a good idea, but with variable geometry turbos its hard to do, if the computer sees a drop in the drive pressure its going to want to slam the vanes shut, thus making more drive pressure. So really on these trucks it doesnt work untill you get into the top end of the power when the vanes are pretty much wide open anyway. If that makes sense, but you are right idealy you would want it set up off of drive, then you drive pressure never gets above the preset limit, unless your gate is too small.
 

·
Registered
Joined
·
268 Posts
Yeah which is generally a good idea, but with variable geometry turbos its hard to do, if the computer sees a drop in the drive pressure its going to want to slam the vanes shut, thus making more drive pressure. So really on these trucks it doesnt work untill you get into the top end of the power when the vanes are pretty much wide open anyway. If that makes sense, but you are right idealy you would want it set up off of drive, then you drive pressure never gets above the preset limit, unless your gate is too small.

I see!!!!!

So what's stoping you from setting a wastegate up to bleed off or open at a drive pressure of 60 psi or above? I would assume that at that pressure you have all ready reached max boost and all you want to do is get that drive pressure less.

Is the drive pressure to high in stock fourm because the turbos are to small to flow that much air? Causing drive pressure to go up.

A wastegate that is properly sized and set-up would not just open and drop pressure it would just let the right amount of pressure out to maintain the set level of pressure.

I'm just asking this as im curious on what all the wastegate is performing on the 6.4. it doesnt sound like it control boost just drive pressure.

Thanks
Mike
 

·
WWDD
Joined
·
10,531 Posts
basicaly thats what the elite wastegate is doing, the drive pressure stays around 60 or so(72-74 absolute) and then the wastegate opens, they are just using boost to open the wastegate. Seems to work well on the ones that ARE working.
 

·
NOT AT THE TABLE CARLOS
Joined
·
232 Posts
basicaly thats what the elite wastegate is doing, the drive pressure stays around 60 or so(72-74 absolute) and then the wastegate opens, they are just using boost to open the wastegate. Seems to work well on the ones that ARE working.
Well, seems like we have a little more clarity. This is what it appears my set up is doing. Currently the boost (speaking in terms of absloute manifold pressure) and back pressure are doing their own thing until the back pressure hit arround 70-71 (55 to 60) actual and then the wastegate is opening.

It was my initial impression that the relationship between the two were supposed to be at a set ratio through out the range. This appears to be incorrect. Which is bitter sweet at this point.

I was racking my brain for a while wondering how when using a regulator, which only allows a set ammount of pressure, was going to allow a varying ammout of presure thru to the wastegate. Pressure gets too high.....gets dumped.
 

·
NOT AT THE TABLE CARLOS
Joined
·
232 Posts
So if I understand correctly, if boost tops out arround 50 psi ( gauge reading and 64 psi absolute manifold pressure), I want 64 on the back pressure for maximum power and 72 or so for driveability. That assuming I have 14 or so for atmospheric pressure and want a spread of 8 psi on the street driveability end.
 

·
NOT AT THE TABLE CARLOS
Joined
·
232 Posts
Two Log files. The file name= date (03) day (##) year (2010) - Time hrs (1954) .

On the later one, done 03/18/10, I highlighted in green back pressures below 70 psi, in yellow back pressures below 74 psi, and in red anything above that.

What do you think we want for max back pressure and max boost on these motors???
 

Attachments

·
WWDD
Joined
·
10,531 Posts
Well, seems like we have a little more clarity. This is what it appears my set up is doing. Currently the boost (speaking in terms of absloute manifold pressure) and back pressure are doing their own thing until the back pressure hit arround 70-71 (55 to 60) actual and then the wastegate is opening.

It was my initial impression that the relationship between the two were supposed to be at a set ratio through out the range. This appears to be incorrect. Which is bitter sweet at this point.

I was racking my brain for a while wondering how when using a regulator, which only allows a set ammount of pressure, was going to allow a varying ammout of presure thru to the wastegate. Pressure gets too high.....gets dumped.
In the ideal world, yes you would want 1:1 Throughout the rpm/boost range, but since you guys have VGT turbos, that flat cant happen, Now if the tuning ran the VGT duty cycle at 0% all the time, this would be achievable, but driveability would suffer im sure of it. So your right its a bit bitter sweet, Thats where im most enjoying the drop in back pressure is cruising around town. As it sounds though your wastgate is working fine, ill look over the logs but it sounds right to me.


On edit after looking at your log yours looks to be set up about perfect, if its pretty drivable i would leave it, I think these trucks are happiest with drive about 10psi higher than boost.
 

·
NOT AT THE TABLE CARLOS
Joined
·
232 Posts
Well i'm satisfied for now. Only the dyno and more so the track will tell for sure. Now we need to get JYFARMER and JOSH in check and we can raise the victory flag.
 
1 - 20 of 67 Posts
Top