Evo3 16g Boost Creep-Solved?

[Mr Peepers]

Despite the title, this applies to all TD05H compressor housing WGA's. 14b, 16g, etc

I was curious how far the flapper actually opened, and found it EXTREMELY limited. Not even close to the 45 degrees I had heard. The cause of creep in internal wastegates was apparent, the mitsu style actuator only moved ~1/2" between fully open and fully closed. The articulation from 14b to 16g WGA's were identical. 2 14b and 1 16g WGA were tested.

Note: The turbo is an EvoIII 16g

Closed and fully open:

 

[Mr Peepers]

Through some testing and a little trial and error I got the actuator to open 7/8", almost double the stock movement(but with over double the articulation of the flapper). This was as far as I wanted to go since the diaphragm is the limiting factor. This was done through trimming the "stops" and extending the body about 3/16". The spring inside the actuator on the 14b is 5-1/2" long so 3/16" won't make much difference, and the 16g spring was about 4" but still would hardly impact the initial tension. I also made the WGA arm adjustable so you can have just the right amount of preload on the spring. I guess you could say "the rod was extended to make it look like it opens farther," but I assure you it fully closes. I will post a video if anyone needs proof.

Before and after:

 

[Mr Peepers]

I need some real world testing as my car is out of commission.

I'm looking for anyone with a 14b or 16g with boost creep to try my actuator. The worse the creep the better to put it to the test. Preferably local, but I will ship it to you, and if you like it I will do the same for your WGA if you desire. I only ask for a review of it on this thread, good or bad.

-Matt

 

[Killa_dsm]

Sounds very interesting. Once you find out if it really works, you should do a detailed write up on how to do it!

 

[Apeximprt2nr]

I would love to try this. I have my boost set to 11 psi and I can not stop it from creeping to around 19 psi.
Also, I was having trouble getting my flapper door to fully close which would equate to horrible spool.

If you want, I would love to try this out. I'm in North Jersey. I can PM you with more info if you decide that you want to ship it out to me.

If it does work, I will def. take one

 

[dsm-onster]

Good stuff! I creep from 15psi to 17-18. I run a 2g o2 housing and a cam upgrade. I port matched my 7cm^2 turbine housing w/ the 2g o2 housing. These helped my creap tremendously. The creep is still there but not as bad. However, I've seen other guys get terrible creap even w/ a turbular o2 housing. Digging into turbine housing iron took hours to do. The 2g 02 housing was 25 bones and though it helped stop drop the creep from 23psi to 20 or so psi, the cam upgrade is what made the most difference in my opinion. This definately looks to be a bit more affordable and faster to do.

It seams that it's a 16g thing after you get a good flowing wastegate pipe. Being that most guys can cure their 14b creep w/ porting and other things that donot relate to altering the flapper throw/diameter. I suspect the 16g compressor wheels are ina range where they are small enough in diameter not to need quite as much energy to keep spinning as the 18g/20g, and they flow enough to hold boost fairly high for a stock longblock.

If you cause the engine to have more VE or displace more volume, the turbo will need a shorter throw to maintain what ever boost setting you desire. I suspect this is why my cam upgrade contributed. Also, these cams "hit" later so theres not so much flow of exhaust gas velocity/volume until later in the rpms where there's more potential volume flow to "suck the compressor down".

This was done through trimming the "stops" and extending the body about 3/16"

Take a pic of this. What do you mean? Did you go inside the actuator?

This should be a perfect fix for ALL "creepy" tdo5h turbos. Much cheaper than upgrading flappers. I have a ford 5 bolt t3 garrett on the porch and the actuator arm doesn't extend farther but the wastegate opens to a wider angle (looks like your modded setup above). This is because of the flapper geometry. The arm directly connected to the flapper (not the arm that connects to the actuator arm) is longer. This turbo does not have a history of creeping.

 

[Mr Peepers]

Take a pic of this. What do you mean? Did you go inside the actuator?

Yes, I cut the actuator open as seen in the picture. This is one of the few pics I took of it apart since I was a little impatient to see it work If I did another I would document the entire process.

The factory "stop" was a cup that is in the center of the diaphragm(trimmed down in the pic). It hits the casing after about a 1/2" of travel. I extended the body by using 2 different WGA halves that I cut open in slightly different spots to add about 3/16" when the longer halves were put together(next time I would weld a metal ring between the 2 halves). The factory "stop" was a metal cup in the center of the diaphragm. I trimmed it down(along with some other minor adjustments) until there was enough articulation, but so it still stops the diaphragm before it reaches its full extension. After a few tests in a vice I welded the body back together along with the adjustable rod.

I could have a shorter throw on the WG arm or a larger flapper, but both will blow open more easily under high boost. I could cut/port a path to the WG hole but would be sacrificing some turbulence. I could run an O2 dump but personally hate the sound especially with an internal gate.
I know going external is still a better option, but money is an issue.

 

[sd_ff22]

very interesting

subscribed.

 

[dsm-onster]

Yes, I cut the actuator open as seen in the picture. This is one of the few pics I took of it apart since I was a little impatient to see it work If I did another I would document the entire process.

The factory "stop" was a cup that is in the center of the diaphragm(trimmed down in the pic). It hits the casing after about a 1/2" of travel. I extended the body by using 2 different WGA halves that I cut open in slightly different spots to add about 3/16" when the longer halves were put together(next time I would weld a metal ring between the 2 halves). The factory "stop" was a metal cup in the center of the diaphragm. I trimmed it down(along with some other minor adjustments) until there was enough articulation, but so it still stops the diaphragm before it reaches its full extension. After a few tests in a vice I welded the body back together along with the adjustable rod.

I could have a shorter throw on the WG arm or a larger flapper, but both will blow open more easily under high boost. I could cut/port a path to the WG hole but would be sacrificing some turbulence. I could run an O2 dump but personally hate the sound especially with an internal gate.
I know going external is still a better option, but money is an issue.

Owning a dsm forces one to learn basic welding techniques!

This is great. This is what I thought you were doing. I live in the eastern shore of VA. I'll volunteer my car if you don't mind shipping it out that far. But like I said my creep isn't worthy to test. Someone w/ some typical issues should definately volunteer. Considering Apeximprt2nr is creeping 8 psi, he is a great person w/ which to test this.

I have a line on another dsm I want to buy. And I plan on a mild reliability build (exhaust, 16g, 650s, safc, 2g maf, fmic, clutch). I'll surely do this to prevent creep if it is successful. I'd volunteer that setup but it will take a while. What's put your car out of commission?

Back to back testing is surely prudent. Verify to where you're creeping w/ dsmlink and a GM 3bar map sensor. Then, swap in the modded actuator and tweek. Pretty simple. Having an adjustable wastegate rod is an added bonus here. I've shortened my garrett rods (easy to do) and had great success raising boost to what ever level I wanted all while running the stock BCS.

 

[Mr Peepers]

In theory, you should be able to hold wastegate pressure all the way to redline with this actuator. That would be a great way to test it. I would be glad to ship the WGA out to you, dsm-onster, and I have been making arrangements to ship it out to Apeximprt2nr as well. I only have one modified actuator though, and I want to keep one stock for reference.

I also want to look into a setup that is completely custom, such as a larger diaphragm with more articulation possible. The larger the area of the diaphragm will allow a stiffer spring to keep the flapper from blowing open(allowing for higher boost), but still have the same cracking pressure etc for a wide range of boost pressures. I am having trouble finding a diaphragm material that will hold up to the heat. Cruise control actuator maybe?

dsm-onster:
On the T3 you said the arm the flapper was on was longer, correct? If I am picturing it right, then that would not effect the angle, only the distance the flapper traveled from the WG hole. But, the downside would be less leverage to keep the flapper shut.
Or am I missing something?

Edit: BTW, the Garret actuator from a t25 seems to have a fairly good range stock, about 5/8" to 3/4" IIRC.

 

[bling5tatus]

hey hey hey easy, I subscribed without making a post for it, but I guess I did now.

Mr. Peepers, I would love to see more pictures, I kinda had a hard time understanding what you did with the "longer halves". I'm a visual learner so... whenever you get another one done, I will be here waiting to see the pictures.

Thank you for pushing the envelope by having the determination to do something different. I love the cheap mods.... don't we all.

 

[dsm-onster]

In theory, you should be able to hold wastegate pressure all the way to redline with this actuator. That would be a great way to test it. I would be glad to ship the WGA out to you, dsm-onster, and I have been making arrangements to ship it out to Apeximprt2nr as well. I only have one modified actuator though, and I want to keep one stock for reference.

No give it to Apeximprt2nr for testing. He's got a setup that most run when running these turbos. I don't even have my stock cams any more.

Apeximprt2nr, what exhaust mods have you done? Modding exhaust does even more to encourage creep. I see that you have an o2 dump. It's classic that it didn't help enough.

I also want to look into a setup that is completely custom, such as a larger diaphragm with more articulation possible. The larger the area of the diaphragm will allow a stiffer spring to keep the flapper from blowing open(allowing for higher boost), but still have the same cracking pressure etc for a wide range of boost pressures. I am having trouble finding a diaphragm material that will hold up to the heat. Cruise control actuator maybe?

dsm-onster:
On the T3 you said the arm the flapper was on was longer, correct? If I am picturing it right, then that would not effect the angle, only the distance the flapper traveled from the WG hole. But, the downside would be less leverage to keep the flapper shut.
Or am I missing something?

Edit: BTW, the Garret actuator from a t25 seems to have a fairly good range stock, about 5/8" to 3/4" IIRC.

Ol' 80's garrett actuators have a longer throw at the actuator arm. They also have a stronger spring. So this counters the less leverage to keep the actuator shut. If you're pretty good at welding, then you can use a garrett actuator w/ it's bit longer extension and a stouter spring by welding it to a 14b/16g actuator bracket, then thread a 14b actuator arm to the rod w/a bolt coupler. A Garrett actuator rod already has threading on it. Then you have the best of both worlds: a spring w/ more seat and preload pressure and an actuator w/ more throw.

. . . Another option is you can fab a bracket to adapt a garrett actuator to the flapper control arm. I see this as inferior because of the angles it would put the actuator spring force vs. the control arm. But being that you have more seat pressure w/ a garrett actuator to counter the loss in preload pressure, it may not be that bad and be VERY easy to do. You'll lose some of the throw using an mor acute angle, however. . .

I have a garrett actuator here on my desk I can ship you if you want it. They're everywhere. I don't know if these are the same as the t25 actuators. I havn't seen a t25 in person for YEARS!

 

[Mr Peepers]

dsm-onster:
I am very interested in the Garret actuator, if you could ship it that'd be great. Let me know and I'll give you shipping info and find a way to reimburse you.

bling5tatus:
I cut 2 different WGA apart. The easiest way to describe it is this:
2 sticks, ---- and ----
cut one stick in the middle --l--
cut the other a little off center ---l-
add the two larger pieces and get this ---l--
Next time I will just weld a metal ring between the two halves.


My car is out of commission from a stock fuel line that caught on fire/cracked/I don't know, destroying all the underhood electronics, melting some of the intake manifold, and burning the paint off the hood and driver's side fender. Sometime I will start a thread on the rebuild process.

 

[bling5tatus]

Hahaha, I appreciate your effort, but that did nothing for me.... Thanks for trying though.

I guess it's because I don't understand how this is actually accomplishing the end result. I have had an idea for a while now, I don't care about having an mbc on my car, I want the boost pressure to be static all the time... so I will run a vacuum/pressure line from the licp elbow to the wga... and that's it. Go off the wga for my boost. The thing I wanted though was to figure out how to make the stock wg hold more boost than the normal 7-10psi or whatever it's rated at... I don't care at this point. I know it can be done though, there is a way. I was thinking if the spring pressure could be raised that would do the trick, but I am unsure exactly of whether or not this idea is really feasible. It sounds like what you're doing is on the track of what I was wanting... so I am interested in your project and any words that you can offer on what I've said... or ds-monster because I know he knows his shit too.

 

[oldman]

Very nice and I would like to see test results, don't send it to Matt he doesn't know shit.

That said, I'm not convinced that this is the only factor in boost creep, it's a major factor but not the only one since there are many examples of creeping O2 mounted externals without flappers. This should however resolve most cases of boost creep like the pivot arm mod, let's make sure it doesn't weaken its ability to hold higher boost level like the pivot arm mod would.

Good job peppers.

 

[dsm-onster]

I really don't know sh!t. what is this "pivot arm mod"? Shortening the arm that connects to the actuator arm? or modding the arm to the flapper button? (too many arms in my head)

I extended the arm that connects to the actuator arm on my BEP housing w/ the 38mm flapper. This housing is famous for blowing the wastegate open and thus limiting boost on deccent flowing setups. Extending that arm gave lots o' leverage. I could hold boost to over 35 psi (I only ran it for literally a few seconds) w/ my boost controller and AGP actuator set as tight as it was. But it worked for me.

However the opposite is what's happening here. so I'm lost.

 

[Mr Peepers]

Finished prototype Ready for its real world testing

To make things easier, I'll call it MWGA(Modified Waste Gate Actuator). The MWGA has an 1/8" longer body than the stock WGA as seen in the pictures, not 3/16" as I guessed before. Anyway, I ground off the weld, sandblasted it, and put a couple coats of Rustoleum grill paint to protect the metal a bit. Great stuff actually, tested it on some old bolts and even after getting red hot the paint still held strong, no worries there. I also pointed the MWGA nipple away from the turbo inlet when I welded everything back together, allowing for a 3" intake tube without risking a pinched line Maybe a little too much but it's a prototype

There shouldn't be a problem with the MWGA blowing open, not any more than stock anyway. And if you want to run higher boost, the arm is adjustable so you can have more spring preload if you desire. Another thing I'll change is using a longer threaded bolt so there is even more adjust ability, next time.

A flapper that opens farther can only compliment porting and/or a better O2 housing

bling5tatus:
The only easy way I can think of doing that is by making the WG arm adjustable. Put more preload on the spring when you want higher boost and less preload for less boost. I do not see any advantage of doing this over a MBC. A MBC will make the boost hit harder because the wastegate will be held shut while the turbo is spooling, and may actually give a more static boost pressure. Someone correct me if I'm wrong.

 

[bling5tatus]

Excellent, it looks really nice, you did a good job on the appearance of the thing. I cannot wait for the write up so I can get to work on doing one myself.

 

[Mr Peepers]

Thanks! If Apeximprt2nr sends me his WGA I'll do a tech article or something.

BTW, I just added a response to post #14 in post #17

 

[DirtyBirdRacing]

Thanks a lot for the last set of pics, it cleared some stuff up for me.

Bill

 

[dsm-onster]

Man, I'm game to give you the garrett wastegate acutator and ship my 14b actuator to mod like you've done yours for it's worth. I'd pay for shipping round trip, too. I think it's all good.

But looking at the extension on that arm on the "MWGA" , I just think that there won't be enough preload. Considering the length needed to "stretch" my OEM WGA to the flapper control arm, it looks way too long. I could totally be wrong. . . Pics can be VERY deceiving. . . How much longer is it from the actuator body to the tip of the actuator arm when it is screwed all the way in? That actuator arm looks adjusted fully tight. I just think you need more thread.

BTW, that's really good finish work on that welding. I can't really see the line you welded on the actuator body

And I like the direction you've placed the actuator nipple. It would work good w/ a mounted manual boost control valve.

 

[Mr Peepers]

The first pic is VERY deceiving, the rod on the MWGA isn't touching the ground while the stock one is. In that pic they are the same length believe it or not, and you can screw the MWGA in for another 1/4" of preload or so. Right now it's at about 1/16" of preload. I will be welding a longer machine screw on next time so it can be set to ridiculous amounts if you want There is also some paint on the threads making the screw look shorter.

In this pic you can (barely)tell that they are the same length from the mounting point to the tip of the rod, and the MWGA still has ~1/4" more to play with.

 

[bling5tatus]

bling5tatus:
The only easy way I can think of doing that is by making the WG arm adjustable. Put more preload on the spring when you want higher boost and less preload for less boost. I do not see any advantage of doing this over a MBC. A MBC will make the boost hit harder because the wastegate will be held shut while the turbo is spooling, and may actually give a more static boost pressure. Someone correct me if I'm wrong.

Is this because there is no "completely closed" if the wga is seeing any pressure at the nipple? What I got from your response is that with the wga connected directly to the compressor outlet elbow, as soon as it starts seeing pressure, the wastegate will begin opening until it is "fully open" at whatever psi the wg is rated at... is that right or am I completely off and the wg doesn't even begin to open until it sees the pressure it's rated at?

I've got another idea as well, but I think I will save that one so I can try it first before it's speculated upon ...

 

[Mr Peepers]

Is this because there is no "completely closed" if the wga is seeing any pressure at the nipple? What I got from your response is that with the wga connected directly to the compressor outlet elbow, as soon as it starts seeing pressure, the wastegate will begin opening until it is "fully open" at whatever psi the wg is rated at... is that right or am I completely off and the wg doesn't even begin to open until it sees the pressure it's rated at?

I've got another idea as well, but I think I will save that one so I can try it first before it's speculated upon ...

There is a "cracking pressure" that the WGA will begin to open at. But, this is measured off of the car. In actual use, there are other factors such as exhaust trying to push the flapper open. This will cause the WG to start to open before it sees its cracking pressure, and continue opening until it reaches a balance between boost pressure being sent to the
WGA, the spring in the WGA, and the exhaust helping push the flapper open. I do not know how much sooner the WG cracks open IRL but I know it depends from car to car and setup to setup.

There are a couple general ways to raise the boost pressure, which is the point it all reaches a balance. All else being the same.

1. Increase the force of the spring, so the diaphragm has to reach a higher pressure before it can open

2. Put more preload on the spring, essentially making it act like a stiffer spring, see #1. There may be boost creep problems associated with this from the reduced range(some of this range will be used in holding the flapper shut).

3. Use a diaphragm with a smaller surface area. The force that a diaphragm can exert at a certain psi depends on its surface area. It will take more psi to overcome the spring and create a balance.

4. The pressure the WGA sees, such as with using a MBC. With a simple bleeder type, air is bled off reducing the pressure in the line going to the WGA, tricking it in a sense. In a ball and spring type, a certain psi is required to lift the ball from its seat and allow the WG to start seeing any pressure at all. In fact, the ball lifts from its seat before you see your set boost pressure. Every ball and spring MBC has a bleeder hole to keep it from acting like a check valve and holding the WG open, this also acts like a bleeder type MBC. So once the ball starts letting air through the line, it still has to overcome the amount of air bled off. There are many other factors to a ball and spring type MBC that I won't get into right now basically it has its own balance as well, with each factor effecting the response of the WG.

To a lesser effect:
5. Increase the leverage holding the flapper shut against the hole. This can be done by decreasing the flapper itself's distance from the fulcrum, or increasing the length of the lever the WGA rod attaches to. This will keep exhaust from trying to open the flapper sooner. More of a factor in trying to run large amounts of boost with a MBC.

6. Decrease the flapper/WG hole size. This will also lessen the effect of exhaust helping push the WG open. Also more of a factor in trying to run large amounts of boost with a MBC.

^ To decrease pressure do the exact opposite of what's stated above.
Many things if changed in conjunction will affect the response of the wastegate, especially when a ball and spring type MBC is used. It's all about balance. It's hard not to keep typing but there are some things I can't explain without a picture or diagram.

It is all a system, and if you change one thing, the balance will shift. You need to think of the entire process.

 

[dsm-onster]

Man, I'll be refering to your above post when another member asks about raising the boost on their turbo car .

Your wastegate actuator setup is in effect lossing some preload pressure w/out letting the flapper lay open. . . From my unerstanding.

bling5tatus, Guys w/ creeping turbos can afford to lose that preload to keep the flapper shut vs. the force applied by the exhaust gases because for their setup there is not enough flow at the wategate hole to relieve the the turbine wheel and keep from over boosting. This means that there's not that much pressure on the flapper any how.

An MBC lets the wastegate actuator fill w/ boost pressure enough to modulate the actuator arm after a certain feed boost (from the manifold ) is achieved. This gives you tha ability to fool the wastegate in to thinking there is a lower boost by simply altering the pressure seen at the wastegate actuator. Unless there is enoguh pressure applied onto the wastegate flapper to blow it open regardless (like a leaky 2g BOV).

Any ol' MBC should be enough to keep the wastegate closed on these 16Gs until you wanted it to open (at whatever psi you set the MBC to). This is because the flapper on a "creepy turbo" (14b/16G) is in NO danger of being blown open. Thus, it's ok to do away w/ some of the force used to hold the flapper shut to give some more throw on the flapper. . . .

14bs arn't as bad because they inherently possess more pressure against the wastegate flapper by having a smaller a/r turbine housing. This creates more pressure against the flapper automatically and the flapper opens earler. BTW, you can get to a point where there is enough compressor and intake flow to still get creap at high states of exhaust flow even w/a 14b. Most 14b setups don't have such high states of flow at the exhaust, or massflow into the engine.

Upgrade to that 7 cm^2 turbine housing (which all 16Gs run) and the pressure against the flapper changes. There's a larger volume/flow. Thus, the gases are competing less for space (the pressure goes down). The gas law reads:

Pressure X Volume = (number of molecules) X (gas constant) X Tempurature

[(number of molecules) X (gas constant) X Tempurature] / Volume= Pressure on flapper​

So you see as the volume or volume flow goes up, the pressure against the flapper goes down. . . and creeping increases. More volume flow through the wastegate can be achieved through the ways Mr Peepers suggested (increasing wastegate hole diameter, opening the flapper farther).

I hope i didn't confuse any more .