welding internal wastegate passage shut when going external

[koroshiya_jason]

i'm going with an external wastegate off of my evo iii manifold, and i was just curious why the existing exhaust passage for the internal wastegate needs to be welded shut. it seems like i should be able to just disconnect the vacuum line running to the internal wastegate, and without a pressure source the internal wastegate won't open. or maybe run a second mbc set slightly higher to act more or less as a safety device in case the system overboosts... any advice/suggestions would be appreciated.

 

[silvercoupe97]

Keeps you from having possible leaks? Why don't you want to weld it?

 

[zachakagoat]

Maybe he wants to be able to resell the turbo when he decides to go bigger. It would be alot harder to sell a turbo that has been welded shut if someone doesnt want to run an external wg

 

[silvercoupe97]

Maybe he wants to be able to resell the turbo when he decides to go bigger. It would be alot harder to sell a turbo that has been welded shut if someone doesnt want to run an external wg

Makes sense.

 

[rjclagett]

I just switched to an ext. gate on my Evo3, and I didn't weld the flapper shut. I put a nipple on the w/g actuator, and also have an o2 housing with the int. w/g block off. I don't have any leaks and my boost creep is finally all gone! Hope this helps.

 

[rowlex]

iit seems like i should be able to just disconnect the vacuum line running to the internal wastegate, and without a pressure source the internal wastegate won't open. )

thats what i did worked at 19psi, u could also drill a hole in the o2 tap it run a bolt throught till it hits the flappper to keepit closed

 

[99gst_racer]

or maybe run a second mbc set slightly higher to act more or less as a safety device in case the system overboosts...

You're not going to overboost. Most any external wastegate is large enough to efficiently control boost by itself.

I welded my flapper shut just for piece of mind. Now I know for sure that it is not slightly popping open under boost.....

 

[zachakagoat]

thats what i did worked at 19psi, u could also drill a hole in the o2 tap it run a bolt throught till it hits the flappper to keepit closed

That's a really good idea, just might wanna be careful not to put it in TOO hard so that it cracks the flapper, not sure if it would or not.

 

[rowlex]

That's a really good idea, just might wanna be careful not to put it in TOO hard so that it cracks the flapper, not sure if it would or not.

Very true, be careful

 

[CryoBlue98]

I just switched to an ext. gate on my Evo3, and I didn't weld the flapper shut. I put a nipple on the w/g actuator, and also have an o2 housing with the int. w/g block off. I don't have any leaks and my boost creep is finally all gone! Hope this helps.

where could I get one of these O2 Housings with the w/g block off and what kind of nipple did u put on the actuator is there any way you could provide some pictures ? This would be much appreciated cause im getting ready to also externally gate my car and I was just wondering what would be the best way to go about dealing with the internal gate.

 

[Black_Bullet]

I have an 38mm external gate on a punishment racing o2 housing and I didnt weld the flapper shut, I just pulled the stock oem actuator off and left the flapper alone. So its just going to blow open whenever it gets pressure.... I didnt want to remove it in case for whatever reason I want to switch the setup back to internal.

 

[tsidrift1]

I just welded the arm coming out of the housing, if I ever want to sell it, Ill just cut the weld and it will be all good!

Anthony

 

[anteversion]

welding the flapper is just like it was said before by many, to present leakage from the flapper and result in a lag or slower spool issue. The only thing that can make the flapper to open with vaccuum boost line disconnected is positive pressure builded between the manifold and the turbine, wich needs to be pretty much high to make the flapper to open up. so if there was no spooling troubles and lag issue with the internal wastegate, should have no problem to ru the thing without welding it, but like it was said, thats for sure a good preventive method to avoid trouble after the turbo kit is installed

 

[Black_Bullet]

Thats only if you are running your waste gate off the manifold... ^

 

[MidnightTSI]

Thats only if you are running your waste gate off the manifold... ^

Has this worked really well for you? I don't see why it wouldn't. I don't plan on ever going back to internal so I might just remove the flapper all together.

Reason I'm asking is because I just ordered the Talon/Eclipse Tial MVS 38mm wastegate / atmosphere dumped o2 housing package from PR.

I'm super excited to get it installed.

The internal on my G50 is horrible. If you look at my engine bay picture you can see I had to put an extra spring on the wastegate arm to even get it to open.

It builds boost super slow and I don't get full boost (20 psi) until around 5K rpm's!

It pulls really hard once I get to that point but I'm done with the internal shananigans. I'm ready for some real boost control!

 

[black_gst]

when i went external i didnt want to weld mine shut so i fabbed a WG closer it bolts up the the same hole that the WG actuator uses and a rod with a 3/16 hole(for the flapper arm) in it attaches to this and the flapper arm and it holds the flapper closed. i can take some pictures when i get home later it works great.
i tapped the rod and the piece of steel so it is adjustable so you can make sure that the flapper is closed tight

 

[99gst_racer]

Has this worked really well for you? I don't see why it wouldn't. I don't plan on ever going back to internal so I might just remove the flapper all together.

Reason I'm asking is because I just ordered the Talon/Eclipse Tial MVS 38mm wastegate / atmosphere dumped o2 housing package from PR.

If the wastegate is plumbed before the turbine housing, then you need to close off the internal wastegate's passage so that it will not divert exhaust flow. Most guys weld them shut, some bolt them shut. But, if using an external wastegate on the O2 housing, you'll need to remove the flapper assmebly (and usually port the passage out a bit).

when i went external i didnt want to weld mine shut so i fabbed a WG closer it bolts up the the same hole that the WG actuator uses and a rod with a 3/16 hole(for the flapper arm) in it attaches to this and the flapper arm and it holds the flapper closed. i can take some pictures when i get home later it works great.
i tapped the rod and the piece of steel so it is adjustable so you can make sure that the flapper is closed tight

Interesting. I'd like to see some pictures if you don't mind.

 

[black_gst]

If the wastegate is plumbed before the turbine housing, then you need to close off the internal wastegate's passage so that it will not divert exhaust flow. Most guys weld them shut, some bolt them shut. But, if using an external wastegate on the O2 housing, you'll need to remove the flapper assmebly (and usually port the passage out a bit).
Interesting. I'd like to see some pictures if you don't mind.

for sure, its 10am now ill be home about 330 so ill take a few pics and post them up.

 

[MidnightTSI]

If the wastegate is plumbed before the turbine housing, then you need to close off the internal wastegate's passage so that it will not divert exhaust flow. Most guys weld them shut, some bolt them shut. But, if using an external wastegate on the O2 housing, you'll need to remove the flapper assmebly (and usually port the passage out a bit).

Thanks a bunch. That is what I was planning for the most part. I'm probably won't port it right away, seeing that I leave in a month for Afghanistan. I plan on running the car at the track within a few weeks. First time with the new motor

 

[black_gst]

If the wastegate is plumbed before the turbine housing, then you need to close off the internal wastegate's passage so that it will not divert exhaust flow. Most guys weld them shut, some bolt them shut. But, if using an external wastegate on the O2 housing, you'll need to remove the flapper assmebly (and usually port the passage out a bit).
Interesting. I'd like to see some pictures if you don't mind.

here are the photos of how i closed my internal flapper

 

[JusMX141]

Seems to be a foolproof method.


The standard procedure is two TINY tack welds where the actuator lever meets the turbine housing. Any more is overkill. In the event that the turbo be sold, the tack welds can easily be removed and the actuator can be reinstalled. The tack welds should be done when the actuator is still in place to ensure the flapper is being held tightly against the housing.

Leaving the actuator in place and removing the vacuum line would also work as long as you're running under what the total spring tension of the actuator will hold. Once you reach a certain PSI (can be as low as 16-17psi for some actuators), the flapper will blow open and you'll basically have *two* wastegates.

 

[black_gst]

when i did this i even had a small welder but i had just pulled the turbo off 2x because the place that rebuilt it messed up and i had to take it back to them within a week and like 2 weeks after that i went external and i didnt feel like taking the turbo off draining half of my coolant to put 2 tacks so i did this. i used 1/4" rod a scrap piece of steel and a tap and die set. i did have to bring the rod to work to flatten the 1/4" rod to have a place to drill the hole for the flapper arm

 

[vanilla gorilla]

I welded mine where the lever arm comes out of the housing. I also welded the actual flapper to the inside of the o2 housing. Im not losing any sleep at night.