How to Build & Install TGV Deletes

[covertrussian]

Recently built my own TGV's and figured I would do a quick writeup with how I did them.

 

Tools needed:

• Die Grinder (I used a compressor one, drill might work?)
  
• Carbide burr bits
  
• Dremel
  
• Sanding Wheels
  
• Polishing Wheels
  

 

Parts needed:

• 4 x 1/8 NPT Plugs with Allen key ends.
  

 

First thing I did was remove the butterflies themselves. You wont be able to unscrew them easily since the screws are flared at the end, to prevent them from walking out. Thus I ground off the threaded parts of the screws and then they easily came out.

http://legacygt.com/forums/attachment.php?attachmentid=252875&stc=1&d=1500862257

 

Next up is puling out the bar, apparently there is a way to tap it out in one piece. I didn't get that memo and broke mine (that's why I got a spare).

http://legacygt.com/forums/attachment.php?attachmentid=252876&stc=1&d=1500862257

 

With the butterfly bar out, you can now see the parts that need to be ground off. The obvious one is the divider, but the one that is sometimes missed is the lower lip, which also will impede flow.

http://legacygt.com/forums/attachment.php?attachmentid=252877&stc=1&d=1500862257

 

Now the hard work begins... I used a carbide burr to cut the divider off, you can use a little saw too.

http://legacygt.com/forums/attachment.php?attachmentid=252878&stc=1&d=1500862257

 

The upper divider is done, now it's all about smoothing everything out

http://legacygt.com/forums/attachment.php?attachmentid=252879&stc=1&d=1500862257

 

Hard part is done, all 4 are roughly sanded with the dremel, you can try to get it mirror smooth on this point, I personally didn't see the need for such a small piece of the intake plenum.

http://legacygt.com/forums/attachment.php?attachmentid=252880&stc=1&d=1500862257

 

At this point I tapped the holes with a 1/8 NPT bit, to install the hex plugs. On one side you will find a metal sleeve that needs to be removed, hard to get out but I was able to tap into it and it came out at that point. Make sure you don't overtap, or the plugs will protrude into the runners!

http://legacygt.com/forums/attachment.php?attachmentid=252881&stc=1&d=1500862257

 

Hole is plugged, I used some red loctite for good measure

http://legacygt.com/forums/attachment.php?attachmentid=252882&stc=1&d=1500862257

 

Here is the finished plug installed and not protruding.

http://legacygt.com/forums/attachment.php?attachmentid=252883&stc=1&d=1500862257

 

All done and ready to be test fitted, but first we need to remove the manifold and stock TGV's.

http://legacygt.com/forums/attachment.php?attachmentid=252884&stc=1&d=1500862257

 

 

Removing The Manifold & TGV's

 

First drain the fuel rail (let it sit a couple days or pull the fuel pump fuse, start the car and let it die, that should drain most of the pressure). Afterwards you can unplug the fuel lines and all the vacuum lines, there are plenty...

http://legacygt.com/forums/attachment.php?attachmentid=264900&stc=1&d=1525744186

 

Remove the intercooler, I also removed all of the throttle body screws at this point since I didn't want to undo the throttle body heater lines and introduce air into the coolant system. After that start working on all of the manifold and TGV bolts. Don't forget to undo the ECU grounds on the driver side TGV's.

http://legacygt.com/forums/attachment.php?attachmentid=264901&stc=1&d=1525744186

 

I tried to pull the manifold out without removing the TGV's, but there is one bolt, that connects the fuel rail to the manifold that's unreachable. Thus the first time around you'll have to remove the manifold and TGV's at the same time.

http://legacygt.com/forums/attachment.php?attachmentid=264902&stc=1&d=1525744186

http://legacygt.com/forums/attachment.php?attachmentid=264903&stc=1&d=1525744186

 

Here is the bolt that you want to remove if you want to be able to remove the manifold without removing the TGV's in the future.

http://legacygt.com/forums/attachment.php?attachmentid=264904&stc=1&d=1525744186

 

 

Finishing Up The Porting Work

 

With the manifold and TGV's off, The final step to porting is test fitting them on your motor and port any areas that protrude compared to the head.

http://legacygt.com/forums/attachment.php?attachmentid=264897&stc=1&d=1525743665

 

You can see the parts that I didn't get as rounded in this before and after pic. Be careful not to over port, like I did a little, otherwise the TGV will be bigger then the head ports creating flow walls.

http://legacygt.com/forums/attachment.php?attachmentid=264898&stc=1&d=1525743665

 

Reinstallation

 

Attach the fuel rail to the TGV's, now we are ready to reinstall everything piece by piece

http://legacygt.com/forums/attachment.php?attachmentid=264905&stc=1&d=1525744186

 

Installed the TGV's & fuel rails first, without that pesky fuel rail bolt, this was a piece of cake.

http://legacygt.com/forums/attachment.php?attachmentid=264906&stc=1&d=1525744186

 

Final shot of the ported TGV's installed:

http://legacygt.com/forums/attachment.php?attachmentid=264899&stc=1&d=1525743665

 

Rest is pretty self explanatory, install the manifold, all the vacuum lines etc.

 

Disabling the CEL's

Final step is to disable all of the TGV related CEL's otherwise your car will be stuck in limp home mode.

 

(P2004) TGV - INTAKE MANIFOLD RUNNER 1 STUCK OPEN
(P2005) TGV - INTAKE MANIFOLD RUNNER 2 STUCK OPEN
(P2006) TGV - INTAKE MANIFOLD RUNNER 1 STUCK CLOSED
(P2007) TGV - INTAKE MANIFOLD RUNNER 2 STUCK CLOSED
(P2008) TGV - INTAKE MANIFOLD RUNNER 1 CIRCUIT OPEN
(P2009) TGV - INTAKE MANIFOLD RUNNER 1 CIRCUIT LOW
(P2011) TGV - INTAKE MANIFOLD RUNNER 2 CIRCUIT OPEN
(P2012) TGV - INTAKE MANIFOLD RUNNER 2 CIRCUIT LOW
(P2016) TGV - INTAKE MANIFOLD RUNNER 1 POS. SENSOR LOW
(P2017) TGV - INTAKE MANIFOLD RUNNER 1 POS. SENSOR HIGH
(P2021) TGV - INTAKE MANIFOLD RUNNER 2 POS. SENSOR LOW
(P2022) TGV - INTAKE MANIFOLD RUNNER 2 POS. SENSOR HIGH

[zactek]

I'm glad you didn't go further and smooth/polish the inside. It's better to leave it a little rough,as it helps with the atomization/mixing of fuel and air/swirl effect in that area,especially when it's cold,as fuel might puddle. It's ok to make things smooth after the combustion part/exhaust valves,as that area doesn't need to mix,just evacuate quickly.

I've ported a lot of heads/manifolds and it's a good theory to follow.

 

Zack K. (Also Russian,lol,just not so covert)

[covertrussian]

I definitely follow that theory when porting post past injectors (usually intake runners on heads). In this case the injectors are at the end of the TGV, which means they are spraying into the head and shouldn't be spraying on the TGV's at all.

 

Unless you mean it will pre-turbulant the air a little before fuel is even involved, for better mixing?

[zactek]

Yes,turbulence of air before fuel is introduced will create a more proper mixture.

 

Zack K.

[covertrussian]

Though I wonder if the air pockets artificially restrict the diameter of the runner (think of a pickup truck with the tail gate up). We need vortexes generators insides our plenum .

 

On serious thought, I do wonder about potential fuel economy penalties (or gains?) for getting rid of TGV's.

[zactek]

In a way,the way our TGV's are cast,they already have a vortex generator. The way they go from round to a smaller oval toward the head speeds up and smoothes the velocity of the mixture.

As far as gas mileage,hmmm,it's a double edged sword; on one hand,you're removing a restriction and providing more space for air and fuel to enter,so more will get used and gain power. On the other hand,pumping losses from the engine will be minimized,so you wouldn't need to use more fuel. All of the above would be minimal at best and I honestly don't think one would notice a big difference.I'm all for removing restrictions though,as long as it doesn't affect drivability.

 

Zack K.

[covertrussian]

Great points!

 

On one side, it's making the engine breathe easier (one big straw vs two smaller ones). Which means engine might work less outside of boost just to ingest air. In theory raising torque.

 

On another side, this mod makes the runners bigger, which usually translates to loss of low end torque, which would require more throttling (which can lead to reduction of pumping loses).

 

 

After I'm done with testing a few other things (intake and probably 3" vs 2.5" downpipe), I plan on installing these and testing my power and gas mileage gains.

[zactek]

Testing would be the only true way to gauge any gains/losses. Remember,any time you're increasing volume per given psi,you might be losing velocity,which might mean increasing boost and therefore using more fuel. But removing restrictions from the air path inside the engine is always good. Many people scoff at the idea of doing little (seemingly minimal) mods,but ultimately it's the sum of all those little mods (lightening rotating mass,porting,removing restrictions) that give you more power,reliability and efficiency.

 

Zack K.

[covertrussian]

That's part of the reason I'm running my turbo at wastegate 13psi right now without a boost controller. I can see things like, boost increase that's not artificially done by ECU (for example EQL Header reduced my boost by about .5psi, but a better flowing intake increased boost by almost 1psi).

 

I also agree with you on the little things adding up, that's how I got to 30mpg on the Legacy (mod or tune change here and there) but I'm having a hard time breaking 31mpg consistently so I'm starting to really look into these little mods here and there to see what will help. Also, that's another reason why I'm running the wastegate 13psi only. It's a game to see how much power I can make at stock like boost levels, but with better flowing components and a fine tune.

[covertrussian]

Finally got these installed, added steps and pictures for the re-installation process.

[SBT]

Thank you sir! Always appreciated.

[PimpFro]

Great walkthrough, I did the same with mine a few years ago, including the NPT plug with an Allen head/loctite. Wish this was made back when I did mine because that bolt on the underside of the manifold was a PITA. After done I Ceramicoated the TGV's and put some of those Grimmspeed spacers in. Huge thumbs up to this walkthrough