External Wastegate On Stock Exhaust Manifold

[ISL33P]

Just in case anyone is interested in doing this mod. I know it's a popular mod and works quite well.

1 - select location, preferably located in the middle of the merge to the exhaust housing and on an angle to make the air entering the wastegate as strealine as possible

2 - die grind the hell out of the standard exhaust manifold until you get rid of the scaley crap on top. Go at least 10mm past where you are going to weld the flange to the manifold

3 - either holesaw or oxy the hole and clean it up with the die grinder, get ready to demolish on carbide tip, they dont like the cast steel. Being a splut pulse exhaust housing, I first drill the hole with the hole saw and since I dont own an oxy, cranked the tig up and blasted the inside of it away. Again, the die grinder came in handy to clean it all up at the end

4 - No just place 3 or 4 tacks around the 'gate flange and weld. did not preheat it at all. Ran 1 root pass and 2 filler passes. One think to keep in mind it is to be slow on the downslope. In my experience, the cast steel doesnt like cooling down quickly, so aim for 1.5-2 downslope.

I used around 90 amps on the root pass, and less on each subsequent pass.

Here is the end result

If anyone has any questions, just let me know

[Muff]

did u shot peen / stress relieve the weld???? No preheat? / RE-heat???

Just asking why???

thanks???

[ISL33P]

No, no and no

Never had the need for it.

[dysonest]

that looks real good mate.. ill be doin this in a few weeks. pics make this look easier haha

[Notorius]

Can you post pics of how they sit in the bay?

[ISL33P]

Good luck, let me know if you need any advise.

Sorry no pics of it back on the engine since the manifold was just bought to me and that's it, but there is plenty of space to the strut tower so no hassles there

[Yeedogga]

Im curious as to whether chopping out the divider in the manifold will affect performance/gas flow in a measurable way... Anyone have any theories on this?

[Frosty]

Can you post pics of how they sit in the bay?

This is how i did mine. now for sale tho

Edited November 20, 2012 by Frosty

[9krpm]

That looks really good. What size are those wastegates?

Would love to see a picture of the completed setup too (if you can)

[Frosty]

That looks really good. What size are those wastegates?

Would love to see a picture of the completed setup too (if you can)

Tial 44mm in my pic

[Notorius]

hey champ im keen to do this one my rb26 i was wondering what it would cost to get you to duplicate those manifolds?

[ISL33P]

Send me a pm if you want this done. I am not an advertiser here........just yet but it will happen shortly

[Frosty]

hey champ im keen to do this one my rb26 i was wondering what it would cost to get you to duplicate those manifolds?

the question has to be asked here!! why? the manifolds are seperate so will need 2 gates unless you some how mate the gate ports together and run one?

[dysonest]

1 would look horse shi7... u would defo be lookin at 2

[9krpm]

The purpose of doing this is to improve top end power. Bridging the two into 1 gate just defeat the purpose of the exercise.

Btw what are the largest external gate turbos can u fit with these modified manifolds?

Edited December 6, 2012 by 9krpm

[Frosty]

depends on the setup.

i could guess that you could get 38 or maybe 44mm if you do it right. 44m is quite big tho

[Ant_r33]

Sorry I'm new to all this, but I have a r34 high flowed turbo by gcg, it has been modified to suit external gate,

Do I need a actuator?

I want to modify my standard manifold for the gate, I'm in Sydney is there anybody I can get to do the fabrication work?

[Frosty]

Sorry I'm new to all this, but I have a r34 high flowed turbo by gcg, it has been modified to suit external gate,

Do I need a actuator?

I want to modify my standard manifold for the gate, I'm in Sydney is there anybody I can get to do the fabrication work?

you just need to buy an external gate and get it fabbed to the standard manifold most workshops will do it for you

[r34unit]

has any one else got some pics of welding their waste gate on the stock manifold ?

[RB25 SKYLINE]

yeh i did it to mine ill try get sum picks up of it all done