Ext. Wastegate On Standard Exhaust Manifold?

[joe2548]

Hey all,

I am looking at putting an external wastegate on the standard rb25det exhaust manifold,

-just wondering if anyone could tell me how they have gone about doing it.

-e.g. welder type used, method of welding, position on the manifold.

Also Pictures would be greatly appreciated.

-i am doing this because i have a bigger turbo.

-i am a student and cant afford to spend $500+ on a nice shiny exhaust manifold.

-i have searched(for 5hrs), and found very little information on the subject.

thanks, Joe.

[jazza08]

If the turbo needs the gate then here's an example of putting it onto the standard manifold. Remember its best to put it in a (manifold < gate, turbo) kind of shape so that the gas's can be split evenly when needed, if you put the gate straight up or off to the side etc the flow distribution would be sh*t.

There is some information on the turbosmart website about it all if you look into it. Get a professional to do this as its not an easy job!

Here's the pic link i uploaded for you and one of the boost line. Boost control with the eboost2/gate is simply awsome

http://img81.imageshack.us/img81/651/manigateturbose1.jpg

http://img182.imageshack.us/my.php?image=300rwhpwi5.jpg

[R31Nismoid]

There isnt a lot of info because its nothing short of a mission, and the rooting around almost offsets the costs in most cases.

I can only remember in the last 4 years seeing pics of 3 or 4 such setups and they were a while ago when turbo range was not what it was today.

So, you have 3 options

1) Somehow mod the stock manifold nead the collector area

2) Have a spacer plate made up with an outlet that leads to the external gate, and have it run off that.

3) Graft/weld the gate onto the exhaust housing of the turbo

1st, is as i said.

2nd isnt that much difficult than #1, but it will cost you a few hundred at the least as there is a bit of measuring to be done.

3rd can be easily stuffed up if the welder isnt as good as they say they are, and will cost you more in the long run if they stuff it up as it will root the housing and/or gate.

Just a few quick questions though.

Why not use an internally gated turbo to begin with? They will rattle off pretty much upto 300rwkw...

For a poor student, im guessing thats miles out of your league to begin with???

Being you'd need the 10k worth of supporting modifications

Now, because i know people who have had similar ideas too yours...

Sell the turbo, sell the gate.

Purchase an int gated/bolt-on turbo and pocket the change for your school books or a set of injectors/ecu/afm/clutch/diff and the countless other things you need

[jazza08]

Id have to agree internally gated turbos are much easier n less messing around heheh

[sinistaGTR]

you can buy an adapter that goes between the manifold and turbo and that the wastegate bolts upto there bout 200-250 i think, but thats what it will cost you too get it welded in as the cast iron is hard to well to and can break really easily

[joe2548]

thanks jazza,

however I couldnt find any information on a modified standard manifold on the turbosmart site, maybe im not looking in the right place or they have changed the site.

Can anyone else please help me with this.

[joe2548]

you can buy an adapter that goes between the manifold and turbo and that the wastegate bolts upto there bout 200-250 i think, but thats what it will cost you too get it welded in as the cast iron is hard to well to and can break really easily

thanks sinistagtst, an adapter will not work for me as my turbo is allready about 20mm from the chassis. And my dad will be welding it, he is very experienced welder but has not had much experience welding cast, and told me of the same cracking problem that could occur.

does anyone know if it would be possible to drill a hole in the manifold and tap it to accept a thread so welding wouldn't be necessary?

Keep the information coming people, it is extremely helpful.

[sinistaGTR]

its just a shit fragile metal........basically apparently the matal has to be heated up for ages and cant be cooled too quickly. even then it can still crack. i mean give it a go and if it doesnt work standard manifolds are cheap as esp on ebay. like 10bucks....

[R31Nismoid]

You must weld it. The heat that its all going to see wont like being tapped/thread.

Your dad it totally correct. Hence your going to be paying $$$ to someone as i wouldnt risk your dad if he isnt expirienced in that area.

It will cost you more money in the end

What turbo as you using?

What motor?

[paulr33]

strongly agree, why re-invent the wheel and go through the same heartaches as someone else has. buy an already built manifold. if you cant afford the manifold then how do you plan to afford all the other ancillaries to run the new larger turbo, not even thinking about the tune at this stage

[joe2548]

thanks R31Nismoid,

the turbo is internally gated(and apparently bolt on- its internal gate was said to be set at 12psi), and on the car atm, and i do have the supporting mods.

My engine is an rb30det and produces too much exhaust gas for the small internal wastegate...therefore boosting up to whatever it wants, e.g. ~20psi at 3000rpm, currently i have the internal wastegate partially open so that it does not boost as quick. But i still cant rev it past 3800rpm as it leans out over that.

-The company i bought the turbo from have kindly sent me an external gate.

-If i want to be able to control boost in the short term this is my only option.

-In the long term i will buy a custom stainless exhaust manifold.

modifying the turbine housing would be no advantage as it is cast iron as well and only further complicates matters, including the possibility of ruining the turbine housing.

i have allready ground out the internal wastegate for maximum flow, it helped but not enough.

[paulr33]

im not sure its a good idea to hack an exgate onto it.

you are really band-aiding the problem with another hack solution.

if the gate is too small then fitting an ex gate just moves that to somewhere else, it wont actually fix it. if this is what you are seeing the perhaps the rear a/r housing is too small for the engine?

[James_03]

I had this same prob not long ago. I ended up making a T3 to T3 adaptor with the gate in it as already mentioned, but if you have no room thats not really an option.

Just take it to a workshop and ask them to do it, you might pay like max $100, and then its done properly.

I found this too which might be a good indication as to if you can DIY:

http://www.lincolnelectric.com/knowledge/a...ironpreheat.asp

[joe2548]

Your dad it totally correct. Hence your going to be paying $$$ to someone as i wouldnt risk your dad if he isnt expirienced in that area.

Dad is free, the cost of someone else welding it would most probably cover buying another second hand manifold. And yes im going to be asking some people i know about it, which is also why i'm posting on this forum.

thanks again.

[joe2548]

im not sure its a good idea to hack an exgate onto it.

you are really band-aiding the problem with another hack solution.

if the gate is too small then fitting an ex gate just moves that to somewhere else, it wont actually fix it. if this is what you are seeing the perhaps the rear a/r housing is too small for the engine?

thanks paul, yes it is a bandaid job, and yes in the future im sure a bigger turbo will go on, when money allows, for the time i just want to be able to control the boost.

[jazza08]

http://www.turbosmart.com.au/index.php?s=f...load&id=112

This shows the flow thats best for the wastegate (bottom of page 3, top of page 4)

If you can't get enough flow out of the wastegate flap then blocking up the wastegate flap and fitting an external gate will fix the problem aslong as the gate is big enough of course

[joe2548]

Thanks james im sure that site will help a lot.

Thanks again jazza.

thanks to everyone for the massive input, if anyone has any pictures or any other information dont hesitate to post it.

Edited January 3, 2007 by joe2548

[R31Nismoid]

thanks R31Nismoid,

the turbo is internally gated(and apparently bolt on- its internal gate was said to be set at 12psi), and on the car atm, and i do have the supporting mods.

My engine is an rb30det and produces too much exhaust gas for the small internal wastegate...therefore boosting up to whatever it wants, e.g. ~20psi at 3000rpm, currently i have the internal wastegate partially open so that it does not boost as quick. But i still cant rev it past 3800rpm as it leans out over that.

-The company i bought the turbo from have kindly sent me an external gate.

-If i want to be able to control boost in the short term this is my only option.

-In the long term i will buy a custom stainless exhaust manifold.

modifying the turbine housing would be no advantage as it is cast iron as well and only further complicates matters, including the possibility of ruining the turbine housing.

i have allready ground out the internal wastegate for maximum flow, it helped but not enough.

What turbo/where is it from?

Im interested as with guys playing with 30DET's now and the new Garrett IW's ... its interesting

[WogsRus]

or take of the stock turbine housing and port the gate, no biggie, takes bugga all time, just ensure there is a min of 1mm overlap to ensure good sealing.

[carl h]

poke around some of the us 240sx sites as proper manifolds are hard to source here stateside and quite a few ppl have fitted external gates to the std manifold.