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Discussion Starter · #1 ·
I'm thinking that it can be made with a plate cut to the size of the exhaust flange and a 2.25-2.50 piece of U Bend, and a seperate pipe for the wastegate. An O2 sensor bung would also have to welded in. One VERY rstrictive piece, especially for those with upgraded RHB5's is the exhaust elbow, even for guys with 3 inch exhaust...it has to pass through a small opening before it gets to the 3 inch piping. And something needs to be done about that. I don't know much about welding or the different types of metals for heat, IE the stocker is CAST (which lasts)....what about welded metal though? :shrug:



and how much would something likethis run?
 

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I made mine. REALLY BIG PITA!!! Not fun. The angles killed me. Took about 10-15 hours with 2 guys. Hand made the flanges and everything. If I ever figure out how to post pics, I will.

Matt
 

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Discussion Starter · #3 ·
posting pics is pretty easy, once you get pics onto your computer, go to a site that will host them, cardomain.com etc etc, upload them to the site, once they are uploaded copy the address and use the IMG icon.

What did you use for piping? What about welds? What type of angles? I was thinking of both pipes coming out and bending 90 but the wastegate would taper into the downpipe before it bent 90 again.

What size pipes did you use, and what turbo are you running?
 

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Hey, there's a few australian boys with that setup, in Brisbane(not much good to you) there's a place called Maztune i think, that make them as a lot of them use the place. PM turbotim I think he'd have pics. Sounds nice.
 
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Heres mine:



Ok, so I'm not running an IHI, and this mitsibushi turbo has a very simple flange :). You can see the 02 sensor bung. Its 3" diamiater. Ignore the unfinished other end.
 
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SixSick6 said:
I'm not sure if a 3 inch pipe would fit on the stock exhaust side, It might fit, but it seems like it would be hard to line up two seperate pipes for exducer and wastegate. There isnt alot of room to work with:confused:
Yeah, this doesnt come down in the stock location. The Turbo I am using has an internal wastegate, so theres no need to have a seperate wastegate output.
 

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Discussion Starter · #10 ·
well using an external would actually be easier than using the stock internal. I plan on removing my A/C, so there would be plenty of room there. Do you happen to have a spare RHB exhaust side laying around that you can take measurements from? I need to know how far the wastegate is from the exhaust outlet, and whether or not a 3 inch pipe would A) cover both the exhaust outlet and wastegate B) Will fit the exhaust outlet and leave a fraction of an inch for a seperate wastegate pipe. C)Would be such a tight squeeze that it might be easier to just use one 3 inch pipe to cover both.
 
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From my recolletion (I dont have any RHB5's sitting around), Option C would be your best bet, possibly, use a 2.5 inch pipe around the compressor output, and a smalled 2 inch pipe that simply bends directly into the 2.5 inch infront of the wastegate.
 

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You could use a 3" and sort of flatten it a little to make it oval, that might cover both ports.
 

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SixSick6 said:
that's what I'm trying to figure out, if one 3 inch would be more advantageous than trying to fit a 3 inch and a 2 inch
PM jimxsix, I've seen his seperate WG pipe setup. He will be able to tell you straight away (& probably has pics).
 

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It can be done, but it won't be all that great because you still have a tight fit with the a/c and PS. I have my 02 sensor housing for my T3 made out of regular exhaust pipe that I pie-cut and welded, and I've had no problems with it. The ideal way to go would be to make some room so that the angle is not as sharp, that's what's killing exhaust flow more that anything if you asked me.

But what if you get a 2.5" pipe from the turbo to the exhaust? You still have a 1.75" exhaust manifold outlet and turbo inlet. Seems rather pointless to me. The better way would be to use a full T3 with a custom manifold. T3 flanges are like 2.5" rectangles.
 

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rebel2k4 said:

But what if you get a 2.5" pipe from the turbo to the exhaust? You still have a 1.75" exhaust manifold outlet and turbo inlet. Seems rather pointless to me. .
It makes a big point. The turbine relies on a pressure differential across the blades to generate spin. The greater the differential, the faster the spin. It's what makes the whole thing work, how can you say it's pointless? I think you assuming flow rate has something to do with it.
 

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I've also seen Vishu Tuning's version for the EVO, and thought it might be a good design to try and replicate. (as far as the elbow goes, obviously not the routing)



You'd probably wanna use thicker tubing than normal, and find a welding technique that will not crack when the turbo goes through heat cycles (or am I just being to cautious here?).
 

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crusty said:
It makes a big point. The turbine relies on a pressure differential across the blades to generate spin. The greater the differential, the faster the spin. It's what makes the whole thing work, how can you say it's pointless? I think you assuming flow rate has something to do with it.
Yes I am assuming that flow has something to do with it. I'm saying that a T3 is better because it not only helps the turbo get the exhaust gases out better, but gets the engine to breathe better. My dyno proves this because I run waaaay lean at a lower boost but my turbo is practically the same size as stock. It flows more air out, therefore more power. The stock turbo could never make 180whp on 10-13 psi with a blown motor at high altitude. Not on my motor at least.

You also left out an important part of that statement, where I said a better option would be a T3. The main problem here is the 190 CFM stock IHI, sure you can put in bigger exhaust wheels and this and that, but a T3/T4 is always going to outflow it, for the sole reason that it is larger.

The point I am trying to make is that if you want flow I think you're going to need a bigger turbo. You can only go so far with the IHI turbine housing. I do agree that the stock elbow is not the best of design though. I am curious to see how much power you'd really gain from replacing it. Maybe 5-10 hp? My dyno fluctuated 5-10 hp between each run without even changing a thing :shrug:
 

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I agree, but the threads not about a turbo conversion, it about a dump pipe for the stock turbo. You said you didn't see the point of a larger better flowing dump, I was explaining the benifit of creating a greater pressure difference across the blades of the turbine. Every bit of hp adds up, I'll take 5-10 where I can, but I think it would be more than 5-10 hp over a stock dump.
 
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