Exh Manifold to turbo bolts... options?

[Kenny_Kline]

Your right about the outlet but the path the exhaust takes from the turbine flange to the wheel is alot bigger than a 7cm and I am not speaking of just the inlet either. When you put this housing next to a 7cm housing, you can see how much fatter this one is over the 7cm. That and the machine work is much smoother inside this one. I think I pointed this out already though... maybe you just skipped over it to argue?

So I was right.. you have something against me. Thats fine.

I am going to log both boost pressure and back pressure vrs. engine load. I will run the 7cm hotside and then this side. I will let you know how it goes.

 

[turbowop]

You're actually going to install a sensor or tubing into the manifold collector to measure backpressure?

Bigger isn't always better either. Especially when it comes to matching a volute to a turbine wheel. I'd say Mitsu did a pretty damn good job with the Evo3 16g. If it ain't broke...

Is that a Chinese turbine housing?

 

[Kenny_Kline]

Yes. Putting it on the manifold. Probably dead center on the collector. Not sure yet. Tubing to manifold.

I know bigger isnt always better but extra small isnt better either. I know I will be giving up some spool time with this hotside but if its spooling before 3500rpm, I will be perfectly fine. Besides, I can play with timing to gain back 200-300 RPM spool up time.

They did do a good job with the EVO3 turbo. I agree with you there but I think you can agree with me that the hotside is still its weak point. A properly ported evo3 turbo can make some decent power. We will see. I dont do the internet what will be better. I would rather just test especially since I think this chinese hotside is going to produce better numbers. Its just common sense, lower back pressure before wheel, better flowing. Will be running my 16g around 25psi and to 7500RPM.

 

[bigblock4g63]

good luck with the build. i have used the knock off hotside ( that is what the guy wanted ) on rail car i built and it ended up going slower.

 

[Brianawd]

Quote:
I think this chinese hotside is going to produce better numbers.



/ubbthreads/images/graemlins/rofl.gif Please tell me your joking.

 

[Lonewolf64]

Kenny Kline is like DSM Socrates--he asks us questions and then we are the ones that end up "learning" something! /ubbthreads/images/graemlins/rofl.gif

 

[bigblock4g63]

ON A ANOTHER NOTE BEFORE YOU GO ALL OUT. FIND A SHOP WITH A SUPERFLOW AND FLOW THAT HOUSING. IT DOES NOT FLOW BETTER THEN A OEM EVO 3 HOUSING THE LAST TIME I CHECKED. ITS ABOUT 30 TO 40 BUCKS
Quoting Kenny_Kline:
Ok here is the deal. I no longer can run the standard length turbo bolts anymore. The hotside I have has the threads drilled out for some reason. If I wanted to use the standard size length bolts but get thicker bolts, I would have to drill out my manifold bolt holes and then tap the hotside for the larger bolts.

As some of you may know, this is a critical sealing point for the turbo. I cannot have a leak and need to make sure I can torque this flange down good and not have to worry about it leaking.

One option is I was thinking of getting 1/2"-3/4" longer bolts and putting a nut on the other side of the flange. Do it to all 4 and weld the nut in place then take it back apart and there are my threads. Its really the only reasonable thing I can think of but then the question is, what material should the bolt be made out of and what thread pitch. I think a stainless steel bolt will be the best w/ a fine pitch?

Need some reasonable opinions and possibly maybe a better way to seal this gasket . Need a bolt material that can take this kind of stress and heat and wont have issues. Whatever the stock bolts are made out of, thats what I want but needs to be 1/2" longer.

I dont know. Here are a few pics of the flange. I have room for the nut to get under there and if I didnt, I could easily clean up to make one fit.

Also, I am thinking about using ultra grey RTV for the O2 housing to hot side seal. They dont make a gasket big enough for the hotside I have.

 

[bigblock4g63]

ALSO I WOULD PORT THE WASTEGATE HOLE AND UPGRADE THE VALVE
Quoting Kenny_Kline:
8cm gasket is to small too. Here is a pic of the 7cm gasket on a 7cm hotside:

to confirm its a 7cm hotside:

Here is a pic of the new hotside:

I dont have any pics of the gasket over it... trust me when I say its to small.



I might just start looking for the material they use to make these gaskets so I can just make my own so it will fit this hotside



I found this for the thread issue I am having. I think this is my best bet. click

 

[curtis]

When I installed the s362 schwitzer with the bullseye housing. I chucked the housing up in the mill and used a 7/16 endmill and drilled out the holes larger then tapped for 1/2 inch threads then I took my 2nd gen manifold and opened the 4 holes up to .525 or so for some wiggle room. I used some heat treated industrial allen heads and used a full stainless .050 gasket. Everything sealed up and with the larger bolts I didn't have to worry about leaks because I torqued them up around 100 ft pounds. There's enough material in the manifold so you don't need to worry about that. Any industrial machine shop should be able to do this for you. Since someones been at the turbine so far it would be hard to center up a drill bit on your own but a set of reamers in a drill should work nicely. I know you said problem solved just though I'd put this out there for someone that might go down this road later.

 

[Kenny_Kline]

Quoting bigblock4g63:

ON A ANOTHER NOTE BEFORE YOU GO ALL OUT. FIND A SHOP WITH A SUPERFLOW AND FLOW THAT HOUSING. IT DOES NOT FLOW BETTER THEN A OEM EVO 3 HOUSING THE LAST TIME I CHECKED. ITS ABOUT 30 TO 40 BUCKS



Wouldn't logging each hotside be the true test?

 

[Kenny_Kline]

Quoting bigblock4g63:
ALSO I WOULD PORT THE WASTEGATE HOLE AND UPGRADE THE VALVE




I am running a Tial Wastegate off the O2 housing and will be porting the wastegate hole

 

[vapid]

Maybe I'm missing something.....are you looking for a turbine housing gasket for the inlet or one for the O2 side?
I've never seen "7cm2" O2 housing gaskets, just evo3 ones, is that what youre talking about?
I don't know how big that Chinese inlet is, but my 7cm inlet gasket is actually larger than the inlet to my 8cm housing, and I havent noticed a difference at the O2 either.

 

[Kenny_Kline]

yes sorry, evo3 16g gasket is to small for the hotside

 

[turbowop]

Quoting Kenny_Kline:


Wouldn't logging each hotside be the true test?



I think the true test would be boost response and power. Why are you so hellbent on worrying about turbine back-pressure? Do you even know what the backpressure is with a Mitsu 7cm turbine housing? It's not like the Evo3 16g is some experimental turbo that few people use. It's proven to work in its current form by the thousands of people out there running them. Even when it's ported, not much is changed. Maybe just a tad bit in the inlet (the fire ring step removed) and outlet or some porting around the wastegate hole for better boost control with a larger exhaust.

Hahn Racecraft tried to do this years ago with their "SUPER" 20g. They used the Mitsu 10cm housing because it "flows more". How many of those do you see people running? Not many. Why? It didn't work as well. The regular 20g with the "tiny" turbine housing is the better turbo.

I think your efforts would be much better spent elsewhere on the car.

 

[Kenny_Kline]

On a ported 6cm hotside, back pressure is known to peak to almost 50! Its just general rule of them that your turbine back pressure should be right around your boost pressure or atleast close to it. The more back pressure, the more heat. It will take me a whole 5 minutes to swap a hotside and about another 5 minutes to log a run. Its really no big deal. I will log the ported 7cm hotside and post results compared to the chinese hotside.

This discussion isnt even what is in question. People dont go faster/slower by doing the same thing everyone else does. Being different and trying new things is when you discover new possibilities. I am sure at one point, people used to say turbos would never work or make power and look where we are now. Im not saying I am trying to make a break through with a new idea but more of doing something different than others and test to see for myself. Who knows... you could be wrong.

 

[jepherz]

New things like RTV on exhausts???

Stainless bolts would be a bad idea for high head applications. It's a good thing it only takes you 5 minutes to swap that housing, cause you'd be doing it a lot.

 

[Kenny_Kline]

ultra grey RTV on hotsides isnt anything new. I was just questioning how long it would last. Its actually used alot in drag racing purposes only.

 

[turbowop]

Quoting Kenny_Kline:
People dont go faster/slower by doing the same thing everyone else does. Being different and trying new things is when you discover new possibilities.



This is why I mentioned Hahn Racecraft. It's already been tried. You're not reinventing the wheel here.

Do you really think some Chinese knock off turbine housing is going to perform better than a housing actually engineered by Mitsubishi? Even if it performs the same, it's a waste of time because you have to deal with those unthreaded holes, which are probably that way because that housing is made from an inferior material.

I'd also like to know where you got the figures for the backpressure on a 6cm housing. There are a lot more factors than just housing size to determine why backpressure may be excessive. Usually, that type of thing is left to the guys running 8's, not somebody running a piddly 16g. /ubbthreads/images/graemlins/hsugh.gif

 

[Kenny_Kline]

I will post the logs in a couple weeks.