Hoosier Daddy

Hey guys, thanks for helping me out in my other thread. The downpipe IS in the way of the flapper opening. The only thing I'm not sure of is if it was always like that, or if the shop I just brought my car to for the downpipe messed it up. What do you guys think? Also, any idea what the cheapest fix for this would be? Would an external wastegate eliminate this problem? I hope I didn't just waste $350 on this downpipe

THIS is the weld they made. They cut my old downpipe to redesign it:



The problem:

RenoRacing

that pipe for your wastegate dump isn't big enough, if you had like 1 1/2" or bigger then it'd clear fine, and it's odd how they have the flange sectioned into two separate chambers, shouldn't matter that way. I'd hack that off and go bigger definately, and maybe avoid the hard 90 degree angle and just angle the pipe into the rest of the downpipe.

lazerus

whoever built that downpipe is a **** nut. yes, a **** nut.

you have to buy a wastegate housing, then bolt a downpipe to that.

if you want to get exotic, you could cut out the wastegate flapper, and weld a wastegate flange off that tube, and you would be externally gated through internal wastgate port, it's how some DSMs choose to Externally gate.

sporkcrx

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lazerus &raquo;</TD></TR><TR><TD CLASS="quote">if you want to get exotic, you could cut out the wastegate flapper, and weld a wastegate flange off that tube, and you would be externally gated through internal wastgate port, it's how some DSMs choose to Externally gate.</TD></TR></TABLE>

That's pretty damn spiffy! Never would of thought about that.

lazerus

let me see if i can find a pic.

lazerus

here!

PHiZ

So from the pictures, it looks like they welded the dumptube piping, INSIDE the flange for the WG flapper. If a larger diamater had been used, and welded to the outside above the WG hole in the flange, would this have succeded?

Is this a Td04 from a greddy kit? I will be having my dumptube enlarged to a 2.5in hopefully next week, but I need research on how to do it right, greddy stock DP is horrible.

-PHiZ

JalopySiR

The flapper door will never open that much under normal use. It only opens like a 1/4"... anyway, the guy that built the downpipe originally was a fucknut, and that is what I got. You will notice that one area of the flapper door has been flattened. That side should be against the divider wall on the turbine flange. It will open/close smoothly if properly seated. Anyway, like someone suggested, try getting a new wastegate flange and starting over. I got the original one from TEC. HTH... Also, that doesn't explain the sudden catostrophic faliure. I had that crappy DP, and you had it, and it worked fine... then one day... it doesn't explain it...

sporkcrx

That's beautiful

lazerus

i've gotten a few Pms...

Yes, you definately can convert an internally gated turbine housing to use an external.

If you are in a bind and/or do not want to weld a wastegate dump onto the manifold (to keep it's value) you can modify an internally gated turbo to work with an external gate.

Here would be a rough procedure of how to do this:

1.) Remove the turbine housing and/or turbocharger from the vehicle. The turbine housing Wastegate arm will need to either be completely removed (Read Cut out with a torch) and the holes welded shut with nickel rod (using the pre-heat weld slow cool down method so the darn thing doesen't crack) or you could perhaps try http://www.muggyweld.com products, i haven't had any personal experience, but they have good claims and demonstrations.

Once the holes are sealed up, you will want to port the wastegate opening as large as possible (Preferably as large as the wastegate you are trying to use, or slightly larger) this will allow sufficient exhaust gasses to exit through the external gate to make it worth your while.

Now, basically, you will have to copy the above posted picture(s) with your external wastegate, using a completely seperate tube for the wastegate hole. What would be the preferable way of doing this would be to weld on a peice of metal between the wastegate and the downpipe since it is recessed, and is unlike most other T-3 style downpipe (normally you can just use a flush mounted unit) So that you can seal off exhaust gasses, and control your boost with the external gate.

With your style turbine housing it makes it a little bit more complicated, but if you are dedicated enough, it can be done, and work fantastic...

The optimal things to do would be:

1.) Purchase a manifold with an external wastegate setup, and weld the internal gate hole shut (or weld the flapper in place)

2.) Find a turbine housing with a flush mount 5 bolt downpipe (internally gate compatible) and then do exactly as the picture above i have posted, only making the tubes to fit your downpipe setup (and making the wastegate fit in the engine bay)

3.) Find a turbine housing with a flush mount 5 bolt downpipe and switch to an internal gate cast housing and 3 or 4 bolt style downpipe.

4.) From the existing downpipe, have the center of the waste gate hole machined out to allow the wastegate flapper to open more (The flange, basically if you need a picture, ask), and then modify the "flap" that has been welded to clear the wastegate flapper. (perhaps cut and re-weld that "door" over enough to clear the WG flapper.)

Hope this helps give you some ideas, there are a lot of ways to make this work.

Brad

iiilgsrlll

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PHiZ &raquo;</TD></TR><TR><TD CLASS="quote">So from the pictures, it looks like they welded the dumptube piping, INSIDE the flange for the WG flapper. If a larger diamater had been used, and welded to the outside above the WG hole in the flange, would this have succeded?

Is this a Td04 from a greddy kit? I will be having my dumptube enlarged to a 2.5in hopefully next week, but I need research on how to do it right, greddy stock DP is horrible.

-PHiZ</TD></TR></TABLE>

Does the downpipe thats included with the Greddy GSR kit also have this problem? Right when I am about to achieve full boost I hear a rattling noise. At first I thought it was detonation but I backed off the timing and its still there. I have a Blitz SBC-ID controlling the boost. Before I had the boost controller I would hear the rattling throughout the whole RPM range. I guess the boost controller holds it shut right up until full boost then the rattling begins. Think the flapper could be the hitting the downpipe flange?

JalopySiR

The external WG conversion would be optimal IMO, also. I actually had a Tial 35mm... I would do as Lazerus suggests.

Hoosier Daddy

Anyone have any idea how much the installation/fabrication of that would cost? Excluding the wastegate cost?

Mighty

Im assuming your trying to go cheap and easy. So Id suggest cutting out that divider plate and seeing what that does. It serves no purpose and is most likely hindering you.

Hoosier Daddy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mighty &raquo;</TD></TR><TR><TD CLASS="quote">Im assuming your trying to go cheap and easy. So Id suggest cutting out that divider plate and seeing what that does. It serves no purpose and is most likely hindering you.</TD></TR></TABLE>

I was thinking about that, but i'm not sure if that's in the way, or the flange itself...

Hoosier Daddy

Can't I just cut the diameter of that right section out, and just make the tube larger?

Full-Race Javier

external gate is the best way to go....but u can also do this

92HB_HB

for $350.. that DP is a piece of sh1tznett.... nO offense though... it looks like they didn't even weld the exhaust pipe onto the flange... and the welding is so crappy... my wife can weld better than the and she don't even know how to weld...

I can make better DP's that cost no more than $50...

Hoosier Daddy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by javierb14 &raquo;</TD></TR><TR><TD CLASS="quote">external gate is the best way to go....but u can also do this


</TD></TR></TABLE>

Where can I get that? Does that go between my DP and manifold?

FredoSP

dude I see ur local, where the hell did u go to get that **** done? Give me a PM if you dont want to say the name, but that is complete **** IMO. Is that an 18g greddy turbo? Id say weld it shut (the flapper) and convert to an external WG, it might even be cheaper.

- Fred

Full-Race Javier

thats a greddy/trust stainless steel turbine extension for s13's or s14's with DET's.

Hoosier Daddy

Do they make something like that for our cars?

PHiZ

Everyone says you need to have the WG dump re-entering the downpipe at least 10inches down. I believe them when they say it, I just don't remember why... I think it is flow turbulence, right at the exhaust opening...

-PHiZ

Overblown-Teg

Honestly man if looks like if you cut that bar out of there it would work fine.. I have no idea why they would have done that. if you remove that cross bar it should work like its suppose to.

Hoosier Daddy

I'm seriously considering going down there with a saw