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Building a TwinScroll Header

Would you use Stainless flanges or Mild? i think mixing up both materials with the right filler could work.. but i'd prefer using both stainless.. but the Mild flanges are cheaper and dont warp like the Enterprise..
 
If you want all the benefits of a twin-scroll turbine housing, do the following with the manifold:

-Equal length runners to the collector
-Pair cylinders 1-4 and 2-3 together (on a conventional 1-3-4-2 firing order engine)
-Wastegate both sides separately with no crossover or leak path until they join back into the downpipe after the turbine

Twin scroll turbine housings take advantage of evenly timed staccato pulse energy from the exhaust flow at low engine speeds, and you need all of the above for it to work well. The fact that the exhaust flow path is divided all the way to the turbine housing also allows negative pressure wave scavenging if you use the right geometry for the engine speed you're tuning for.
 
waaaaaaay tooo hot!! you gotta cut way down on that heat. you're burning up all of the base material for a filler material that's so burned and sugared up it's going to crack crack, bad bad.

Are you running a standard cup? what amperage? tungsten? more details? technique? Just how much heat are you putting into this thing? what shape do you grind the tungsten in, even?
 
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waaaaaaay tooo hot!! you gotta cut way down on that heat. you're burning up all of the base material for a filler material that's so burned and sugared up it's going to crack crack, bad bad.

Are you running a standard cup? what amperage? tungsten? more details? technique? Just how much heat are you putting into this thing? what shape do you grind the tungsten in, even?

Looks to me like he actually needs more heat, more speed, a tungsten much closer to the work piece, and a much cleaner workpiece. Just because a weld isn't shiny doesn't automatically mean turn the amps down. If your technique is right you should be able to perform that weld at 160amps, maybe even close to 200. not that I would, but I could. The filler rod would need to be fairly large and it would get dipped in the puddle about twice a second. That pace is hard to keep up, but the point is you could make a shiny weld on a flange like that with a machine set to 200Amps, and the pedal to the metal. I doubt he's running that hot. What I see is spots along the tube where the arc has "wandered" up away from where the weld is being done. Need to practice holding the torch in whatever way allows you to best brace and steady your hand so you can keep the tungsten damned close to the puddle.

Yes the internet wisdom is turn the heat down, use a gas lense, and weld 1/4" at a time to make the welds look "pretty", but those are all half truths and don't necessarily equal a mechanically sound weld...

Especially on a curved surface, always do a "dry run". Figure out how to position yourself and the workpiece so that you can move in a way that's precise and steady.ave a clear plan for how the torch is going to move and how you will hold it and how close it will be form the workpiece before you strike the arc. With enough time this becomes second nature, but starting out, it's very important.
 
Thx Bondo, appreciate your help very much :)

i bought a house recently which made all my projects come to be disrupted...

I definately post more pics when my 16v goes into the racecar :)
 
Hey my recommendation on the welds is fuse as much as you can keep your heat down and have your pedal all the way down at your desired heat and keep your tungsten sharp and practice before adding filler on a piece of scrap good luck!!!!
 
getting back to this project...

T3 Twinscroll or T4 Twinscroll.. which is "better" more suiteable to a 16v 4 banger? T3TS looks so damn tight...
 
I believe nathan went from a T3 TwinScroll to a T4 TwinScroll on the same turbo just with a matching housing and he picked up quicker spool up and more top end power.

My next manifold is for sure going to be T4 TwinScroll.
 
No question. T4. I don't fully understand the dynamics behind it, but Mike is right, quicker spool and less header back pressure. I ran a divided .84
 
Do you know where to get hx 40 t4 housings?

I have also read about the first holsets with watercooling.. But only on the hx35 cores..


Towz... Mh.. Yes.. Maybe you should get me some fries so i have more energy to do so.. ;)
 
A garrett t4 housing for a p-trim wheel fits the hx40 with very minor tweaking. I did this with an hx40 pro on my t6. It was very awesome. 540/467 with full boost by about 2500rpm.
Youd' think it would suck since turbos are such precise things, but it was amazing, I loved it. I could honestly not have imagined a better street turbo.
 
That really sounds great.. :)


Do you have any infos on those modifications which need to be done to the housing?

I would fear the missing exhaustvolume.. T6 has 3l.. My engine only 2.3..?
 
The exact details can be found via Google, but basically the major diameter of the holset is a few mm larger so the opening in the housing needs to be enlarged. Not really a diy job, but a simple task for a machine shop.

As far as exhaust volume goes, well, it's a 600+whp capable turbo. Good spool is relative. It's an 86mm compressor wheel. IMO this size of turbo is definitely not for everyone, for a street driven 2.3. In my opinion response vs power capability is about as good as it gets though. It way outspooled my borg warner 83/75, which had a good reputation itself. I guess there is fancier stuff now days but the holset is still a good option just because it can be easily rebuit with basic tools and is very cheap to do. P trim housings are cheap and there are many a/r ratios to choose from.
 
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