Twin Scroll Turbo

[squaab99t]

Dennis, any progress?

I wish I could say yes. Day job, 4 year old, kitchen remodel down to the studs, and engine compartment fire put the turbo project on hold.
I have been practicing on my buddy's big block V8 headers. Trying to figure out what kind of filler rod to use on the cast stainless Y fitting. Sent e-mails to Garrett twice and stopped by their booth at SEMA. Still don't have a good answer. Any suggestions? There are only a few grades of stainless that can be cast.

[DrewP]

Are you having weirdness happen with 312? I use that for joining most dissimilar grades of steel, whether they are stainless or alloy unless heat treatment is a concern.

Jody likes Hastelloy W for dissimilar or cast stuff, but I don't have any and I believe it can be expensive to buy now. It's mostly nickel and molybdenum, moderate strength and very ductile as welded. ~80 ksi yield and 35% elongation at break.

Tigdepot has 1 lb. of 1/16" rods for $114... ouch.

http://www.tigdepot.net/products_detail ... oductid=75

http://www.haynesintl.com/pdf/h3017.pdf

[Price]

Hastelloy W would probably be the most appropriate filler to use, however as mentioned before it can get expensive.

A decent alternative, especially for casting, is to use straight nickel filler. Nickel filler rods can be found pretty easily (mcmaster, airgas, sims, etc) and is not crazy expensive. Another alternative to nickel TIG filler is to find nickel stick welding electrodes, also easily available, and just knock the flux off the outside. For comparison, half a pound of nickel TIG filler on mcmaster is ~$40, where as a half pound of nickel stick electrodes are ~$25.

[squaab99t]

Hastelloy W would probably be the most appropriate filler to use, however as mentioned before it can get expensive.

A decent alternative, especially for casting, is to use straight nickel filler. Nickel filler rods can be found pretty easily (mcmaster, airgas, sims, etc) and is not crazy expensive. Another alternative to nickel TIG filler is to find nickel stick welding electrodes, also easily available, and just knock the flux off the outside. For comparison, half a pound of nickel TIG filler on mcmaster is ~$40, where as a half pound of nickel stick electrodes are ~$25.

Thanks all for the input. I'm leaning hard towards just buying the right stuff. Seems kinda steep for filler rod,but it is a drop in the project bucket. I just hate reworking a cracked weld or fighting a popping splattering bead for what? Saving $80?
It being a casting is the driver for the funkiness. Might be good material but the porosity is what will dork you. I doubt it was vacuum degased prior to casting.

[Jon1]

http://www.rolledalloys.com/dotAsset/305aff5a-ee82-448d-b8ad-255635c582c7.pdf
Page 32, near the bottom: RA330-80-15 DC lime is the preferred 35% nickel rod for cast
heat resistant alloys. Alternates RA333-70-16, RA330-04-15

Way more information on HK30 here: http://stainless-steel-world.net/pdf/11022.pdf Skip to page 48 to 59.

[squaab99t]

http://www.rolledalloys.com/dotAsset/305aff5a-ee82-448d-b8ad-255635c582c7.pdf
Page 32, near the bottom: RA330-80-15 DC lime is the preferred 35% nickel rod for cast
heat resistant alloys. Alternates RA333-70-16, RA330-04-15

Way more information on HK30 here: http://stainless-steel-world.net/pdf/11022.pdf Skip to page 48 to 59.

Thanks Jon for the reference material. I was happy to see that they distinguished cast over wrought. I'll have to take some time to read vs scanning.
Thanks again.

[squaab99t]

Dennis, any progress?

Your prompt and the holiday break has kick this project into full gear.
Spent my X-mas money with Burns Stainless for the merge collectors. My friend Kevin, who I'm helping with the big block headers was staying 2.5 miles from Burns on his holiday. He spent some time to visit with them and get some consultation on his project and mine.

Decommission of the old. Need to break some eggs to bake a cake.
https://www.flickr.com/photos/28852287@N05/16145965746/

The gopro will live on the battery tray for the duration. Hope to get a nice photo doc of the build from that vantage point.

[Mezzanine]

Awesome decommissioning video! I'm excited to see the progress and especially the results of this project.

[squaab99t]

Slow progress, but progress none the less.
Built these sweet little gems. My buddy called them velocity bars. Should help nicely to increase spool, right?

Okay what the hell is Dennis up to now?

It is all about the tooling. I'm going to be using the Iceengineering modeling blocks to mock up the primaries for the header.
http://www.trick-tools.com/icengineworks-1-5-8-inch-header-modeling-kit-120-piece-1625basic-7834#.VLvrhEfF-9U

These will center the the first block on the flange and keep it on plane. This will help keep the tubing honest and no cheating of the tubing. Just a degree or two makes a huge difference at the end of a long runner length.

The long socket bolts are a QA check on how I did at hand tapping the holes.

Next project is the turbo hanger bracket. Since the log manifold goes away, I need a better way of supporting the turbo. No longer solely using the T3 flange on the turbine housing.

[Jon1]

Are you making equal volume runners?

[squaab99t]

Are you making equal volume runners?

1 and 4 will have the same primary length. 2-3 will be shorter, but their length will be the same. That is why the Ice engine stuff is so nice. The block are all 1" on centerline. Just count them up. No filling with rice or your favorite grain.

Pretty good progress on the hanger. Worked on it before and after the Seattle and Green Bay game. Go Hawks!
Using the center cartridge turbine bolts, I built this to support the turbo when the T3 flanges goes away.
I'm planning on a two or three bar strut that is cantilevered off the cam cover bolt location. Design is still in work, but for now I have the rod end that I will be picking up.

Trial fit up. Might flip the fastener heads in the other direction.

[Crazyswede]

At what sort of hp range do equal length runners start to be of benefit? Other than looking cool they don't seem to offer any noticeable improvement on a 250 to 300 hp engine. I would think they would improve things...but so far I have not seen any numbers that say they are better than the stock log....at least for the normal tuning range.

They do look nice though.

[DrewP]

Mine are close-ish to equal length, and they make a huge difference in spoolup and throttle response, and my car is about 190 hp at the wheels right now.

I have never done and before and after with only changing the headers though.

[squaab99t]

At what sort of hp range do equal length runners start to be of benefit? Other than looking cool they don't seem to offer any noticeable improvement on a 250 to 300 hp engine. I would think they would improve things...but so far I have not seen any numbers that say they are better than the stock log....at least for the normal tuning range.

They do look nice though.

Darn good question. For a N/A engine it is all about getting the lengths right. The pulses and scavenging effects. That was seen when I helped Kevin tune his big block headers on the dyno. For a turbo app not so much for peak horsepower. I currently have plenty of that. The problem is getting to the power and boost quicker. The plan with the twin scroll is to keep the pulse pair from the cylinders from communicating with each other, or fouling each other, and to just feed the turbine.
It is an experiment/hobby to keep the mind busy and do something fun. The proof will be shown at the dyno. I ran this turbo with the oem log and standard T3 housing. We will see if spool up and torque is achieved at a lower engine speeds with the new setup. I'm not anticipating higher peak HP.

BTW, yes they will look bitchin...

[Jon1]

Dennis, what are you using for header material? 304L stainless steel? Tubing or IPS? What size and wall thickness? I am guessing you are going to use 1.625" outside diameter tubing. (Based on the 1-5/8" modeling kit.....)