Twin Scroll Turbo

[DrewP]

I definitely will next time. We have machinery in the Federal Way plant, and I think we are bidding for some more work at the northern campuses. Will definitely be in touch if I get to head up there!

[squaab99t]

I definitely will next time. We have machinery in the Federal Way plant, and I think we are bidding for some more work at the northern campuses. Will definitely be in touch if I get to head up there!

Sweet. The north end campus is where I have spent the majority of my career. A lot of future growth and they are building for it.
Give me a heads up when you plan on being in the area. We can talk Saabs, visit the holy shop of Scanwest, drink some craft beer, runs some TIG beads, and hopefully boost this twin scroll. May not be in this particular order.

[squaab99t]

Built some goodies on my buddy's lathe.

Index gauge for location the open end of the tube. The flange is bolted to the plate any then the articulating arm find the face of the open end. Creates planner and height at the same time.

I will swap out the 2"dia that was used on the big block.


In order to separate 2 and 3 I built this top hat. Will create the index for clocking and clamp the flange in place.

oversized the hole in the flange to the minor od of the top hat

[squaab99t]

Drilled and tapped the plate to accommodate my flanges.

Welded my gauge to a 1/4" dia bar stock for the articulating arm on the mag base.

I made a plumb bob tool to help mark the radial cut lines on the tubing. A string on a board, and the board indexes to the inner periphery of the U bend.

This should be the last of the tooling. Now we start cutting

[squaab99t]

After Father's Day dinner, it was go time. Started cutting and fitting.
The hardest one is the first segment coming off the head. Since it is an oval port, you have to clock the tube and squash it in the right place or the open end will not start up in the right place.

After that it is connect the dots with the correct arc length and straight length if required. Clock, mark, and temporarily held in place with more blue tape.

Admittedly primary one is pretty easy because it is out in the open, but it went surprising quick and true to the modeling blocks.

Tomorrow I'll tack up segment 1-1 to the flange and dolly the dimples out. Die grind the tubes that have thick sections that have to fit up to any thin. This comes from the tube bending. The outer radius thins and the inner compresses and the material thickness increases. Reassemble and tack the butt joints. Need to setup the back purge to make nice tidy tacks.

[squaab99t]

The blue plastic and tape is slowly going away and replaced by metal.
Having this on the spinner and bench made the tacking and fit up so much easier and higher quality than trying to do it in the car.

[Crazyswede]

Pretty and shiny...you sure you want to put that on the car? Would make a nice sculpture

[squaab99t]

Pretty and shiny...you sure you want to put that on the car? Would make a nice sculpture

Sure, it will be a mobile art display.

[squaab99t]

The flanges and first segment take to most amount of time. Need to get it right or you will be fighting the whole way to get to the merge collector.
This one took about 2 hours to fit up.

The dimpling to get the tube inserted in the flange. Getting better and not over crushing it with the hammer. You will notice the tube is a bit short of flush. This is to have area for a lap joint. You belt sand it flush and if you go full flush you grind away all the weld.

Knocking them out slowly, but progress none the less.

[squaab99t]

A bit more progress. One segment left on number two primary and it will be all fitted. Had some trouble getting the final set of modeling blocks to line up. I tried clocking the joints and fudging the fitment but no workie. End up changing out two straight block for curved (2-5) This actually worked out better since I had been pushing the clr on the last segment. Now all seems well. Still the same overall length.

[squaab99t]

Finished tacking up number two primary. Running by the skin of my teeth on the argon, as I used up a bunch on the diff covers.
Fit up well with clearance of the cam cover, primary 1 and 3. Life is good... so far. The goal is not to paint myself in a corner.

[squaab99t]

Final fit-up of primaries 3 and 4. Still have to massage the circularity of each end and die grind with the carbide burr bit the wall thickness. You actually die grind before you squash the tube. The metal behaves more normal when the wall thickness is consistent.

[Crazyswede]

Those turbo headers are starting to look like they will work really well at 11000 rpm. Interested to see how they perform....would be great to see a stock turbo on them before the crazy turbo.

[DrewP]

This is so awesome.

[Luke]

This is so awesome.

Yeah a true work of art Dennis! Very inspiring, thanks for showing all the steps along the way, there's some really neat tricks you've used!