LQ4 into a 3rd Gen/1972 Nova by frojoe

6 minute(s) of a 891 minute read

Finished the mock up routing of the wastegate recirculation pipes this weekend.

Here is how the driver side recirc pipe is routed.. it's pretty slammed to the exhaust manifold, and merges with the downpipe about 16" back from the turbo outlet. There's still decent room to get a wrench on the UCA cross shaft bolt, and room for camber shims. I'll be flipping the bolt around also for ease of full removal.

Here is the passenger side.. significantly more straightforward. The wastegate recirc pipe merges with the downpipe about 14" back from the turbo.

Crazy to think how much time and mental power it's taken just to produce this set of pipes here. Off the car en route to final welding. The passenger side downpipe and wastegate recirc pipe are two pieces (middle two) because I never bothered to tack weld the recirc pipe to the downpipe for fitment, like I did with the driver side.

Last step to do to the turbo piping before final weld was making the merge holes for the wastegate recirc piping into the downpipes.

Passenger side process for this is shown below:

1) I placed the wastegate recirc pipe on the downpipe, and traced the outline of the pipe as a guide. Then used a tiny 1" cutoff wheel to make a cut following this outline but offset about 1/8" inboard (tubing is 1/16")...

2) Then I use this carbide bit to smooth out the cutoff wheel marks and make it closer to finished shape...

3) then I used the nose of Dynabrade air belt sander to really final massage the curvature of the opening...

4) then I used a rounded file to remove any burrs on the inside edge of the hole that may have been created from the previous cutting/grinding...

5) then I buff all the mockup marker lines and other scratches/imperfections, and it's ready for final weld! I'll be fully welding the downpipes and the wastegate recirc pipes separately, and reassemble on the car one last time to tack weld the recirc pipe back onto the downpipe in the exact right location/orientation.

I got a little impatient and really wanted to see how the China SS304 would weld without backpurging.. it sugared bad, so definitely had to cobble together a backpurge setup. But it suuuuure does look pretty...

I was only able to do MOST of one pre-turbo hot pipe... using 12' of filler rod... before I ran out of filler... this thing was just EATING up filler material with the heavy 45* bevels on the joins.

The welder at work.. this thing welds as smooth as a dream, it's such a treat to use...

This was the first test pass, just kind of sat down and gave it a shot. I forgot how quiet and calming welding DC is vs AC...

Mmmmm.. pretty colors! This is why I spent time buffing and cleaning pre-weld, because I want to just leave them like this after weld...