Jadz928

Dan,
How have you confirmed the cats are heading straight back along the longitudinal center? And "leveled", if you will?

If your left downpipe it mounted tight to the manifold flange (with or without gasket), I'm concerned you may not be square.

I'm sure you are close, but your 2-axis adjustment may not be necessary.

Though this approach should work just fine if you can assure the correct location of the cat exits.
I propose you can only my this determination with everything mounted up in the car.

LT Texan

a little worried about that.

I remember hearing a exhausts with cats but no muffler. Cat didn't muffle much at all.

LT Texan

I think I am pretty close.

With the left pipe attached, all looks lined up based on centerline and level with the ground. Will confirm with some measurements soon.

I was not able to confirm the height of the cat in relation to the engine.

Also, it seems that these have been installed with the left pipe attached and a "spacer" on the right. So, it makes sense based on other's feedback.

I think I need a 2 axis adjustment because the flanges are parallel. I think moving the flanges "together" 32mm and the exhaust pipe outboard 12mm will do the trick.

Maybe one pipe extension close to the flange doing both?

This weekend will tell.

sharknoob

I could hear sounds from a empty cat I meant. Kinda like the pulses bouncing around inside a empty can

tilac999

What are the drawbacks? I love the sound of mine. I think Brian w/ the '84 Euro here in MA may have been the culprit

After talking to Jim last year at Rick's, I may do the 32V manifolds too.

Landseer

Jim's 84 Euro is getting 32V manifolds and 87 S4 cat. Will probably then Y-down to his existing 3" single pipe exhaust with the spintech mid. Its what we had on-hand / should flow well, sound good and still be compliant.

danglerb

As I recall the 85 manifolds on a 16v the adapter offset is only front to back, not up and down.

Landseer

I'll get you another data point by tomorrow night.

SnakeFeeder

Very keen to see how this comes out....I'll be doing the same thing very soon.

LT Texan

I think I'm going to buy a simple arc welder and some stainless steel exhaust tubing tomorrow. Maybe a cutter. Why not? What's to lose?

I can drive to HF for the welding stuff. But can't find a place for mandrel bent and straight tubing. Maybe JC Whitney. And do it in a week.

Jadz928

Summit or Jegs, Dan.

LT Texan

Advice? Stainless, aluminized, mild steel.

What material to weld in to stock pipe?

I figure the stock is stainless just because it survived 33 years

Jadz928

^^^^
Dan, I think it is stainless too. Stainless or aluminized steel would work just fine. There is no moisture collection there.

Landseer

I had some downpipes replaced with SS.

Dan, here's a similar situation to what you found.
This is 84 car, 85 manifold, 87 cat --- bolted-up on the drivers side
Both pictures below show passenger side gap / misalignment.
Muffler is a little misaligned in the tunnel, too.

I'm going to have 2 things done.
First, in place, have exhaust guy heat drivers side pipe red hot, then twist hole muffler arrangement to center the discharge pipes in the tunnel. (Bends easy when hot)
Second, cut the cat input pipe on the passenger side. Bolt-up the flanges, add a joiner pipe (again, in-situ).

LT Texan

Good luck Chris. Let us known how it goes.

I aligned the exhaust with the centerline of the engine today. It was pointed towards the right.

Used a wedge. The gap to get it centered is more like 40mm's.

Welding gear and tubing in the mail. I do think one strategically placed cut and one straight extension will do the trick.

Guess I'll bond on other little projects for the rest of the weekend.