SMOKNZ

Just wanted to know what guage tubing is commonly used when making turbo headers?

INTMD8

I used 16 gauge mild steel tubing.

sleeperz28

16 is good for the headers. I use 14 on the rest of the exhaust.

INTMD8

Curious why you made the rest of the exhaust thicker than the headers?

Whistler

I used 321 stainless 18 gauge for the headers and 16 gauge 304 for the y-pipe and downpipe.

If you use mild steel use at least 16 gauge. Any thinner will crack in no time if your EGTs get above 1400'

mongse_1

Sorta OT, but what's the advantages of 321 vs. 304? I'd assume 321 is a little stronger than 304 since you're running a thinner wall on the 321. Just curious. I'm planning on running 304 throughout, but haven't decided on a thickness.

Whistler

321 is a titanium alloy. It will retain its strength at extreme temperatures moreso than 304 or 409. I wanted the header and collectors to be 321 because they'll hold up better when the EGT gauge passes the 1700 mark, and I wanted them polished and the 304 will dull down faster when exposed to high EGTs. You'll be fine however with the 304, 16 gauge.

You can get away with using mild steel, but if you go stainless you can get away without a thermocoating because the stainless will radiate half the heat of the mild steel.