I want to try making my own simple turbo manifold for my mk1 1.6. What size internal diameter and external diameter tubing should I use?
Also any idea of thickness for the flanges?
Thanks.

 

http://jgsturbo.com/thk1.html

 

Thanks

 

http://acestainless.com/
They have what you need as well.

 

+1 on acestainless, best prices

get your flanges from weirtech ($40 ish maybe)
get your pipes from ace ($depends on what kind of mani)
use sch40 with the 1.6"ID SS pipes....
fab away

 

Cheers for the advice. Is weirtech a member of this site?

 

yup

 

don't waste your money on making one now and than another later. make the right thing the first time trust me it will save you time and money in the future learn from my mistakes. but use the advice from above i made my this way.

 

This thread will point you in the right direction.
https://www.miataturbo.net/forum/sho...ange+group+buy

 

Hi cheers for the link. Musanovic are you suggesting I build tubular instead of log type?

 

Yes he is, that's what he did and i know he regreted not doing it right the first time.
I'll try to explain the difference, on his old log style, even though it worked and was cheap, boost wouldn't come on smooth, it would kind of just hit all of the sudden and even he was EWG by a 38mm Tial he kept getting pretty bad boost spikes. This was tolerable, but by no means ideal. With his new homemade near-equal length mani, boost comes on a lot sooner and a lot more linear and sees absolutely no boost spike at the 11psi that he is running. The car feels a lot more like it did when NA, well only more than twice the power, but it's really smooth and steady.
I think i'm quoting Joe here, but in DIY kits, perfect is impossible, you want ideal, and the near-equal length is much more ideal than the log style.