I'm piecing together a 12a dellorto low boost (5-8lbs) for my 1980 626. I have a rotary works 12a exhaust manifold and tial 44mm external wastegate. I need to make a decision on a turbo. Here is what I'm looking at:
Goals are a fun car. No drag racing or competition. 12a is stock port and I won't be running an intercooler. Thoughts?

 

Something like this. Waiting on turbo hat for the dellorto

 

The car

 

I would say your best bet is to go with a turbo the same as a turbo II fc or the same as a race tech kit from the 80s if you want a fun ,fast and street friendly car . I would also not be afraid to throw 15lb at the 12a .

 

Thanks Matt. Problem is I already ponied up for the fancy manifold. I have an fc t2 turbo and manifold but would have to modify heavy to work on the 12a

 

What about one of these?? Cheaper, current aero, good turbine options... 57mm Enhanced S200SX-E 7670 Turbo ? Full Race

 

You'll need to start by plotting your engine's operating points on the compressor map you intend to use to see if it's a close enough match.

Info on how to do that:
https://turbobygarrett.com/turbobyga...Tech%20103.pdf

T04E "57 trim" map:
COMPRESSOR MAPS

S200SX-E map:
http://www.jegs.com/images/photos/10...19turbomap.jpg

P.S.-What do you have planned for ignition timing control?

 

Locked dizzy with leading timing at 10-12 degrees adv. trailing at 0

 

thanks for this info...

 

there are adapters for t3 to t4 mounting on e bay and i think ace race stainless has them

 

Taking the centrifugal advance springs out should work fine, that's what I did for my blow through setup a while back. You may want to see if you can find a JDM 12A turbo dizzy. It's all setup by Mazda to work with boost.

 

those things are rarer than hens teeth!!

 

Semi-locked is the way to go. Or in other words, just limit the advance to 10 degrees.

 

Redirection was necessary and steps have been taken

I figured timing was critical and since oem pulleys are notoriously variable I got this
Found some rot to be dealt with so this had to happen
Got an rx2 manifold and a s4 turbo with 12a fitment
Some time with a grinder and some high temp paint will go a long way toward making this look presentable
Turbo that came with the manifold is seized but I have another.
Jeff20b might have had something to do with recent decisions lol 😂

 

Much better solution!

 

cutting the stock fc turbo manifold only involes enlongating the holes like 5mm, its really easy... but looks like you found a solution.

 

Do you know if that RB pulley has 100% accurate marks? It should as they base it on the woodruf key. Might want to double check it though.

 

https://www.rx7club.com/1st-generati...-boost-1077251

Looks like an effective solution.