Hey Guys,



I have some questions about the Jap Spec 12A Turbo.

Information is limited on it, but I need to know about the distributor.



http://www.mazdarotary.net/images/te...s/12aturbo.jpg



As I understand, it's the ONLY Mazda OEM distributor that retards timing as well along with boost.



Can anyone give me some good clear pics of it, and

maybe the specs?



Do you set the timing like a regular dizzy?



Max Retard? Does it have a boost sensitive nipple?

Does it work well?



Any and all specific info you can provide will be great.



For now, I am switching to a blow through setup, while my Haltech goes back to AUS for repairs.



I plan on keeping the blow-through when I get a Series V convertible anyway (they are non-turbo in the U.S), so I want to know regardless of the Haltech



So I just want to know if this little distributor will keep my engine peppy, my timing dead on, and my engine from detonating.



Thanks!

i wish i had an answer for you, but i don't. have you tried e-mailing Racing Beat or Mazdatrix. i e-mail Henry at Mazdatrix every once in a while with puzzling questions that i have. maybe try that. i'm sure this question is pretty rare.



just curious, but are you thinking there may be an advantage to tracking one of these over locking a stocker?

I am thinking that since they retard under boost, I could run the correct timing throughout the whole RPM band instead of just under boost.



Thus, giving me better EGT's, better fuel economy, and better response off boost.

makes total sense ... i'll give it a shot and see what i can find out for you.

Thanks!

Directfreak

sadly, i haven't found much info for you. no one seems to know the answers to the questions you asked.



however, i think i did locate a few of the 12AT dizzies for you, if you do end up wanting one. i'll tell you straight up that i don't know the guy selling them so i don't know if he's yankin' my chains or not ... but if you choose to pursue it at least it's one more lead than you had yesterday.



i didn't post the info here, just in case someone tries to snake it out from under you, so i PM'ed you.



1

ah but see thats why they have the vacuum advances. if you set the na dizzy so it runs 15degess at full mechanical advance, then you are more advanced than stock, plus it will give you another 5degrees cruising

Excuse my ignorance.. but you lost me. https://www.nopistons.com/forums/pub...1047683561.gif





Diabolical,



I already bought one, I am just waiting for it to arrive from

Down Under - thanks!!!

You can always lock your distrubuter for max advance? Its pretty easy to do and gives better lowend response and highend response then a stock distrubuter on a turbo'd n/a 12a. The drawback is you need to compromise a little between how much advance is safe for your setup which is 95% as good as having one of those OEM 12a turbo distrubuters that can retard and advance timing.

ok it goes like this. the vacuum advance advances about 5 degrees, but its load dependent, the more you push you foot down the less advance you get. the centrifical advance works just on rpm, it advances something like 12degrees by 2000ish rpm.



so if you have a gsl-se idling its at -5L and -20T, right?

if you look at the timing at 2000ish rpms with the vacuum disconnected, its only 12 degrees more than idle, or 8L and -2T, if you look everyone says you can run 15L on a turbo at 15psi, so the stock setup isnt running as much timing as the turbo guys.



plus you can add the vacuum advance and it will give you a little more timing in the cruising ranges just like a stock fc will. the vacuum advance will also go away under boost.



mike