im trying to tune my semi pp(1" port) cosmo block,im running a jaytech maifold and a holley 750, the turbo is a turbonetics t72 .96 exhoust p trim,
well right now i think main thing i want some help is the timing , if anyone out there has done some tunning on a combination like this a semi pp cosmo block,
i had timing retard at 12deg on led and 2 on trailing on a locked distributor the car was popping as soon as i punch it then it cleared, i decided to retard a bit more to 15deg leading and 5 on trailing, the car did clear up more still a liltle popping, the fuel well i dont have a wideband but i have it set to jets at 70 prim and 95 on sec. im running 100 octane fuel, spark plug are b10egvs and gap at .22 , the boost is set on a manual boost controller to around 18-20 psi ,should i retard the timing more? i know some high hp rotaries out there are being run as much as 24 deg retard thanks for your help
julio

 

I would think you'd need a little more control on the fuel. a carb can only do so much.. get standalone.... but I'm sure someone can help you...

 

hit up ebargainllc for a microtech, or haltech. he's out by you.
tell him dave sent you.

 

Judge Ito phone number 973-800-6908 he has experience with semiPP and is very good with holley carbs. Personally with that combination I would go standalone. They are hard enough to tune with a standalone system even harder with a carb I would imagine.

 

What accelerator pump is on the carb? It sounds like you are not getting enough pump shot when you mash on the gas.

By the way, 15 degrees btdc is actually more advanced than 12 degrees, you have it backwards.

-Marques

 

He never stated BTDC he simply stated he went from 12 degrees to 15 degrees retarded. I'm pretty sure he knows what he's doing with his timing if he's messing around with a semiPP motor. 15 degrees retarded is less timing than 12 degrees retarded also the example he made of 24 degrees retarded seems alittle far off seems that would heat the hell out of your exhaust.