what is it and do i need it? i think it's the shutter valve??? it's in the intake manifold; this isn't the clearest shot. (carb is removed; looking down manifold) thanks,

-zac

 

I've got one of those too for the bottom set of butterflies on my throttle body...i'm assuming it's probably needed for your secondaries...but i know practically nothing about carbs.

 

Yeah, thats the shutter valve.

~T.J.

 

what does it do? i noticed that on my spare rex when we pulled the motor.

 

I assume it's vacuum secondaries?

 

Yes its the famous shutter valve. You can remove the external actuator and wire tie the butterfly to stay open. Removing the butterfly is not reccomended. Itll cause an imbalance in the runner sizes. That runner is bigger then the front one if you look at it. Its bigger to compensate for the butterfly.

Whats it for? Its to prevent backfiring on deceleration. Nothing more.

 

iiinteresting.....

I just noticed this "cut-through" between the front primary and secondary runners. What's that all about?

 

coincidence, that moajority fo them time and egnines dies it is the rear rotor?

 

easiest way to fix it

get a '79 intake

 

WAIT, you mean that isnt supposed to be like that/??????????????? WTF!!!!!! how could that happen?

 

No its supposed to be like that. Not sure why, but my cars all have that cutout. And yes, that is the shutter valve, if you don't have inspection get rid of it.

 

You must have small furry Ewoks inside the intake.

 

so your telling me somehow my intake manifold just got this cut out from somewhere???? hahahah THIS IS CRAZY!!!! ooooorrrr, someone put a bad intake in there before i got it maybe? it's supposed to be flat i guess huh? i am so lost.

 

I believe it is supposed to be there!

 

dont worry they are supposed to be there

mine has one on each side heh

 

The cut is there to balance the air/fuel mixture. For example if you got a RB intake and it didn’t have the cut through channel, you would want to get an adaptor that simulates the cut through.

-Error

 

yea i just talked to rotorsports racing about it too and he was like, "don't worry zach, every 12a i've worked on has it." i'm like, well god damn! hahahaha you guys scared the **** out of me! i'm very sensitive right now LOL!!!! i am picking up my new Nikki thursday, car should run well after that. i'm not 4kin with this rebuild stuff again. thanks guys!

-zac

 

Errr sorry for the confusion... I know it's suppose to be like that I'm just wondering why it was designed by Mazda that way.

 

ooooohhhhhhhh, LOL!!!!! damn yea you got me way out of wack in the head. hahahahhaa, WOOWEEE!

-zac