Hey Guys,

I am running a 12A Streetport with a Dellorto 48 side draft (RB Modified Dell). Ran this all last summer and loved it. Very reliable, good powerband, easy to start cold and warm up. Found I could get pretty good AFR's by tuning with fuel pressure and an idle jet change.

My current intake setup is the Racingbeat two piece wrap around intake.

-Noticeable is the dropoff in power beyond 7500RPM
-The manifold sits quite low and does not leave room for common airfilter/airbox options. Currently running twin foam filter 'socks' over the trumpets and am certain there is plenty of hot air being picked up.

I can live with the powerband. I think most of this is attributed to the long length of the intake. My 12A seems to have plenty of low end torque and has a very 'streetable' powerband from 3500-7500RPM.

The other common sidedraft option is from Rotaryshack. I am not sure if they make this or is from another company that produced the castings.

RotaryShack Mazda 12A Sidedraft Intake Manifold | Rotary Shack Store

Does the Rotaryshack manifold sit higher than the two piece RB manifold? Also wondering if anyone knows if it flows better?

I am trying to sort out a airfilter and cold air box setup for my car. The best option to do this seems to be the Rotary Shack manifold and relocating my alternator to the drivers side of the engine. This will free up enough room.

 

Atkins sells the same manifold but its not chromed, so may be cheaper. Not sure it gives you any extra room, might ask the vendors.

I ran a Dell for 20+ years and it sure is a fun intake. Sounds incredible and really shines in the higher rpms. A couple of years ago I modified a nikki and put it back on. Wow! What a difference, no stumble to drive around on certain turns, much better torque across the whole powerband, from low to high and it revs so much faster. Won't go back on this car. I'm gonna save that Dell for another project.

 

That is one thing that you can't beat with the Dell is the sound. The induction noise up front during WOT is too much fun. It sound like motorsports haha. This is one of the biggest reasons I want to stay with it.

I hear you regarding the Nikki. I have a genuine Sterling Nikki and high flow 1970's 12A manifold up for sale.... making me rethink this decision.

I am naturally drawn to the Sidedraft and love the velocity stacks/trumpets and want to make an airbox for it.

I emailed Rotaryshack but did not get a response.. I may email them again.