I have a side draft manifold i was going to have drilled for injector bungs and have a plenum fabbed up to bolt to it. My question is will 2 injectors work fora bridge.. when making the plenum what size/ how much volume should it hold? and what would be a good throttle body to use? i was thinking of a single mustang throttle body or a LSx truck throttle body? Will it allow enough flow for a NA engine? Any insight would be greatly appreciated.

 

That's all I've got in mine.

Plenum manifolds suck, tried that. Drivability will be much better with independent throttles. Has to do with the intake pulses and reversion at low load, it just seems like the exhaust backpressure seesaws the air in the intake from one side to the other. That can't happen if the two rotors are separated.

If it was me, I'd keep scoping eBay until a cheap Weber 50DCO or a 48mm Dell'Orto in gummed up, nonfunctional condition came up for sale for cheap, then use that as a throttle body.

That's basically what I've got, except with a Holley manifold and a disused 750cfm carb. Works just fine. I did have to clearance the carb flange on the manifold slightly where it interfered with the fuel pressure regulator, and I had to switch back to a GSL-SE rail I had that had the pulsation damper removed since that would be in hard interference.

 

What are you using for TPS? or are you using MAP based acceleration enrichments on MS?

 

The MAP is only for load sensing, I removed everything related to the choke/fast idle, slotted the end of the carb shaft, and used a Ford TPS. No idea what application, it was from the infamous Bin of Known Good Parts at work that we will never actually put on anything, but we will never throw them out either because they're known good.

The pressure signal is actually a little smoother than what I was getting with the Mazda intake manifolds. I use a length of carb cleaner straw in the vacuum line as a damper orifice.

Another option that might work well is a pair of smaller throttle bodies. I think the 3.0 Chryslers, if any still exist in junkyards, were 52mm and are already set up for cables. Then the hard part is figuring how to put an air cleaner on it, since here you DO want a plenum.

 

I was also looking into trying to retrofit a set of snow mobile throttle bodies off an artic cat f1000 since they are 50mm .. but i cant seem to find info on the spacing between them to see how much work it would be to make them mount

 

I actually did what Peejay mentioned and used an old gutted Weber 50CDO as an EFI ITB. You said you already have a sidedraft manifold, and assuming its for a weber, this would the easiest bolt on route, anything else that you will try to retrofit of make work on thie manifold you have will require fabrication, adapters and/or heavy modification of you current manifold. 2 injectors will work just fine, as pretty much any NA 12A or 13B will never need more than a pair of 1000cc

For my TPS, I used one for an 89 Eldorado cause it has an external lever that simply gets pushed by the throttle arm. Its another one of those parts bin sensors that can be made to work on virtually anything

 

now comes the fun part of trying to source a dco that is out of comission... they are kind of hard to find since they are so easy to fix... most times they have bent throttle shafts

 

lol, mine was a perfectly good working 50 DCO/SP... and still can be if I put it back together.

ide say price and prioritize, if you cant find a good sized old weber for a good price, then maybe you should check out after market EFI ITB's, as most of them are based on the DCO and IDA flanges already, so itll again be a direct bolt on

 

ive been pricing everything from extrudabody to jenevy.... too rich for my blood at this moment... but i have the ability at work to make a plenum and have my intake drilled out for bungs... so i was going for more of a DIY(a.k.a. cheaper) option lol

 

well let me know when you want to put it back together My carb is too small

 

Anyone have a 12a intake for sale?