Direction for EFI to carburetor?
 

New to the group and I just needed some guidance on what threads to pursue for EFI to carburetor conversion, rats nest delete and bit about turbo charging with carbureted. Just as a quick over view I’m putting an 87 13b into a 90 Ford Festiva converting it to rear wheel drive.

Why not stay EFI?

Carb is simple and can work well but only if done properly and your components are compatible. I was carbed for a long time (and loved it) but later had trouble with it and couldn't work the bugs out which eventually led to me going to EFI (although I went aftermarket, air-only four barrel with Haltech and trigger-wheel ignition).

If you plan to turbo it stay EFI as Zach says. Carburetion works OK for naturally aspirated engines (fuel ratios aren't that critical). Turbo engines, on the other hand, do very bad things when fuel ratios drop to even slightly too lean conditions. You will also need a good aftermarket ECU and the tuning skill not to slag the engine in the process. Check out MazdaTrix and Racing Beat's websites if you plan to go carbureted.

I still have the EFI I just really want to do this project, I want the sound the response and the difficulty. Yes I could get an aftermarket ecu and do the whole turbo route and tune it but that’s not what I want, I want something that needs attention. I’ve done many other engines in this car model so I’ve got the tools and know how I just got really board with the newer way of fuel management. I guess I have a taste for old school Frankenstein twisted builds. I already have a Holley 4 barrel 600 with a 12a distributor setup that is assembled on a Mazda remanded 13b(remaned in 2006 by Mazda). Jay Leno put the Ford SHO fwd package in the rear and loved it well now I want to put Mazda’s pride engine in this Mazda designed, Kia built, Ford sold 90’ Festiva.

I will first ride around carbed for the first bit but I’m completely fabricating the subframe, interior, wiring harness, role cage, suspension etc. when I get older I can have the knowledge and a youngster like you are to me now but for now I want the crash and burn experience of a turboed carbed rotary.

Zach knows what he is talking about. He went from EFI, to one of the sexiest carb set ups, back to EFI.

What didn’t you like about it so much that you went back?

And I feel like maybe I’m not being clear that I’m wanting to do electronic fuel injection with the carb when it is turbocharged if that makes sense? Kind of like how the Chevy 5.7 made its first steps into fuel injection with an over the butterfly injector yet it’s still carbureted.

So I’m going to do a draw through set up with a costum exhaust and intake out of stainless, to compensate for the fuel pressure needed as stated before I will feed the bowls on the carburetor with boosted air off the turbo that will increase pressure in the bowls as the turbo spools up. Any hesitation on application of methijection for cooling of air?

Here's a link to my thread, I explained what I did and didn't like as well as unforseen issues I had to deal with along the way while converting it. Most were out of my control and completely avoidable but all was worked out and still worth it in the end.

http://rotarycarclub.com/rotary_foru...ad.php?t=18618

A carburetor is just that. . What you are describing above is not a carb, it's the TBI system GM used on 95 and older engines. Take away the injectors and you have a TB, there are no bowls.

Yes and that’s why my proceeding post was a change to my plan, I really just want to use all mechanical means to control fuel administration. With draw through I can use the forced air to boost the fuel pressure in the bowls of the carb I have now, plus if I cool my fuel and use a temp sensitive kick on switch for the methiject I won’t have heating(thermos expansion) problems with the fuel coming into the plates through the turbo.