Turbo with carb?

[roadhouse]

Just curious........can an EJ22T be modified to accept a carb and run without the ECU?

[vrg3]

http://bbs.legacycentral.org/viewtopic.php?t=1116

If you put enough effort into it, I'm sure you could do it. But why? EFI goes so well with turbocharging.

[douglas vincent]

Ha ha ha, I was such a noob! Now I am a supercharged Noob!

[BAC5.2]

Subaru + VTEC = Noob.

I am also curious as to why you would want to carb a turbo engine?

[-K-]

I would run a carb turbo but I wouldn't de EFI a car. It's hard to get a carb turbo to run real well and you can't push the power up much with much safety.

I'd say that some people are just scared of EFI, me I'm more scared of adjusting points all the time...

[roadhouse]

I may be able to get my hands on an EJ22T with out the harness,etc.
I wanted to ask this question for several weeks but was afraid to brcause it could be one of those dumb questions.
My second dumb questioin is what is a NOOB?

[-K-]

A noob is someone who is new, or inexperinced.

What are your plans with this engine? Do you have a car you want to put it in? You can get a nice Legacy Sport for $3-4000, less if it's got a few dings, bad paint etc.

Like I said it's hard to get the performance out of a turob carb set up.

[professor]

You may notice that the advent of turbocharging automobiles for serious power for racing and street use completely coincided with the use of EFI systems.

If you did get it to "work" I suspect you'd have to run super rich much of the time, like gas pouring out of the exhaust rich, and would get horrendous gas mileage.

[vrg3]

What car do you have, roadhouse? If it's a non-turbo Legacy you don't need a new harness... And you'd probably be better off trying to run it on the non-turbo ECU with some hacks than carbureting it.

[Brat4by4]

Have you guys ever seen a carb turbo? The carb actually mounts onto the inlet of the turbo. So the fuel and air get boosted into the engine, pretty nuts. It is very very rare. Almost impossible to tune. Plus, I'd be scared of some nasty backfires if you overspin the turbo.

[vrg3]

You can do carb turbos both ways... Draw through or blow through. The draw through method you're describing is easier to tune, and you don't need a blowoff valve, but there's no good place to put an intercooler and you get some fuel puddling in the turbo as well as reduced efficiency since the fuel has to go through the compressor.

Blow through setups require some fancy modifications, since the carburetor has to be sealed up and modified so boost pressure doesn't push fuel the wrong way, and somehow fueling has to be increased. But at least you get to intercool.

Interesting note -- some of the early fuel injected Chrysler turbos were actually draw-through. The turbo compressor was placed downstream of the throttle body.

[evolutionmovement]

So the turbo pulls air through which in turn pulls in more fuel through the carb? Seems like a nightmare to tune for any kind of driveability if even possible.

Steve

[vrg3]

Yup, and yup.

[roadhouse]

I had no real project in mind, I have 2 SS's and a TW. I like the turbo motor and have access to a spare EJ22T. I also have a VW powered BMW sidecar motorcycle. I have another BMW frame and I was ......well you know. I love all kinds of machinery, cars and motorcycles but wires and springs drive me nuts. A turbo without wires, if it could have been done easy, might have gotten me dreaming about another project.

[-K-]

I would go for a draw through. How hard to tune would it be, I mean you put a carb on a V8 and it sucks the engine air through adding the fuel as it goes. So you put it on a turbo inlet... same thing. It should be about as easy to tune as a N/A.
Now if you put it after the turbo... a carb uses air speed to draw fuel. Compressed air won't draw any more fuel so it messes up your afr on boost.
This is the simple explanation...