Boosted carbed festiva

[Dom88festy]

Hello all!!! I have an 88 festiva and it's carbed. I would like to turbo the stock b3 in it and I'm just wondering if someone could please help me. My questions are.... first what all materials do I need I already have a turbo and fmic, it's a wrx turbo btw. I'm just wondering if there's threads on this that I missed or is it even possible with a carbed motor? I would just like the easiest way to finish it and what i would need. Any help would be appreciated!! It has a weber carb and a cat back exhaust
ThanKS in advance!!!

[william]

https://youtu.be/Jtn4PyzFspc

[bhearts]

How does draw through work at low rpm. Or idle. That just seems like a no go to me.

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[bravekozak]

I have a extra set of twin Mikunis for sale.

[sketchman]

How does draw through work at low rpm. Or idle. That just seems like a no go to me.

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Why? There's still air moving through the turbo even if it isn't making boost.

Problem with a draw through with today's turbos (or so I've read) is the dynamic seal won't seal under vacuum, so you'll pull oil into the engine. That video didn't mention that if I remember it correctly, so IDK if it's as much of an issue as it should be.

[bhearts]

Why? There's still air moving through the turbo even if it isn't making boost.

Problem with a draw through with today's turbos (or so I've read) is the dynamic seal won't seal under vacuum, so you'll pull oil into the engine. That video didn't mention that if I remember it correctly, so IDK if it's as much of an issue as it should be.

It's all have to be uphill of the head. That fuel wouldn't want to climb a hill during cranking

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[sketchman]

Hmm. I think the heat from the turbo and the mixing ability it has would probably help with that, but IDK.

[jdobbs86]

I have the entire draw through setup from a 1979 mustang in my garage right now. The intake path is so ridiculously short, and is all part of the intake manifold. Common sense tells me this is to make sure the fuel doesn't have a chance to fall out of suspension, but I think sketch may be onto something since the intake would stay fairly warm as well. I vote do it! just keep the turbo as close to the intake manifold as possible (hang it over top of the transmission?). Look at Corvair or VW forums for more info...The Corvair used a draw through from the factory and drag VW and buggy guys bolt on draw through turbos all the time.

Draw through stuff is pretty simple, no carb mods are necessary...you can use any turbo...dynamic seals may or may not fail after a while there are some conflicting views on this...
Also, If you're going to do a draw through you can't use that FMIC unless you're trying to turn your car into a time bomb. First that would make your intake path WAY TOO LONG, second since the air your pumping through the intercooler will be full of fuel some (or lots) of that fuel is going to fall out of suspension in the intercooler, which means you're only one backfire away from having a really bad day.

more specifically...that wrx turbo is probably too big for this application. A draw through setup (sort of by design) will be a bit laggier than a normal setup, and assumming you have a td04 you might see boost somewhere around redline lol...so sell that...sell the rest of your parts...
Then get a cheap teeeeny tiny turbo, one of the two turbos from a twin turbo car is usually a good bet (see volvo t6 or 3000gt or newer bmws)
I would recommend a weber side draft on one of these manifolds http://carcraftstore.com/carbmanifold-dcoeanddhla.aspx
Find a decent low pressure electric fuel pump and regulator
Then if you wanna go nuts lookup DIY water injection on google and buy all of those parts, if done right this could help you from absolutely melting your little B3
With all of that together you may be able to make a little bit of power...and might not burn your car to the ground

[TominMO]

I have a extra set of twin Mikunis for sale.

With an appropriate intake?

[bhazard]

I have a holley 2bbl that was modified by Matt Dickmeyer for blow thru if you're interested.

[Dom88festy]

Thanks for all the help guys! It seems pretty complicated to do this lol... but bhazard can you show me what that looks Like please?

[jdobbs86]

Not THAT complicated lol but there's some doin to do for sure. A blow through carb like what brad has is maybe a bit more simple, and probably a better option for performance since the carb will be less of a restriction. Main concerns there (assuming the carb is squared away which I'm sure it is) are finding a way to keep the bowl pressure about 1psi higher than your boost pressure (this will be with a fuel pressure regulator takes in boost pressure ... See eBay) then just some way to seal the boost in at the top of the carb. Then spend the rest of your time tuning the carb. There's a lot of reading elsewhere on turbo'd carb setups...just google draw through and blow through turbos...

[Dom88festy]

The guy I bought it from acually made an air box where no air can escape I'll get a pic when I can. And I wish I could run a front mount! Lol. But I guess I'll have to find a smaller turbo

[jdobbs86]

If you've got an airbox for your carb and are planning a blowthrough setup you're ok to run a front mount since there wont be any fuel in the air coming from the turbo...sorry for rambling and being confusing
With a blow through you might be able to get away with that wrx turbo, I would personally size something smaller but I am by no means THE authority on these things... you'll probably see lots of lag if you make boost at all, but that's what makes turbos fun!

[bhazard]

Thanks for all the help guys! It seems pretty complicated to do this lol... but bhazard can you show me what that looks Like please?

I can get a pic when I get back from vacation, but I asked what was done to the carb a while back, as I got it with the (junk) car it was used on at one point.

"It's been modified for blow through turbo. Brass foam filled float .135 needle & seat, .035 Accelerator pump nozzle, 50 cc accelerator pump, 10% accelerator pump cam, milled choke horn, power valve block off, high & low speed air bleeds, threaded & adjustable air bleed jets installed, replaced throttle plates with drilled idle bleed holes with solid throttle plates, installed down leg boosters, polished & deburred venturi bores, 362 cfm @ 1.5" of vacuum, drilled power valve restriction in metering plate."


He said the work ran the guy $500-600, not sure if that included the original carb or not. I wouldn't need nearly that to let it go.