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Discussion Starter · #1 ·
Hello guys,

I am new here and would like to get thoroughly schooled on turboing my carb'd mustang. Here is my intro thread: http://www.fordmuscleforums.com/makin-progress/508452-82-fox-intro.html#post1671367


Assume I am a bunny rabbit with a pancake on my head. Help me build a parts list on getting this thing up and running for summer (I understand a big part of this is tuning, I have a reputable tuner i just need to assemble the car)


Thanks!
 

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Thoroughly read Mike Sitar's stuff at toohighpsi.com Lots of good information there.

Assuming this is a budget build, off the top of my head you'll need :
Turbo(s)
oil feed lines & drains plumbed into your oil pan
flipped manifolds/headers/fabricated headers
piping for boost/exhaust system
carb set up for a blow-thru application.
Boost reference your manual fuel pump or go with an electric pump and a rising rate regulator
carb hat
intercooler (optional but recommended)
 

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You said you already have a turbo kit - but want a parts list? Pancake bunny, we need more info on exactly what you have in parts, and a better description of the engine you're boosting. We have to know what's in the kitchen so far to make a recipe. List it ALL and be specific. Okay, you can skip the individual bolts and nuts. BTW - 450hp on a 351 is just lazy, but it's a reasonable starting place. ;)

David
 

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Discussion Starter · #6 ·
Thanks guys. David I like your style! The goal is simple I want to keep stock heads and internals and just run boost, this is just a cruiser with mild track duty. I'm pulling the heads and and putting studs and mls gaskets. My turbo kit is air to air intercooled with a 76mm turbo.

My motor is stock minus my edelbrock intake.

So, this old outdated stang needs fuel and spark. Where do I go from here? What pump, reg, carb, hat etc? What else is there? By the way I am on the turbo forums, its just a bit overwhelming
 

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This build is similar to what you are doing. Several pages long, but you can pull a lot of basic info and tips from it. Read it all, then come back with whatever questions you have left.

David
 

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Any decent performance mechanical or electric pump will do. You only need about 250 pounds per hour (42 gallons per hour) to feed 500hp. I would pick a pump with double that capacity, and plumb all lines at 3/8" to ensure solid flow. Most carb pumps do not need a regulator, and with a blow-thru, you do not need boost referencing. Just do the fuel system like you would any NA race carb system, and perhaps plan for future mods and upgrades so you don't have to re-do it all later.

David
 

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There are three ways to use a carb with forced induction - draw-through (roots blower and old pre-turbo setups), blow-through (turbo and centrifugal superchargers), and enclosed (first common on factory Paxton setups). Only the enclosed carb sees any change from ambient pressure in the float bowls, and requires a referenced regulator to maintain the pressure differential at the needle and seat (float valve), e.g., 7 psig no boost, and 17 psig under 10 psig boost. With draw and blow-through versions, the bowls are vented at atmospheric pressure all the time, so there is no changing differential pressure at the needle seat.

David
 

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Mav, I just realized on my drive home you are probably running a non-vented system (venting to the carb inlet - not to atmo), and so you would have pressurized bowls. My oversight - if that's what you're running, then yes, you would have to boost reference your fuel pressure to maintain the pressure differential at the float valve. Blow through can be set-up either way, and thanks for catching that as it would certainly be an option. Non-vented is not as easy to tune for low-boost street, but is better for higher boost or high-flow applications when pressure differentials become greater. If the OP is going to use a box-stock Holley and slap a hat on it, then yes, boost ref would be needed. Other carbs could or would be directly vented to atmo. Along those lines of variants, draw-through is always vented, but always sees vacuum at the base plate. Those are referenced to boost, but to the power valve - not the fuel pressure. Thanks again for the catch.
:tup:
David
 

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Discussion Starter · #13 ·
Thanks for the information guys. Keep an eye on my build thread as it progresses. I've got my work cut out for me making this thing look the part, Hopefully by June I will have collected everything to finish my motor.
 

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There are three ways to use a carb with forced induction - draw-through (roots blower and old pre-turbo setups), blow-through (turbo and centrifugal superchargers), and enclosed (first common on factory Paxton setups). Only the enclosed carb sees any change from ambient pressure in the float bowls, and requires a referenced regulator to maintain the pressure differential at the needle and seat (float valve), e.g., 7 psig no boost, and 17 psig under 10 psig boost. With draw and blow-through versions, the bowls are vented at atmospheric pressure all the time, so there is no changing differential pressure at the needle seat.

David
Look at a typical carb hat for a blow through application and you'll see why it needs to be boost referenced. You could modify it so the bowls don't see boost pressure but it's just easier to leave it alone & boost reference the pump.

 

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I suppose since the pressure differential is what forces fuel through the main jet (well...in a nutshell) that I'm doing it correctly by referencing.

I experimented with a home-built blow through when I was quite a bit younger. Found out real quick that it must be referenced. At elevated pressures, the fuel was actually pushed back out of the bowls.

Now on a couple other blowthroughs (Mikuni side draft), I've not had to reference because I didn't use pressurized bowl. Ran like poo too no matter what I did. Just never was able to get it quite right. It either was good off boost and lean with the pipes packed, or perfect when packed and not so good under vacuum. Solved it by running a pitot tube from the bowl vent into the IC outlet pipe just before the carb inlet. Some manufacturers are doing this now-even on NA stuff (ram air inlets on some of the crotch rockets).

turbocharging is cool. Super easy to make 1000+ HP. Just build a more or less 450-500 HP engine with a bit lower compression and pack the air into it with a hair dryer (or a pair). Pretty easy to double the HP. Friend of mine (who really got me started into all this boosted stuff) used to run a '84 GT that laid down around 1100. Overkill on the street but fun to light 'em up at will. He crashed it. Imagine that. Engine is still on a stand in his shop collecting a few inches of dirt.
 
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