kinda a twin turbo

429idi

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i have 2 tdo4 turbos and by looking at them i couldnt see how 2 of them would be the right size for a 7.3. the turbos i have are off my 92 mitz 3000gt vr4. i also have 2 tdo5h turbos from 1st gen eclipses. i got the tdo5h turbos for the 3000gt, but have thought about a real twin turbo system for my 7.3. the real reason for a twin turbo system is so you have more usable boost throughout the rpm range then a bigger turbo that only boosts at higher rpm, or a turbo that boosts well low to midrange and over spins at high rpm.

There are different size tdo4 turbos, some can flow 30lbs/min. A baby h1c holset will will only do 35. hx35 will do 52. You would need to find a turbo map that would work for your engine.
The gassers rev twice as high as us, so the turbos we use are a lot smaller. A 7.3 gas motor would need a way bigger turbo than a 7.3 diesel. Like I have said before, usually twin turbos are used for large displacement v8 engines making 1200hp. Compound turbos are usually used to get more boost because you aren't limited to the pressure ratio of the one turbo.
 

429idi

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what kind of boost would i get from two parallel tdo4's?
and just had the thought of parallel compound turbos :dunno maybe the td04 going into a 1st gen PSD

In the compound turbo, you run the big (low pressure) turbo compressor into the inlet of the small (high pressure) turbo compressor, that's how you get the compounding effect of the pressure ratios, so i. If you are thinking of just one set of compounds, the td04 would be way too small, if you are thinking twin compounds (quad turbo) then a psd turbo pushing through a tdo4 at each bank would work. That is eventually what I want to do, just to have a quad turbo on a 6.9.

For an answer to your question, if the two tdo4's could flow 30lbs/min, you would have 60lbs/min total flow. Remember both of these turbos will be essentially feeding two 3.65 4 cylinder engines. Without an intercooler, at sea level, at 3500rpm, at 85% volumetric efficiency, it would take around 30psi to flow that, that is around a 3:1 pressure ratio. If you have turbos pushing into say 5lbs into those (19.7psia), your 3:1 p/r turns into almost 45psi outlet pressure. Get an intercooler, and you could flow the 60lbs/min with 20psi.

Now that all of you are probably sick of me posting, I'll be done now. Sorry if I sound like I'm trying to be a know it all, I'm not.
 
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MUDKICKR

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There are different size tdo4 turbos, some can flow 30lbs/min. A baby h1c holset will will only do 35. hx35 will do 52. You would need to find a turbo map that would work for your engine.
The gassers rev twice as high as us, so the turbos we use are a lot smaller. A 7.3 gas motor would need a way bigger turbo than a 7.3 diesel. Like I have said before, usually twin turbos are used for large displacement v8 engines making 1200hp. Compound turbos are usually used to get more boost because you aren't limited to the pressure ratio of the one turbo.

twin turbos are used for many apps, not just 1200 hp v8s. there are many people using them on v6 and straight 6s and have great success. a good twin turbo system will build boost longer then a single turbo, as long as its set up correctly. that being said, a believe that a twin turbo setup would do good for a 7.3 just for the amount of boost it can built throughout the rpm range. and yes, you are correct that a gas engine needs a bigger turbo, but that doesnt mean anything since we are talking diesel here. but since you are talking about gas engines,

http://v6power.net/vb/showthread.php?t=30970
 

429idi

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twin turbos are used for many apps, not just 1200 hp v8s. there are many people using them on v6 and straight 6s and have great success. a good twin turbo system will build boost longer then a single turbo, as long as its set up correctly. that being said, a believe that a twin turbo setup would do good for a 7.3 just for the amount of boost it can built throughout the rpm range. and yes, you are correct that a gas engine needs a bigger turbo, but that doesnt mean anything since we are talking diesel here. but since you are talking about gas engines,

http://v6power.net/vb/showthread.php?t=30970

Hey man, you are the one that started talking about 3000gt and eclipse. I just made that comparison because you said the turbos looked too small. I don't look at gas, diesel, or really even boost numbers. It's all about air flow. Boost is just a byproduct of all this. I look at displacement at rpm. Now explain to me please, why a twin turbo will build boost longer than a single turbo. And keep in mind boost isn't everything, you can make more power with a bigger turbo at the same amount of boost since the bigger turbo is always more efficient. I know that twins are used for a lot of things, and there are usually three reasons for that. One, because they will spool faster, two, because sometimes it is just impractical to have ha gt60r turbo under the hood, and three, because it is just cool. I never said twins wouldn't work, I actually said the opposite, but
I still maintain that a compound turbo is the best system for a diesel.
 

MUDKICKR

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Hey man, you are the one that started talking about 3000gt and eclipse. I just made that comparison because you said the turbos looked too small. I don't look at gas, diesel, or really even boost numbers. It's all about air flow. Boost is just a byproduct of all this. I look at displacement at rpm. Now explain to me please, why a twin turbo will build boost longer than a single turbo. And keep in mind boost isn't everything, you can make more power with a bigger turbo at the same amount of boost since the bigger turbo is always more efficient. I know that twins are used for a lot of things, and there are usually three reasons for that. One, because they will spool faster, two, because sometimes it is just impractical to have ha gt60r turbo under the hood, and three, because it is just cool. I never said twins wouldn't work, I actually said the opposite, but
I still maintain that a compound turbo is the best system for a diesel.

go back and read my first post, i told what the turbos were off of, only reference to a gas engine i made. also what im trying to say is 2 smaller turbos will build boost which will last throughout the rpm range, instead of one bigger turbo that has to spool up to build boost
 

429idi

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go back and read my first post, i told what the turbos were off of, only reference to a gas engine i made. also what im trying to say is 2 smaller turbos will build boost which will last throughout the rpm range, instead of one bigger turbo that has to spool up to build boost

Sorry man, I'm not trying to sound like a jerk. That's what I was trying to say, that they will spool better off the line. I must have misunderstood you.;Sweet
 

MidnightBlade

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In the compound turbo, you run the big (low pressure) turbo compressor into the inlet of the small (high pressure) turbo compressor, that's how you get the compounding effect of the pressure ratios, so i. If you are thinking of just one set of compounds, the td04 would be way too small, if you are thinking twin compounds (quad turbo) then a psd turbo pushing through a tdo4 at each bank would work. That is eventually what I want to do, just to have a quad turbo on a 6.9.

For an answer to your question, if the two tdo4's could flow 30lbs/min, you would have 60lbs/min total flow. Remember both of these turbos will be essentially feeding two 3.65 4 cylinder engines. Without an intercooler, at sea level, at 3500rpm, at 85% volumetric efficiency, it would take around 30psi to flow that, that is around a 3:1 pressure ratio. If you have turbos pushing into say 5lbs into those (19.7psia), your 3:1 p/r turns into almost 45psi outlet pressure. Get an intercooler, and you could flow the 60lbs/min with 20psi.

Now that all of you are probably sick of me posting, I'll be done now. Sorry if I sound like I'm trying to be a know it all, I'm not.

i plan on running intercoolers from a PSD (6.0 or 7.3) i was completely backwards on the compound turbo then, i thought the exhaust went into the small turbo, spooled it, then the small turbo's exhaust flow went into the larger turbo and spooled it.
i will probably only do twin turbo for now, not quad. that is a thought train for the future though...
 

MidnightBlade

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how would i fab something to combine the intakes at the manifold? and would my intake into the turbo have to do a 180* bend the way i am thinking, i know it is either the exhaust will do it twice or the intake will do it once right, depending which way the manifols are flipped?
 
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429idi

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i plan on running intercoolers from a PSD (6.0 or 7.3) i was completely backwards on the compound turbo then, i thought the exhaust went into the small turbo, spooled it, then the small turbo's exhaust flow went into the larger turbo and spooled it.
i will probably only do twin turbo for now, not quad. that is a thought train for the future though...

Ya, that's right, I'm talking about the cold sides. The turbines don't matter as much as the compressors.
 

MidnightBlade

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AHHHH now i just had an info overload
now that i have everyone on this thread thoroughly confused now...
i will look into flipping the manifolds, will definately happen one way or another (how much would two RayJay manifolds be, or how would i make my own tubular design?)
i plan on running 2 tdo4's, one on each bank of cylinders (need ideas on how to combine intakes)
will i need 2 intercoolers? (one for each turbo)
 

mabc926

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You could try and make headers, I just don't know how well they will hold up with the heat of these engines and the pressure of the turbo.
 

429idi

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You'll only need one intercooler, as long as you y it before the cooler (you can get an aluminum intake y from summit racing). I don't know if you could find two rajay manifolds, I have never seen one for sale. If you could get some header flanges, some assorted j bends, and a couple merge collectors (or you could build your own), you could build your own turbo manifolds. You just have to make sure to use some thick gauge steel, some guys use sch40, or sch 10 stainless, but 16ga works for some people. Turbo flanges are usually 1/2" thick.

If you are buying the turbos, be careful, try to find a compressor map for the turbo before you buy it to make sure it will flow the air you want, and at the right pressure ratio.
 

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