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Has any one tryed twin turbo's (1 on each side of the engine, not compound)
You should be able to build 45 to 50psi with less back pressure, smaller turbo's, and quicker responce. Something like what banks is doing with the chevy. under 50psi should be able to still use stock long block with headstuds. is my thinking right or am i missing something:dunno:
 

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That is a Compound setup not sequential like the OP was asking about. ;)

I am not sure if I have seen or heard of anyone doing them.

Many guys have said they might try, but nothing yet.

Really Compound setup would be the way to go :thumb:

It would be a nightmare to get the Sequentials setup :doh:
 

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If I had the money, you could have seen a twin setup on my truck. I do most of my mods in head.:crazy:
 

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For these applications the compounds are really the way to go. With the paralell twins you can't make the boost you can with compounds. The advantages are that you have smaller turbos that will spool quicker. That's why Banks used them on their Chevy. It's a road race truck so they don't care about the huge psi of boost but rather getting it instantly. You'll also likely have as much or more drive pressure with it set up that way as well.
 

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For these applications the compounds are really the way to go. With the paralell twins you can't make the boost you can with compounds. The advantages are that you have smaller turbos that will spool quicker. That's why Banks used them on their Chevy. It's a road race truck so they don't care about the huge psi of boost but rather getting it instantly. You'll also likely have as much or more drive pressure with it set up that way as well.
thats kind abeen the point that all of us are trying to make that have thought of the ideah of paralell turbos some of us would rather have lightning quick response. something that fun to drive rather than some one who wants to hold the brake and the throtle to the floor for 5 minutes and waiting for the green light so they can blast down the track at insane speeds. most of those trucks are not practical for street use and are verry un responsive on the bottom end. personaly I bought a diesel for the low end power not huge insane number of boost on the top end.


ive actualy thought about doing the paralell turbos with a combined 30 lbs of boost but get high compresion pistons. that way you wouldnt need high boost and the low end response would be better with higher compresion pistons.
 
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i dont htink higher compression pistons would work. remember the old IDI's that liked spit headgaskets out? You want lower compression and more boost. Use boost to raise your compression ratio back up. Mine is sitting somewhere near 16:1 compression.
 

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....................subscribed:popcorn::popcorn:
 

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Yes, it has been done, Darrell at DPP did it with two stock turbo's.
 

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i dont htink higher compression pistons would work. remember the old IDI's that liked spit headgaskets out? You want lower compression and more boost. Use boost to raise your compression ratio back up. Mine is sitting somewhere near 16:1 compression.
the problem with diesels low end response is the decreased low end compresion. you have to build boost before you have enough compresion to get response. as far as head gaskets go im sure if peope can build motors to handle 100lbs of boost surely some one can build a motor to handle 1 more point in compresion with 40 lbs of boost.
 
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the problem with diesels low end response is the decreased low end compresion. you have to build boost before you have enough compresion to get response. as far as head gaskets go im sure if peope can build motors to handle 100lbs of boost surely some one can build a motor to handle 1 more point in compresion with 40 lbs of boost.
You could leave your compression stock and use a drop in turbo (TN, garrett, etc..) and feed it with a 76mm large charger. That setup would be a pretty nice responsive tow setup if you ask me. I think the only other mods you'd need would be headstuds and valve springs.
 

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Darrell did have them operational but weather they were actually working very good as intended is questionable. IIRC he didn't have them on long to really test it. Also I think there would be much better options for turbos than just useing two stockers. I can't imagine thems pooling that well with getting half the exhaust flow as they would in a stock application.

As for compression I'm not really sure what you are talking about. Diesel engines have TONS of compression when compared to a gas engine. I think it has alot more to do with proper turbo selection and tuning.
 

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You could leave your compression stock and use a drop in turbo (TN, garrett, etc..) and feed it with a 76mm large charger. That setup would be a pretty nice responsive tow setup if you ask me. I think the only other mods you'd need would be headstuds and valve springs.
youve just gotten used to turbo lag. :doh:



Darrell did have them operational but weather they were actually working very good as intended is questionable. IIRC he didn't have them on long to really test it. Also I think there would be much better options for turbos than just useing two stockers. I can't imagine thems pooling that well with getting half the exhaust flow as they would in a stock application.

As for compression I'm not really sure what you are talking about. Diesel engines have TONS of compression when compared to a gas engine. I think it has alot more to do with proper turbo selection and tuning.


actualy the older diesels had about 5% more compresion that the newer ones.
they lowered the compresion and increased boost for emmisions and noise.


I dunno Im just trying to think out side the box here. maybe im wrong. sure wish i had the money to find out.
 
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youve just gotten used to turbo lag. :doh:
Yes i've probably got a little more tolerance to lag than most others since ive ran some bigger singles. However im sick of lag and am going another route ;). Just waiting on the engine and i'll get started on it.

I dont think your going to get anything to spool up better than a garrett 38r ball bearing turbo, couple that with a 76mm and i really think lag will be minimal. If you want off idle tq, put the damn thing in low range. With turbos there is going to be lag no matter what, there's no way around it. 76mm ran as a single would be/ is terribly laggy but with the 38r in front of it it should spool very nice.
 

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I don't think so much that you are wrong in saying compression effects spool up, just that you might not be comparing apples to apples. What older engines are you talking about? The 6.9/7.3 IDIs? Or other older DI engines? And were those other older DI engines the same configuration? Every engine will have different specs. Especially if you are talking about difference like IDI vs. DI, I6 vs. V8 etc.
 

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I really don't think twins will decrease spool time. I would think the optimum twin set up would spool at nearly the same rate as the optimum single. Since the exhaust energy is being halved, I don't see twins being that much quicker. I imagine it would be just as difficult trying to find the best twins as it would one single that works just as desired.

That being said, I think the allure of twins is more of a "cool factor".
 

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Derrick I agree abou the "cool factor."

The key to any set up is proper sizing for the application and how you set it up. Having the smaller turbos they have less weight to the rotateing assembly and can spool a lot faster. Haveing them paralell won't give you any more boost but the quickness of spool up is the main advantage. Again it all depends on the set up. You need to have a small enough turbine housing to get it to spool real fast yet have a big wastegate to control it and dump the excess exhaust so that your drive pressures don't go crazy.
 

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Its not practical to have 2 stock turbos compuonded right? Right now I have 3 Stock turbos and one is similar to the D66 witha 1.0 housing and the others are stock. Can I change the housings to a .84 and 1.15 to increase boost and spool or are they too close?
 

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correct. The system will only flow as much as the big turbo. So if both turbos are the same size there is no point.
 

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Lukecline is on to something.
I fed my little 'ole H2E with a 76 charger last summer and it made tons of boost instantly. Not a tested, designed set-up, it's just what I had. Those twins are going back on in a week or 2, this time with a waste gate to really see what they are capable of.

Problem with Parallels is you make boost quick, but it dies out.

So do you want to beat someone off the line (with paralles), then get blown away by them later, or do you want to beat them off the line and never see them again (compounds)?

It doesn't take money to do this guys.
I've built 3 different compound twin set-ups for what I consider very little money. Just takes some tools, fab skills, and a little money for the hardware. We're talking hundreds of dollars not thousands.
Of course if you want the best engineered and designed system, with both turbos complimenting each other, your only option is to dish out your $$$ to a good turbo builder to do this.
But if you want to get your feet wet, start cutting and welding. :thumb:
 
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