Competition tripplets

[Halfbakediesel]

I am building my own setup just to see if it works and would like some feed back from those that know more about turbos or if you just have a opinion thats great also. I have two turbos of equal size on top side by side. they are S300s, and S400 on the bottom. On the hot side one runs directly into the other. On the cold side the S400 Ys into the S300s then they y back together, I am also using 50mm external wastegate to by pass them. I am currently waitin on the hot pipes. I would like to know some of the cons to this setup or things i could change. I will Hopefully test this in less than a week if it dont work I will have a S300 to sell.

 

[GO 4LO]

So you're running it as two stages, with the primary stage being an S400 and the secondary being twin S300's? What are the specs on each turbo? Unless you're running tiny S300's and a monster S400, I don't think it will work as well as you hope. If you're running two 'normal' S300's in the 62-64mm inducer range and a 'normal' S400 in the 74mm inducer range, your secondary stage will likely equal or outflow your primary stage.



A small S400 in the 71mm inducer range on top of a pair of big S300's (66+mm inducer) would work pretty well, but I don't know if you have the fuel to push 'em...



What are your goals with the truck?



Chris

 

[NoSeeUm]

I like everything so far, and even better if you post up some pics when you get them done.



Jim

 

[ThrottleJockey]

Go 4 Lo is right about the cold side, you're defeating the purpose of running three chargers. Plumb the S-400 into the first S-300, and then pipe all that into the second S-300 then to your intercooler (water) pipe, then to the intake. All this is cold side only.



Now on the hot side, reverse what you have so the truck will 'think' it's only a set of twins on the exhaust side. Put the S-400 as the secondary off the manifold (the small charger) and use the two exhaust housings of the S-300s as the 'primary' (the total square centimeters of the TWO smaller 300s are BIGGER than the S-400) See what I mean? The hot side will FLOW like a set of twins (drive pressure), while the COLD side will compound THREE stages of air. It's only triples on the compressor side. The exhaust gasses won't cool as much after the 400 'cause you're gonna split it to both 300s instead of passing it across 3 stages of turbine wheels, which tends to cool about 300 degrees F after passing a turbocharger turbine.



The exhaust housings on the S-300s are the same size, right?

 

[mattymac]

Piers (I think) did this years ago on a P-Pumped 24v. I seen many pics of it but the kid that had it was worried that the pics got out on the internet so he never ran it last I heard.



Impressive looking setup to say the least!

 

[RickFox]

I know if you look at woodruff diesel's website they have some pictures of how they did it on a truck. I think they used 2 hx35's and one s300.



http://woodruffdiesel.com/Projects.htm

 

[Forrest Nearing]

sounds like there'll be an S300 up for sale soon

 

[WUnderwood]

I know if you look at woodruff diesel's website they have some pictures of how they did it on a truck. I think they used 2 hx35's and one s300.



http://woodruffdiesel.com/Projects.htm

I wish they had some bigger pics on their website

 

[Forrest Nearing]

looks like they're blowing the HX35's into the S300... that would actually work though the packaging nightmare wouldn't overcome any potential benefits over a single larger turbo.



but blowing one S300 into another S300 is just going to cause a restriction...

 

[GO 4LO]

Go 4 Lo is right about the cold side, you're defeating the purpose of running three chargers. Plumb the S-400 into the first S-300, and then pipe all that into the second S-300 then to your intercooler (water) pipe, then to the intake. All this is cold side only.

I don't see that setup as being ideal either, honestly. The best way I can see to work it would be two big S300's run in parallel as the primary stage and a small S400 as secondary. So compressor side would be two filters, each feeding one S300, then those two discharging into the S400, and then dumping to the intercooler and then intake manifold. Turbine side would be exhaust manifold to S400 then Y'd to the S300's.



A setup with an HT60 secondary and twin HT3B's run in parallel as the primary stage has been run with success in the midwest.



Chris

 

[ThrottleJockey]

So it's just really 2 stages only then, huh? The 2 in parallel are just one giant charger.



So it's really not triples.

 

[ROADWARRIOR]

Piers (I think) did this years ago on a P-Pumped 24v. I seen many pics of it but the kid that had it was worried that the pics got out on the internet so he never ran it last I heard.



Impressive looking setup to say the least!

I think this was the truck Mark Kendrick built. I never heard anything more about it.



Dan

 

[Redram 1]

re

Just call Josh,at the shop I am sure he can send you some more pics,he is a cool guy. He sells all the pieces you need to do the job.

 

[Jim Fulmer]

I think this was the truck Mark Kendrick built. I never heard anything more about it.



Dan

That's because it never worked, that was a mistake from the word go, you can't even begin to imagine all the issues David (the owner) dealt with on that whole project. I talk to him from time to time and the truck is for sale right now with the motor, DTT transmission, N2O system everything including the T106 and T-88 turbos, intercoolers. The Motor has a cracked Firering and Haisley's have the fix for it.



It is running with a big water leak but has a set of old Mitchell Twins on it.



Wish I had the money to buy it!



Jim

 

[GO 4LO]

So it's just really 2 stages only then, huh? The 2 in parallel are just one giant charger.



So it's really not triples.

Exactly, the two run in parallel would be a single stage. It would be triple turbo, but only two stages of compression. You can build three-stage setups, but you don't gain anything if you're running two identical turbos as two of the stages (e. g. S300-S300-S400).



You could run S300-S400-S500 as three stages if you choose the sizes carefully, but it's far more complicated than building a two or three turbo two-stage setup, and you really don't gain much, if anything, over a well set-up two stage setup.



Chris

 

[ThrottleJockey]

Exactly, the two run in parallel would be a single stage. It would be triple turbo, but only two stages of compression. You can build three-stage setups, but you don't gain anything if you're running two identical turbos as two of the stages (e. g. S300-S300-S400).



You could run S300-S400-S500 as three stages if you choose the sizes carefully, but it's far more complicated than building a two or three turbo two-stage setup, and you really don't gain much, if anything, over a well set-up two stage setup.



Chris

Oh, okay. I like to learn new stuff off of you extreme horsepower guys. I could take GO 4 LO, RedRam, Jim Fulmer and Forrest to lunch and just listen to the bench racin'.



Here's what I was reading from the book:

"Now that youv'e digested the above (twin turbo systems on competition diesel pulling tractors) I must tell you this method (twins) is now obsolete. Manifold pressures of 100 psi are not enough to win consistently. The next, logical -are you kidding?- step is to add a third turbocharger stage. With three stages of turbochargers and three inter/aftercoolers, the engine disappears under a maze of tubing ducts"



I like Chris' 300, 400, 500 compressor sizes. I wonder if I could run 2 of them in parallel on the exhaust side only, and stack 'em like Chris said on the cold side as 3 stages?

 

[GO 4LO]

Man, I shouldn't even be mentioned in the same sentence as those guys. There's plenty of people more knowledgeable than me around here.



Regarding the S300-400-500 setup, I don't know anyone that has tried that, but I don't think it would be optimal for spoolup. First, the flow would be very uneven, since your larger turbo would no doubt have a much larger exhaust housing and bigger turbine wheel/heavier comp wheel/etc. Second, the way twins spool is complex, but a large part of spoolup time is based on how fast the secondary stage (manifold charger) spools. You'll only have 3 cylinders feeding an S300 secondary, and another 3 feeding a 400. You wouldn't have enough airflow to light 'em before 3k, I bet.



If you want to run two different-sized chargers in parallel on the hot side, you're going to be giving up most of the advantagee of that extra stage of compounding you just added. I think it is potentially possible, but just don't know enough to say for sure. You could set up a wastegate on the 300 to dump over into the 400, but that wouldn't get your spoolup all back.



You could run a pair of small S200's on the manifold and a big S400 below them if you're wanting to run two turbos in parallel, though.



The easiest way to think about twins is this: You have a 359cid diesel you're trying to feed with your manifold charger, so size it appropriately. Let's say we use an S300. If we want to add another stage of turbocharging, we look at the system as a whole now. Our 359cid engine on x amount of boost requires the airflow of a naturally aspirated yyy cid engine. Let's say it's equivalent to 800 cid. Now we size our next stage of charger based on those requirements. And so on for however many stages you're adding.



The problem with triples is that by the time anyone gets to the stage where they need that kind of power, they don't care about spoolup anymore, so there's no use keeping the littlest stage. Look at the pro mod pullers - they're running top chargers bigger than Big Brothers because spoolup is not an issue, and their engine/head/cam/pump setups reflect the same thinking.



Chris

 

[ThrottleJockey]

Man, I shouldn't even be mentioned in the same sentence as those guys. There's plenty of people more knowledgeable than me around here.



Chris

I don't know. You sound pretty knowledgable to me.

 

[JVolpe]

I don't know. You sound pretty knowledgable to me.

I agree! I try to learn something new every day, I think I am covered for the next few days for sure .

 

[ThrottleJockey]

Don't you want to keep the littlest stage to benefit from compounding the air charge 3 times. I agree, spool up is not an issue with a competition puller.....



... . but boost is. Were talking air density here, not lag.



150 psi. Well, it is what it is.