Compounds - A due diligence quest

[88 Ford]

@ Hairy: Yea Ive got the HX35 and HX50 for my compound combo. I had a helluva time finding maps for Holset turbos, the ones I did find looked homegrown so I don't know how much stock to put into them. On my other computer I have a bunch of links saved to all my research, I hope to get it to come back to life. Naturally it decided it no longer wants to turn on (laptop power supply crapped out)

Since this thread had some rekindled interest I decided I best come clean with my project. I just feel akward having peeps think I'm doing one thing, when in reality its going a different direction right now. The twins are kind of sitting on the sidelines right now. My buddy who is the uber good welder (I am not good enough for this type of work) his TIG crapped out on him, and he just got a new job so time is really short for him to help me finish this all up. Between his time constraints and all the time constraints I've got I've lost interest in really getting this completed. I figured maybe all the road blocks were a sign that nows not the time to bolt this project on.

HOWEVER, I have been working on a possibly more simplified solution to my desire for low end boost. I bought an HE351VE a few weeks back on FLEABAY that is darn near brand new off a new dodge. I've built a homegrown actuator to control the vanes using a wastegate actuator arm. I'll load some pics later, I'm headed over to my buddies house now to work on it all a little more. We have to remote mount the turbo because the exhaust housing on this thing is MASSIVE and it's just too tight under the hood to effectively do it. Truthfully I have no idea if this all will work or not. It sounds somewhat plausible, the displacement motor these were designed for is not that far in size from ours, and I know alot of the 12v and 24v Cummins guys are using these turbos to support quick spooling 500rwhp trucks with great success. If it all works, and I can get good sub 2k rpm boost without EGT or drive pressure issues I'll likely ditch the compounds all together. If it doesn't work out I'll complete the original project. I figure I don't have a ton to lose by testing this one out.

I'll try and get a few pics up tonight, I'm headed over his house now to get a few things done on this project.

Man that is funny. I just mentioned that to hairy like yesterday. The way I mentioned it though is to use it in a compound setup. It will spool hella quick and you would have two good flowing turbos up top providing good cool boost. Also, if the wastegate setup closes too quickly, you can use a duel air cylinder that runs off of drive pressure to open it up and boost to close it. Using both would allow it to not slam shut. Here are a few pics...

Also the last pic is that Vgt arranged as a compound. If you have any questions as far as Vgts go just ask me. I have done so much research and it is the type of turbo I plan to eventually use along with my SC setup...

 

[88 Ford]

Guessing.

No just kidding (partially)

Since finding maps for the Holsets is harder than finding an original copy of the Declaration of Independence; I used things like Garrets' website which has a neat turbo calculator, as did some other website that was squirrelturbo.com or something like that. When using Garrets site, obviously I didn't get selections for the Holset turbos, but what I did was look at what was suggested in the Garrett shopping cart, and compare the suggested turbo specs (i.e. compressor wheel, AR, etc...) and find something that cross referenced decently in the Holset category. I really preferred to stick with Holsets because they are so readily available and inexpensive, like others have mentioned. The 35's can be bought easily and cheap because anyone with a Dodge Cummins takes them off to get bigger go power. The 50's come on alot of the larger Cummins like the N10, etc... (IIRC the Volvo trucks commonly came w/ HX50s)

Basically what I did on those sites, is plug in all the info powerwise for my small turbo, with putting peak power @ 2300 rpm, and mid range @ 1800 rpm. Then for the atmospheric turbo I plugged in mid range @ 2100 rpm and peak @ 2900 rpm. My thought process (right, wrong or indifferent) is that I'd want some overlay where each turbo is carrying an equal piece of the load in the mid range. Besides using the online turbo calculators I probably spent upwards of 25 hours reading, mainly on the Cummins forums (because those are the guys most commonly going Compounds) It seemed reading from the guys that had done it (well) the rule of thumb was that your atmospheric turbo shouldn't carry anymore than about 50-60% of the load. This fit pretty well for the Hx50 IMO. THe 35 would be WAYYYY out of it's map range if it were a single application, but keep in mind, that turbo would "think" it's operating in a different atmospheric condition once the 50 started to spin.

Thats the nuts and bolts of how I pieced together these 2 turbos. The added "toughness" in my research was, that I couldn't do what the other guys could in terms of pushing big boost. I had to try and figure out what I could get out of these turbos in sub 25 psi range. I'm sure someone more educated in pairing could do better than I, but since you asked, that's how I came up with the 35/50 combo. I certainly would never suggest anyone take my work above as "the right way to do it" and go out and build said twins without doing their own research OR looking at the potential ramifications that could come with screwing this up.


Update on my HE351VE project: we may have stalled out a few more days. My buddies Uncle had a BAD stroke, is on life support, and it sounds like they might be pulling the plug on him this week. He'll probably have to go out of state for a while to help on the family farm. I might be delayed even a little further. No complaints by me though, family and his friendship is WAY more important than some stupid turbo project.

That is how I also woulda sized um. We gotta remember that we don't need as much boost as a Cummins so those would be about perfect.

 

[wmoguy]

Man that is funny. I just mentioned that to hairy like yesterday. The way I mentioned it though is to use it in a compound setup. It will spool hella quick and you would have two good flowing turbos up top providing good cool boost. Also, if the wastegate setup closes too quickly, you can use a duel air cylinder that runs off of drive pressure to open it up and boost to close it. Using both would allow it to not slam shut. Here are a few pics...

Also the last pic is that Vgt arranged as a compound. If you have any questions as far as Vgts go just ask me. I have done so much research and it is the type of turbo I plan to eventually use along with my SC setup...

Thx 88. Yea the guy that built that setup is in Golden, CO, only an hour away from me. It started out as a single turbo'd Cummins, then he added the atmospheric turbo later on for more giddy-up. Thats a super nice setup to say the least. My thinking is if this rudimentary setup works, and the turbo does what I want it to, I'll check out Fleece Performances upcoming controller for this turbo. Right now they have a controller that is electronic but only works for the 12&24v Cummins pickups. In speaking w/ Caleb @ Fleece Performance last week, they hope to have a universal controller available around the end of January to February. Price point TBD, but sounded like around $700 according to Caleb. Not cheap, but not out of the question, once I can determine if this HE351VE will be a good fit for my ride.

 

[88 Ford]

Sounds good man. I didn't know fleece was working on that. That's good to know.

 

[IHdiesel]

Are there other ways one can contol the turbo? Just looking for other ideas if any....

 

[88 Ford]

Are there other ways one can contol the turbo? Just looking for other ideas if any....

Ok there are quite a few ways to control a variable turbo. One way that I have seen to do it is to use a wastegate controller and use either boost or drive pressure to contol the vanes of the turbo. As boost or drive pressure rises in this type of setup the vanes will slowly open. But the problem with this type of setup, is that is is either all or nothing. The vanes will be closed until they slowly creep open and then they will slam open fully when it hits the preset level. So in my opinion I don't like this method quite as much but it does work. Also another problem with this method of control is when you take for instance let of the throttle and boost or drive pressure drops quickly it can cause the turbo to chirp. This is negated a lil bit by using drive pressure instead of boost due to the fact that drive pressure doesn't fall off quite as quickly as boost does and drive pressure will always be there to certain degree due to the back pressure of the turbo. Another thing that can help prevent the turbo from chirping would be a blow off vavle. It will release the excess air to the atmoshere and will keep the air from slamming back into the turbo.

Another method of control is to use a spring type of setup. There are wastegate contols called a Turbomaster that Heath Diesel sells for the old Chevy 6.5 diesels and this is similar to what I am talking about. The way this setup works is that the centrifugal force of the vanes start spreading the vanes out and slowly over powers the spring until they are fully open. The problem with type of setup is finding the right spring for your setup so that the turbo acts like you want it to. Too light of a spring and the vanes will open too quickly and cause turbo lag. Too stiff of a spring will keep the vanes closed too long and cause higher egts and will overdrive the turbo too much. With this setup it is all about finding the right spring and finetuning the setup. Also it will have the same problem of slamming the vanes down like a wastegate type setup when you let off the throttle and can cause the turbo to chirp too. I would highly recommend a blow off valve with this setup also.

Another method is to use a double acting air cylinder. This is my favorite type of setup and the cylinder can be had off ebay for next to nothing. The way in which this setup works, is that you can use drive pressure to open the vanes and boost to close them. Drive pressure is used to open the vanes because drive pressure is usually higher than boost. Once the pressure equalize on both sides the vanes will stabilize and stay open at that spot until the pressure changes. This type of setup allows foir tuneability cus you can use bleed off valves on either the boost or drive pressure side to control the mannerisms of the vanes. Also having pressure on both sides of the cylinder will keep the vanes from slamming down like the other setups and will prevent turbo chirp. This setup by far allows for the most ability to tune the turbo how you want it to act. This is the setup I will use when I have a Vgts blowing into my supercharger eventually. It will be one cool setup.

Any other questions, don't hesitate to ask and I will do my best to explain it.

Also wmoguy, any updates or pics of you setup? I'm really curious to see how it going...

 

[88 Ford]

Oh also IHdiesel, do lots of research. There are a lot of Cummins guys running these types or setups and there are even some videos on youtube to watch also.

 

[94IDIT]

Are there other ways one can contol the turbo? Just looking for other ideas if any....

I made a thread on this awhile back. There's allot of good info in it, check it out it might help ya out some http://www.oilburners.net/forums/showthread.php?t=52222

 

[88 Ford]

Yep I remember that one too...

 

[wmoguy]

@88:
no exciting progress really. I decided to go up to the mountains and play this weekend for my bday vs work on this project. If the stars align some major progress will take place this coming Saturday.

 

[88 Ford]

I'll keep an eye out next weekend then...

 

[wmoguy]

Few pics. The pickup is carrying a 2nd turbo now.

 

[wmoguy]

Few more pics.

On the agenda this week is to get the oil lines made up. I'm hoping by end of week the N/A Y pipe I got from towcat will arrive. Then the following week turbo gets plumbed and in operation.

We had to redo the wastegate actuator, and it works like a champ now. 15-16 psi gets me complete control of the vanes from closed all the way to open which is 26cm. . I'll be using a $20 adjustable boost controller in the cab for the fine Adjustments.

 

[Ididriver]

Looks real good. How far back is the turbo mounted?

 

[wmoguy]

Looks real good. How far back is the turbo mounted?

Thx.

It's right towards the front edge of the bed, if you look closely in the frontal pics you see a edge of the cab body which I'll have to do a minor trim job on to clear the charged air piping.