Supercharged 7.3

[superpsd]

Shewee. I like the idea of it all and I sure do love me some roots style supercharger whine on a v8 when the go pedal is matted but no way I could handle the sucker whining like it did in that dodge video. Sounded like an old fire siren.


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Yes the whipple have a pronounced whine. They are quite loud. That's why I chose the newer TVS roots technology as the TVS is oem equipment that is geared towards sound reduction. Whipples are a twin screw charger. Twin screws do make some internal compression between the rotors. A roots blower does not compress air it only pushes it.

 

[97White'nSilver]

So this might be a dumb question but if your tvs is capable of 1400cfm would it still be a restriction once it was flowing more than the turbo is capable of (767 from what I've seen) if you were to change pulleys again? Or is it a restriction because the turbo is flowing more cfm more quickly than the tvs can produce at a given rpm regardless of pulley set up? Also I never saw what your max total boost was on a wot run before or after the b codes?

 

[superpsd]

Max boost I have seen is 23 psi and the blower does not change that number. That was stock injectors with a tune, downpipe, and completely stock turbo with EBPV intact. I plan to drive the blower faster down the road to experiment. However as you drive the blower faster to create more pressure you also increase the power needed to drive the blower which can start to effect things like fuel effeciency. It will also increase noise due to higher rotor speed and higher discharge pressure. The blower is not for high rpm performance it just complements low end performance and can get a turbo up to speed a little quicker. Once the turbo is spooled up it takes over. It's kind of like a sequential turbo setup where you use a smaller turbo for low end response and then gate around it for a larger turbine. Also the blower is not a restriction as is. Once the turbo starts to pull more air than the blower can push it pulls a large 3" check valve open and pulls from atmosphere and the blower just free spins technically still pushing air as well but not enough to overcome the suction of the compressor inlet. That's why a better turbo is needed for the high end. Even if I could push 1400 cfm out of the blower I don't see the stock turbo lasting long compounding all that air.

 

[97White'nSilver]

I've been trying to read up on procharger setups but there's so little actual info about sizing, mounting or even results. I realize they're a different style of supercharger but this seems like the only active thread on alternate methods of forced induction. So my next question is why don't you want to have the tvs flowing more than your turbo? With your original m122 it made sense since it was only capable of about the same flow as the turbo at max rpm but with the tvs wouldn't you see substantial gains by increasing the flow of the tvs so that it was flowing more than the turbo like other compound set ups? Especially since you have more fuel available now. Awesome fab work thus far by the way, very interesting read and I'll definitely be following for more results.
Edit: I missed your last sentence about the stock turbo going bang but are you planning to have the supercharger continue to be bypassed when you upgrade the turbo?

 

[superpsd]

I have been turning an adapter on one of my lathes to piggy back a 9.55" pulley on the crank for the blower to have its own pulley. The ratio would go from just under 10,000 blower rpm to 13,500 rpm. There is also a company that can drive these blowers 30% faster with an aftermarket gearset but they are not cheap. Trying not to go that route. To spin 19,000 rpm @ 3400 you would need to drive the 2.4" pulley with a custom piggy back 13.5" pulley. That's a big pulley. For now the setup works but I have a few things that need to be improved upon. Keep in mind that the faster you spin a blower at higher pressure ratios the effeciency starts to drop off and you start to create a lot more heated air. The TVS is far more effecient than the older generations but once you spin them high enough they will still start to leave the sweet area of the map. Keep in mind the map below is a standard r2300. My blower is a r2300 rotor pack in an aftermarket high flow housing.

 

[Charles]

My mind is still blown as to why the blower isn't south of the turbo with a nice T6 framed charger in the 80 to 90mm flavor bringing the pain up top...

The blower would run the truck around town and the turbo would pump up the jam when you wanted to get the F down the road. They would work together instead of ALWAYS fighting each other.

Mind is still blown on this subject. Lot of going around your ass and spending money to still only have a stock charger's worth of air and nothing more. In fact, probably a tad bit less power up top because you're also spinning the wee out of a blower drive while a stock turbo still provides all your available induction.

This thread hurts my soul. God it would be so easy to flip this all around. The difference would be UNREAL.


On Edit:

Apparently I'm not the only one who understands this. People using the TVS blower you are also agree. Just look at the Hellion kits SPECIFICALLY blowing turbos THROUGH the blower you have!!! If it's not the exact one you've got, it's gotta be damn close. Regardless, these guys make POWER, unlike the others.

http://www.svtperformance.com/forums/showthread.php?799483-Compound-Boost-Hellion-kit

 

[superpsd]

believe it or not there are quite a few super turbo diesels that have been built and or are being built. Quite a few dodge guy have. I even ran into a guy on another forum that has a VMP TVS on a 5.9 CR. Gale banks uses super over turbo combo just like the pikes peak freightliner I posted. There was a roots blower over compound duramax making 1000hp... Also Eaton themselves have been testing superchargers on diesels. Then there is also the Van Dyne Super Turbo setup for larger commercial trucks that has been developed. Technically it can work either way but the concensus has been blower over turbo is more effecient. even if you blow thru the blower you still need to bypass the blower at some point as the turbo will likely be moving air faster than the blower can and then you have a restriction.

Here is the Eaton study on a super turbo T-800 kenworth. Same blower feeding turbo however it goes further to use a clutch and a bypass valve that is PCM controlled.
http://www.sae.org/events/gim/presentations/2013/dorobantu_mihai.pdf

This is the Detroit 60 series banks built for the super turbo freightliner that runs the pikes peak challenge. As you can see there is no bypass so the whipple is spun fast vnough to keep pressure on the compressor.

https://www.youtube.com/watch?v=rvs5jYCMSD8

 

[TyCorr]

Yea. You explained that before. We understand what you're saying. Flip it around, adjust your tunes and see how much better it works. Install s483 and discard the notion that a 1khp freightliner and gale banks gave anything to do with a potentially 450hp powerstroke zf5.

You're a smart kid, and resourceful...but this is painful.

Although, i could swore id have my truck "together"(that means different things on any given day) and self tuned before you and you beat me there...

 

[superpsd]

I still have a lot of work to do to this rig but its a slow process as this is my daily driver it sees the road everyday so I always have to plan and work around that. I have other rigs I can drive but they are not toys and not fun to daily drive. The guy who builds and sells the whipple kits for the dodge guys started out with blowing thru the blower and went with a blower over turbo combo. Now he has a 3.3 whipple feeding compounds with a bypass as I have so when the turbos light up they can pull around the blower. There are a few rigs running his kit I have seen. This one is his rig.

 

[Charles]

The blower can ONLY be a restriction when you place it ahead of the turbo. It can NEVER be a restriction after the turbo unless it is literally displacing less than the engine.

Period.

The turbocharger does not make the engine ingest more air volume, only more air mass. The volumetric flow of the engine will never change with boost, only the mass flow. The boost the blower puts on the engine alone will always stay the same whether or not you have atmo or atmo minus 5, atmo plus 5 or atmo plus 25 coming into the blower. Blower doesn't care. Only way I see the blower getting unhappy is with an inefficient charger being overdriven sending superheated air into the blower. But that's why you intercool between turbo and blower. Thankfully on most diesels the intercooling is already in place, as is the turbo.

At 3000rpm a 7.3 inhales 385 CFM at 100% VE. Figure say 80% VE and you're looking at 308 CFM @ 3000rpm. If your blower moves 308CFM or greater, you are even, or making boost. Done. This will never change. And if the blower inhales say 800 CFM, the engine is NOT moving 800 CFM..... it's still moving 308, but each of those 308 cubic feet of air now WEIGH more. You compressed the 800 cubic feet down until they were only 308 cubic feet so it would "fit" into your engine of a FINITE volume. The cylinder walls don't swell (appreciably, lol) and the heads don't balloon out, so the volume is NOT increasing, you are compressing air with the blower. This is important, so that you understand why the blower will never get in the way of the turbo when you place it AFTER the turbo.

Because even though the turbo might be inhaling 2000 CFM, the turbo is compressing that 2000 CFM, down to the 800 that the blower is taking in. The blower is then compressing it farther to the 308 the engine is taking in. Everybody doing their part. This is the beauty of compounding and doing your compression in stages.

However.....

If you reverse all of this and place the positive displacement ahead of the dynamic unit, all hell breaks loose, as you now know. Then out come the bandaids, bypass the thing, unload it, clutch it, blah, blah, blah...

You have been given a positive displacement engine, with a dynamic compressor feeding it thanks to the boys at international, and the rest of the known universe for that matter.

Then you add another positive displacement device, but make the mistake of sandwiching a dynamic device between it and the positive displacement engine.

You should have the positive displacement engine, then positive displacement blower, then dynamic compressor and life would be soooooooo easy.

As a side-effect it would no longer be pointless, as the truck would make more, instead of less power than the stock charger alone as you have it configured now..... less powerful than stock.

And it would make a LOT more power, because you could run a VERY large turbocharger and lite it off very quickly. The turbo would be sized to the displacement of the BLOWER. You would be sizing the turbo for like a 14L engine!!! And it would jump up on boost exactly as if it were ON a 14L engine!


https://www.youtube.com/watch?v=X9lF8NI9_uk

 

[superpsd]

Compounding can work both ways. Although banks is not highly praised here he is one of aftermarket companies that have R&D in super turbo diesels. On all of the setups they build which they have built many including a marine application Duramax that uses blower feeding twin parallel turbos which they sell. You would think they with all their money are doing so for a reason. Also Eaton themselves who are the biggest oem supplier of blowers and huge testing R&D labs have also been testing blowers on diesels to feed a turbo with a blower. They as well are likely doing it for a reason. As for me the setup works but has much room for improvement. The blower is not a restriction in a blower over turbo combo. Once the turbo is lit it pulls a bypass open and thus there is a 0 pressure differential (no load) on the blower. So when the turbo is getting the work done the only power draw the blower is using is the power to spin the mass of the rotors. eaton states that the TVS blowers use as little as 1/2 hp in a bypassed state. I am sure as rpm increases a unloaded blower will require a little more power but not likely a huge draw.

 

[superpsd]

Its not just banks doing it. Eaton themselves have ran it that way. empire feeds turbos with prochargers. Multiple dodges. I have even found competition Mercedes diesels that use a blower over turbo and the started out with a turbo feeding the blower. It does work mine needs improvement but its been on the truck for 2 years now. I have had some belt issues but that is just a few issues with alignment that have been cured and idlers that were needed and a stronger bracket that I still need to fabricate to run correct belt tension. I need to go load some more test tunes to cure a cold running issue I better stop here.

 

[TyCorr]

Compounding can work both ways. Although banks is not highly praised here he is one of aftermarket companies that have R&D in super turbo diesels. On all of the setups they build which they have built many including a marine application Duramax that uses blower feeding twin parallel turbos which they sell. You would think they with all their money are doing so for a reason. Also Eaton themselves who are the biggest oem supplier of blowers and huge testing R&D labs have also been testing blowers on diesels to feed a turbo with a blower. They as well are likely doing it for a reason. As for me the setup works but has much room for improvement. The blower is not a restriction in a blower over turbo combo. Once the turbo is lit it pulls a bypass open and thus there is a 0 pressure differential (no load) on the blower. So when the turbo is getting the work done the only power draw the blower is using is the power to spin the mass of the rotors. eaton states that the TVS blowers use as little as 1/2 hp in a bypassed state. I am sure as rpm increases a unloaded blower will require a little more power but not likely a huge draw.

Ask what practical things banks sells to any make or model diesel enthusiast. An aluminized exhaust with a different bend in it for six times what mbrp asks. I think some of their r&d developments are just as wasteful. Cool? Yes. Practical? Not really.

Theres a reason people build sequential setups for street trucks. Because its the easiest and most effective for the dd use. Good nanners and cool useable power.

Ask Charlie, he had decent sized chargers on his last truck.

 

[superpsd]

Banks aside as they don't share R&D data anyways. Here is a shot of a couple of graphs from Eatons Kenworth test. The blower is before the turbo again with a bypass for the turbo to pull around the blower once the turbo is spoiled. Their setup is more advance as it has a electronically controlled bypass and a clutch on the blower to increase effeciency. They do not say what blower is used but the r2300 rotor pack is the largest they have. They are testing a r2800 and r3300 rotor packs but very little information is available and the TVS2 (second generation TVS) line is being released.

 

[superpsd]

As far as having a turbo blow into a blower. It's has been done. For example a Detroit 2 stroke. I own a few of the green beasts. They have a roots blower and will not run without one. They are Naturally Aspirated as the blower is only scavenging the cylinders by pushing out the exhaust and replacing it with fresh air charge. So there is no positive pressure due to the port to valve timing events. Some are turbocharged by feeding a turbo into a blower. These do create boost not because of the turbo itself but due to the exhaust back pressure of the turbine allowing positive pressure to build. In the 80s Detroit Diesel improved the 2 strokes and released the Silver Series. The silver's had many improvement sto reduce sound and effeciency one of which was a blower bypass so once the turbo was flowing air to a certain pressure ratio it forced a spring loaded bypass to even the pressure differential of the roots blower. This reduced the load on the blower and improved effeciency. So you see even if I had a turbo feeding a blower...Once the turbo is lit you would want a bypass to route around the blower to maintain effeciency and unload the blower. Also to note a the blower on a NA 2 stroke is geared to turn faster than a turbo Model blower. You can see the bypass in the end of the blower below.

 

[2000wa250]

I think what Charles is getting at is right now you're using addition where as if you reverse it you'd be using multiplication. The blower moves air, where as the turbo compresses is. When you compress air then send it through a unit which just moves x amount of air, you are feeding x cfm of y compressed air. When you feed the turbo with the blower your end result is simply y compressed air of x cfm. You're ONLY using the blower for down low. When placed after the turbo you're forcing more mass of compressed air into the motor and it's benefitting you 24/7. Either way works, Charles way just would make making BIG power extremely easy and simple because the total mass of air being forced into the motor would be in essence compressed twice.

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[superpsd]

The thing is a few have ran the turbo into the blower. Most of them found it very ineffecient. You had to bypass the blower once the turbo is lit. So there is no compounding advantage. They found that without the bypass the blower would get extremely hot and air charge temps would be highly elevated. Also roots blowers typically do not like more than 1 bar of pressure being fed into the inlet as I have been told the seals are not designed to withstand that kind of abuse. I am unsure completely but could look around for documentation. The guy who sells the whipple kits started out with a turbo feeding a roots only to find that the blower as a low end helper worked substantially better.

 

[TyCorr]

Oh boy...quit thinking...

Compund the charges make power. You are making them compete. If your induction was working as it should you'd be running bald tires and your clutch would be rolling you through stop signs foot to the floor already from the amount of 0ower those 300cc injectors and 200% nozzles could make.

 

[superpsd]

Sorry keeping it as is. Like I said the few diesels that have ran a turbo into a blower to compound it found out that it creates a lot of heat. There is a guy who built a turbo feeding blower 4bt and now he is rebuilding the setup with the whipple feeding the turbo. On the gas engine cars the twin charger setups are at lower pressures than seen on a diesel that's why they can get away with it. Try to cram 30-40 psi down a blower and find out how hot it gets and how long the bearings and seals last. It just does not work well and is not effecient. If it was the multiple super turbo diesels would be doing it that way. In the end you will have high eggs, poor thermal effeciency, and possible blower damage. I paid good money for the blower on the truck I rather it last a long life.

 

[Charles]

At the end of the day you make less power than you would have if you'd done nothing but left the induction system stock all while having to listen to that god forsaken racket all the time, while getting poor fuel economy at all times.

A guy with a drop in replacement turbo, or just a wheel upgrade will be miles ahead of you as you still can't move even one CFM more than stock, yet you've incurred additional losses.

Good luck with that. Just figured I'd give it one more go.

Supercharger guys always seem to produce the same results. Nothing....