Super myth

How hard (and expensive) is it to mess with the drive hub size after its all setup? Say if I wanted a little more or less pressure before the turbos kick in.
 
You can swap pulleys at will. Very easy, 5 mins. We use an adjustable idler location so one belt length can be used for a wide range of pulleys.
 
The super definitely made for better response down low on my manual trans truck. Sure they use a little power to turn but I gladly gave that trade up. The effeciency of the newer roots and screws is greatly improved over the older generations. Here is also an example of technology the Eaton roots 5th generation series VS the newer TVS line of blowers...
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Any supercharger than employs internal compression is still going to be considerably parasitic even when it's bypassed. If its only external compression the parasitic loss will be a tiny fraction. Without question though a small amount will be there.
 
heres an excerpt from an article about the charger:
"Ford claims its new Mustang GT will have roughly 420 horsepower on tap, meaning Whipple’s upgrade adds 280 horses to the tally. But it's not all about peak power as Whipple says the supercharger has a “discharge down” design that gives more power at lower boost levels and a relatively flat torque curve. The setup is also said to be quite efficient, as it consumes less than a horsepower during cruising."

http://www.motorauthority.com/news/1091138_2015-ford-mustang-gets-700-hp-supercharger-kit-from-whipple
 
Likely loaded marketing. At cruise they likely have it perfectly sized to add some VE to the NA engine that nets an almost zero net loss.

There is no question a supercharger with internal compression will waste power even with its output is a net zero PSI.
 
The point your arguing is pointless...........Its simply NOT possible to turn anything and not use HP to do it, UNLESS it was in a vacuum state....MAYBE. I think thats what joesixpack is getting at anyway.
 
I'm in no way stating it doesnt use some power to spin, I AM saying its not much, certainly no where near what some people seem to think.
 
I'm a bit lazy to expand on what my thoughts are in regards to VE so did a quick key word search and grabbed something of the net that was already in print.....

"Interestingly enough, where a supercharger might reveal a power advantage over a turbo is in low-boost, street-type applications. This is because a street supercharger, despite its 10-20hp drag on the crankshaft, doesn't have the backpressure-inducing turbine that a turbocharger has in the exhaust stream. Street-type turbo systems typically have smaller compressor wheels and smaller exhaust housings in hopes of lessening lag and quickening spool up. Small turbines and housings induce a lot of backpressure, typically one and a half to two times the boost pressure. As a result, because of its much lower exhaust backpressure, a supercharger can yield better volumetric efficiency and a greater power potential than a small, quick-spooling, low-boost turbocharger. The turbocharger's big advantages of superior compressor adiabatic efficiency and waste energy usage usually do not come into play until larger, less-restrictive turbine turbochargers are fitted and higher boost levels (8 psi and up) are realized.

Read more: http://www.superstreetonline.com/how-to/engine/0802-turp-supercharger-tech/#ixzz3Ixk1WUeu


The other thing that comes to mind and why I brought up internal compression is while being the most efficient under normal use and lower boost that design is almost the worst to just bypass as the internal compression will be wasting power and making heat for no advantage. Even an old roots blower would freewheel consuming less power.

What a guy can't argue is the huge power advantage under the curve with the supercharger and should really be the selling point. No question what would be more fun on the street unless your one of those guys that likes LAG LAG LAG then the big hit like some big single guys do.

Max power combinations are kinda unproven, I've yet to see huge power with a super/turbo combo. Ponci must have the biggest setup that I've seen and its hard to say where it will end up with the limited time on it this season but it sure spools awesome.
 
Joesixpack said:
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The other thing that comes to mind and why I brought up internal compression is while being the most efficient under normal use and lower boost that design is almost the worst to just bypass as the internal compression will be wasting power and making heat for no advantage. Even an old roots blower would freewheel consuming less power.

What a guy can't argue is the huge power advantage under the curve with the supercharger and should really be the selling point. No question what would be more fun on the street unless your one of those guys that likes LAG LAG LAG then the big hit like some big single guys do.

Max power combinations are kinda unproven, I've yet to see huge power with a super/turbo combo. Ponci must have the biggest setup that I've seen and its hard to say where it will end up with the limited time on it this season but it sure spools awesome.
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Old roots dont freewheel, they have drag from the rotor seals.
I honestly dont care if it takes 5-10hp more from peak numbers since the curve is that much fatter.
It makes the truck a joy to drive, if I REALLY need uber peak dyno #s, I can always just swap to a stock belt and not turn the SC at all. Simple.

Ponci's truck may change the sport if he decides to use the tree to his advantage. Wade got booed bad by doing this @ island years ago, but the strategy is sound. The current crop of 9 sec trucks takes 20-30 secs to spool up @ the line. The tree only has a 10 sec bulb delay before red light. A stock prius could beat every 9 sec diesel If they used this advantage. It will force the others to start spooling before they get to the lights to try to compensate and many will make mistakes doing so.$.02
 
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TURBOLVR said:
Ponci's truck may change the sport if he decides to use the tree to his advantage. Wade got booed bad by doing this @ island years ago, but the strategy is sound. The current crop of 9 sec trucks takes 20-30 secs to spool up @ the line. The tree only has a 10 sec bulb delay before red light. A stock prius could beat every 9 sec diesel If they used this advantage. It will force the others to start spooling before they get to the lights to try to compensate and many will make mistakes doing so.$.02
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Have seen the drive by wire guys race in prostreet? Everyone I saw the last time out had no issue with the 7 second staging timeout. Not that I think the SC/turbo is a bad combo, just there are other ways around the assumed handicap.
 
Roll into first bulb at 20psi. Roll into second bulb and hit trans brake and go to 60psi+ as fast as a gasser (or damn close). There is sooooo much more on the table that hasn't been tapped. Were still not even close to max shaft speed of the procharger yet. Chassis first power last. Yes I can screw somebody at the tree if I want but that's just not me. Unless there a dick! Then its on.....lol
[ame="http://www.youtube.com/watch?v=DXdp39drsbU"]http://www.youtube.com/watch?v=DXdp39drsbU[/ame]
 
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TURBOLVR said:
Old roots dont freewheel, they have drag from the rotor seals.
I honestly dont care if it takes 5-10hp more from peak numbers since the curve is that much fatter.
It makes the truck a joy to drive, if I REALLY need uber peak dyno #s, I can always just swap to a stock belt and not turn the SC at all. Simple.

Ponci's truck may change the sport if he decides to use the tree to his advantage. Wade got booed bad by doing this @ island years ago, but the strategy is sound. The current crop of 9 sec trucks takes 20-30 secs to spool up @ the line. The tree only has a 10 sec bulb delay before red light. A stock prius could beat every 9 sec diesel If they used this advantage. It will force the others to start spooling before they get to the lights to try to compensate and many will make mistakes doing so.$.02
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Kinda showing my age but back in the day the old roots blower's never had seals and it was just tight clearance.

What I'm still getting at is a supercharger utilizing internal compression still wastes energy in a bypassed state.
Now say on a factory installed car with a throttle plate in a partial vacuum condition a lot of that loss would disappear. However void of that throttling and just open to atmosphere work would still be done by internal compression and expansion along with heat. Mostly a SWAG but sure does seem to reflect in the dyno data you provided and pretty sure could dig up some support on the interbrain if was motivated.

30hp at 500 might seem more trivial 90hp or better at 1500 is getting gross when a guy starts thinking about auctioning off his mama for 10HP.

Any ways, always find it interesting and have always kicked the idea around of fooling with a SC.
 
Joesixpack said:
30hp at 500 might seem more trivial 90hp or better at 1500 is getting gross when a guy starts thinking about auctioning off his mama for 10HP.

Any ways, always find it interesting and have always kicked the idea around of fooling with a SC.
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The net loss doesnt increase as HP does, it stays the same. The SC doesnt increase hp usage unless the rpm or pressure increases as well. So, it would be the same 30hp @ 500, 1000, or 1500whp.
 
Nice job Brad, really looking forward to seeing that thing run full tilt consistently!
 
joefarmer said:
Have seen the drive by wire guys race in prostreet? Everyone I saw the last time out had no issue with the 7 second staging timeout. Not that I think the SC/turbo is a bad combo, just there are other ways around the assumed handicap.
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For a street driven vehicle, 7 seconds is a lifetime:lolly:
 
TURBOLVR said:
The net loss doesnt increase as HP does, it stays the same. The SC doesnt increase hp usage unless the rpm or pressure increases as well. So, it would be the same 30hp @ 500, 1000, or 1500whp.
Click to expand...

Parasitic loss as how I'm describing it in a supercharger that is using internal compression will go up with rpm and supercharger displacement in an unloaded state. Loaded will be a function of efficiency.
 
You guys can feel free to call this a stupid idea, but you know what I think would be friggin sweet?
Positive displacement turbocharger.

Picture roots style positive displacement blower, with a similar positive displacement pump on the exhaust to drive it, not a turbocharger turbine, but positive displacement pump to drive the blower.

Would that not be the absolute cats a$$ ?
 
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