I see all the benefits with this set-up. More torque for around town driving and top end all in 1. If they make something that will support 600whp, I'm in.

 

Seems it is planetary but no gears... The design is some sort of oil / friction arrangement. The compressor shaft has to be driven from the spur elements which seem fixed with the ring spinning with the pulley.

Regarding sizing a compressor; Keep in mind when looking at the compressor maps the effeciency islands are equatable to heat relative to flow. Your peak performance target for the engine needs to be in the highest percentage island; in other words you want to operate the engine in the highest percentage island as much as possible. The less efficient the compressor is utilized (ie running in lower percentage effeciency islands) the more heat relative to given mass air delivery is created. Best to try to establish peak engine torque at the outer upper right edge of the most efficient island; that way the compressor is running at it's highest effeciency all the way up to that point. Also need to stay away in all cases from the surge line on the left of the map; most likely a belt driven compressor will not be as affected by surge but good practice not to even go there as running on the left of the surge line will tear up the compressor.

I usually plot my entire engine curve on a variety of maps to help in selecting the best compressor then size the turbine to fit exhaust flow and compressor HP demand (for a turbo). I created a spreadsheet to calculate P1/P2 vs engine induction flow demand to plot the curve. The second critical factor is heat of compression; this is the primary reason there is not a straight correlation to horsepower with induction air flow as you are trying to establish. The third factor is the parasitic drag from driving the compressor; No doubt the large one will demand close to 100 HP to drive it. There is no free meal...

 

these super charger are rated at an efficiency of 98% so it won't eat up that much power at all, its not like a roots super charger or screw that involves moving heavy internal objects

 

+1

 

Also, HOLY crack pipe on the pics above! Call me crazy, but what the hell would you do with that car. A well built single turbo 20B can make 650whp all day. Even with the benefits of more low end from a crazy setup like that, traction becomes a major issue.

I guess he's doing it to say he can. But WOW, what a setup!! Completed pics & video would be amazing to see.

 

I'm sure you can make a setup to make 600 but what do you really need that much power for ? most of the time you just can't hook up properly.

 

Quick question. Why not use a larger unit that could reach your desired boost level earlier in the powerband...

And control it with a wastegate on the intake after the SC? Or is that what this bypass valve is? I am unfamiliar with supercharger specific details.

I would just think that having peak boost sooner would be a good thing. And having it controlled by a wastegate would work just fine. Just dump the excess filtered air to atmosphere.

(Disclaimer: multiple beers and brain already shot from 10 hours of work and 3 hours of class today.)

 

i'm sure that 20B pictured is capable of over 1000 at the wheels, if it works as well as he thinks it will. hopefully he has the clutch disengage after the turbos begin spooling or it will create drag and cut the gains.

what do you do with a car like that? eat tires, just like the 700+WHP supra guys. there is a point where too much is too much, driving on the street with slicks full time isn't my idea of a fun ride.

 

The highest efficiency island in the map is 80% (which by the way is very good) and that is the efficiency only of the compressor; The drive assembly will be a debit from that. You would probably be looking at around 75% in total. Keep also in mind that the 80% is a measurement in ideal conditions. Just to give you an idea for comparative purposes a Turbonetics T61 compressor requires 30.3 horsepower to drive it at a P1/P2 of 2.8. So in hindsight it is probably less than 100 HP but it is still a significant impact. For entertainment a top fuel hemi blower consumes over 1000 horsepower from the crankshaft to drive it at max Q.

Another consideration for application to the 13b is the limitation of the front E-shaft bearing and the long lever from the bearing to the supercharger drive belt. There will be some rather large forces on that shaft (both torsional and bending). An auxillary outboard bearing may be in order.

 

Hmm I'm curious as to how this supercharger will work in low load conditions? Since the boost pressure increases with rpm, does this mean that it will be making positive manifold pressure while just cruising on the highway? I'm having a hard time picturing how it works.

 

Don't know if this was directed at me but that hp figure is something I wanted to reach for a long time. 20b's get there all day long on pump gas. When I get tired of doing the NA thing. We'll see what happens!

 

Putting a SC on a rotary is like making a beautiful woman wear a full snow suit all the time... Why would you take away the natural benefits that the rotary is giving us?

 

so the you can hump that beautiful women all you want when you want ?
not just a one nighter and shes gone ?

LOL

 

Lets try to keep an open mind here. You know if you never try anything new, we can never advance the R&D when it comes to rotary.

 

I was speaking of the twin turbo supercharged 20B pictured.

NA 20B is also something I HIGHLY considered when I went single turbo. I'll bet your setup sings .

 

I am very open minded and I make a living out of advancing the rotary through R&D. But I also know when I see a waste of time... There is nothing "ground breaking" about SC'n a rotary. I believe it does the same, if not a little worse, than any other SC'd internal combustion engine.

Show me the big "ahh ha!" moment with a SC'd rotary and I'll be right there with you

-J

 

this is quite interesting to me. Seems this supercharger could level the playing field a bit more. We won't know until someone sets one up aaaannnnnnnddddd I already purchased a baby eating holset so yeah not gunna be me at this point.

 

look at my link I just bought one for the rx7

 

Can you explain what "playing field" it will level and how?

 

i am interested in supercharger setup running 17psi

i think it would be more traffic / street friendly ...i have single turbo gt35r now and driving in the street its really annoying.... i cant give it to much gas or i will take off....but if i go slow i am holding up the traffic...

it would be nice to have some more low end

i am also thinking of going 20b n/a but going 13b supercharged would be more cost friendly

so i am not looking for big hp 370 to 400rwhp on e85 is all i need

i would like to see a kit out there

 

I'm sure those number are probably achievable, just need to get the right blower in there and the right pulley. Like I said much research and development will be going into these blower kits but we'll just have to wait and see how things go down the road.