Open Source Electric Supercharger

[al3k]

Originally Posted by Matt@Cosworth

Only trouble there is you will definitely need a bypass to avoid it being a restriction at high engine speeds
I'm assuming the x axis is in kg/sec? as even a stock FA20 is about 160g/sec flat out

I prefer the look of the previous TD04 map as I need 220 g/sec or 29 lbs/min air flow at full revs

and its looks like the OEM's have finally brought something to market too

looks like the 1st one out of the gate is Audi
as the latest TDi Q7 uses an electric charger to provide low end boost on top of the turbos

https://jalopnik.com/this-is-how-audis- ... 1823681637

just need to find a crashed SQ7 and strip it mercilessly of the interesting stuff - hopefully the breakers won't cotton on too quick to this one

You missed post #765!

Yup you will need something different for the whole powerband and its difficult doing this with motors currently easily availble, I think you need around 13kw elmotor to do this while still having enough speed on the motor, not very practial to make this.
But having low end response will still be very fun for a street car.
The more I research about this the lower my expectations get, having around 7.5psi to max 3000rpm should be doable with direct drive 5-6kwmotor and easy to access hardware, anything pass that will be very hard to acheive if Im not totally messed up.
For my useage I found the T04E maps to probably have highest succeed rate as its possible to get some good low end flow without going over 55k-65k el-motor rpm

[al3k]

if you found a strong enough motor the T04E 57trim could probably work for you.
These are my candidates now.
The green line is a estimate if the el-motor speed is constant im not really expecting to go any further than the dot tho, but it will need to be physically tested I guess.
As pointet out earlier by the owner of the thread the Td06 will need custom made backplate as its a permanent part of the chra, these T04e turboes you can unmount the backplate from chra and if needed machine the spot where the motor will be connected so it should be easier to make

[pcguru2000]

Originally Posted by Matt@Cosworth

trouble is you need to make a gearbox / belt / chain drive that's happy with 75K + shaft speeds
this is not easy

direct drive is right route

If it's a direct drive, it would interface like a supercharger with a drive belt. Not sure what the limits are for those drive belts. But adding 50 horsepower 746watts/1 HP
50HP=37300 watts.
Split that up into 4 batteries would be about 10000 watts per 12v battery or supercapacitor. 833 cranking amps per battery. All we would need is about 5 second max burst. If you used deep cycle lead acid batteries...this would add about 160lbs to the trunk which would probably balance the car 50/50. LOL

Just some rough numbers and thought.

Or in hub motors for the back wheels, and shorter runs of the wiring.

[Matt@Cosworth]

I can't fault your logic but centrifugal compressors don't take 50bhp to turn

if you take a look at the audi device on the link I posted a while back you'll see its a direct drive
and yes with where electric motors are at present I think these will only ever be a low boost / low end torque booster device

however on a low torque engine like FA20 / 13B renesis then this is exactly whats needed - providing the price point is right

[pcguru2000]

Originally Posted by Matt@Cosworth

I can't fault your logic but centrifugal compressors don't take 50bhp to turn

if you take a look at the audi device on the link I posted a while back you'll see its a direct drive
and yes with where electric motors are at present I think these will only ever be a low boost / low end torque booster device

however on a low torque engine like FA20 / 13B renesis then this is exactly whats needed - providing the price point is right

I was talking about driving the engine itself, not a compressor. Adding 50HP from 1000RPM to 7200RPM would have great benefits.

[Matt@Cosworth]

yes but then you need a much more powerful motor akin to a KERS drive and much higher voltages something like a YUASA motor with a 400V bus, inverter and all the associated high power electronics and cooling etc etc

[al3k]

I made a list of some of the most high performance inline rc motors I could find so its easier to compare, and just came across alien power system which have a lot of interesting motors they also state on their site "can supply different motors, with custom power and KV.".

MODEL KV VOLT KW RPM SHAFT (random order):
-TP 4070-CM 3200 23.5v 5-9kw 75200rpm 5mm
-TP 5650 2060kv 26v 4.6-8.4kw (MAX 323A) 53560rpm 8mm
-TP 5650 1148kv 48v 4.6-8.4kw 55104rpm 8mm
-Alien power system 3650 3840kv 15v 2.35-4.5kw (MAX AMP: 400A) 57600rpm 5mm
-Alien power system 4070 2250kv 22v 3.85-7.6kw (MAX AMP: 320A) claim 70000rpm? 8mm
-Alien power system 4070 sensored 1440kv 40v 3.85-7.6kw 57600rpm 8mm
-Alien power system 56114 1000kv 45v 12kw 45000rpm 10mm
-Alien power system 5860 1000KV 50v 7.2-15kw 50000rpm 8mm
-Hobbyking X-Car 4976 1740KV 44.4v 6kw 77256rpm 8mm
-Turnigy AquaStar T20 3T 730KV/1280KV 41v 5.3kw 52480rpm 8mm
-INFINITE 1/5 1.5T 1320KV 37.5v 4.12kw 49500rpm 5mm
-Hobbywing XERUN-4268SD 2200kv 22.2v kw? 48840rpm 5mm
-Leopard LBP5682/2Y-1360KV 29.6v 4.5kw 40256rpm 6mm
-Leopard LBP5692/3D-1340KV 29v 5.5kw 38860rpm 6mm
-Leopard 58113 V2 1050KV 37v 8kw 38850rpm 8mm
-Razer X5.2 5,5TY 810KV 46v 5kw 37260rpm 8mm
-Leopard LBP5692/4D-1000KV 37v 5.5kw 37000rpm 6mm
-Castle 2028 Extreme 800Kv 44.4v 5-6kw? 35520rpm 8mm
-SkyRC Proteus X524 2Y 1580kv 19V 6.3kw 30000rpm 8mm

[al3k]

Heres what I think is the minium requirement for a motor to make a "practical" EBC system (2.0l engine):
22v
45000rpm (lower may work but need some margins as I guess we wont see those numbers under load)
3.5kw


Alien power system 4070 sensored 1440kv 40v 3.85-7.6kw 57600rpm 8mm (They use TPpower motors?)
This motor seems very interesting its also sensored which can be a huge plus, and a solid motor rpm range.
I was hoping to see more higher rpm engines but they have too low kw and the ones I found which claim 70k++ rpm seems to be very questionable

[neutron256]

al3k, since your only looking at this as an anti lag system have you considered using ultra capacitors rather than batteries to power it? Since you’re only going to be using it for a fraction of a second while the conventional turbo spoils up you wouldn’t need much battery capacity, and ultracapacitors provide virtually unlimited current and recharge much faster and have a longer charge/discharge cycle life.

[al3k]

Originally Posted by neutron256

al3k, since your only looking at this as an anti lag system have you considered using ultra capacitors rather than batteries to power it? Since you’re only going to be using it for a fraction of a second while the conventional turbo spoils up you wouldn’t need much battery capacity, and ultracapacitors provide virtually unlimited current and recharge much faster and have a longer charge/discharge cycle life.

Thats a very good point! I will need to look into that for sure.
I also just discovered that since I have the ESC in series after the main turbo and all the air that the ESC gets on inlet is taken from the main turbos outlet (after the FMIC), so this is actually a twincharge system so there will be a compound effect happening.
This will reduce the boost requirement for ESC, since the total boost is Pr X Pr (Pressure ratio).

Wikipidia Twincharging series:
"series configurations exist where no bypass system is employed and both compressors are in continuous duty. As a result, compounded boost is always produced as the pressure ratios of the two compressors are multiplied, not added. In other words, if a turbocharger which produced 10 psi (0.7 bar) (pressure ratio = 1.7) alone blew into a supercharger which also produced 10 psi alone, the resultant manifold pressure would be 27 psi (1.9 bar) (PR=2.8) rather than 20 psi (1.4 bar) (PR=2.3). This form of series twincharging allows for the production of boost pressures that would otherwise be unachievable with other compressor arrangements and would be inefficient."

This is with my current setup (turbo only), 2nd gear pull:
2000rpm 1psi
2500rpm 4psi
3000rpm 8.5psi
3500rpm 16.6psi

So if I make for example constant 5psi on the ESC result would be:
2000rpm 6psi
2500rpm 10psi
3000rpm 16psi
3500rpm 26.5psi

I also found a chart with precalculated final boost numbers for twincharge series setup:

[Matt@Cosworth]

are you planning to run the ESC before or after the intercooler?

also how about running a combination of ultra caps and a battery?

[al3k]

Originally Posted by Matt@Cosworth

are you planning to run the ESC before or after the intercooler?

also how about running a combination of ultra caps and a battery?

The easiest solution is to have it after, cause space and heat is a problem.
Im runing the turbo top mounted and also have T4 twinscroll housing with a quick spool valve (sequential turbine scrolls) and it just barely fits.
(Edit: I removed images, not relevant to the thread topic.)

The caps seems to be a good solution for a buffer for the battery, but it depends on the voltage reguired by the el-motor if its a 30v++ system you need a lot of caps and batteries, space and safety must be considered.
The supercapacitors seems to drop linear in voltage as amps is discharged, so this is not good for the elmotor speed controller but I guess if its parallell to car batteries the dropoff will stop, until the battery gets the load and it will probably drop a tiny bit more with high loads.
Ive seen youtube video where a guy started a car multiple times with normal size battery sized boostcap unit, no batteries and he shut the car off immediatly so it wasnt recharged much so they lasted much longer than I thought, really awesome stuff! Ive never heard about this supercapacitors before today, so it blowed my mind how the performes compared to normal capacitors.

[al3k]

I have ordered a T04E turbo, 50.5mm inducer / 76.0mm exducer (44trim) as a starting point.
The plan is to have a 70 000rpm motor 4kw (7kw peak performance) with a custom made axle (no couplers). This is with a 30v system which is max for that spesific motor, I might only need 24v system to achive the goal.
Made a mockup in photoshop, also tried to match the scale.
I will make a more correct sketch once the turbo arrives so I can do better measurements, also need to look into the sealing under the comp wheel.

[Matt@Cosworth]

Looks good

any idea of the shaft power needed for your compressor?