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(non-Ebay) Electric Turbocharger (Supercharger?)

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Found this 48V Li-ion battery:
http://www.lithiumion-batteries.com...m-batteries/48v-100ah-lithium-ion-battery.php
They say it can provide up to 400A continuous or 1000A burst. While it is not cheap (about $5000) it is not that heavy at 120 lbs and can be charged quickly at up to 400A. Would be a good investment for a serious racer. That site does have smaller batteries as well. A stack of two 24V 500 CCA batteries might be enough. It would be cheaper (about $3000 for both) and will weight only 60 lbs.
 
Found this 48V Li-ion battery:
http://www.lithiumion-batteries.com...m-batteries/48v-100ah-lithium-ion-battery.php
They say it can provide up to 400A continuous or 1000A burst. While it is not cheap (about $5000) it is not that heavy at 120 lbs and can be charged quickly at up to 400A. Would be a good investment for a serious racer. That site does have smaller batteries as well. A stack of two 24V 500 CCA batteries might be enough. It would be cheaper (about $3000 for both) and will weight only 60 lbs.

Well I do have good news regarding that. I'm working with a lithium Ion manufacturer to create lithium Ion battery pack that's about 20lbs or so using 156 Samsung 25R's (Ones found in vapes). Each battery pack comes with a BMS and will be $799.

Battery pack specs are 48V and 30AH which would be good for about 37 16 second track pulls or if you're looking to go hardcore.. a full 10 minutes of straight WOT.
 
That's good news! What is the longest that turbo could run continuously before the battery overheats though, in other words what would be it's duty cycle? From using a Li-ion powered drill i noticed that battery overheating as well as speed controller overheating are major issues, especially if it's hot outside already.
And since this turbo is not connected to the exhaust an is not getting all that heat would it be possible to make it's housing out of something more light weight than aluminum? Or even make the wheel out of composites like carbon fiber or kevlar (to make it spool just a little bit faster), or is heat from air being compressed still too much for it?
 
That's good news! What is the longest that turbo could run continuously before the battery overheats though, in other words what would be it's duty cycle?

Glad you asked. We're looking at an estimated of 7 - 10 minutes of continuous use (Think driving at WOT for 7 minutes) or more simply 26 ~ 37 16 second track pulls. Also, you can run the electric turbo at a maximum of 40 Seconds straight before needing about 5 ~ 10 minutes to cool off.

From using a Li-ion powered drill i noticed that battery overheating as well as speed controller overheating are major issues, especially if it's hot outside already.

This will need to be tested but the BMS on the battery should also have a temperature setting to make sure we don't overheat the batteries. Still more to learn on this.

And since this turbo is not connected to the exhaust an is not getting all that heat would it be possible to make it's housing out of something more light weight than aluminum? Or even make the wheel out of composites like carbon fiber or kevlar (to make it spool just a little bit faster), or is heat from air being compressed still too much for it?

I looked in to Carbon Fiber wheels and found an article somewhere (can't find it now) on a physics forums that it wouldn't work for compression. Wouldn't mind trying other metals though.. Still need to measure outlet temps but based on my testing; tremendous heat only occurs during surge but not the actual compression.. but once again, more testing is needed.

I would be 100% open to a custom compressor wheel with lighter metals.. I think that's doable. I'll ask my CNC friend to see if this is something he can do.
 
Any idea how much torque a 'typical' turbocharger turbine makes? Since you might be getting wheels machined maybe you should look into different wheel geometry since it seems like the electric motor's torque is higher that that of the turbine, while RPM is somewhat lower. If that is true then this turbo would benefit from a different design. If you take a wheel of a large slower turning turbocharger and shrink it to fit this one that should do the trick since that large turbo would already be designed for lower RPM and higher torque (of the turbine). Gotta say though, i am not that familiar with turbo chargers, so hopefully you'll get to talk to an expert before trying any of this.

Don't forget to put a 'battery overheat' light somewhere just so the driver won't get confused if the system suddenly shuts down during a time trial race for example. On second thought if that does happen then voltmeter would show a 0 and that should be enough of an indication.
 
I forget which Dodge Ram I seen putting out high voltage with a grounded field circuit. Should be less weight then adding a secondary battery system if you are still looking into a secondary alternator.
 
Will do!

Check out my first crack at how I envision the turbo ecu Tuner app to look like..

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What do you all think?

Very very interesting thread.

Sub'd.

What program is this that you are using to talk to the arduino?
 
Greetings! I've been busy and I was finally able to take the car to the Dyno and let it rip :)

In the lower RPM range, I made 10ish PSI but as it increased it evened out to 5 PSI. Not a bad starting point and the fact that I made 61more WHP than stock proves that I'm on to something. I honestly think that I can break 8 PSI once I get a well balanced electrical motor shaft/wheel. As you can hear in the video; there is a violent tap which I suspect is robbing the system of some potential power.

That being said; I'm working on a wheel design specifically made for electrical applications. Should be around the ball park of what 91-GS was saying and I should see some promising results from that.

We're on the right track guys! Still not at the finish line but we are slowly getting there :)

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I just got onto Facebook (but still don't have my own account there) and noticed all the problems you're having. I'm sure this is a balance problem. Your compressor wheel is probably just single plane balanced. I don't know what the electric motor company does about balancing. You should look into having the entire assembly, compressor and motor, VSR (vibration rate sorting) balanced. Not all turbo rebuilders have VSR machines as they are very expensive, so you may have to do some searching. Most turbos today have the entire CHRA VSR balanced. VSR balanced turbos can usually be identified by slight grinding on the compressor NUT.

Having the compressor "overhung" past the 2 bearings in the motor, as opposed to having a bearing in front of the compressor wheel, can amplify any unbalance. This can lead to slight whipping/bending of the motor shaft. You might want to consider having a high quality ball bearing installed in your adapter/backing plate, right behind the compressor wheel. Maybe even 2 bearings, one on each side of the adapter/backing plate.

I like your idea of "cooling fins" on your backing plate but I would consider having them machined in the form of one piece wheel spokes, tapering from full width at the hub to very little at the outer edge. This will reinforce the backing plate to prevent any bending.

Good luck!!

Jim

.
 
I just got onto Facebook (but still don't have my own account there) and noticed all the problems you're having. I'm sure this is a balance problem. Your compressor wheel is probably just single plane balanced. I don't know what the electric motor company does about balancing. You should look into having the entire assembly, compressor and motor, VSR (vibration rate sorting) balanced. Not all turbo rebuilders have VSR machines as they are very expensive, so you may have to do some searching. Most turbos today have the entire CHRA VSR balanced. VSR balanced turbos can usually be identified by slight grinding on the compressor NUT.

You are 100% correct; it's a balancing problem that we are trying to fix. We are going to add a bearing to the backplate as close to the wheel as possible hoping that will absorb some of that. It makes sense though; one half has bearings the other has a giant 88mm compressor wheel and unbalanced system. It's probably what cause the previous catastrophic failure. At least this go around wasn't as bad and we were able to pull some numbers out of it.

Having the compressor "overhung" past the 2 bearings in the motor, as opposed to having a bearing in front of the compressor wheel, can amplify any unbalance. This can lead to slight whipping/bending of the motor shaft. You might want to consider having a high quality ball bearing installed in your adapter/backing plate, right behind the compressor wheel. Maybe even 2 bearings, one on each side of the adapter/backing plate.

Yep! the motor shaft is now bent by a thousandth of an inch. Probably became much worse after our dyno runs.

I like your idea of "cooling fins" on your backing plate but I would consider having them machined in the form of one piece wheel spokes, tapering from full width at the hub to very little at the outer edge. This will reinforce the backing plate to prevent any bending.

Good luck!!

Jim

.

Thanks! I figured that I wanted the backplate to have some kind of usefulness to it. I'm speaking with the machinist and they are recommending me to have the backplate bolt on directly to the compressor housing which is not a bad idea.

All in all, 61WHP on an untuned engine isn't bad. I'm betting that I could have squeezed 25 ~ 30 more WHP out of it with a tune. The motor without that loss of energy during the vibration could very well get us into the 100WHP range during the initial peak of accelerating.
 
I've seen a system similar to what you're trying to build.
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As a complete turbocharger replacement, it's a bit of a stretch. But you can do low RPM torque fill, where flow rates are lower, with a reasonable amount of power. The calculations posted earlier in this thread are correct concerning the amount of power required to drive a compressor wheel. At higher flow rates, the turbo has spooled and a bypass opens so the electric supercharger can be idled.

For torque fill applications, a small compressor wheel, think T25 or 13g size with a modified geometry and a nice high-efficiency island, can be used to get the most bang for your watt.

That's Audi listed earlier is probably just the first of many vehicles that will have an electric supercharge. Expect to see more as more cars go hybrid, especially once they get 48V and higher systems for other reasons.
 
I'm still around. I completed it and doubled the HP on the honda I was using as a test bed. Videos can be found on YouTube if you search for eturbo.

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I have the Dyno sheet showing pressure and power curve.. will upload it later this evening.

What I learned from the project is that electric turbos work, R&D projects are expensive, people can be jerks even if you have the data to prove them wrong
 
I agree with everything you said you learned... I had never heard about this until today, so its nice to have some closure... I was feeling quite disappointed not knowing how this all hashed out in the end...

Thanks for the response! I wouldn't mind seeing your dyno sheet, but no rush!
 
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