1.8T E-Turbo

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powy

Member
Hey, I'm new here and to E-Turbos. I have a plan i would like to build my own E-Turbo. The car is an Audi TT with a bigger turbo, aftermarket ECU etc... of course with some boost lag, and boost did not come till 3500-4000rpm. It would be nice to get some boost 0.3-0.5bar till 3500rpm from an E-turbo to get really good torque and get the turbo spool earliert. I already have batterie with high C, BMS with around 400A.
I don't need that big Turbo like Alex, because my car is already with turbo :)
 
I'm not sure which motor would be the best for this project, i thought maybe a TP4040CM-2850KV-Open-5F is okay, it can 95k rpm, and 1650/4200W.
 
Hello! Of course i saw all your videos :)
I just checked some compressor maps, a gt35 is doing not much till 50k rpm. I’m thinking about a gt45, it will already make some boost on 20k rpm. I dont really know how much power i need to turn those wheels :)
 
I think you will be better with the 4041-CM and bigger. Has we know, electric motor likes to run to fast to be efficient. I don't think you will be able to achieve 95k rpm with the 4040. Since my turbo and motor is smaller then alex ones, Im able to turn my set up faster but when we look the data im pretty much to the limits of my gear with 60k rpm (still need to confirm the rpm). They claim a max of 75k rpm but it's still far from it.
 
Last year with my old battry set up, I was able to reach 55k ish RPM with 4-5 PSI
Now I peak about 7psi (unkown RPM for now) with my new batterys.
The most important thing is to go with a good batterys set up and a good ESC. We saw that MGM ESC is the way to go (user friendly) and for the battery, the pouch cells is verry impresive but we can't really compare to the lishen LTO cells of alex. I personnaly think the A123 pouch cells is the way to go. The ESC will depend of the motor and compressor
 
Hey! I have some a123 cells from a different project, they can 120A each cell :)
I think you are right, i cant reach 96k rpm, but a gt45 compressor wheel is already efficient at 30k rpm, of course it will be need more power to turn as well.
 
i have already some of these battery cells at home for 15s1p and those are really impressive, if i build this i just by 15 more of them, i didnt need that much capacity-> https://lithiumwerks.com/products/lithium-ion-26650-cells/
50k rpm with a gt35 is reaal good :) altough this rpm on a gt45 is something different :) buuut there we need more power for the motor.
i dont want to full boost my engine with this e turbo just help a little :)
 
I really don't need that much capacity. The real reason is the voltage drop. I had some LTO at first with way less capacity. Capacity that I really need. But I also had a huge voltage drop and it's a real problem
 
powy - you bring up a good point about compressor maps, but WB's results are hard to argue with. In theory, a gt35 at 45,000 rpm would likely support 200 hp at just under 4 psi. My understanding is stock boost on a TT is around 7-9 psi. But you won't need much just to fill in your turbo lag area. A few things that I've learned the hard way that might be useful to you:

- you'll likely never see a motor's peak rpm under load

- battery "C" rating is one thing; as WB mentioned, it's voltage drop under load that counts. I happen to have 180 of those A123 cells you're talking about (I bought them on a whim - they were cheap). They should be fine for a smaller unit, but I haven't done load/voltage drop test. You may need a few in parallel in the long run. Not a big deal, just be aware of that.

- If you need to run long motor cables to install in your car, a sensored motor is your friend. I have a sensored Castle Creations sitting here that I intend to test against the TP Power motors I have. The TP power motors are quite good, but they have two issues: no sensors, and 6 poles (which means an ESC has to work harder at high rpm; but theoretically, they should have more torque)

In any case, WB has been giving you great input. Your goals are pretty modest, and you should be able to achieve them pretty easily. We're here to help! Just be careful - this stuff can be dangerous.
 
WB, okay so you built that big battery because of voltage drop. i'm thinking now about 16cell of my battery 8S2P which has 28,8 Volt and can 240A burst for 10sec, i have already turbo so it don't need it to run long. What if i use some supercapacitors? they can hold the voltage pretty long without drop.
I'm thinking about this Motor-> TP4060CM-2080KV-Open-5F
KV: 2080 KV
Max Amps (A): 189 A
Max Volt (V): 8s Lipo
Dauerleistung (W): 3500 W
Max. Leistung (W): 7000 W
Max. RPM: 78K
I don't really know why is a sensored motor better? This motor is just 4 poles.

Yes i thought about that i will never reach the max rpm under load, that's why i'm not sure is a gt35-gt40-gt45 would be a better choice,
You said in one of your video that the power need with the rpm goes extremly up.

AlexLTDLX i don't want to argue, you guys have a working e turbo i have nothing just plans :)
I just want to build/buy once thats why i thinking about the bigger Compressor wheel.
I'm running now on 24psi boost from around 3800-7400rpm, so i just need to get on boost with some extra air down low.
I attached a log from my engine with actual airmass and boost, rpm.
 

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It's okay, don't worry! You can argue on some thing if you want! If I listen every body here whitout arguing, my set would have be verry different haha! Yes we have worcking set up but we don't know everything 🤘 can't wait to see an other worcking set up and learn new things 😁
 
Haha okay :)
I think with a 4060cm which is stronger then the 4041, should be enough to turn a gt45 at 30k rpm right?
i read about sensored motors, they should be good for torque down low from rpm from 0-. And many esc switch for high rpm to sensorless mode because its better and stronger.
I would like to build this really small batterie near the turbo behind front bumper-> short thick cables should be less voltage drop as well :)
 
I think the 4060-cm is new from this year! At the time it doesnt exist! It's a really good bet to start with I think!
 
No arguing here - just discussion and opinions. We're all breaking new ground. I might discover that the superchargers aren't the way to go. Who knows. As for why the sensored motor is advantageous - it helps on start up. If you have long motor cables (which most of us will, to varying degrees), the ESC has to guess where the rotor is, so it pulses the phase coils until is gets a readable back EMF signal. Long cables make that tricky, and start up is harsh. If you can keep all the cables short, it won't make too much practical difference. WB's setup uses fairly short cables, but any longer and I do believe he'd start running into issues. You can, of course, put the ESC by the motor, but then you have to keep an eye out for current spikes which can destroy the ESC - capacitor banks help, but then everything starts getting bigger.

Frankly, so far I'm impressed with MGM ESCs the most; though I wouldn't hesitate to try APD again. VESC is still a bit of an unknown - and definitely needs a sensored motor, since it's very finicky (but also has the most control and realtime data is comprehensive). I'll get back around to that fairly soon (this summer, I hope).

The way you describe your setup, you'll probably be fine without a sensored motor; but if you decide to move things around later, you might have issues. One thing I can tell you for sure won't work would be supercapacitors - they have a linear voltage discharge curve (as well as very low power density). They're great for an instantaneous burst, but the voltage drops right away, and keeps dropping. Where as lithium batteries don't do that - they hold pretty steady.

Your setup is definitely closer to WBs than mine - I'd follow his lead. Have you considered the Castle 4 pole motor? It's actually cheaper than the TP Power motors, and sensored (whether you use the sensors or not). And I will say, it's better built. FWIW, I now have two TP Power motors and the Castle motor. The Castle motor probably isn't as powerful as the bigger TP Power motor, but it's a little smaller (about 2mm smaller in diameter, and about 10mm shorter). Until I actually do some tests, though, we won't know for sure. The guy at Castle told me he's pushed 20kW through this thing. That's more than the bigger TP Power motor, if I can reproduce that.
 
When you said the ESC send pulses to read EMF signal is interesting! That may be the weird sound of pulsation we ear on my set-up! I will see your reasult with the castle motor and maybe I will go with them too!
 
I read today soo much about VESC, that is some really intresting thing, i found already one which can run that firmware.->https://flipsky.net/collections/ele...e-foil-fighting-robot-surfboard-agv-robot-arm
it is freely programmable, can more voltage like i need ( maybe later it is fine).
what do you guys think about this esc? i found mgm controllers to expensive, and this one should be strong enough.

Thank you for that info about supercapacitors :), i just leave them and if i need just buy more lifepo4 cells.

about the motors, i'm not sure which castle motor do you think? why there isnt any info about castle motor how much power and amp do they pull? just from the weight and kv rate this should be around the same
CASTLE 1717 1Y SENSORED MOTOR - 1650KV ,but here in austria it will be cost 270dollars, because just the shipping is already 70, im not sure about tax.
TP4060CM-2080KV-Open-5F this tp power motor is just 146euro :)

VESC should be work fine without sensors as well, i already downloaded the app just to check how its working :)
 
MGM controller is user friendly and they just work out of the box. The VESC look sooo much tricky. Alex can relate. He's the one who can help you with it. Don't try to go with chinese ESC, this is a waiste of money.
I think if you go with a VESC, you should go with a sensor motor to use all the potentiel of the VESC
If you get an ESC, sensor or sensor less motor will be fine for your set up
 
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