Open Source Electric Supercharger

[churchx]

belt driven may solve battery drainage when constantly using it, but with added complexity it still won't be as simple, almost drop-in, mod as "normal ESC". As for spinning speed and blowing power, from Audi's ESC implementation youtube vid, it seemed to me beneficial to have higher voltage electric motor in blower to handle more amps, thus probably changed controller circuitry to use several batteries in serial to up voltage, no? And wasn't already Phantom ESC 24V vs car's 12V electric sys?
In my eyes "ideal" ESC set would be something like Phantom ESC+Procede throttle controller+overpipe/frontpipe/whatever alike "drop-in" bolton exhaust part with integrated turbo electric generator. Phantom+Procede as proven working set simple to install/maintain, +that turbo to add extra charge in batteries for if used always on and on track, for some energy recuperation, instead of putting all load of recharging on main generator.

[neutron256]

Churchx

I get what you’re saying about the added complexity of a belt driven system. I only mentioned what Rotrex is doing as an example of what professionals are working on in the area. Rotrex traction drive super chargers are particularly well suited for electric and I even considered adapting one of their regular super chargers. The simple self contained units could be fairly easily adapted to be driven by an electric motor rather than directly off the car’s engine.

As for voltage it’s tricky, since the electric motor max RPMs will relate directly to the system voltage yes higher voltage will lead to higher RPMs but the RPMs needed are really pushing what current brushless motor technology can do. Smaller motors can put out the RPMs needed but not the power and the opposite is true for larger motors.

The biggest issue as I see it is most people interested in this are looking fo a relatively cheap alternative to a convention Turbo or Supercharger. It’s just not likely to happen, Phantom was able to do this because he was running it as more of a hobby then a real business from what I understand. Once it started to be more of a real business and demand increased it just didn’t work out and I suspect he also lost interest. I know I would have. I like to tinker not run a business.

[churchx]

I don't see as relatively cheap alternative. I see it as alternative with some cons (need to rework electrical power for high enough boost, as standard 12V and with standard generator might not be upto job for constantly on ESC, only in phantom ESC fashion), and several pros - one can full boost right away even from idle rpms, due electric nature one has much more freedom/flexibility in controling it, unlike "normal" SCs due no mechanical linkage to engine it's much easier to retrofit electric SC to car, as it's placement does not needs to take into account from where/how guide belt at it, and if it's enhanced with turbo electric generator, it can enhance efficiency too due energy recuperation like turbo, but unlike turbo again it's easier to retrofit, as that turbo generator is not linked with SC part mechanically, so it can be anywhere on exhaust, not somewhere close to SC, so no need to design new exhaust piping to route wherever mount place for it is found (if any). From mount point one can simply guide back wires to ESC controller/it's battery pack. Due no mechanical linkage of turbo<>SC, no need to design blowoff valve and so on too, and there will never be any turbo-lag, as SC can go at full rpms even when turbo generator spools slowly.

[Matt@Cosworth]

The big thing for me is the ease of installation, and relative lack of modification to to get boost onto any car
I agree that these systems are never going to be a hefty gain but I think they can certainly be a worthwhile mod

[ecologymagnet]

Hello,

I am interested in this type of turbos.

What size of motor and turbo are you using and Phantom?

Thank you very much.

[neutron256]

I’m not sure what motor the phantom system used although if I recall correctly he was having them made to custom specs

I was using a larger more powerful (but slower) motor tied to a much larger compressor allowing for much lower motor speed.

Here are the specs. All of this information and more is in the thread if you have the time to weigh through it.
2350KV
19V Max
126A Max
2400W

[ecologymagnet]

Originally Posted by neutron256

I’m not sure what motor the phantom system used although if I recall correctly he was having them made to custom specs

I was using a larger more powerful (but slower) motor tied to a much larger compressor allowing for much lower motor speed.

Here are the specs. All of this information and more is in the thread if you have the time to weigh through it.
2350KV
19V Max
126A Max
2400W

I chose an engine with the same specifications, a Neu Castle, ¿size 3660 mm?

What size of turbo engine do you use?

I'm trying to make an electric turbo to my NB2 1.6

Thank you very much for your work.

[neutron256]

This system I was developing was for the FRS/BRZ/GT86 platform (as being on this forum would suggest). It’s 2.0L 200 HP engine.

The biggest limitation of an electric supercharger is the volume/mass of air it can deliver. Because of this the smaller the engine it’s connected to the better it should work.

[al3k]

Is it possible to buy a working prototype somewhere? Mostly interested in a working compressor housing with a motor adapted to it, I can figure out battery and esc.
I have a 2.0l with upgraded bigger turbo and I think this would be very usefull to combat the lag in the system, it would only need to run while engine is less than 3000rpm under wot condition.
The new Audi SQ7 does this stuff too (using electric supercharger to precharge the turbocharger).
Audi uses bypass valves to isolate/bypass the electric compressor when not used but I think you could use a electric turbocharger in series with a conventional turbo even tho it would cause some restriction in the high revs but not sure.

[neutron256]

Originally Posted by al3k

Is it possible to buy a working prototype somewhere? Mostly interested in a working compressor housing with a motor adapted to it, I can figure out battery and esc.
I have a 2.0l with upgraded bigger turbo and I think this would be very usefull to combat the lag in the system, it would only need to run while engine is less than 3000rpm under wot condition.
The new Audi SQ7 does this stuff too (using electric supercharger to precharge the turbocharger).
Audi uses bypass valves to isolate/bypass the electric compressor when not used but I think you could use a electric turbocharger in series with a conventional turbo even tho it would cause some restriction in the high revs but not sure.

As far as I know there is no source to buy a ESC compressor. That’s why so many were disappointed that Phantom shut down operations.

I had to look up the system on the SQ7, I think you’re going to find it extremely hard to do a similar setup. In addition to the complex system for isolating the different parts (turbo and ESC) under diffent conditions you would need to do some pretty complex tuning.

I did look at doing a similar isolation system to bypass the ESC when not in use to prevent the compressor from causing intake restriction. It was just too complex and would have required too much custom made hardware. I opted instead for a system that used a MAP sensor in a closed loop control setup to keep the ESC running at a minimal speed to keep intake pressure constant when the ESC is not boosting. Later versions of the Phantom did something similar.

If your goal is to run the the ESC in series with your existing turbo I think you’ll find the ESC just can’t provide enough air too the turbo when it’s boosting and would just act as an intake restriction. It might help with lag but as soon as you exceed its own ability to boost it would be a restriction.

[al3k]

Thanks for the input! Its a very interesting thread, I have read about 2/3 into it and that first aquastar motor you used was exactly the same thing I was thinking about trying since it had a rating upto 5kw and pretty much the biggest cheapest engine I could find.

I guess the isolation part is a bit tricky or it least due to limited space its hard to find all this stuff to make it work like that. The turbo I use today is Borg warner EFR6758 which is probably one of the best in the class for its size but I still miss some bottom end response in the 2k-3k area.
I wonder if I had a simular sized or bigger ESC compressor at the throttly body side of the engine and like the EFR which does have a diverter built innto the compressor cover and theres also a sollinoid diverter which can be used from audi/vw to control this valve that should make it more flowable when not in used if the DV was forced open when not in use.

[neutron256]

Originally Posted by al3k

Thanks for the input! Its a very interesting thread, I have read about 2/3 into it and that first aquastar motor you used was exactly the same thing I was thinking about trying since it had a rating upto 5kw and pretty much the biggest cheapest engine I could find.

I guess the isolation part is a bit tricky or it least due to limited space its hard to find all this stuff to make it work like that. The turbo I use today is Borg warner EFR6758 which is probably one of the best in the class for its size but I still miss some bottom end response in the 2k-3k area.
I wonder if I had a simular sized or bigger ESC compressor at the throttly body side of the engine and like the EFR which does have a diverter built innto the compressor cover and theres also a sollinoid diverter which can be used from audi/vw to control this valve that should make it more flowable when not in used if the DV was forced open when not in use.

Looking at the compressor map for the EFR 6758 it gets optimal boost around 125K RPM. It should be easy to match that using the same compressor for the ESC under no load, but I’m not sure under load. I’m also not sure how the two compressors would interact.

I’d suggest looking into sequential turbo setups. That’s basically doing what you’re proposing but with two convential turbos. They use a smaller turbo for lower RPM and a larger one for higher RPM. I think they control the system by adjusting percentage of exhaust that feeds each turbine i.e. more exhaust to the smaller turbo at lower RPM, more exhaust to the larger turbo at higher RPM.

I think your biggest challenges would be:

1. Can your ESC feed enough air to the turbo at peak boost/RPM

2. Controlling the ESC so that it feeds the right amount of air to the turbo at the right time. A closed loop control setup like I was developing would probably be the best option, but you’d need to have some sort of micro controller and probably other inputs like RPM and throttle position.

I had a thought (maybe a crazy one). If your goal is to simply spool the turbo more quickly and reduce lag would it be possible to use an electrically driven compressor to feed into the exhaust and increase pressure there. That would take a lot more thought. I think the biggest issue would be making sure exhaust didn’t backflow through the electric compressor, and where to locate it.

Ideally you would use an electric motor tied directly to the turbo to spool like the rotrex VC8 system uses. Sadly as far as I know it’s not for sale to private individuals at this point.

[churchx]

Won't sequential turbos need different shape of blades if they further accelerate/pressurise air stream vs standalone compressor, which may complicate finding off the shelf compressors, no? Also adding two blowers imho will add unnecessary complexity both to mounting and for controller for those two, rising price of development and kit itself and reducing simplicity of retrofit of such. Imho mild boost but keeping things simple would be more beneficial then aim for high boost levels of classic SCs/turbo-s.

[neutron256]

Originally Posted by churchx

Won't sequential turbos need different shape of blades if they further accelerate/pressurise air stream vs standalone compressor, which may complicate finding off the shelf compressors, no? Also adding two blowers imho will add unnecessary complexity both to mounting and for controller for those two, rising price of development and kit itself and reducing simplicity of retrofit of such. Imho mild boost but keeping things simple would be more beneficial then aim for high boost levels of classic SCs/turbo-s.

I agree, and that’s what I was getting at when I said I’m not sure how the ESC and turbo would interact. Conceptually it’s an interesting idea but I agree it would probably be cost/complexity prohibitive for most of the aftermarket crowd that would be interested.

I actually did some quick research and there is an electric anti lag crowd funding project on indiegogo right now but it’s only raised about $100. It’s a pretty simple system that uses an air compressor, tank, electrically operated valve, and micro controller. The concept is compressed air from the tank is released into the exhaust manifold. The compressed air then expands both due to pressure differential between the tank and the manifold, and the cool air being heated by the hot manifold(Boyle’s Law). This in turn increases the exhaust pressure spooling the turbo. They control it by tying the throttle position sensor into their controller so that when the throttle body is open more than a predefined setting it opens the valve releasing compressed air into the exhaust manifold.

https://www.indiegogo.com/projects/e...charged-cars#/

It’s a pretty slick idea and supposedly they have a working prototype. I have a few thoughts/concerns

1. How does the system know when the turbo has spoiled enough and stop supplying compressed air rather then just continuing until throttle position lowers or the tank is empty

2. Is there any risk to the hot manifold/turbine by suddenly introducing cool air

3. Where is the optimal and/or most practical place to introduce the compressed. Probably easier on an aftermarket turbo vs. a factory turbo like the one on my C30 that is integrated into the manifold. I’d probably have to weld a bung into the manifold to connect the compressed air

4. If they aren’t already I’d add a pressure regulator to get consistent air pressure and the ability to adjust pressure

5. Would introducing fresh air into the exhaust cause problems with emissions controls i.e. the O2 sensor(s). If so is there a way to manage that

I wouldn’t count on that indiegogo turning out a real product but the concept may have merit.