Open Source Electric Supercharger

[solma]

Originally Posted by SloS14

If you're asking me the answer would be somewhere in between but leaning towards the short burst.

I'd like to be in 6th on the interstate, give it some throttle and get *some* boost (1-2psi would be great) without having to go WOT and getting full boost, then level off to cruising speed and recharging.

So in that case, I would over simplify thing by using a blowoff valve connect back to the intake and then you go full current on the motor depending on the throttle position(70-100%), with enought charge capacity, you should be able to do short acceleration when passing.

That simply thing a lot as no real control is needed and you sure not to over or under pressurized the intake.

[solma]

Originally Posted by neutron256

That's what I'm looking for, the only difference being that I want it to activate a little before WOT (say 80%) and then to start low and quickly ramp up to full boost by the time it's at 100% throttle. As you let off the throttle the same processs would happen in reverse. The only objective of this is to give a smoother transition into boost.

I think the mapping ideas are great but I think it's over engineering for what I want. From my prospective I only want this boost during hard acceleration, and I want as much as it will give me so what is the point of a map?

The other side is when the system is in standby to keep it running at a minimum speed to prevent the compressor from causing restriction in intake. I think this is something that will require some testing to determine how best to go about this, and if it really is a benefit at all.

Point is, if you want a smooth transition(by controling pressure boost before throttle body), use the throttle to do so, like i said, pressurized full but just open partially the throttle and the transition will be smooth depending on your foot, it will not be as efficient electricaly speeking, but will be so much simplier

[jamesm]

Originally Posted by solma

I am starting to be mixup on what you want to built, is it a short burst WOT system or to you want to emulate a belt driven supercharger that can constantly pressurized the intake?

we want the end user to decide that. we just provide a way to indicate what he wants, via a boost target map. he's free to set it up any way he chooses.

[solma]

Originally Posted by jamesm

we want the end user to decide that. we just provide a way to indicate what he wants, via a boost target map. he's free to set it up any way he chooses.

I agree it to the end user to decide , but if you want useful info from other, it need to be clear to other what the goal are, if not, it start to be a mix up useful and not so useful info that can cloud solution.

Sorry if I am to strait forward to what can done to reach goal, its because of the type of work I do, project managing and design.

[jamesm]

Originally Posted by solma

I agree it to the end user to decide , but if you want useful info from other, it need to be clear to other what the goal are, if not, it start to be a mix up useful and not so useful info that can cloud solution.

Sorry if I am to strait forward to what can done to reach goal, its because of the type of work I do, project managing and design.

no problem. i think (and again, this is just my opinion) the goal should be to allow the user the ability to map boost any way they choose. our goal should only be to provide a good tool to allow them to do that. we shouldn't make any assumptions about how they'll use it.

[Toma]

Originally Posted by jamesm

no problem. i think (and again, this is just my opinion) the goal should be to allow the user the ability to map boost any way they choose. our goal should only be to provide a good tool to allow them to do that. we shouldn't make any assumptions about how they'll use it.

I've yet to run into anyone that is limited to ~6 psi, say they actually WANT less than 6 psi. They all want 8 psi lol. Not daydreamers, but guys with actual boost on their car. It's human nature.

But I've only been doing this ~20 years, so maybe they are out there.

My first supercharger was the old ball drive paxton. Made 5 psi., and I wanted every single bit of it lol.

I bet that say you got the controls down, and the blower was capable of 4 psi at bottom, 2 psi at top, and you spent hundreds of extra dollars on limiting boost, 99% of guys would just end up running it full on anyway. Once you drive it, you will understand.

This control stuff would be cool if this thing could make 20 psi, then you can tailor a boost curve to deliver a cylinder pressure curve that the motor would be happy with....

So the control is actually the very very easy part. Even if it was a simple open loop duty cycle table with rpm and tps or mph as the axis. There are ecu boost control devices on the market that can be mapped on a laptop to do it, for like $250.

The hard part is generating enough boost to where someone would actually want it tapered down. ie, the mechanical and electrical parts.

[jamesm]

Originally Posted by Toma

So the control is actually the very very easy part. Even if it was a simple open loop duty cycle table with rpm and tps or mph as the axis. There are ecu boost control devices on the market that can be mapped on a laptop to do it, for like $250.

The hard part is generating enough boost to where someone would actually want it tapered down. ie, the mechanical and electrical parts.

none of them are open source, and $250 is far more expensive than what could be achieved with an open source stack.

it's never a good idea to start a project without considering future advancements in the domain. this is why game developers write game engines to exploit hardware that won't be available for years to come.

i believe it is important not to presume that the state of affairs today will be the state of affairs 5 years, or even one year from now. it's quite possible that you'll have your 20psi within a reasonable timeframe, with all of the money being dumped into battery research these days. in any case you'd want to be prepared for that eventuality.

taken into consideration with the fact that such a system to control boost has other benefits outside the scope of this particular argument, and that the development effort is relatively low compared to the other elements involved (as you alluded to in your post), it seems like a no brainer to do it right and do it once.

[Toma]

Ahhhhh. We see it two different ways. Takes 150 amps to do what the Phantom does now
.. 1.5 psi at the top, so I see generating boost and airflow as the realistic limitation. Here and now. Control system would be easy if it was required.

You think the control system Is hard..... but boost and airflow will come easy.

A Vortech blower moving 750 cfm at 1.7 bar takes 40 hp to turn it. Convert that to electrical draw and tell me how soon you think it will happen.

[jamesm]

Originally Posted by Toma

Ahhhhh. We see it two different ways. Takes 150 amps to do what the Phantom does now
.. 1.5 psi at the top, so I see generating boost and airflow as the realistic limitation. Here and now. Control system would be easy if it was required.

You think the control system Is hard..... but boost and airflow will come easy.

A Vortech blower moving 750 cfm at 1.7 bar takes 40 hp to turn it. Convert that to electrical draw and tell me how soon you think it will happen.

no you misunderstand me. i agree that the mechanical challenges are far more difficult to overcome, and that the control is the easy part. my point is just that better hardware is an eventuality, and the rate of development in the field suggests that it may come sooner rather than later. do it once and do it right. if there were no other benefits (short and long term) to an intelligent control strategy, then i would side with you on this one, but there are in my opinion.

btw i have sitting next to me an 11hp brushless motor that is smaller than a beer can. i run it on a battery i can charge at 5-10c. it's not that far off, especially if you're willing to pay for it.

[Toma]

Originally Posted by jamesm

no you misunderstand me. i agree that the mechanical challenges are far more difficult to overcome, and that the control is the easy part. my point is just that better hardware is an eventuality, and the rate of development in the field suggests that it may come sooner rather than later. do it once and do it right. if there were no other benefits (short and long term) to an intelligent control strategy, then i would side with you on this one, but there are in my opinion.

btw i have sitting next to me an 11hp brushless motor that is smaller than a beer can. i run it on a battery i can charge at 5-10c. it's not that far off, especially if you're willing to pay for it.

[SloS14]

I think an onboard MAP sensor would be pretty cool if they can be found for cheap enough. At a minimum it would be nice to be able to be easily scaled to different MAP ranges.

[neutron256]

Originally Posted by SloS14

I think an onboard MAP sensor would be pretty cool if they can be found for cheap enough. At a minimum it would be nice to be able to be easily scaled to different MAP ranges.

You can find all kinds of MAP sensors on eBay for as little as $10. The other option is to just tap into the existing MAP sensor.

[neutron256]

I've added the MAP & TPS sensor connector types to the OP along with a good link for where to buy these.

This is useful if you want to build a wedge to tap into the sensors without cutting any wires.

[SloS14]

Originally Posted by jamesm

btw i have sitting next to me an 11hp brushless motor that is smaller than a beer can. i run it on a battery i can charge at 5-10c..

power porn: http://imgur.com/a/nzq04

Speaking of power....and this is a bit off-topic but what about a TOUGH battery box for LiPo/lifepo4 with self-powered cooling and ventilation...Just thinking out loud.

Originally Posted by neutron256

I've added the MAP & TPS sensor connector types to the OP along with a good link for where to buy these.

This is useful if you want to build a wedge to tap into the sensors without cutting any wires.