Full throttle Electric Supercharger Build Thread

[fenton]

Originally Posted by bfrank1972

It's a bit different than other FI options out there since it's driven by an electric motor. I'm no engineer but here's my attempt (I *think* it works this way):

- When you go WOT, it closes a switch and the electric motor driving the ESC goes wide open. It's an all or nothing type deal, so in an open situation (not forcing air into a motor) it will deliver a fixed CFM.

- The motor, on the other hand, has variable CFM requirement roughly proportional to RPM. In other words a motor may need twice the CFM at 4000 rpm than 2000 rpm (in real world this of course varies but to illustrate a point).

-At high engine RPM, the ESC motor is able to flow a little bit more than the motor does at atmospheric, so you see maybe 1-2 PSI pressure above atmospheric at high revs.

-At low engine RPM, the ESC motor is able to flow MUCH more than the motor at atmospheric, so it is capable of producing much higher PSI.

In other words, the motor will *try* to stuff a fixed amount of air into the motor regardless of RPM. Since there is no 'wastegate' or other limiter, at very low rpm this thing could *potentially* boost to damaging levels. Other FI types don't really have this problem because they're limited by belt speed (RPM dependent) or wastegates (boost dependent).

Experts please excuse if I'm over-simplifying things.

Exactly right. I will simplify it even more.

Max boost at 0 RPM is 5psi
Max boost at 7500 RPM is ~2psi

If you try and stuff 5psi into a engine at 0-1500 rpm it isnt going to be that happy. Then engine isnt very efficient at that range and focing air into it during that time doesn't net you anything except increase load on everything.

If you do go WOT at that low rpm, i have once, the car just kinda bogs and isnt happy. At the same time it goes very rich because it doesnt really know whats going on.

ThaTruths drift office tune starts as low as ~1800rpm(i heard) and it was happy, however; just remember the load your are putting on your poor engine

[fenton]

Originally Posted by Thatruth2001

The drift office ecutek option is tuned to go WOT at 1,800 RPM. Talk to Rob, he has seen the AFR reading. I only use the ESC at 2,500 in either 4th or 5th gears so I do not have to downshift to pass on the highway. Puts a big smile on my face!

Thats great to hear. I just feel so bad going WOT that low lol.

[Thatruth2001]

Originally Posted by fenton

Thats great to hear. I just feel so bad going WOT that low lol.

Going WOT in 1st took me a couple of weeks to do. I really do not recommend doing it in the rain!

[Gary in NJ]

My kit arrived today. My batteries should arrive tomorrow. I will be driving an ESC boosted -86 on Wednesday. I need to get with @moto-mike shortly thereafter to have the BRZEdit tune flashed or possibly a custom tune. Don't know about the tune details yet.

[JDMenrique]

i went to their website and didnt see anything. where can i get one of these and how much are they?

[Robftss]

Originally Posted by mid_life_crisis

That assumption is a mistake. This is exactly the kind of system that will appeal to guys who consider tuning as something they don't want to get involved with. Easy bolt in, easy removal, minimal fuss.
If I have to limit the power gain slightly to keep my motor safe without a tune, then I'll do that knowing I won't be getting as much out of it as the guy who does get a tune. It'll still be a nice bang for the buck, just not as big a bang as the next guy.

Presently you can:

Build a connector/box/circuit MAP Vclamp as per PUG's diagram (values not tested yet).
Buy /splice/wire/calibrate an adjustable rpm window switch.

or

BRZlite/Tantrix/Toma file.

Either one has costs, one gives you more, one gives you less.


or
Run stock tune/CEL/ mindful boosting below ~3K.

[raven1231]

Originally Posted by JDMenrique

i went to their website and didnt see anything. where can i get one of these and how much are they?

You can't

[Robftss]

Originally Posted by JDMenrique

i went to their website and didnt see anything. where can i get one of these and how much are they?

We are testing production prototypes/tuning options/electronics/Auto-X/durability/drivability/& most important user feedback.

[JDMenrique]

Originally Posted by Robftss

We are testing production prototypes/tuning options/electronics/Auto-X/durability/drivability/& most important user feedback.

Originally Posted by raven1231

You can't

im sorry guys, i couldve sworn i read someone actually ordered one. thanks for the heads up

[raven1231]

Originally Posted by JDMenrique

im sorry guys, i couldve sworn i read someone actually ordered one. thanks for the heads up

Not yet but hopefully soon! There are quite a few testing them though.

[mid_life_crisis]

Originally Posted by Robftss

Presently you can:

Build a connector/box/circuit MAP Vclamp as per PUG's diagram (values not tested yet).
Buy /splice/wire/calibrate an adjustable rpm window switch.

or

BRZlite/Tantrix/Toma file.

Either one has costs, one gives you more, one gives you less.


or
Run stock tune/CEL/ mindful boosting below ~3K.

or
get @Robftss to cough up an explanation on how the controller works so we can build our own rpm sensitive circuit to provide partial boost starting at 1500 rpm building to full on at about 3250 when the pedal is to the metal.

[Thatruth2001]

Originally Posted by mid_life_crisis

or
get @Robftss to cough up an explanation on how the controller works so we can build our own rpm sensitive circuit to provide partial boost starting at 1500 rpm building to full on at about 3250 when the pedal is to the metal.

Here is the funny thing ......Chinesse manufactures are looking at this thread and are attempting to develop a unit... Some have gone as far as contacting some people about testing and tuning.

Knowing how long it took Rob to R&D this unit I have a feeling there will be many knock offs around the corner.

Concerning modulation of the unit's output, I can send you about 20 emails debating it with Rob. At the end of the day is it achievable, yes but it becomes more complicated which leads to driving up costs.

We all want the bells and whistles, but the cost of the feature might become a turn off. Personally, I thnk Toyota should write Rob a fat ass check and incorporate the unit into an hybrid version of the car.

[Anaxilus]

Originally Posted by Thatruth2001

Here is the funny thing ......Chinesse manufactures are looking at this thread and are attempting to develop a unit... Some have gone as far as contacting some people about testing and tuning.

Good luck w/ that. I'd rather drive a Geely, that way death will be quick and relatively painless.

[Pug]

Originally Posted by mid_life_crisis

or
get @Robftss to cough up an explanation on how the controller works so we can build our own rpm sensitive circuit to provide partial boost starting at 1500 rpm building to full on at about 3250 when the pedal is to the metal.

It's doable, if you want to do it. My problem is that sensing RPM on this engine seems to be a major PITA; the only "easy" way to do it that I've found is with an ODB connector.

The way I was originally planning to try was to add a Bluetooth module to my advanced monitor and use that to poll the RPM every 0.5 seconds (practical max) to decide to enable/disable/modulate the throttle switch, however my ELM327 bluetooth ODBII connector can't handle two masters, so that would mean Torque doesn't work. For this reason, I haven't bothered to build that in.

A more complex way is to tap the sensor lines leading to the ECU, like here: http://www.arduinoos.com/2013/08/engine-rpm-part-1/, but that's beyond my comfort level; it'd need a separate Arduino microcontroller just to handle that sensor, and then report back to the "main" microcontroller.

I'm afraid I'm not an EE, just a poor dirty mathematician and computer scientist; I'm having all manner of fun screwing up my monitor circuit each weekend and it isn't working yet