Thanks. I swapped to a throttle trigger and this has actually increased run time in the 'twisties'. Basically I drive it with 100% N/A power through the corner and only go into boost on exit and down the straight. Whereas before I'd trigger the eSC on a lot more often and earlier, and it would just be fighting the throttle. PWM control would be the logical solution but I actually kinda like it as is (for now).

 

Cheers AAaF , and thanks for your help with the wiring as well!
Yes it's awesome, but actually not as awesome as my turbo setup that uses the same manifold you have!

 

Brett,
I am glad that you did this, and posted what you did, thank you. I call this a great success.

I appreciate the fact that you are still developing stuff for these cars.

 

Something in your ballpark

 

Thanks, had not seen that.
Watched it through. He obviously knows way more about the electrical side of it than I do so will be interesting to see how successful his approach is (which is way different to how I went about it).

 

the issue is that a wankel rotary engine needs ~30% more intake airflow to make the same piston engine power

so his setup is likely too small for a Renesis/13B right out of the “box”, and also bench-only status. Not to say it won’t work or to be overly critical, but since he thought a 2” charge tube from the trunk to the engine intake was going to be suitable in the original trunk-mounted version, then there’s a chance he might be overlooking a few things once the current intake box setup is actually installed and operating in the vehicle.

 

He's fitting it to a Honda s2000. My concern from his video is that he was using a mickey mouse method of tuning the engine for boost.

 

yep, totally agree.
.

 

After adding another cel to battery and raising the voltage a little .... getting close to 300whp!

 

Very excited for the future of electric forced induction especially for this platform. Low boost for
reliability and just enough power. The consumer technology may not be here just yet but soon enough it will.

 

Yeah I agree on both counts.... it's just perfect power for the Renesis.
And re the tech, what I have isn't really 'fit for the masses', more of a DIY setup. But it isn't that far off something that could be boxed up and sold as a kit. The battery might be the one major sticking point as it is built rather than off the shelf. And shipping batteries is a major issue.

 

After fitting a larger drive wheel and upping the voltage I started getting the issue seen below. Wild MAF sensor swings and an odd noise from under the bonnet. Spent today trouble shooting. Tried retiming the ssv valve, changing the water injection amount etc etc and was running out of ideas. But while contemplating my navel this afternoon it hit me! Compressor SURGE! This is what it does to mass airflow at low rpms. Raised the ESC turn on by 500 rpms and .......... all gone.

 

showing where on the flow map it was crossing the surge line.

Also : found the limit for the Hobbywing Max4 ESC . Anything over 300A for more than 4.5s approx. will trip the ESC . You can go way over 300 for short bursts though. I've hit over 400A without tripping it.

Advantages of an Esc vs traditional turbo making same power:

*Easy to remove and refit as desired.
*Lower fuel requirement - currently running stock injectors, pump, lines etc.
*Less heat generated within engine - less cooling requirement
*Lower stress within engine due to lower combustion pressure
*Less chance of damaging detonations
*Reduced need for larger exhaust system
*Lends itself well to W/M vs intercooler . No IC means no restriction to Radiator.

Disadvantages:
Batteries add weight .... but overall weight should be close if you consider no IC or intake piping
Power is not available once batteries are drained. Only an issue on a race track. Never run out on the street
Diy requires electrical knowledge and skills.
Components are designed for Hobby not automotive use.

 

Have been finding that, at max. power the eSC delivers too much boost/power to make it useful around town. The only time I'd every use it realistically would be on the open road when overtaking or having fun through the twisties - between corners. I shied away from using the Aduino for an infinitely variable system but had a spare speed control circuit board.
So............
Spent the last few days setting up a two step speed control. Gotta say it was a major PIA to do but it's now operational and working!
Too much boost put SC into surge at low rpms and I wanted to be able to use it at any rpms. After some messing about, I've finally found a good setting that doesn't put SC into surge but increases acceleration sufficiently to make it useful.
So now it's possible to dial in more power than stock such that I'm able to utilize it much more around town etc.
Woot!

 

I do not know the details of what you attempted, but a proportional speed control is attractive. How to get the data is @ciprianrx8 territory, definitively not mine, but if possible I have a strong believe in making a speed signal to controller that is based on a feed forward given by:
- RPM
- Throttle position

Something like this:


Of course, you can add a portion of the actual pressure as well, but I think a straight feed forward will work well.

 

Yeaaaa... sure. There's 50% result with 1% effort and 100% result with 100% effort. To each his own!

 

It's more like 90% result with 50% effort ....but who's counting.

 

Just came back from 'Mad Mike's Summerbash'.
Had three one hour sessions on track. These sessions are not full blown race pace. Generally it's more about just cruising around the track until you reach a certain part of the track where it becomes a full on roll race for all and sundry. This is perfect for the eSC system as you get a full lap to recharge before each few seconds of mayhem.
Bluey went great for the whole day. Roll raced all manner of performance car and was pleasantly surprised at how competitive she was. Definately well into in the top 1/3rd of the cars there. Without the Esc ..... an RX8 is well into the bottom 1/3rd.
During the course of the session the steady state battery voltage dropped down by 4v at most and performance was not noticeably affected. Electric motor was getting too hot to touch and charger was getting hot as well. If I go for more power I'm going have to address that. The ESC does have a motor heat protection setting but I'm not sure what it is or if it's even turned on. If it was, it didn't trip out all day.
As far as the engine was concerned .... ran nice and cool (90C) in the first two sessions but in last session ambient temps were getting up so I closed the windows and turned the A/C on and temps went to 95C. I'd say the lower stress on the engine is a major advantage with this setup for this kind of use.

 

My attempts to reach that magic 300WHP milestone have been unsuccessful. Have tried a few ideas which haven't really worked so I I saw two choices for the way forward.
1/ Buy an additional ESC and motor and set up a twin motor drive. This is actually the least expensive option. It has some advantages in that the esc and motors would be under a lot less stress plus the possibility of going even higher in the future.
2/ Buy a more powerful ESC and take the motor to it's peak power output.

While option 1 would seem more logical it has two major drawbacks, complexity and space.
I've decided to go for option 2 and max. out all the current componentry rather than replace everything and go for even higher power. Wait ...did I really just say that !!!!? Must be getting old.
New speed controller arrives next week with the goal of breaking through the 300whp barrier.

I've also been working on a new engine especially for this project. With some porting designed to take advantage of the best attributes of an eSC.

Also : there is a possibility i'll get a DBW/PWM controller setup afterall ... depends on a few things happening so not definite.

 

This was taken on 'the dipper' at MM Sumerbash. The straight on right hand side is where all the roll racing takes place. The upper left is part of the same track but can be used as a separate track as well.

 

In the beginning of the thread you mentioned Speedmaster C2 SC, I can only find P2 when I search online. Is it a discontinued model or a typo?
which new controller did you get?

 

Yeah .... that was a typo sorry. P2 SC is the one.
I've gone for a XC E3 pro (400A) which is the same as a mad max 20........... however, I've trying to get that going for the last few days and so far it's not syncing with the throttle .

 

As you go into the "weird" stuff of RC motors/ESCs, you will find that some motors are just a pain to drive. In RC cars I believe the term is cogging, which is the motor being unable to start from 0 RPM because it faces a major torque disadvantage. The way these (sensorless RC brushless motors) work is they need to get going at least a half turn before they can unleash massive power. That's so the controller can figure out which way the motor went and when/where to fire the next voltage pulse.

If that's not it but a PWM signal range issue, some ESCs will need to be taught what's 0% and 100%, and that's quite a faff. Get one of these, if ever in doubt, they are called servo testers:


https://hobbystation.co.nz/servo-tester/

Note they need to be supplied with 5V DC to work. Some ESCs, notably those with bonkers voltage/current ratings, do not supply this voltage at all. Your E3Pro 400A seems to have this voltage feed.
Doesn't need to be _that_ one in particular, and they all do the same stuff. An arduino + chatgpt will surely provide the same functionality.

 

I have two of them already plus two of the boards I used for the hobbywing. Plus, I took it to a friend who sells RC cars for a living to try using a receiver .... NADA!
Supplier is supposedly contacting manufacturer for a solution ... it's taking a while. Might end up returning it.

 

Ok... I see it's marketed as a RC car ESC, but it can be configured to run in various modes: https://en.xc-bldc.com/uploadfile/up...1617292831.pdf
The default seems to be forward, brake and reverse enabled. Are you feeding it 1.5ms pulse width PWM at bootup? That's what car/boat ESCs consider as 0%, ~1ms being -100% (full reverse) and 2ms being 100% (full forward). If it doesn't get this... it won't go.