How To Size a Turbo or Supercharger

This video is a pretty in-depth discussion about how to choose the right compressor/blower; in this case we're focusing on an electric supercharger, but the concepts can be applied to traditional forced induction. I also explain why the little electric turbo will never make boost and why I feel a Vortech supercharger is a great candidate for electric conversion. If you'd like to contribute a buck or two to the cause visit my patreon page: / alexltdlx

[@fernandohood5542]

I would like to see more analysis on determination of power required to drive the compressor in relation to the compressor map.

[@AlexLTDLX]

That info is stuff we need to learn empirically. I have an idea of what my Whipple took, but with centrifugal setups it's dependent on so many variables - for example, it took 13.9kW to support 650 hp on a 510 hp base engine; but it takes 35kW with the same compressor on the same engine to support 800 hp.

[@evil_me]

The only thing I can see becoming an issue is at low rpm you might cross the surge line if you run the motor full speed. Might need to be throttled down somewhat until rpm builtd. 😎

[@of_lion22]

I was thinking the same thing. Possibly like a staged nitrous setup, increasing boost in near instantaneous steps throughout the rev range.

[@AlexLTDLX]

You're probably right.

[@dylandesmond]

Use a wastegate on the intake, will stop low rpm surging... I had this same issue when testing a v-15 hit 1700hp on the dyno at 2500rpm, stuffed my torque converter and my gearbox was completely destroyed. Had a 2500stall converter.... Now I'm bench testing looking at a small setup with added nos. 530hp centrifugal with a 250 wet nos shot should be good for 1000hp, and 400kw daily

[@grimlogg174]

I'm rdy to see how this thing turns out

[@keisuketakahashi3597]

I want to build e-supercharger too but high revving motor is issue.

[@armaggedon4christ]

Step up gear box?

[@keisuketakahashi3597]

@@armaggedon4christ it is the best option but it is so complex and I am not that much skilled to pull this thing on my own. Thanks for advice.

[@cdrbews]

Seeing your rpm numbers im assuming your direct driving the compressor wheel frm the motor. Superchargers use pulleys for a reason as you know. So why direct drive. Use pulleys to increase the rpm to make significant boost. Youll have parasitic loss but the rpm will be greater in the end. Seems it would be easier to balance the set up as well.

[@AlexLTDLX]

Power to spin the compressor increases with the cube of rpm. There isn't a commonly available (and reasonable) motor/esc available that would work as far as I can find.

[@cdrbews]

@@AlexLTDLX with pulleys couldn't you add a 2nd motor to assist.

[@AlexLTDLX]

@@cdrbews You could, but then you're getting really complicated. You can also gang the motors (in series - so the shaft of the second motor is coupled to the back side of the first); but I'm trying to keep things reasonable.

[@cdrbews]

@@AlexLTDLX a little research for you kzbin.info/www/bejne/bZLCe2WObZ2Ziac

[@dylandesmond]

@@AlexLTDLX I'm using the me1616 motor (hallsensor version) on pulleys. 8000rpm and 134nm stall... definitely not an rc motor. I'm running 134.4v fully charged at 800amps dc peak and sitting around 160amps dc. Using a khb12101 controller, about to use a khb14601 for 168v 600amps, probably only peak around 400amps dc... Hope this helps

[@williamzoom]

An RC turbine would really hit the spot, 240k rpm! )

[@AlexLTDLX]

Hi William. 240,000 rpm - that's scary territory for sure. I wouldn't trust anything I built at those speeds...

[@marlo0oty213]

@@AlexLTDLX I wouldn't even trust the turbines to hit any of these rpm's in a turbocharger since they are made to have a high rpm's they are not tourqy enough