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Updates on 2 fronts: 1) shrink fit shaft, 2) cooling system 1) I have been struggling to make my shrink fit extension shaft. I just can’t seem to make the hole small enough for a 20ish micron interference fit. After each iteration I am consistently disappointed when the motor shaft slips...

Ohh, how disappointing… I feel for you. At least you are an amazing machinist and have that piece working for you. Here’s to Finding A Way to a viable electric super charger for our power and torque hungry 4 cylinder engines.

Thank you marnrach. Here is an update . If I pull ~ 190 amps @ 32Volts that is about 6,000 watts. 6,000 watts x (100-85% motor efficiency) = 900 watts x 10 seconds = 9,000 joules. If I have a half liter of water as coolant 500g x 4 J/g degrees C= 2,000 joules per degree C thermal capacity. So...

I am trying to get my head around how much cooling I need. Check to see if I am thinking about this correctly. If I pull ~ 190 amps @ 32Volts that is about 6,000 watts. 6,000 watts x 5 seconds = 30,000 joules. And the thermal capacity of water is about 4.2 J/g degrees C which has 4.7 times more...

I look forward to the day I have a reliable system on my car like you! Do you know how many amps you pull and for how many seconds on typical spool up? I am just trying to get a sense of the area under the curve in terms of heat input. The motor consultant based on boat racing experience...

Regarding my burned motor rotor. I talked to my motor consultant today, and he provided some great thinking. Here are some key insights: Windings get hot rapidly under high load (I am running in the 6,000 watt realm) and transfer heat inward to the rotor and outward to the casing. The rotor...

Thank you for all of the thoughtful comments. Quite helpful in guiding thinking and technique around fabrication. Yep, I plan to measure the shaft of my new motor once it is in hand with 0.0001” caliper. Agree. I added some precision shims last night to my lathe tailstock to get height match...

At first I was looking for metric 7.98 mm reamer and it was hard to find. Instead I tried searching for 0.3140” reamer, for which I found a Drill America version for $22 on Amazon. Check my math. 8 mm / 25.4 mm per in = 0.31496” ~ 0.3150” - 0.3140” = 0.001” Interference equals roughly 25...

What are you using for a bearing? Are you still using the SPEC self lubricating plastic route or are you using a ball bearing now? When I searched for 100K precision bearing on McMaster, the only options that came up had a very small diameter (in the realm of 2 mm). after sleeping on it, I am...

Thank you for the blazing trails, the great insights and thinking, and sharing the fabrication techniques.

Thank you for the thoughts. I did not have a lathe when I started the project, but now I do. I’ll have to go find the equations and figure out the required interference like you said. I could go either way with boring bar or reamer. I am guessing that the shaft needs to be made with the hole...

I cranked up the cc knob on the boost controller and got it to feed 10 amps to charge my battery. But it quickly wattage dropped quickly because my battery was already charged. Seems to be working well. I was just set up to do a healthy set of bench runs with temperature measurements to wear my...

Wow, I really like what you did with the shaft. I am still trying to get my head around what you did. I like eliminating the spacer. How low did you get the run out? I already have a functional system, but have kept the RPM for now around 60,000 which is about 6 PSI. So, what did you do to...

I am treading new territory here in electronics for me. I have been enjoying my new desk top power supply and just learning about constant current and constant voltage charging. But, I have only been charging half my battery at a time at 21.3 volts as my power supply is limited to 31 volts and...

How are you going to evaluate the need for a blow off valve? Are you going to look in the data log at the manifold pressure when the Throttle position sensor goes below boost threshold? Or do you have other thoughts on how to assess?

Wow, that is some serious fabrication. Is that 1/2” aluminum? My TIG torch would probably melt down trying to weld that. And where does this sit? It is hard to imagine how you got the LS engine in a Miata. Are you placing the electronic super charger it in the trunk?

Well, I cleaned up the motor contacts and it seems to work fine. It is probably for the better that I had the issue, as when I took the system apart, I was able to fix a few pesky problems. 1) compressor wheel evenness from side to side. turns out my counter sinks were too close and it would...

Well, I am back in town, so I finally had a chance do something this week on my project. I charged my batteries last night. And my system has been running well with my 3 levels of boost 2 PSI, 4 PSI and 6 PSI. These boost levels correlate with the step levels on this data log. The boost is...

I get it… The battery is a big deal. I was stuck there too. In fact until I found the solution below, I thought this project was going to be a no go for me due to battery cost. I was also considering using 1/4 of a Prius battery (200 volts / 4 = 50 volts). But found the budget build outlined...

I have taken apart and reassembled the motor / compressor assembly more times than I can count. Each time, I have made a little adjustment / fixed a small problem. I am finally in a place where I am getting some data. Also, I finally have switched from the servo tester (left) to the arduino...