Smaller high boost compressor?

R

reuben.h

New member
Hey guys,
This is an awesome forum that has many of my interests in (boost and electric shit)
One thing I seem to notice is that nobody really has a smaller frame supercharger that can do 1 bar+ kind of boost

The P2 supercharger is interesting however I think the compressor is far too large for a 2l engine. Seems from the videos that I have watched that it will surge unless a large amount of air is going through it.

This leads me to my question about if someone has used a turbo such as a GTX3076 - taken off the exhaust wheel and driven it from an electric motor.
Another option that comes to mind is keeping the turbo exhaust housing and having the electric motor drive from the compressor side - allowing for as much boost as required at low RPM then letting the exhaust flow make the turbo spool up at high RPM.
it could even act as a generator while on the highway.

I believe I saw BMW or Mercedes do this with some of their vehicles which would allow super fast response without choking the engine.

I am using a Toyota 3SGE Beams engine in an MR2 and am pretty sure it could withstand 8 psi at 3500 RPM and 14 psi at 7000+ RPM

I likely won't be dabbling in the electric boost side of life until I get a couple of my other projects out the way (like the 15hp electric moped)
 
I am literally using a "GTX3076" 1.6L going for 5psi

2L @ 7000 RPM @ 14psi = a 29hp motor ... and looking at the compressor map that would be 33lb/min. That will happen at just under 100,000rpm
This wont happen with a direct drive E-turbo and so will need to be geared. On this forum so far gearing has not been proven to these RPM's..
 
As MakingStuffAwesome says, you really can't get to the RPMs needed with that small of an exducer - the P2 has a very wide compressor map, which is what makes it so perfect for so many applications. WB on here has actually converted a turbo and has seen boost with it; but I'm not sure what he's using off the top of my head.
 
I didn't say you couldn't do it.. i said you couldn't do with without gearing it.
As this guy and i have said many times .. The P2 is not a viable option for many cars because it is physically to large.
WB projects uses a fake "GT35" compressor wheel
 
Here's the compressor map for that turbo - you don't even get on it until 50,000 rpm. Keep in mind, the larger the exducer, the less rpm you need for efficient operation. By comparison sake, the P2 has a 127mm (6") exducer. If it was me, I'd figure out a place to mount the bigger unit since you're not limited to where you put it. Of course, WB does see boost with his setup, but you can see that at a 1.25 pressure ratio you're limited to 250 hp at 50,000 rpm. In his case, though, the tiny compressor wheel is an advantage to a point because you can maximize the motor's duty cycle and perhaps even over-volt it by a bit to get above 50,000 rpm. Hope this helps.
Comp-Map-GT-3582R.jpg
 
I've post pictures of the ESC datalog at the bottom of page 1 in this thred. I've **almost got 50k rpm with the weak batterys

Troubleshooting WB Projects' E Turbo

Hi All, WB Projects has been talking with me about his project through PMs. Since this is a "let's all learn together" type of forum, I asked him if I could move our conversation to a thread here. I'll start by going be to a point in our PMs that makes sense. WB Projects: Good new for me 🤘...
www.electrifiedboost.com www.electrifiedboost.com
 
Well, thats interesting.. I've always read something like 3000watts for this motor but they have no "official" power rate right? So *maybe they are enough powerfull? Because when I first look for my motor I have hard time to decide between the 2
 
oh ... and one more thing:

NeuMotors

Neu motors and Castle worked together to bring the best combination of motors and electronic drives.
www.castlecreations.com www.castlecreations.com

not sure though how much "Neumotor" is in the 1721 though 🤔
 
WB projects said:
If you want to see
Click to expand...
Any updates? I have a similar displacement engine 2.0 liter 1971 Opel GT. I am exploring options for an e-turbo now that I have a modern fuel injection system with stand alone Terminator X ECU. I am just exploring compressor options, motor options and ESC options. I was hoping to use my 56 volt 5AH battery and charger from my EGO electric leaf blower.

Is anyone aware of a smaller version of the P2 or said another way a smaller super charger model as a starting point for a 4 cylinder 2 liter engine to boost on the realm of 5-7 PSI?
 
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A Rotrex C15 is the right size for a small engine but they are a bit spendy ~$2000.

For a cheap option I think that salvaging the compressor side from a used turbo is worth investigating.

Both these options will require some machining - not sure how well equipped your shop is or if you have friends in low places.

I think when you get into this more you'll find that 5AH of battery capacity is not enough. There are limitastions on how fast batteries can be discharged (C rating) and it helps to have more AH's. I'm thinking more like 40AH for a car that going to to be on and off the throttle unlike a drag strip car. Most people are shying away from Lithium polymer batteries and using LiFePO4 or Lithium titanate (LTO)
 
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