I decided to supercharge my 1.2 16v 80HP Stilo with an electric turbo

The project is the following

1) Sport Stainless exhaust manifold 4-2-1
2) Sport Cat 200cpi
3) Exhaust stainless tubes D=50mm
4) Intercooler
5) Electric Inrunner motor 7.6Kw/10HP (350A 22volt) 70.000-80.000rpm
6) An IHI VL37 turbine without the exhaust gas side
7) Lipo Batteries

I hope to get at least 0.3Bar (110hp) Boost up to 0.45Bar (125hp)

Will not modify engine(pistons or compression)

Cheers

Electric motor



Oil Pressure gauge



Intercooler fitted

No way that a motor 40mm in diameter by 104mm long will produce 3.85kW never mind 7.6kW The figures on the datasheet are rubbish. What driver are you using, this is a brushless motor? How are you going to control it? Charge the batteries? Modify the fuelling?
You can't just stick a blower on a modern engine and do nothing else.

Robert G8RPI.

Brushless motor with Kw as stated, sorry for those not accept the datasheet
Control via ESC
TEG charging
LPG fuel, so can modify fueling...

I don't understand the dislikes...

Hmm... ? feels like ive been blinded by science!

It's the laws of physics. At best the ratings are input power and a lot of that is dissipated as heat. They also have short duty cycles and require a lot of cooling. This is not an issue on model aircraft where the propwash also acts s cooling air. You have not explained our drive or control system, obviously an "ESC" but what one? Most are desigined for radio control system command signals. Where are you getting the 250 amps (at 14V and 3.5kW) to charge the batteries? Even if you only need an average of 10% of the 7kW rating that would be 50A. Using LPG does not answer the fuelling control question either. Aditionally how are you going to couple the motor to the compressor? This is not a trival task at 50,000 RPM. Oh, that reminds me, the turbo needs about 150,000 RPM. You will be wasting your time and money.
By the way, if you do make it work, it will be an electric supercharger, not a "turbo". The turbine that gives the turbocharger it's name is the bit that you are getting rid of.

Robert G8RPI.

This is an example how to couple the motor to the compressor...

Also shows a cooling option (cooling jacket) so don't be afraid.

If you have the appropriate person who knows programming that's not an issue...you can ask from the motor to start at full throttle for example,or at a certain rpm let's say at 3000rpm...this is not nuclear science...

My LPG system has a parallel ecu that you can adjust the fuel injected and monitor Fuel trims, fuel mixture etc...

As for the compressor rpms we can use more aggressive wings to have the boost we want at lower rpms...

Ok then supercharger no problem...

Ahhh I forgot to say that I will put and a Blow Off Valve also...

Well that just shows a motor and a disc stuffed into a compressor housing wth a c-clip. It does not show the rotor mounting. The original turbo uses a hydrodynamic bearing and thrust washers. The turbine and compressor axial loads tend to balance each other on a turbocharger, but your system will have to take all the compressor axial as well as radial loads. You also need a means of fitting the compressor wheel to the motor shaft, another non-trivial task. Maybe I'm under-estimating your capabilities, what is your engineering background and how well equipped is your machine shop?

Robert G8RPI.

My personal engineering backround is almost to zero, I am a General Surgeon who likes cars, but my best friend is a genius in engineering and car modifications which his job is having a very big car brakeyard...

We have every tool and equipment you can imagine...he proposed me this setup (e-supercharger) and he can complete it.

g8rpi said:

Well that just shows a motor and a disc stuffed into a compressor housing wth a c-clip. It does not show the rotor mounting. The original turbo uses a hydrodynamic bearing and thrust washers. The turbine and compressor axial loads tend to balance each other on a turbocharger, but your system will have to take all the compressor axial as well as radial loads. You also need a means of fitting the compressor wheel to the motor shaft, another non-trivial task. Maybe I'm under-estimating your capabilities, what is your engineering background and how well equipped is your machine shop?

Robert G8RPI.

Click to expand...

Steady on fellah, you're going a bit full bore on the lad.

for what it's worth I agree with you completely Robert; I dont think this will work, at least not with the proposed setup. That said it's the lad's car and his money to do with what he likes, if he wants to give it a go then fair play to him for having the stones to try it.

Niki,

For what it's worth, as I hinted at above, I dont think that motor is going to be up to the task.

I don't believe the RPM that the motor will generate will be sufficient; I would expect you to require something around twice that RPM, in the 150,000rpm range to be effectively building pressure.

I would also question whether that motor is going to have the torque required to be able to spin the mass of the compressor wheel fast enough, even before you add in the resistance of the air pressure being generated.

Then even if it could manage it the amount of current it's going to be drawing will be BIG. and i mean really big. That carries with it two problems . Firstly the risk of the wires getting that hot that they melt, resulting in a fire. Or; the constant significant current draw damages the batteries, resulting in a fire.

Seriously; for the sake of your stilo... Please do not under estimate or abuse LiPo batteries. They're genuinely nasty and unstable bits of kit - to the point that I keep mine locked in their own shed away from anything I value, just in case.

I do think it's a good and interesting project you've got on the go here and I'll be excited to see how you get on, but if I were to add my 2p - why don't you just create a genuine mechanical supercharger out of an old turbo?

Artermis said:

Steady on fellah, you're going a bit full bore on the lad.

for what it's worth I agree with you completely Robert; I dont think this will work, at least not with the proposed setup. That said it's the lad's car and his money to do with what he likes, if he wants to give it a go then fair play to him for having the stones to try it.

Click to expand...

Hi,
Sorry if I came on a bit strong, I just know that this is going to be a difficult task. The model motors have very optimistic power ratings, but they are all the same and virtually no-one has the equipment to test them properly. I'm an electronics engineer an have also worked with high speed drives and turbine machinery so have some idea of the problems involved.


Robert G8RPI.

I like the irresistible compulsion for power.... but starting from a 1.2, I detect the triumph of optimism over the laws of Gravity, if not even Physics..

That beast will probably not work... but it might work... and it could even work well.. but, if it does not end in the smell of burnt oil spattered over the windscreen, and fractured pieces of alloy and steel embedded into the bonnet liner and through the radiatore, it will at best produce 75bhp.

On the other hand.. if the impetuous enthusiasm of youth cannot be taimed and if the car is destined for Valhalla... then at least it should die with a metaphorical sword in its hand.

You don't need one of those... ^ You need one of these...



Ralf S.

I'm guessing the odd 10 second burst might be feasible but anything more is going to require serious cooling of both motor and batteries, engine coolant would be too hot so you're talking separate pump, rad, fan, expansion tank. Why not just fit a VNT or for the money you could probably shoehorn a little aisin supercharger into it

http://www.ebay.co.uk/itm/Aisin-AMR...3e1cec0&pid=100011&rk=1&rkt=6&sd=121148232372

g8rpi said:

Hi,
Sorry if I came on a bit strong, I just know that this is going to be a difficult task. The model motors have very optimistic power ratings, but they are all the same and virtually no-one has the equipment to test them properly. I'm an electronics engineer an have also worked with high speed drives and turbine machinery so have some idea of the problems involved.


Robert G8RPI.

Click to expand...

I know what you mean. I have a whole heap of RC equipment, all of which I run off electric using LiPo batteries, so I got a bunch of first hand experience using this sort of kit too. I would agree with the degree of optimism on the figures the motors report - particularly the chinese made stuff which seems to have massive variation in what the put out.

So called electric superchargers have been well myth busted, have a look at the experiments on youtube, some quite laughable creating negative gains
I like the thought of a small mechanical supercharger cobbled together somehow, plenty of room alongside a tiny 1.2 engine!!

If you mean the cheap "ebay superchargers" then ok, they are crap...

We will built a powerful electric supercharger with a strong motor, not cheap vacuum cleaner fan...