[Diy_efi] This turbo assist stuff, suggestions

[Mike]

In reference to all this stuff about assisting the spool up of turbos,
presumably for fast takeoffs and gadget value, what do people think of
this dual approach (a=motor, b=boost):-

a.	The "Motor" part,
	Engineer the compressor plate to make it the rotor of a brushless
	(induction) motor - by placing polyphase windings behind it and
	driven by a 2 - 5 Kw motor driver, which could work as follows:-

	1.	The compresor plate is your classic induction motor rotor
	2.	In 'normal' mode, the motor is off and the compressor
		plate at idle would spin as per normal and accelerate as
		per normal when foot placed on pedal. Eg. I observed my
		little T3 spinning at 300 rpm when engine at idle.
	3.	In 'power' mode, brushless motor keeps the compressor
		running at a higher speed in readiness for planting the
		foot - such as a 10,000 rpm - but not for long as the comp.
		housing will get 'warm' and the windings likewise. In this
		mode induction motor at say 20% of rated and exhaust pumping
		away nicely.
	4.	When pedal to floor (during 3 above), full power to induction
		motor windings! So the comp is boosted as fast a possible
		by the induction motor and exhaust gas.

*and*

b.	The "Boost" part,
	Compressed air is injected tangentially to compressor plate to
	also aid in spinning up with an extra injector to add the correct
	amount of fuel (slightly) rich to match the air injected. Some
	issues are:-

	1.	Compressed air feed via PWM injector to ensure control and
		of course to prevent over-spinning that poor turbine.
	2.	Motor control and Boost control would work best if integrated
		to the same controller with feedback on turbine speed, this
		could also datalog the operation quite effectively.
	3.	If there is enough power from (a) above and the compresor
		air injection is also 'optimum' - I would expect the turbo
		would act much like a one-way valve such that large amounts
		of additional compressed air and fuel could be added without
		the need for nitrous or special fuels.
	4.	Having a tank with compressed air would be helpful which matches
		the 'boost spurt' people are looking for at launch, with a water
		trap and cooling so the compressed air can be cool enough to
		resist the detonation point - ie. It chills as it expands.
	5.	A cheap way to get compressed air is to use one of those
		scuba tanks that hold 5000psi or so (need a regulator) from
		a scuba outlet - costs $5 to refill.

Comments ?

rgds

mike


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