[Diy_efi] This turbo assist stuff, suggestions

[Mike]

At 10:49 AM 1/1/03 +1300, you wrote:
>You my friend have 
>a) got too much time

Comparatively speaking, took 20 mins to write and I needed a rest ;)

>b) smoked too many drugs in your youth

Well I was a bit high on red whine, cheese and glazed ginger,
and who says I aint still in my youth. Hey ! I feel like a 20
year old - trouble is I cant find a 20year old when I want one !

>c) are a smart cookie ;)
Now thats what I've been aiming for, but havent quite got there
yet cause most people dont like the taste of dem cookies ;)

>Why not use a properly sized exh housing with a BB core and a modern
>compressor design?

Yeah sure, but that is a 'static' setup, the whole point of the dual
system I described is its controlability allowing widest range of
possible control - from mild drivable city use with optimum economy
to full on powerhouse street racing output and best transient response :) !

>Modern GT turbos can spool as low as 7psi @ 2200rpm on a 2l and produce over
>400hp.

Yeah maybe, cost a bit for my 3L and I dont ike the ceramic exhaust wheels,
these have a habit of shattering if they go over speed or handle too
large a boost spike.

I just like the idea of doing something different which has a wide
range of controllable aspects and can use cheap off the shelf turbos,
I've been doing some figures last night on a dual turbo setup, as thats
done on the Nissan Skyline GTR's with the same RB30ET block on my car,
there may be room for a pair of comp nozzles to spin em up nicely.

>Quire frankly I don't like boost that low so I'd go bigger, and nothing is
>simpler that a quick wiff of nitrous setup on pressure switches to get a
>massively oversized turbo up and away ;)

Sure, thats one way to go, Nitrous is illegal here for street use (AFAIK),
but compressed air aint and doing it differently is part of the challenge
and may well attract some commercial interest,

rgds

mike




>-- 
>Matt Porritt
>RC Race Cars and Supplies
>ICQ #22776813
>
>
>On 31/12/02 5:36 PM Mike wrote
>
>> 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
>> 
>> 
>> _______________________________________________
>> Diy_efi mailing list
>> Diy_efi at diy-efi.org
>> http://www.diy-efi.org/mailman/listinfo/diy_efi
>> 
>
>
>_______________________________________________
>Diy_efi mailing list
>Diy_efi at diy-efi.org
>http://www.diy-efi.org/mailman/listinfo/diy_efi
>
>

_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi