[Diy_efi] RE: Throttling intake air -- references

[Mike]

mmmm, More and more handled by ECU, yes turbine speed is of
interest - clearly I need more comparative data and should
finish my datalogging system soon in between client demands...

The delay from throttle position change to reduction in boost
seems to be only a few hundred milliseconds, and gets progressively
less the more load the engine is under. Its really not much if
in a comparative sense fuel economy is improved over a wastegate
system the data is unclear but seems sensible if you are not
venting energy past the turbine,

rgds

mike



At 08:54 AM 16/1/2003 -0500, you wrote:
>You might want to add EGT and MAT to the list as well, Turbo speed might be
>interesting as well. Have you given any thought to the speed the system
can or
>should respond? the only reason I bring this up is with a large turbo on a
small
>engine that will make 20 or so lbs of boost you have a problem if you do not
>have a BOV.. High rpm and a quick throttle lift is pretty tough on the turbo
>which is essence what the control scheme you are proposing can do under
certain
>situations. There is some time delay between closing the throttle and the
>turbine slowing to reflect the new energy level in the exhaust. Unfortunately
>the compressor is still spinning at the old speed.. Real hard on the shaft
and
>thrust bearings.
>Dave
>
>Mike wrote:
>
>> I suppose what I should do first, for my current setup, is plumb a
>> couple of pressure gauges, pre turbine and post turbine or better
>> still log these with manifold boost pressure vs a digital input
>> so I know when wastegate actuated. Might be of interest.
>
>> rgds
>> 
>> mike
>
>
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