Re: interesting source for intercooler cooling setup, other stuff

[Chris Wilson <chris@maximum-bhp.u-net.com>]

In article <9706242304.AA13943@mashtun.JPL.NASA.GOV>, in mail.Audi_List, 
wrote:

> I think there is one other reason to NOT spray water at the
> turbo end.  Cooling before the IC decreases the deltaT and
> reduces it's efficiency.  Spraying after keeps the IC operating
> at max Eff.  The net result of spraying after should be a more
> dense air charge (cooler).  If the dispersion and evaporation 
> rates differ, that could negate this effect however.  More ideas?

Your statement is perfectly correct.However,in real world tests,measuring 
temperature at the engine side of the throttle body,it seems that in _most_ 
cases,injecting water into the inlet of the compressor gives a bigger temp 
reduction...

Maybe it is due to the good atomisation the turbo imparts? I too worry 
about droplet fall out across the intercooler,but it has only once been a 
problem,and that was on a vehicle with too long a pipe run,and possibly too 
large an IC.

Having said all that,my own car (not an Audi),has the water injected after 
the cooler,just before the throttle body.This was really for plumbing 
reasons,as I inject fuel into the turbine side of the TC,in order to 
minimise lag.(It runs a wild cam and huge exhaust valves,so I get lag after 
coming off boost).


-- 
    Best Regards,
                 Chris Wilson
http://www.netcomuk.co.uk/~komondor
mailto:komondor@netcomuk.co.uk