Low temp thermostat

[Dr.Acacio]

Hi
 I am writing to the ftp the eprom bin file off Camaro Z28 1993. ( BDZL M
131610469 )
 Does anyone know where is the address of the radiator fan coolant
 temperature????
 Here in Brazil's interland  I have problems  with the fan  starting at
 109-110  Celsius,
 I would like to down to 99 -103 Celsius.........
 I have looked at the ftp and did not find info about this file.....
Probably the address will be at the same place off another calibration for
same ECU model??????
I friend told me that Hypertech chip normally change the start fan
temperature, is it true?????
 Many thanks in advance.
 Flavio



-----Mensagem Original-----
De: G. Scott Ponton <gscottp at ix.netcom.com>
Para: <gmecm at efi332.eng.ohio-state.edu>
Enviada em: Quarta-feira, 27 de Outubro de 1999 11:39
Assunto: Re: Low temp thermostat


> Tyler wrote
> <snip>
> >Since we are talking about people who are trying to optimize a
> >particular heat pump it would be of interest to everyone to know at just
> >what temp that pump gets the best HP given optimal conditions. A blanket
> >statement that this temp is 159 or 220 or 190 does an injustice to all.
> >It is obvious to all that you have an experts knowledge of what is going
> >on here but there are three temperatures that are critical to an engine
> >for hp, water, oil and inlet air.  So if an engine can have an under
> >hood water temp range that optimizes these one would set chip
> >programming to take advantage of this range.  It may be that the LT-5
> >motor sees 190 deg oil temp 130 deg inlet temp at 159 deg water temp and
> >this is the best balance that can be attained in a C 4 body style.  I
> >believe that this is a thought process that should be a part of any
> >effort to design a system for a given engine.
>
>     All this is right on the money. The last line in particular says most
of
> what needed to be said. Lower block temps do have an effect on the
> horsepower that is a vaolable in the application that you have specified.
I
> think that there is a lot of misunderstanding as to the real effect water
> temp has on the system. In the end it is all "engine" dependant.
>     The actual effect water temp has on the equation is due to thermal
> expansion of the block and pistons. A higher oil temp with a lower water
> temp speaks volumns as the oil temp is a direct indicator of the
temperature
> of the pistons and the rest of the rotating assembly. Whereas the water
temp
> is a reflection of the temp of the block and heads. Inlet air temp is also
> important as it obviously indicates the differences in the density of the
> air the engine is ingesting.
>     I find it hard to believe, under WOT and a reasonable engine speed
> (above 4,000), that the temperature of the engine will effect the inlet
air
> temp by more than a couple of degrees. Air is a great insulater from heat.
> The lenth of time that it remains in the intake track during racing
> conditions isn't going to be long enough to really effect it's
temperature.
>     Yes if your air inlet is "underhood" the temperature of the underhood
> air becomes the inlet temp.  At this point the temp of the cooling system
> has an effect on power production and installing a lower temp thermostat
> will have an effect. But if the air inlet is isolated, by either a "ram
air"
> system or a hood scoop the underhood temps have little or no effect on
inlet
> temps.
>     If you look at auto racing in all of it's forms I think you will find
> that in every instance they run their water temps at 200+ F. This includes
> Indy, NASCAR and formula 1 as well as most SCCA cars. If it was benifitial
> to operate engines at a lower temp I think that these racers would have
> figured out how to reduce their water temps by now.
>     I drag race a Pontiac. After extensive testing on an engine dyno, a
> chassis dyno and at the track I have found that the engine produces the
best
> power at 200 F, water temp. Through this testing I have found that a
change
> in the piston skirt clearance of .0005" is enough to effect the temp at
> which the engine produces the best power. Through this testing I have
found
> that if I set tolerances slightly looser, at the piston, and run the
engine
> at a water temp of 200 F I can produce 30 to 40 more horses and as much as
> 50 ft/lbs of torque. I also can run the engine with less ignition lead and
a
> leaner AFR under these conditions while still maintaining the same power
> levels. Lastly I have found that the engine is more consistant at the
higher
> temps.
>     Naturally I am speaking about racing here. In a street or OEM
> application things are slightly different as the engines are designed and
> built to last for a longer period of time. As such the initial tolerances
> are "tighter" when the engine is new to allow for wear and tear. If they
> were built to optimize their power levels they would need to be rebuild
> every couple of thousand miles in order to run optimally.
>
>     just my .02
>
> Scott
>
>