Turbo miata showing hot temperatures

In article >,
pws > wrote:

> Would it make sense to you that I would seem to be getting
> better/quicker cooling from a completely open turn signal hole than from
> the headlights being up?

Sure. But bear in mind that a TSI's opening is much smaller than the
hole left by removing the light assembly entirely. Leon can tell you how
boundary layers restrict flow even further through a small opening.

I also wonder if auxilliary air inlets don't reduce the efficiency of
the radiator, by "competing" for the ability to raise the pressure of
the engine bay. I have no data that this actually occurs, it's just a
thought experiment, but if airflow is limited by the exit capacity, you
might be robbing Peter to pay Paul.

What's more important: reducing the temperature at some arbitrary sensor
location in the engine bay, or helping the cooling system operate
according to its design?

> I also seem to remember that you had a method for diagnosing the
> intermittent fan problem. If you have those instructions that would be
> great because I would still like to check that out to be certain it
> isn't the problem.

I removed the suspect fan (shroud/motor/blade assembly) and connected it
to a spare battery. I marked one blade so I could keep track of its
position. Repeated connections revealed that if the blade stopped in a
certain position, it would not restart without a push. My conclusion was
that the motor had developed a dead spot on its commutator; sometimes it
would stop and not restart, until--presumably--a bump in the road jarred
it off the dead spot. Or something. Replacing the motor with a used part
solved my problem.

---
Lanny Chambers
'94C, St. Louis
http://www.hummingbirds.net/alignment.html

pws > wrote:

>Leon van Dommelen wrote:
>
>>
>>
>> I would stay away from the funnel-shaped ones. A screen type might be the
>> best, I would think.
>>
>> Leon
>>
>
>Would this be to keep debris out or is there a design problem that you
>know of with the funnel-style intakes?

There is a designer problem. When the area of a duct decreases, the velocity
goes up. So the designer obviously reasoned that by contracting the duct [s]he
would get a powerful blast of air into the engine bay. Unfortunately, it does
not work. You cannot get a blast of air if no air enters the duct at the other
side in the first place. The best would be to have a diffuser, not a funnel.

Leon

--
Leon van Dommelen Bozo, the White 96 Sebring Miata .)
http://www.dommelen.net/miata
EXIT THE INTERSTATES (Jamie Jensen)

Lanny Chambers > wrote:

>I also wonder if auxilliary air inlets don't reduce the efficiency of
>the radiator, by "competing" for the ability to raise the pressure of
>the engine bay. I have no data that this actually occurs, it's just a
>thought experiment, but if airflow is limited by the exit capacity, you
>might be robbing Peter to pay Paul.

There is no given exit capacity. When you raise the pressure in the engine
bay, more will go out. But it has been claimed that air may go out of the
ThIs instead of in. And the critical question is not really how much air goes
out, but the amount of heat the air takes out, and from where the air takes
that heat. That depends on the pattern of flow, not the amount.

I would think the real questions are
1) is the coolant temperature within safe limits.
2) is the intake air temperature as low as possible.
The Link ECU shows both of those temperatures, and the Tec might too. The Link
has logging capability, so if I worried about mine, I would have my Palm or
portable hooked up during driving to see. (Actually, I already know both
are problematic. Air temperature I cannot do much about, not liking TSIs, but
hopefully the coolant might be better now.)

Leon

--
Leon van Dommelen Bozo, the White 96 Sebring Miata .)
http://www.dommelen.net/miata
EXIT THE INTERSTATES (Jamie Jensen)

(Leon van Dommelen) wrote:

>ThIs

Isn't spell checking wonderful?

Leon.

--
Leon van Dommelen Bozo, the White 96 Sebring Miata .)
http://www.dommelen.net/miata
EXIT THE INTERSTATES (Jamie Jensen)