outside temps affecting power

[boogeyman]

lately here in chicago it has been massivly hot 120+ with heat index i recently changed the t-stat, flushed the cooling system cleaned the radiator out. now what i have noticed is that my car runs much cooler than normal just above the bottom line on the scale.
my main concern is that when iit is above say 85 degrees outside my car is way down on power but once it cool below 85 outside it runs fine and has all the power it normally does.
is this normal to loose alot of power in the high heat like that?
and why would my car run soo much cooler now than before it should run at 195 but its running much cooler than that.

 

[SHOmethewayhome]

I'd make sure you burped the cooling system really well.

 

[boogeyman]

is there a specific method on these cars ? i ran it for about 45-1hr minutes cap off heat on high with my cooling system filling funnel on it to get all the bubbles off it. or am i doing it wrong

 

[SHOmethewayhome]

nah, that sounds about right.

only thing I can think of is the heat mixed with the humidity is doing you no favors.

and when I had my SHO the temp gauge rarely went hotter than between the bottom two letters.

 

[kevinspann]

Thermostat stuck open?

 

[RonPorter]

My '89 was flushed last year, along with a new t-stat and rad cap. Driving to/from Charlotte, loaded down in 90F - 100F temps, it would run at the "L" if there was no one in front of me. If I had a vehicle ahead, it would creep up to the "A".

On the way back, I started experiencing some surging in 1st & 2nd under load. Car ran fine after that in the upper gears and while cruising, so I'm hoping it was just the heat.

 

[boogeyman]

before i did the t- stat and cooling system stuff it ran dead center in the middle of the guage tho thats what has me puzzled
do you guys have any experiance with cooling system additaves such as water wetter, dei anything like that i was going to use something like that for the added protection water pump lubricant, and corrosion resistance

 

[SHOZ123]

Those temp gages are one step above an idiot light.

 

[boogeyman]

Those temp gages are one step above an idiot light.

yea i been thinking of putting a real set of guages in the car just because of that reason

 

[SHOZ123]

What I've seen on the Gen 1-2s is the radiator cap is bad or the tanks will leak on the radiator. Both of these cause you to lose pressure and hinders the cooling. But if you an maintain pressure when hot and vacuum on cool down then the burping takes care of itself.

On my Coupe the OEM temp gage is like the one on the Gen 3. It only really shows cold, normal running temps and hot. The needle will not move when in the running engine temp even thought he temp is swinging up and down as much as 30F.

I put in some AutoMeter gages. One was an oil temp but AutoMeter uses the same temp sender for all three of the temp gages so I got a DPDT switch some indicator LEDs and wired the two senders to the switch. I can toggle between oil and coolant temp with it.

 

[boogeyman]

the cap and radiator are both new along with hoses,heater hoses. so thats not the issue

 

[rubydist]

so the new thermostat opens at a little lower temp than the old one, so the gauge shows its not as hot. either change the thermostat to one that has a higher opening temp or live with it.

the extreme temps make the air less dense, so you have less mass of air going into the engine, therefore the power output is less. its just physics.

 

[SHOZ123]

Or maybe the sensor is bad.

 

[jayro]

I'd say, since it is running cooler now, it is the thermostat opening earlier. Like suggested, you could try one that opens a little later.

As far as being down on power when it's hot out. Sounds about right. It happens to all vehicles due to air density, but it does seem to effect the sho a little more than most. The humidity is a real killer too.

Mine really perks up on those cool 60 something fall days.

 

[boogeyman]

yea im familiar with loosing power when its hot out i know thats normal but i was just wondering if the large drop was normal
jayro thanks for the awnser

 

[SHOspazz92]

Autcross is always ran in the summer, luckily it does not take much power to be fast on the Auto-X course, otherwise I'd be hurting. I also only drag race in the winter. =)

-Sam