okay, so whats the friggin deal. 88, l98, mostly stock (k&n, flowmaster cat-back, 160stat and hypertech fan switch). when its hot outside, 90-110 degrees, the car runs cool; around 175-185. when it cools down, 65-85 degrees, the car runs hot, or i guess normal for these cars, at around 200-235 degrees. what gives??? do i just need to put a toggle switch in for the fan?? i know that the cars were designed to run 'hot' but i dont really care. i also know the thermal ramifications of the engine running hot and i want the temp to stay down. i dont care about the minimal mileage loss due to cooler engine temps. any help here???

 

A cooler thermostat won't make it run any cooler. Once the water temp reaches the opening point of the stat, the stat opens. After it opens, it's totally out of the picture. THINK about what the thermostat does. All you can gain with ONLY changing to a cooler stat is increased warm up times and accelerated wear and tear on your engine. Haven't you seen the frequent and heated debates on this subject?

RACE ON!!!

 

It sounds like you may have a low temp T-stat but no fan switch to match.

If you want it to run cooler, you can:
-install a manual fan switch
-install an aux fan switch to match the T-stat and wire it to control the main fan
-have your EPROM programmed to control the fan around the cooler temp to match the T-stat

First you should find out what temp is your current T-stat.

 

Something doesn't make sense here!

As said previously, once the thermo opens, it is out of the picture!

So you are saying at high air temps, engine runs cooler and at low air temps engine runs hottter? And it sounds like by a wide margin! I am assuming we are talking about the same driving conditions!

I think you need to check the guages...what you are saying shouldn't happen! Or else check your thermostat! But with the temp swings you are talking about, i don't think thats the problem

 

You have your a/c on when it's 95-100 out right?
that means both of your fans are on.

In coolor weather, your a/c is off right?
... so fans are off until 225* (or whatever the stock setting is in your car).

 

Word.

 

okay, i think my original post was a little vague.
i installed a 160 hypertech stat. (and yes, i know what a stat does and how it works.)
i also installed a hypertech fan switch that is SUPPOSED to turn the fan on at 185 and shut it off at 170. at least thats what the paperwork said.
now....
when the ambient temp is hot-90 to 110 degrees (i live in fresno cal.), and i have the top down (no a/c running), the engine temp is cool-170 to 185 degrees. sometimes even cooler!! which is fine by me.
when the ambient temp is cool-60 to 85 degrees, the engine temp is usually 200 plus!!!
i dont understand this. this is the first and only computer controlled car i have ever modified. i have built several older cars, gtos, t/a's, el-caminos etc. so i understand how things work. just not with computer controlled cars. although this doesnt make any sense regardless of it being computer controlled.
i am going to assume that the main fan is not being controlled by the new hypertech fan switch the way the paper work said it should be.
if that seems like an accurate (and obvious) assumption, i guess i should put in a toggle switch for the fan. if i should just throw in a toggle, can i just wire it direct, or do i need to go through a relay, and if so, which relay??
any and all help is mucho appriciated.
james.

 

Well, this should make you happy. You gave me advice a while back. Even though I'm in the hot desert, I had been running way too cool with a 160* t-stat, fan programed to come on at 180*, and a hugh Ron Davis radiator. Just got my '93 back from a heads-cam package and had them install a new water pump, 180* t-stat and fans on at 195*. Now I am running a 195-205 on the highway, and 195-220 in traffic. Feel much safer now.

 

i am also going to assume that the hypertech fan switch 'turning on the fan at 185' is a load of hooie from typertech.

 

Well, first of all, 170-185* is just too cool for these engines. Second, the first thing I thought of was that your t-stat was stuck open. I know it doesn't make sense, but I had that same problem back in the old days when we would completely remove the t-stat. Cars would run fine in the summer, but then overheat in the winter. Go figure.

 

Probably not, however as with everything else there are tolerances. Remember, unless you have rewired your fans, that HyperTech fan switch only controls the axillary fan. You can have your chip reprogrammed if you want the main fan to come on at a different than stock temp.

Is there a reason not to use the existing main fan relay?

As Lichen states that is cooler than you SHOULD want your engine to run.

RACE ON!!!

 

Your engine should be running that hot.
On a semi-related note, my center air dam fell off and it wasn't until after it was gone that i ever got temps into the 205+ range...

 

The only way to make it run cooler after tstat opens is a better radiator or fan switch or override.

I wired mine up so I can override both fans at any temperature. When my switch is off, they operate as stock. Would you like this or would you like them both to come on at a lower temp all the time?

 

central, thats what i want to do. switch them on manually, and then let them go on when computer tells them to when the switch is off. how exactly do you wire it for that???
the radiator is new by the way.
also, as far as where i should want the temp....the car runs better, i.e. better 1/4 mile times when the temp is down. runs 6 to 7 tenths slower at high engine temps regardless of ambient temp. thanks for the input though.

 

http://www.domesticmisfits.com/forum...pic.php?t=6048

Your wiring may vary, this is on my 85.

PM me if you have any questions. I leave my car idling in the staging lanes, at every run I'm between 180-185 degrees with a 180 stat.

Sure beats pushing a hot car around like the ricers do.

Maybe next I'll do an alternator cutout switch.

 

Running abnormally cool for a specific purpose and for a limited amount of time is a whole different situation than a constant day in, day out, over cooling condition. Six to seven tenths is not normal, however, mine is more like a tenth or less.

I run my fan, no auxiliary, in the pits with the engine off. I spray my radiator with water from a garden sprayer. After about 10-15 minutes of cooling, I start the engine for approx 45-60 seconds to circulate the cooled water from the radiator to the engine, and vise versa. Then I start over on the hotter water from the engine. I usually do this a total of 3 times. When I leave the pits the water is usually in the 150° range. I drive to and through the staging lanes. I don't run my engine any more than necessary. I don't move my car every time the line moves a car length. I turn the fan off before my burn out, and my engine temp is usually about 170°. In cool weather (under 90) it COULD be lower, but that would mess with consistency.

Driving down the road the water temp is usually 185°-195°, borderline too cool, with a 180° thermostat.

RACE ON!!!

 

aside from emissions, what is the problem with running the engine at a cool temp?? ive never had any issues with binding a piston skirt, havent had any issues with abnormal ring wear or cylinder galling.
running at a cooler temp has helped keep detonation away, allowing for more timing and prolonged valve and valve guide life. not to mention not burning up the oil and extending oil life-not certain about 'oil life' but it keeps the oil looking like oil longer. (i change it at 2500 miles anyway)

 

Wear of most engine parts, most notably cylinder walls and rings, is accelerated at lower than ideal engine temperatures. Do a search for references to research and studies done on the subject. In addition, water condenses into the oil as the engine cools. Blow by gas mix with the water and oil to form weak acids that etch bearings and cause other damage. Higher operating temps boil out more of the contaminants more quickly. Your search will reveal additional discussion on this topic, too.

RACE ON!!!

 

my thermomaster hypertech chip turned my only puller fan on dropped from 210-15 or so to 200 fan comes on really soon. center air dam tore off finally went to 205. water pump leaking a little put in a ported polished intake took out air pump crap lower hypertech 160 stat still no air dam now dropped to 170 sometimes more up to 185. never run air conditioning. the only thing that changed is no air pump egr blocked off which i dont think should change the temp and the thermastat. which did it?

 

If the fans were coming on early enough, it could be the thermostat. You should be able to cure that problem by changing to a 180° or higher thermostat and reprogramming the fans(s) to come in at a more reasonable temperature, like 205°-210°.

RACE ON!!!