my factory switch is bad and i need the fan to kick on way earlier. this is supposed to be 176* on 166* off. anyone running one? hows it working out for ya?

 

From my research on here I think quite a few people do use these. I have one in mine. It wasn't doing enough for me even with a new bigger aluminum radiator as I have a performance motor with mods and a supercharger. I actually just yesterday made a jumper to my primary fan so they both now kick on at 176, my car still ran at about 220 today (assuming the gauge is accurate). It had redlined the day before so it lowered the temp about 30 degrees.

 

I prefer Hypertech's part 4028 instead. On at 200°, off at 185°.

Granted, AZ and TX will have the secondary fan on whenever the A/C on (all the time) and anytime we're stuck in traffic with the A/C off. But the 200/185 gives you more alternator voltage when the fan isn't running, gives heat on that rare winter day when we switch to heater. And at 200° it's on regardless of which switch you choose. What are the odds our cars get back to 185° and actually shut off the fan?

At 184°, I don't see the need to have both fans running.

The 176/166° fan switch is essentially on forever once it turns on. You'll never get the car to 165° while at the same time be driving at less than 40 mph. (The fans shut off at 40 mph).....When I lived in Canada and had the primary fan set for 176/166 (w Hypertech Thermomaster) and stock secondary fan (it would never turn on), the primary fan would turn on and stay on even when the weather was 65° and low humidity at night with no traffic or stop lights.

 

wait so the fans shut off when you are going less than 40mph? thats where 90% of my driving is done! i have it on all the time now via a/c. but i pretty much need it that way since it gets so hot here. so will the 4026 switch give me what i need?

 

No, that would make no sense, the fans are needed at low speed to compensate for less airflow, I think he was saying the fans shut off above 40mph.

 

okay just got a little confused.i have a single fan. sounds good

 

Interesting, what about people with a single bigger fan? I'm running the 176/166 switch with a 160 thermostat, and a thermomaster chip.

I will admit, the voltage is great untell the fan kicks on and it lowers from 14 to 13, so it stays in the middle most of time, even dips more at idle when headlights on.

What thermostat are you using? 160/180? I'm wondering if i should switch to the 4028, given my car runs in the middle line between 100 and 220, think it's 180, and never moves, the fan runs 24/7, however i'm thinking the 4028 will do the same exact thing, only change would be in the winter where it might shut off I'm assuming, and improve the heating, however it my car will run hotter with the 4028 during the summer, i think i'll stay put.

I'm still happy with my current setup, I'm also running a 140amp powermaster alt, but at idle its only 80 amps, i wonder if a 200amp would change my voltage issues at night with lights on, it just seems ghetto.

 

I just got one of these and plan on installing it this weekend. I was planning on installing it with a 180° thermostat, but after a little thought I' thinking about going to a 160° thermostat. Its not that i think 180 is too hot, im just afraid that if i go with 180 that the fan will be on all the time.
What temp thermostat are you running Reid?

Also i seem to remember seeing something about this switch not being on the passenger side cylinder head on my car (havent checked) can anyone confirm the location of the switch on an 87 iroc 305 TPI

Thanks!!

 

yeah 160 thermostat will be fine.

I prefer Jet's fan-switch ( http://store.summitracing.com/partde...5&autoview=sku )

on at 195 off at 185, comes with somewhat a better connector for install, a crimp connector, i forgot what my hypertech came with, but I had to use a wirenut and electrical tape.

 

Fans automatically shut off at 40+ mph. (they would disrupt the natural airflow going through at higher speeds)

I've run a few different setups. Originally when I lived in Canada, I had the 160° thermostat and the Hypertech thermomaster. The Hypertech turns the driver fan on at 176/off at 166°. Same as their #4026 fan switch. I ran the stock fan switch (on at 243°.....never in my instance)

Switched to a 180° thermostat. Makes no difference with the Hypertech chip as once the fan turns on at 176°, the only way it will turn off is either by driving over 40 mph or "somehow" getting the coolant temp back to 165° while driving less than 40 mph. Not likely to happen unless you're driving in freezing temperatures with a 160 thermostat.

I switched to the 200/185 fan switch.....Living in Canada and not dealing with traffic jams, the 200/185 was more insurance than anything. It rarely to never turned on. Maybe after pulling into a gas station and shutting the car off on a hot day only to start it up a few minutes later. The majority of the time my car ran at 175° (160° stat, Hypertech chip, driver fan on at 176°). Switching to the 180° stat, the car ran exactly at 180°.

I changed the Thermomaster to a custom burnt chip with fan on/off at 190/185° The driver fan would sometimes be on when I'd shut the car off. Sometimes it wouldn't. The passenger fan was still off.

Why did I switch to the 180 stat? Because on the open highway on a cool spring or fall evening, the car would dip down to 160 then go back to 175.....160,175,160,175 (remember the fans are off at highway speeds, so it's just the thermostat that's determining coolant temps. We'll ignore air dam and antifreeze ratios)

I currently live in hot as hell Texas where rush hour stop and go is common and the temps are high. Humidity is high as well.

I have a 180° stat, custom burnt chip with fan on/off at 190°/185°, and the hypertech #4028 fan switch (200/185). My car seems to like 180 better than it did 160. Currently it will shoot up to 180 fast, then sit around 185-190. With the A/C on and bad traffic, the highest it gets is 200° (stopped, going nowhere, 5 mph stop and go etc)

My car with both fans on means it's somewhere in the 185-200 range. Thermostat is open at that point. Texas heat (plus A/C condenser heat) means that in the city, I can't do much better than 185° no matter what. Going to the 176/166 fan switch wouldn't change anything for me.

Wintertime (rare in Houston, but it does happen for a few days)....My car will warm up a bit slower to 180. Thermostat opens. It "might" hit 190, but not likely. Car remains in the 180-185 range. I get good heat this way. Running the 160 stat and turning both fans on at 176 would assure me of no heat and it's better for the engine to have the coolant warmed up anyways.

So the only time my coolant ever goes above 190 is when I'm stopped in traffic. You get a bit better gas mileage at 190-200° and performance is a non issue since you're not moving anyways. On the highways, it settles around 180°

The way I figure it. Why wear out your fan motors that much sooner with the 176/166 fan switch? It's also using extra voltage to run both fans. Hard enough on the alternator as is.

Although I run the A/C a lot down here (which negates all the fan switch and chip options since the fans are on with the A/C), I still like having the 200/185 fan switch in there for when the A/C is off. It allows a bit of extra air to be pulled across my transmission cooler. Plus it allows the car to never go above 200° when the A/C is off and I'm in the city. Faster cool down of coolant after gas station stops.

I get 80° temps in December here from time to time. It's 80° by 10AM in the morning this time of year. The 160 thermostat wouldn't do me any good in the city. And I doubt it would ever run any cooler than 180 on the highway in Texas. It ran 175 on the highway in Canada during the summer. Only getting down to 160 on those cool fall evenings (55° ambient temps?). So ultimately both the 160° thermostat and the 176/166 fan switch wouldn't give me any improvement over what I currently have.

I asked a C4 Corvette guy how much mpg difference he had at 160, 180, and 195° coolant temps. (C4's have an instant fuel economy digital readout). He said at 180°, it was 1.5 mpg better than 160. At 195, it was another 0.5 mpg better.

 

Thermostat choice (160 vs 180) shouldn't make any difference. By the time the fan turns on, the thermostat will be open. The fan shuts off before either thermostat closes.

As far as I know, the fan switch is in the same area on the 87 Camaros. Between the #6 and #8 plug on the passenger side. You won't be able to see it from the top. Need to get the car on a lift to see it easily.

The 87 models are a bit different from the 88-92 in regards to A/C. On the 87, the fan switch alone determines the passenger side fan turning on/off. On the 88+ models, both the fan switch or the A/C head pressure will determine when the passenger side fan turns on/off.

 

I don't mean to jack this thread but I was planning on getting what the op is interested in until the mechanic who just did my rear brakes (got tired of looking at brakes) told me something. He said if the fan turns on to soon other sensors won't work right and the car will run too lean and burn up the motor. I've never heard this before but I've known the guy for a while and trust him. So is he full of crap?
Thanks, Alex

 

I have a digital readout that plugs into my cigarette lighter that tells me the battery voltage (car off) and alternator voltage (car on). Turning on my headlights drops the voltage by a full 1 volt. I'm not sure if it's that I have Sylvania Silverstar headlights (brighter, whiter......more power use?) or if it's just the way our headlights are. I seem to recall a 0.6 volt drop with the cooling fan on. I can't remember if that was one or both fans running.

I too have the 140 amp Powermaster and it's hard to keep things charged during the summer hot months. Especially at night when you have the headlights on, A/C on (and of course both fans with the A/C) and driving stop and go in the city. I may upgrade to a bigger alternator/battery wire in the future.

I thought about getting a 200 amp alternator. But the main problem with our alternators is heat rejection. The CS130 "small" alternators that we own have a hard enough time with it. The CS144 "large" alternators (used on trucks) seem to have an easier time with heat. Larger engine compartments on trucks probably helps too. The 200 amp in a CS130 sounds like even more trouble with heat.

If I were you? Sure, go for the #4028 fan switch (200/185). Cheap enough to switch over. It all depends what temp you want your car at though. If you're aiming for 160-170, then keep your current switch. If you want 180-190, go for the other switch.

 

Running too cool would more likely result in running too rich. Unless you live in Alaska, it's just about impossible for these cars to run too cold during the summer.

 

Well it's been 80's lately, it runs directly in the middle line between 100-220 on hot days, i believe it to be about 170-175. I had a 180 thermostat in for the winter to make my heat better, and it ran a tiny bit past the line i mentioned before, so used that reading for a 180 degree mark.

Would my setup be ok with a Jet fan switch? it's 195/185 and has a easier connector for install, last time I had to use a wirenut for hypertech's part, I'm not a mechanic lol.

I'm pretty sure it will work fine with my thermomaster chip and hypertech 160 stat, I think hypertech said it was only recommended to run a hypertech powerstat with the chip.

Ultimately I'm looking to switch to the jet part for winter/heater concerns and a hope to use less of the fan during night driving, As i don't want to keep switching thermostats.

My battery wires look to be decent size, 4 gauge i believe, however the alt wire i think is like 8 gauge, I believe it goes to a junction box which in return goes to a feed to the battery, it has a fusible link as well, so me being somewhat inexperienced with wiring, might be difficult.

 

no dude, youre mechanic is totally right!!!. He's so rite, everybody is using 160* thermostat which wicked bad.(it hurts people more than it fixes) not good. Has to be 185*-195* always when running stock.!! If you did run a 160* stat, then you need a themistor fan switch thats lower turn on temp, and you would need a new THERMOMASTER hypertech prom. it changes the injection pulse and fuel curve. and i heard higher octane fuel recommended. if the computer doesnt go into close loop mode, then the computer runs rich rich rich. I had a stuck thermostat couple months ago. id be running 150* on gauge on the highway, and 220 during street. but as soon as i go 75mph for a while, then engine got fussy and went into open loop which runs on a default parameters. The computer only goes into closed loop, when three things happen. COOLANT thermistor SENSOR (not fan switch) reaches a specific temp, O2 sensor reaches 600*F, and the MAT sensor reaching a specific temp. I heard some people with coolant TB bypass have problems with startup in cold climates. You need to remember that next to CORVETTES, the 3rd gens are like luxury cars for NEW YORK BIG BUSINESS man. GM designed these cars many for NEW YORK climate in my opinion. Guys in suits would get their valet Trans Am and burn rubber living the great life. HAHA>in a sense. YOUR mechanic is cool man, and if you got rear disc brakes, becareful, theres a defect in a few models, including mine. the whole caliper needs to be rebuilt with GM#18019028 . I just ordered mine today, i got ripped, but i think of it as a donation to the failing GM COMPANY ((

 

Thanks for the info! My fan is hooked up to a toggle switch right now (came that way) and it runs richer than my friends Chevelle with NOS. I mean you can smell gas from 100ft away. Explains a lot. Thanks Again!

 

The 195/185 fan switch will work fine for your application. Closed loop depends mostly on the O2 sensor getting hot. Coolant temps need to be hotter than 40°C (104°F) which is never a problem.

A stuck thermostat running at 150° would result in rich conditions and problems. But in hot climates, a 160° thermostat will be open all the time anyways.

 

OK! So I installed the hypertech 4028 and a 180° thermostat today and now the passenger side fan will not turn on at all. The driver’s side fan turns on at what seems to be the same temp as before and cools the car down to about 220. The switch that was in the cylinder head is the same style as the hypertech, so I didn't use the adapter cable that came with the hypertech. It looks as though its installed right,... What do you think I did wrong? The temp gauge works but it seems that I did was disable the passenger side fan.

Here’s a link the hypertech so you can see the cable that I left out. The plug was just the wrong shape to connect to the one that came out of the car. The car had the gray connector in it already and clipped right into the new switch. I didn’t see anything on the car that looked like it needed the black one.
http://store.summitracing.com/largeimage.asp?part=HYP-4028&Prod=Hypertech+Cool+Fan+Switches&img=hyp-4028.jpg

Thanks for any info gang! I think the main problem is that I did the install. I know just enough about cars to be dangerous,...

 

**UPDATE**

I installed the hypertech 4028 with a 180° stat (had to do install the switch twice, the first one was bad out of the box)

Now that it works, when the car warms up to 200° the fan comes on, but the Problem now; The fan stays on. The car never makes it back down to 185° with just one fan. even on a cool 65° day.

I understand that the fan should turn off at 40mph, but by the time I pull over and pop the hood to see if the fan is off I'm not going 40mph anymore. can anyone confirm this for me?

 

It's hard to confirm the on turning on/off at 40 mph unless you had a light in your dash that turned on with the fans on and off with the fans off....I don't have that.

Think you have air bubbles in the system? Have you let the car idle to about 100° coolant temp with the radiator cap off and then top it to the top of the radiator?

Guaranteed you got a 180° stat and not a 195° by mistake?

Does San Diego even get 65° days this time of year?

 

Use a 160 thermostat, then it will definitely shut off occasionally, night driving, cold climates, etc.

You gotta understand you're using a 180 thermostat, it doesn't mean it's going to run at 180 unless you have a beast radiator like i do, however using a 160, which will probably make it run at 180/190 in hot weather anyway, but it will have a better chance of shutting off the fan that's controlled using your hypertech switch.

Hope I didn't confuse you, also make sure your air dam is there, and not bent backwards.

In 85/95 degree weather, using a 160 hypertech stat, 2-core summit alum radiator, single fan, 176/166 off fan switch, which runs always ( soon to be 195/185 ) it runs at around 170-175, and in 40-50 degree weather, it will actually run at my thermostat ( 160 ), I actually have to give credit to the summit radiator for this tho, it really is nice, sucks I had to mod it to get it to fit tho.

 

whats the perfect operating temp for the 3rd gen/

 

Hard to say.

My car doesn't like a lot of heat, could be a problem somewhere I'm to lazy to find.

With my old radiator and a 195 stat and stock switch, it would throw a code 43 all the time and run like crap, good cooling fixed that.

So i just threw in a 2-core summit alum radiator and a 160 stat/switch and it runs like a champ in all conditions.

I'd have to say 180 would be the perfect temp, not too cold, not too hot.