Diablosport Forums

This is intended for Mike L. or someone else that is on the Diablosport tech department payroll.

There are a lot of threads, on a lot of forums, with a lot of opinions, about, "What should the Fans be set to?"

Then, there are cars that are stock, have 170* thermostats, have 180*'s, are race cars, are daily drivers, etc.

It would be great if the company that gave us the option to adjust those settings, would tell us what settings they suggest, all in one sticky.

Please create a sticky, or turn this into a sticky; and explain for us, with a lot of very clear information and rationale, "covering all the bases," the following. You could even lock the thread to future posts.

I know this may be a lot of work; but, it would be extremely valuable for all of us, and may cut down on a lot of threads posted by a lot of confused people.

The settings we can adjust are:
AC off, high MPH, high speed fan on temp
AC off, high MPH, low speed fan on temp
AC off, high MPH, medium speed fan on temp

AC off, low MPH, high speed fan on temp
AC off, low MPH, low speed fan on temp
AC off, low MPH, medium speed fan on temp

AC on, high speed fan on temp
AC on, medium speed fan on temp
AC on, low speed fan on temp

1. Please clarify, just to eliminate the confusion about this: The MPH settings are just that. They are tied to the MPH that the car is traveling, correct?

2. And aside from that, the fan itself has three different speed settings: Low, medium, and high, correct?


For all of the following, if the 6.1, 5.7, and V6 use different thermostats, or if you recommend different settings anyway, you may need to break each of these down by specific platform:

3. What are the factory fan settings? Please give us the individual numbers for the following. It would be great to know this so we have a point of reference. Again, if different cars or models use different thermostats, we would need the settings for each platform.
AC off, high MPH, high speed fan on temp =
AC off, high MPH, low speed fan on temp =
AC off, high MPH, medium speed fan on temp =

AC off, low MPH, high speed fan on temp =
AC off, low MPH, low speed fan on temp =
AC off, low MPH, medium speed fan on temp =

AC on, high speed fan on temp =
AC on, medium speed fan on temp =
AC on, low speed fan on temp =


4. If using a factory thermostat: What should we change the fan settings to? Please give us individual numbers that we should set the Predator to. Not "-10* across the board," unless that is true in all cases; that we should simply set every individual setting to "X* less than the factory setting" (now that we'll have the factory settings above, we can understand that).
AC off, high MPH, high speed fan on temp =
AC off, high MPH, low speed fan on temp =
AC off, high MPH, medium speed fan on temp =

AC off, low MPH, high speed fan on temp =
AC off, low MPH, low speed fan on temp =
AC off, low MPH, medium speed fan on temp =

AC on, high speed fan on temp =
AC on, medium speed fan on temp =
AC on, low speed fan on temp =


5. What settings do you recommend if we install a 180* thermostat?
AC off, high MPH, high speed fan on temp =
AC off, high MPH, low speed fan on temp =
AC off, high MPH, medium speed fan on temp =

AC off, low MPH, high speed fan on temp =
AC off, low MPH, low speed fan on temp =
AC off, low MPH, medium speed fan on temp =

AC on, high speed fan on temp =
AC on, medium speed fan on temp =
AC on, low speed fan on temp =


6. What settings do you recommend if we install a 170* thermostat?
AC off, high MPH, high speed fan on temp =
AC off, high MPH, low speed fan on temp =
AC off, high MPH, medium speed fan on temp =

AC off, low MPH, high speed fan on temp =
AC off, low MPH, low speed fan on temp =
AC off, low MPH, medium speed fan on temp =

AC on, high speed fan on temp =
AC on, medium speed fan on temp =
AC on, low speed fan on temp =


7. Do you recommend any different settings (from above) if the car is a:
A. Weekend only cruiser?
B. Daily Driver in Florida (extreme upper temperatures)?
C. Daily Driver in Michigan (extreme lower temperatures)?
D. Race car?


8. And the icing-on-the-cake would be: If you told us all the fan settings that you already have programmed into the Predator for the 93 & 91 Octane tunes. Again, it would be a great point of reference for us.


I hope you see all the different "what if's" that we see posted on forums every day. To have the "official" "Diablosport recommended" settings all in one sticky, would help a lot of people. Then, they still have the option to set them wherever they want.

Thanks for considering this.

Its really best to experiment with each vehicle though, since as you stated, driving style, mods, geographic location, etc., will all have an impact on the proper settings for your car.

Hi Mike,

The problem is, while we're driving: We don't know when the fans are on, or at what speed they're on: Other than the high speed fans because we can hear them screaming.

People are suggesting to set the low speed fans to come on at 181* when a 180 thermostat is installed. That sounds crazy to me because a 180* thermostat doesn't even start to open until 182*. It's only half open at 184* (Tested in a pot of water on the stove). They're setting the fans to be running full time (after the car is warmed up), even if it's 70, 40, or even 20 degrees outside. That makes no sense to me.

A lot of people are thinking, "As long as the motor's cool, I'm making more power." That's not quite true.
When a fan is on it draws current from the battery. The alternator immediately steps up to replace that "used" current.
The alternator does not spin for free.
To replace that current the alternator (drags, if you will) and puts a load on the engine. That extra alternator load reduces the power available to the rear tires. The faster those fans spin, the more the load. . .

Yes. You have reduced the temperature of the motor, hoping to increase your HP available.
But, you’re having the alternator put a load on the engine; thereby, using up (at least) some of that power that you’re trying to save.

So, it makes more sense to me to only have the fans on when they're needed. Not all the time.

Just my way of thinking. . .


Anyway, could you please tell me what all those factory settings are for an 09 Challenger SRT? AC On and AC Off, please.
And, if you will, the fan settings that the 93 & 91 octane tunes come with. That would at least give me a reference point.

Because right now, I'm thinking: 203* - 180* = 23*. So, maybe, I should just set my settings to 23* lower than the factory settings. . . ???

Thanks,

Ricks, here is a start:

Factory settings - this is a direct copy of an E-mail from a Chrysler Service Manager:

RE: 6.1L

They run hot about 215 -220 on the gauge (it's a emission legal racing motor LOL) it likes hot coolant and cold air !

low fan comes on @ 217F, shuts off at 212F

high fan comes on @ 226F, shuts off at 219F

remember the t-stat starts to open at 203F and I believe is fully open at around 208F so normal conditions driving down the road the car will run around 210-215F. hard driving will normally get high speed fans to come on.

My aftermarket comments: The Motoraid 4128 (180 degree) runs about 3-4 degrees hotter than a Jet (180 degree). The 4128 seems to be the one that works about 20 degrees lower than stock. Going down the road the 4128 runs 186 on a cool day and 188 above 75 degrees. The 4127 runs about ten degrees below the 7128. Over at another Forum we have TONS of input that says the HS setting turns off about 7 degrees below it's set point. That is also consistent with the info from Chrysler I posted above. Most people go with a 185/195 degree setting for the 180 degree thermos. One real knowable guy even uses that setting with his 4127 and only changes the setting when he goes racing. Most people use the 170 degree thermos for racing applications since the 180 degree is so hard to keep under 190 degrees when running hard. Also, some people report that the 170 degree thermos can cause intermittent engine codes to come up if you set your daily driver settings too low.

Since the settings are different with AC on and AC off, it is most convenient to set them different. Even in Minnesota I assume hot climate settings are with the A/C on. I set the HS/MS settings higher with the A/C on. That keeps the A/C on HS fan speed reserved for when it is setting in traffic and/or running the car hard. The A/C off setting is for a cooler day regardless of where you are at. I use my car in -30 below temps and at temps approaching 100 degrees. I never change the A/C off settings. All that is different is that on a -30 degree day it runs at about 186 and on a hundred degree day it runs 188-190. I have a HS/MS AC on setting at a few degrees hotter.

Regarding the load on an alternator causing lost HP - I personally cannot imagine that a few amps of load will make anything but a difference you cannot measure with regard to performance.

You want to check the fan settings with all canned and/or CMR or custom programs, I have several programs and never load a tune without checking the fan settings, because everyone has their opinion on what settings they want anyway.

Hope that helps.

Hi...new to this...loaded the 91 octane tune...runs great...hear a fan coming on and staying on longer that usual with stock tune, while aircon is running...is this an aircon fan or some other fan...what are 'fan settings' exactly and how do they affect performance/engine if they are on more than usual...what are the suggested settings for 5.7 hemi 91 0ctane tune...thanks!!

I support "ricks" request for stock, canned tunes, and recommended fan settings. It would be very helpful. When I load the canned 91 octane tune my high speed fans run constantly with my factory thermostat. i got so tired of listening to it that I unloaded the Predator tune and went back to my factory stock tune. I did that because I don't want to screw with the fan settings without knowing what is ok and what isn't. I assume the Predator canned 91 octane tune uses different fan settings than the Chrysler factory settings???? So, I support Ricks request for a little information we can use to set things properly and have some better understanding.
Respectfully
Probb

Hello fellow searchers for speed and fan advice (bad pun)...I don't mind have the predator tune settings intact when the air con is on as long as the setting is doing what it is supposed to do...but what is that?: to cool the engine at different settings because of load issues or to keep a constant engine thermostat setting...I have heard there are issues with going to a 180 degree t-stat and I don't mind running my OEM but I would like to know the facts about fan settings and the consequences of: either altering the settings or leaving the settings as they are but having the fan run more often that is intended with the stock setting.

Predator 91 octane fan settings are set significantly lower than OEM settings for stock 203 degree thermostat. Stock 203 stat is set at 216/227. With stock thermostat and Predator 91 octane CAI tune, your fans will run amlost constantly. I left my 91 octane CAI tune in but reset fan settings to Dodge OEM settings. Fans run minimally now and temp read out on EVIC remains same as stock. If Diablosport disagrees with this, please tell us SOON!
Thanks
Paul

Predator 91 octane fan settings are set significantly lower than OEM settings for stock 203 degree thermostat. Stock 203 stat is set at 216/227. With stock thermostat and Predator 91 octane CAI tune, your fans will run alost constantly. I left my 91 octane CAI tune in but reset fan settings to Dodge OEM settings. Fans run minimally now and temp read out on EVIC renmains same as stock. If Diablosport disagrees with this, please tell us SOON!
Thanks
Paul

Thanks for the reply!! Not sure what I am going to do...my fans don't run all the time and I have heard the fans are rated for so many hours of run time that the latter should not be an issue in terms of replacement...but if the fans could be set to run less without endangering the engine I would like to know the temps as well, in terms of keeping the OEM t-stat, which is what I prefer to do.

I have a 2006 Charger R/T with the 93 Octane tune installed. I have had the tune in the car for over one year now and my fans just went out the other day. I never messed with any of the fan settings or the like. I have only modified the shift firmness and points and changed the tire settings. I have not had any problems with my Charger until now. The fans come in an assembly unit that is stupid expensive from the dealer at around $450.00. I found a place in CA called OEM Direct that stocks everytyhing needed but it is made out of the country. I paid $95.00 for a fan assembly today and it is in the mail. I also recently noticed that my fans were running more than ususal but I never really paid attention to it. I put the Predator on it when I had around 40,000 miles and I am at 84,000 now if that says anything to fan life for overuse.

Please let me know if anything needs to be changed so I don't burn up these cheap Chinese fans.....

Thanks.

i agree that there needs to be a sticky with "recomendations" for starting points. I have searched this too many times and its frustrating.
Also there should be mention about running too cool as the oil temp may not get hot enough to burn off condensation.

I'm thinking about buying a predator and 180 tstat but have the same concerns about fan settings as mentioned here.

I don't know if the folks from Diablo go back to these threads, but I noticed that Mike posted the following reply to a question about fan settings on a 180 tstat a couple of days after this thread was launched.
http://www.diablosport.com/index.php?na ... ic&t=25077

Is 20* below stock for all fan settings the official word from Diablo regarding the 180 tstat?

Inquiring minds want to know.

Thanks.