Guys, is anyone running a stock thermostat on their supercharged setup?

I just pulled my 170 thermo in favor of the stocker which hopefully will aid in passing California SMOG. I'm wondering if I should leave the stocker in the truck till summer or swap back to the 170 once I pass the test? Is this asking for trouble if I leave it in?

I'm seeing temps around 194ish with the stocker compared to 178ish with the 170.

-Chris

 

The 170 stat should be accounted for in your custom tune. If this was done you should have no problem passing. May want to touch base with JDM.

 

I run the stocker...

 

I run the stock one year round.

 

I had the same question when adding the SC. I stuck with the stocker as well.

 

Truck passed easy with the stock thermostat and the smog guy said it would have trouble with a lower thermo on the smog dyno. I've heard something similar in the past.

With that said, he refused to pass me for running the popular oil/air separator on my PCV valve hose. I need to throw a male-male barb on there and I will be set.

It was funny though, the tech must of asked me 50 times if the Whipple intake was stock or modified. I laughed and just kept showing him the Carb EO numbers.

California is such a pain in the rear!

 

You should run the stock thermostat. With the 170, you will get poorer MPG, increased engine wear, and more contaminants in your oil.

 

Couldn't help but laugh at this

The cooler stat will help you get rid of the heat produced by that beast. SC'd motors need this as well as the added protection against detonation. It is important to make sure the tune accounts for the stat you are running. Otherwise it will not run self test that are only performed at operating temp and it will struggle with the fuel and timing trying to warm the motor up to stock operating temp and eventually throw a code. Once it knows the new temp its fine. Another benefit of the cooler stat is engine oil temps coming down. Stock thermostat, your oil temps will average between 240*F to 280*F. With the cooler stat, your oil temps would be 232*F to 260*F. Cooler oil means you may be able to run a lighter viscosity. Just depends on the oil you run and when it shears. And as any performance enthusists does you always warm up the oil to burn off any moisture.

 

The stock thermostat in the Lightning is 190F. A oil cooler should be used to control oil temps, NOT a cooler thermostat.

 

I run a 180* thermostat with my Efan kicking in at exactly 190*. I only replaced mine from the whipple provided one due to the fact that I dont know what temp it exactly was. I thought 160* but I didnt know for sure. I wanted my efan to kick on 10* over thermostat hence the replacing.

As far as needing it for emissions, Cali sucks nuts when it comes to emissions crap. Thank god we only do a check engine light test here in AZ. My no cats overly rich beast passes with ease!

 

I never said to use the stat to control oil temps. Don't put words in my mouth. I simply pointed out that it is one of the benefits having the oil temps drop a bit. As for your point about the stat in the Lightning....its moot. The same is true of the GT500, 03-04 Cobra, sc'd Harley trucks, Thunderbird SC, Grand Prix GTP, etc, etc. Most any factory ride is going to run 185f plus. All of them running 6-8psi. Point is the pcm is programmed for this and manufacturers have to have the vehicles ready for all climates -0 to 100+ with usually only one oil recommended. The GT-500 crowd runs the 170's year round where winters aren't so rough. The northen guys run the 170 and switch to 190 in the winter. Basically anyone with increased boost or aftermarket tuning can benefit from the 170 stat in the performance dept.

 

I've seen this topic discussed a few times and the logic still escapes me. How does a stat with lower opening temp run any cooler than one with a higher opening temp once they are both fully open? We are looking for optimum operating temps ~ 200* so, the lower opening temp slows the warm-up process.

 

What you have done to the motor and how its tuned dictates operating temp. Not every setup should run at 200.

 

If the cooling system is operating properly, the thermostats will not stay fully open. They should cycle from fully open to partially closed to maintain temperature. The only time the thermostat will stay fully open will be in a over heat condition.

 

Hey twinskrewd, got a question just for my own gee-whiz!

Is it normal for blown guys run an oil temp gauge of some sort? How do you come across these numbers?

I've been running an oil temp gauge on two trucks for about a combined 200,000 miles. On a N/A 5.4, oil temps hover right around 100* above outside air temp under normal driving conditions. There's a few variables, but it takes some serious towing or agressive driving to drive them much above that point; it's very consistent.

I do imagine forced induction adds a bit of heat to the motor, especially when running it, but that's substantially hotter and it would take a sustained energy to drive the oil temps up that much.

Like I said, 100% complete curiosity on my part, nothing more.