160F Low Temperature Thermostat = higher horsepower

[BRAN]

"... a cooler engine will have higher volumetric efficiency. Lower temperatures will also allow for more timing without detonation since the ECU is capable of changing timing based off of fuel quality and engine operating temperature. This can result in higher horsepower and better fuel economy as well..."

Theory or Reality?

[JFP in PA]

Originally Posted by BRAN

"... a cooler engine will have higher volumetric efficiency. Lower temperatures will also allow for more timing without detonation since the ECU is capable of changing timing based off of fuel quality and engine operating temperature. This can result in higher horsepower and better fuel economy as well..."

Theory or Reality?

It is real, but the gains are very small, 2-3 HP on a dyno. Bigger advantage is reducing the heat stress on the engine castings and lowing the oil temp by 25F, which is a huge advantage.

[Gelbster]

After an expensive and unexpected engine rebuild ,I have become much more interested in protecting the engine from the many MOF's than getting more power...Yemv
I love the lower temp thermostat for that reason alone.

[911monty]

Originally Posted by JFP in PA

It is real, but the gains are very small, 2-3 HP on a dyno. Bigger advantage is reducing the heat stress on the engine castings and lowing the oil temp by 25F, which is a huge advantage.

And thanks to JFP this is now why my base sports the low temp and a new S oil cooler.

[RandallNeighbour]

It has a downside though... the vents don't produce as much heat when you need it in the middle of winter!

For this reason alone I'm glad I live in Houston. But that's the only reason.

[JFP in PA]

Originally Posted by RandallNeighbour

It has a downside though... the vents don't produce as much heat when you need it in the middle of winter!

For this reason alone I'm glad I live in Houston. But that's the only reason.

I would not bet on that; one of the most common comments we get from daily drivers in cold weather is that the car seems to warm up more quickly, which is actually not correct but is the perception you get because warm water starts circulating earlier with the 160 F stat. Even at 0F, I get more heat than I need out of my cars.

[Jake Raby]

The 160*F Low Temp T Stat from LN was developed in -20F conditions, in Chicago.

The real difference comes from not just when the T stat starts to open, but the temperature that it reaches a fully open position.

I have used NOTHING else in my engines since 2007. If someone requests a factory unit, I request that they take their business to someone who isn't a developer, and will do whatever they want.

[pjq]

Haaaaaaa! when I did my rebuild a few years ago I used the 160 low temp thermostat from LN. It was because of all the advice I received and read from these forums and it made sense. It had nothing to do with the cold temps I live in or it could operate in, because my BOX has not seen snow nor is it ever going to see snow as long as I own it!
It is my daily driver from May through to November.
I think I just went for my last ride of the year yesterday when I did a 5 hr drive taking my daughter back to university. The car runs great. Daytime Temps are still above 0 Celsius up here in New Brunswick Canada but any day now someone is going to pull the plug and we'll be in a deep freeze.
HP - my S has all I need.

[lkchris]

The temperature rating of a replacement thermostat must be the correct one for the application because of the adverse affects the wrong thermostat can have on drivability, engine performance and emissions.

The temperature rating specified by the car manufacturer is especially important in many 1981 and newer vehicles because the onboard computer monitors coolant temperature through a coolant sensor to control fuel enrichment, spark timing and operation of the EGR valve. Even on vehicles without computers, thermal vacuum switches that react to a specific coolant temperature are often used to open and close various vacuum circuits that regulate fuel enrichment, timing and EGR. If a colder thermostat is installed, the coolant may never get hot enough to trigger the appropriate control functions or to allow a computer system to go into “closed loop”. Too hot a thermostat can also interfere with the proper operation of engine controls, and increase the engine’s operating temperature to the point where it may experience detonation (spark knock).

http://www.crankshaftcoalition.com/wiki/Thermostats_explained

[JayG]

I put in a low temp thermostat when I changed the waterpump a little while ago.

The one thing I noticed is the water temp takes longer to reach normal, the needle in the middle of the 8.

My butt dyno say at least 25 more WHP

[78F350]

I'm thinking that I should do this on all my Boxsters. I see there is an option to buy just the 160F insert on Pelican for about $40.
Besides the extra work, is there any reason not to just replace the insert in my original thermostats and save $100+ each over buying the full replacement product?
I like to save money, but not if it is a big compromise to the effectiveness & reliability.

[JayG]

You can find low temp thermostats with the housing for under $50
The thermostat without the housing is around $100

go figure.....

[winter.k]

Originally Posted by Jake Raby

The 160*F Low Temp T Stat from LN was developed in -20F conditions, in Chicago.

The real difference comes from not just when the T stat starts to open, but the temperature that it reaches a fully open position.

I have used NOTHING else in my engines since 2007. If someone requests a factory unit, I request that they take their business to someone who isn't a developer, and will do whatever they want.

I have struggled to understand the lower steady-state operating temperature. How does the thermostat opening earlier (@ 160* F) actually lower the steady-state temperature, instead of just delaying it? The cooling system must have the ability to lower the temperature below 160*?

160* thermostat sounds like it has benefits, but what are the drawbacks? I'm sure Porsche didn't select 180* for their operating temp without reason.

[JFP in PA]

Originally Posted by winter.k

I have struggled to understand the lower steady-state operating temperature. How does the thermostat opening earlier (@ 160* F) actually lower the steady-state temperature, instead of just delaying it? The cooling system must have the ability to lower the temperature below 160*?

160* thermostat sounds like it has benefits, but what are the drawbacks? I'm sure Porsche didn't select 180* for their operating temp without reason.

Think of the function of thermostat in your car as similar to the one in your home. It functions as a throttling device which restricts water flow if the coolant is too cool, opens wide if it gets too hot. Can the engine get above 160F? Yes, in fact the "steady state" cruising temp tends to settle in in the low to mid 170F range (which is way below the normal 205-210F with the OEM stat); but if the car gets caught in traffic, it will heat up until the fans kick in; but then when you get moving again, it drops back down to the 170 range.

After years of using them in my personal cars, as well as in customer cars, I have seen no "downsides". If fact, because the coolant also cools the oil in the M96/97, the oil temps tend to run much cooler, which also shows up in UOA's were the oil tends to show slower degradation over usage time.

[BoxsterSteve]

Originally Posted by winter.k

I'm sure Porsche didn't select 180* for their operating temp without reason.

For emissions reduction purposes as a hotter running engine produces fewer NOx pollutants.

Possible, but I'm unsure; may also have something to do with their being able to claim longer oil change intervals if oil is hotter and burns off contaminants more completely !?
At least in theory, anyhow.

[JFP in PA]

Originally Posted by BoxsterSteve

Possible, but I'm unsure; may also have something to do with their being able to claim longer oil change intervals if oil is hotter and burns off contaminants more completely !?
At least in theory, anyhow.

Just the opposite is correct: as I noted above, years of UOA results say the lower temperature stats actually do more to help the oil live longer. The same UOA's also back up the fact that oil contamination (fuel and water) are the same with the 160F stat as they are with the 186F OEM unit.

[BoxsterSteve]

JFP,
Appreciate the clarification, thanks for the info.