Modifying for " Dummies"

[Darth_Emma]

I have read that folks put in a "160 degree thermostat." I'd like to know why this is desireable and how this is different from stock.

Thanks to those of you who have provided so much valuable information in this thread. Because of you kind folks, my Kooks headers are off being coated this week. They'll be installed next week with my Borla Touring exhaust and a tune next Tuesday.

[DSteck]

Originally Posted by Darth_Emma

I have read that folks put in a "160 degree thermostat." I'd like to know why this is desireable and how this is different from stock.

Ultimately... underhood temps. A lower coolant temperature actually reduces burn efficiency in the engine, which gets compensated for with more timing. It's a give and take scenario.

[06MonteSS]

Originally Posted by Darth_Emma

I have read that folks put in a "160 degree thermostat." I'd like to know why this is desireable and how this is different from stock.

Thanks to those of you who have provided so much valuable information in this thread. Because of you kind folks, my Kooks headers are off being coated this week. They'll be installed next week with my Borla Touring exhaust and a tune next Tuesday.

it's NOT desireable... the stock t-stat's are already a 187* t-stat... which is perfectly fine... at most, you could go down to a 180*...

but by going down to a 160* t-stat (old school, not needed), the t-stat will actually stay open all the time allowing the coolant to constantly flow... and because it's constantly flowing, it doesn't stop at all in order for it to get cooled off in the radiator.

don't do it.

[DSteck]

Originally Posted by 06MonteSS

but by going down to a 160* t-stat (old school, not needed), the t-stat will actually stay open all the time allowing the coolant to constantly flow... and because it's constantly flowing, it doesn't stop at all in order for it to get cooled off in the radiator.

What? I'd love to see some proof of this. With a 160* thermostat in my Z06, my coolant temps stay at about 176-180* all the time. If it didn't have time to stop and cool, cars would overheat left and right with lower thermostats... and stock temperature thermostats would do the same thing.

[Duke]

Originally Posted by 06MonteSS

it's NOT desireable... the stock t-stat's are already a 187* t-stat... which is perfectly fine... at most, you could go down to a 180*...

but by going down to a 160* t-stat (old school, not needed), the t-stat will actually stay open all the time allowing the coolant to constantly flow... and because it's constantly flowing, it doesn't stop at all in order for it to get cooled off in the radiator.

don't do it.

I hope you know more about tuning than you do about cooling systems.

[2SSCAMARO]

One thing I'm not quite sure about when running long tube headers and a 160 degree stat is.....how does the ECM interpret the "cooler than normal" coolant temps and the "warmer than normal intake air temps".(heat soak) I'm curious as to what calculations the ECM makes when using this information that differs from what it would be receiving if the vehicle was being operated within the stock parameters.

[jbsrace1]

Originally Posted by 2SSCAMARO

One thing I'm not quite sure about when running long tube headers and a 160 degree stat is.....how does the ECM interpret the "cooler than normal" coolant temps and the "warmer than normal intake air temps".(heat soak) I'm curious as to what calculations the ECM makes when using this information that differs from what it would be receiving if the vehicle was being operated within the stock parameters.

It will run rich if not tuned to compensate.

[DSteck]

Originally Posted by jbsrace1

It will run rich if not tuned to compensate.

No. It will run different timing.

[2SSCAMARO]

I think perhaps you are both right. Maybe the ecm sees less than say 185 or 190 for example and believes the engine is still warming up and therfore keeps the mixture a little more rich until a fully warmed coolant temp is seen.(but it's not going to see it, only maybe 170 to 180 with the 160 stat depending on ambient air temp). Also it sees warmer than expected intake air temp and probably pulls some timing.

[06MonteSS]

Originally Posted by Duke

I hope you know more about tuning than you do about cooling systems.

heh, whatever... don't you worry....

and 176-180 is on the cold side... you know these camaros make more power when they're warmer than that, right??

[DSteck]

Originally Posted by 2SSCAMARO

I think perhaps you are both right. Maybe the ecm sees less than say 185 or 190 for example and believes the engine is still warming up and therfore keeps the mixture a little more rich until a fully warmed coolant temp is seen.(but it's not going to see it, only maybe 170 to 180 with the 160 stat depending on ambient air temp). Also it sees warmer than expected intake air temp and probably pulls some timing.

Closed loop begins a little over 100* F, so your thermostat isn't going to affect your final fueling.

Originally Posted by 06MonteSS

heh, whatever... don't you worry....

and 176-180 is on the cold side... you know these camaros make more power when they're warmer than that, right??

During WOT, they get into the 190+ range almost immediately anyway.

[jbsrace1]

Originally Posted by DSteck

No. It will run different timing.

There is a cold offset that adds to o2 switching voltage with cooler temps.

[Darth_Emma]

[DSteck]

Originally Posted by jbsrace1

There is a cold offset that adds to o2 switching voltage with cooler temps.

The offset doesn't change an appreciable amount between the temperature a 160* thermostat engine operates at and a 180* thermostat engine operates at, and beyond that, the extra 100mv or less to the base switching voltage of 450mv is a difference of probably a couple thousands of an AFR point. It's not something that'd even show up on a wideband.