fst100

iTrader: (5)

originally ran a 186* F tstat and noticed the coolant temps were in the 210-215* F range (which is normal operating temps but been getting spark knock). i'm currently scanning the ODBD2 via torque app. my fans are set to turn on at 175* on high speed. i then replaced my 186* tstat with a 160* tstat in hopes the coolant temps would d go down. we have been getting a heat spell where the ambient temps are above 90* with heat index in the mid to high 90s if not over 100*. the fan settings were then lowered to 170* but i noticed the overall coolant temp goes to 190*, 199* if i do a few WOT pulls.

grant it, it did help in eliminating the spark knock but when it went above 190* i would get some, but not as much as when the temps were over 200*. i currently continuing to use the dexcool fwiw. i did try to take as much air out of the system as possible by: loosening the 2 top ports on both sides of the intake manifold and that didnt help, and topped the radiator off.

so, those who ran/are running 160* tstat and had the ambient temps above 90* F what were your overall coolant temps?

edit-previous owner swapped the LS1 waterpump to LS2 style.

HCI2000SS

iTrader: (2)

Can't remember where my tuner set my fans at for the 160 stat, but it most definitely helped with spark knock. With the stock thermostat I couldn't run more than 26 degrees timing at WOT. Withe the 160 we were able to add another degree of timing with no knock whatsoever

fst100

iTrader: (5)

^do you know what your temps were/are when the outside/ambient temps above 90*F? im currently able to run 24-25* of timing when originally i was only able to run 23* but only when the coolant temps under 180*F. i still get half a degree when the coolant temps 190*-ish with 24* of timing. i dont know if my stock radiator's in need of an upgrade or if running the 160* tstat is 'normal' to reach 190* when outside temps above 90*F?

one other idea is to drill a hole in the 160* tstat? i saw the older threads about swapping shims but i dont want to go that route.

HCI2000SS

iTrader: (2)

I can't say for sure when temps were above 90, but I wanna say it ran right around 185 in general, and it was maybe around 80 degrees that day when we did that. I run the stock radiator as well

fst100

iTrader: (5)

gotcha. i may just upgrade to the LT1 style rad like i did on my old build and it drastically lowered the temps by 15-20*F running the 186* tstat.

HCI2000SS

iTrader: (2)

I didn't realize the LT1 radiator worked that much better. Is it a direct swap basically?

fst100

iTrader: (5)

basically yes, only difference is the LT1 has an extra hole on the driver side that can be easily capped.

HCI2000SS

iTrader: (2)

Interesting! I may look into that. No downside to running one? If not, it sounds like cheap insurance which is,always,a good thing

fst100

iTrader: (5)

only 'downside' is capping the extra hole on the lower driver side. thats basically it.

back on topic, anyone else had thoeir coolant temps go above 190* with a 160* tstat when temps were above 90*F?

HCI2000SS

iTrader: (2)

Double post

pozesd99'

iTrader: (3)

I currently have a 160 stat. Its around 110-115 here during the summer and the car rarely sees 215*. When it does, its stopped for a long period of time and have the ac running. Usually in 90* weather, its stays around 175-185*.

fst100

iTrader: (5)

hmm, mayb my radiator is old and clogged up then. it's been around low 90s here but the humidity makes it feel like closer to 100*F so my temp via torque app shows 195-200 with ac on and in stop and go or after I would do a WOT pull.

Launch

Definitely look at your radiator. Mine with 160 stat on a hot day will run 175 to 180 max at the cylinder head confirmed with logging it. I have a custom aluminum 2" wide solid core width radiator though, and I run the high speed fans permanently to come on soon as temp hits 170 and off at 165 and it just always cools it back down instantly

fst100

iTrader: (5)

well I already have the LT1 rad sitting around lol. it'll be my winter project when I install LT headers :-)

thanks for sharing your answers/responses.

conan

iTrader: (5)

Stock LS1 radiator with 160 stat here, it runs around 175-185 when I'm taking it easy. It will get in to the 210-215 range when I'm in the throttle for extended periods of time.

usnfenix

iTrader: (11)

stock setup with 160 T, never seen the car get into 210, and this is a 98 which is the only year with a true and accurate temp gauge. Mine hovers around 180 or a tad under most of the time.