Why not just remove thermostat? - ZR-1 Net Registry Forums

KILLSHOTS · 05-30-2014

I've seen colder thermostats for the LT5 discussed and they're apparently extremely desirable but tough - if not impossible - to find. I live in Phoenix and my car is just a weekend toy. We all know that a cooler engine produces more power. We also know that thermostats are basically only designed for 2 things: allow the engine to run "efficiently" (read: please the EPA) and to produce heat for the cockpit. I don't care about either. So can anybody think of a COMPELLING reason for me to retain my thermostat? Less heat soak, less wear on the engine, more power. Opinions?

Thanks!

mike100 · 05-30-2014

The car runs rich until it warms up and it will wash down your cylinders in short order if you take it on short drives with no thermostat.

I once thought I'd be smart and ran a 160 'stat in Flagstaff on a carb'd muscle car. It got to 15 deg that night. I never could get my windows defrosted. You should always try to get your water and oil temp up as soon as possible, the engine will last much longer.

Vetman · 05-30-2014

Thermostats when open let the correct amount of water flow to optimize cooling. I understand removal will allow the water to flow too rapidly through the radiator before it is cooled. Guess there may be other reasons too with water flow too fast.

tccrab · 05-30-2014

I've got to guess that emissions control are a big reason why the engineers design engines to run within certain temperature ranges.

I'm also guessing that the thermostat provides some restriction to water flow as well. The volume and pressure of coolant the water pump pushes when the engine is at 7500rpms is vastly different than at idle.

'Crabs

efnfast · 05-30-2014

I asked Marc H about a 160 thermostat. He said it may gain as much as 10 hp, but was concerned that the oil and gas are engineered to run at higher temps. Not that I mean to put words in his mouth, but that is what I heard. -Steve

XfireZ51 · 05-30-2014

ECM doesn't go Closed Loop/Learn mode till 81C or 178F. So you pretty much lose any fuel trim from the O2 sensors. The motor is really designed to run better at a warmer temp than 160F.

GOLDCYLON · 05-30-2014

Chris I run a 160 Degree T-stat on my Daily runner. For Phoenix it works well as the days are now in the Century range. Even in the brutal winter season when it gets into the 30s I have zero issues with defrost and heat as well as we all know very well the car heats up rapidly. Keep in mind my car is highly modified engine wise and I run a larger Dewitts radiator and SPAL fans. So your mileage may vary. I do not recommed running without a T-stat GC

XfireZ51 · 05-30-2014

GC,

What temp does your motor run at?

GOLDCYLON · 05-30-2014

Quote:

Originally Posted by XfireZ51

GC,

What temp does your motor run at?

About 80% of top band is the highest Ive ever seen it go in winter it never goes above 50%

Bob Eyres · 05-30-2014

Remember, 160deg. is where a 160deg thermostat is designed to open, and not that the thermostat keeps the engine at that temp.

The LT5 is a lot stronger with cool intake temp, but that's another issue.

I have run a 160deg. thermostat for 17 yrs. in my ZR-1 with no ill effects. It has helped keep temps down in the hot Florida environment.

I would think that it would be ill advised to remove the thermostat entirely.

05-30-2014	#1
KILLSHOTS Join Date: Feb 2014 Location: AZ Posts: 860	Why not just remove thermostat? I've seen colder thermostats for the LT5 discussed and they're apparently extremely desirable but tough - if not impossible - to find. I live in Phoenix and my car is just a weekend toy. We all know that a cooler engine produces more power. We also know that thermostats are basically only designed for 2 things: allow the engine to run "efficiently" (read: please the EPA) and to produce heat for the cockpit. I don't care about either. So can anybody think of a COMPELLING reason for me to retain my thermostat? Less heat soak, less wear on the engine, more power. Opinions? Thanks!

05-30-2014	#2
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,802	Re: Why not just remove thermostat? The car runs rich until it warms up and it will wash down your cylinders in short order if you take it on short drives with no thermostat. I once thought I'd be smart and ran a 160 'stat in Flagstaff on a carb'd muscle car. It got to 15 deg that night. I never could get my windows defrosted. You should always try to get your water and oil temp up as soon as possible, the engine will last much longer.

05-30-2014	#3
Vetman Join Date: Feb 2013 Location: Yakima Washington Posts: 401	Re: Why not just remove thermostat? Thermostats when open let the correct amount of water flow to optimize cooling. I understand removal will allow the water to flow too rapidly through the radiator before it is cooled. Guess there may be other reasons too with water flow too fast. __________________ Jim 1990 Z # 2441 1959 c-1 230 HP 4 speed frost blue/silver 3 owner 2011 cts-v 556 HP, manual 6 speed 1955 chev 2dr ht PP 265 3 speed w/OD

05-30-2014	#4
tccrab Join Date: Oct 2004 Location: Folsom CA Posts: 1,655	Re: Why not just remove thermostat? I've got to guess that emissions control are a big reason why the engineers design engines to run within certain temperature ranges. I'm also guessing that the thermostat provides some restriction to water flow as well. The volume and pressure of coolant the water pump pushes when the engine is at 7500rpms is vastly different than at idle. 'Crabs __________________ TomC '90ZR1 #792 Honorary Pirate [B]If it ain't FUN, you're doing something terribly WRONG. [/B]

05-30-2014	#5
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,486	Re: Why not just remove thermostat? I asked Marc H about a 160 thermostat. He said it may gain as much as 10 hp, but was concerned that the oil and gas are engineered to run at higher temps. Not that I mean to put words in his mouth, but that is what I heard. -Steve

05-30-2014	#6
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,708	Re: Why not just remove thermostat? ECM doesn't go Closed Loop/Learn mode till 81C or 178F. So you pretty much lose any fuel trim from the O2 sensors. The motor is really designed to run better at a warmer temp than 160F. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

05-30-2014	#7
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,155	Re: Why not just remove thermostat? Chris I run a 160 Degree T-stat on my Daily runner. For Phoenix it works well as the days are now in the Century range. Even in the brutal winter season when it gets into the 30s I have zero issues with defrost and heat as well as we all know very well the car heats up rapidly. Keep in mind my car is highly modified engine wise and I run a larger Dewitts radiator and SPAL fans. So your mileage may vary. I do not recommed running without a T-stat GC __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V Last edited by GOLDCYLON; 05-30-2014 at 09:55 AM.

05-30-2014	#10
Bob Eyres Join Date: Jul 2005 Location: Jupiter, Fl. Posts: 815	Re: Why not just remove thermostat? Remember, 160deg. is where a 160deg thermostat is designed to open, and not that the thermostat keeps the engine at that temp. The LT5 is a lot stronger with cool intake temp, but that's another issue. I have run a 160deg. thermostat for 17 yrs. in my ZR-1 with no ill effects. It has helped keep temps down in the hot Florida environment. I would think that it would be ill advised to remove the thermostat entirely. __________________ "It's about the car, not the people." 1991 ZR-1 White/Black #1236 (Owner since 1994). Stock engine with bolt-ons: Hurst shifter,"Forced Air" intake, Coplon duct, Bee Cool Radiator, Demon coils, Jeal prom, Watson headers, X pipe, 3" B&B's, Rippie flywheel, 4:10 gears, A molds, Toyo Proxes-R888's 12.06@117mph. 1.76 60ft.