Mk3 Thermostate Question

zuni · 06-12-2007, 11:47 PM

i have a 89 supra 7mgte 5 speed targa top. i find that my car is way quicker off the line and in the long run when my car reaches between 100 to 160 degrees. my car normally heats up to between 190 and 220. im woundering if i take out my thermostate is there any reason that would be a bad idea. i dont need my heat but i want my car to run cooler. Way cooler. Is there any Bad Longterm effects from pulling out the thermostate. If anyone has experience with this please let me know.

cre · 06-13-2007, 02:15 AM

I wouldn't recommend running without a thermostat. If anything find a lower temp thermostat. Running without a thermostat can actually cause your engine temp to fluctuate, this is bad.

You might also want to check and see if there's any correlation to engine bay temp. It's possible that the heat of the engine bay is saoking some of the electronics, or that (if you've got an aftermarket air filter) your car doesn't like sucking warmer air into the intake.

zuni · 06-13-2007, 07:45 PM

Quote:

Originally Posted by cre

I wouldn't recommend running without a thermostat. If anything find a lower temp thermostat. Running without a thermostat can actually cause your engine temp to fluctuate, this is bad.

You might also want to check and see if there's any correlation to engine bay temp. It's possible that the heat of the engine bay is saoking some of the electronics, or that (if you've got an aftermarket air filter) your car doesn't like sucking warmer air into the intake.

I have a aftermarket k&n. so your saying i should try to isolate the filter so that its sucking in cooler air. such as a ram air or cold air intake. where would i beable to find a thermostate that is only 120 degree's. do you know of someplace i could find that at.

f00g00 · 06-13-2007, 08:34 PM

Running a lower temp thermostat will not make the car run at that temp. It will still run at normal operating temp but the lower thermostat will probably just let it take a little longer to warm up.
The reason your getting more power is cause your running a little richer fuel mixture while its still warming up. Is that what you really want? If your running rich all the time then your fuel economy will suffer. But if you must have this extra power all the time without playing with your cooling system there is a mod you can do electrically that will get you what you want without sacrificing the cooling system efficiency.
You can read about the mod here.
http://www.supras.com/06/techcenter/display.php?QID=23
I tried it years ago but to try and make mine run leaner for better fuel economy. That was before I found out that leaner on these cars is a no no.

zuni · 06-14-2007, 12:08 AM

Quote:

Originally Posted by f00g00

Running a lower temp thermostat will not make the car run at that temp. It will still run at normal operating temp but the lower thermostat will probably just let it take a little longer to warm up.
The reason your getting more power is cause your running a little richer fuel mixture while its still warming up. Is that what you really want? If your running rich all the time then your fuel economy will suffer. But if you must have this extra power all the time without playing with your cooling system there is a mod you can do electrically that will get you what you want without sacrificing the cooling system efficiency.
You can read about the mod here.
http://www.supras.com/06/techcenter/display.php?QID=23
I tried it years ago but to try and make mine run leaner for better fuel economy. That was before I found out that leaner on these cars is a no no.

im building a acrylic cold air inclosure right now to try and isolate the intake filter from the heat. any other tips. how does anyone else feel about removing the thermastate completely.

cre · 06-14-2007, 02:54 AM

A cooler temp thermostat will reduce the engine's operating temps a bit. It's not going to change the temp of the incoming fuel mixture which is more important. Forget about running without a thermostat, hell, most of the race cars I've seen still use them and for a reason. There are a lot of reasons why automotive engineers choose a specific operating temperature range for an engine. I'll keep it simple, they did the thinking for you, take advantage of it. I highly doubt you'll find a 120? thermostat that'd fit, and I wouldn't recommend it either.

If you want to see the car run better when it's up to temp, do it right. Fix what's broken, make sure the engine is getting the coolest air possible, make sure the ignition system is in good order, adjust the timing to suit your driving style, make sure the engine is breathing well (intake and exhaust restrictions minimized), and make sure the vacuum system is in good shape and free of leaks and obstructions.

Do it right or don't do it... otherwise it'll just bite you in the ass.

btwilson86 · 06-14-2007, 04:43 AM

I've read that running with no thermostat will cause your ECU to run in an open loop, giving incorrect A/F mixtures and ignoring some of the sensors (such as MAF, IAT, etc.) until the car (finally) reaches it's proper operating temperature. This is because the computer thinks it's alot cooler than it is (since the engine takes so long to warm up)... In any case, it's worse for emissions (if that matters) and is very likely to cause premature wear on your engine. I wouldn't recommend it. Found out the hard way that it's bad (destroyed the cold start system on my 92 Jetta)

zuni · 06-14-2007, 07:59 PM

Quote:

Originally Posted by cre

A cooler temp thermostat will reduce the engine's operating temps a bit. It's not going to change the temp of the incoming fuel mixture which is more important. Forget about running without a thermostat, hell, most of the race cars I've seen still use them and for a reason. There are a lot of reasons why automotive engineers choose a specific operating temperature range for an engine. I'll keep it simple, they did the thinking for you, take advantage of it. I highly doubt you'll find a 120? thermostat that'd fit, and I wouldn't recommend it either.

If you want to see the car run better when it's up to temp, do it right. Fix what's broken, make sure the engine is getting the coolest air possible, make sure the ignition system is in good order, adjust the timing to suit your driving style, make sure the engine is breathing well (intake and exhaust restrictions minimized), and make sure the vacuum system is in good shape and free of leaks and obstructions.

Do it right or don't do it... otherwise it'll just bite you in the ass.

what do you mean adjust the timing. what would that do and how would i do that.

supramacist · 06-14-2007, 08:14 PM

Don't remove the t-stat. Don't play with your timing after you get it set to where you want it. If you run rich all the time you'll be removing the entire intake to maintain your plugs.

Do Not remove the thermostat.

Listen to what these guys are saying to you.

IHateHacks · 06-14-2007, 08:39 PM

Yeah don't remove that thermostat. The thermostat not only regulates minimun operating temperature, but flow also. You will totally screw up your cooling system by running without one. Use a 160 or 180 degree thermostat.

How do you know it runs as hot as 220? Do you have an aftermarket gauge?

My aftermarket gauge ran at 190 all day today, actually I couldn't get it above 190 even under boost. Mine normally runs around 195-200 at its hottest with a 180 degree thermostat, stock radiator, new waterpump and a new fan clutch.

06-12-2007, 11:47 PM	#1
zuni 3" Exhaust Join Date: Jun 2007 Location: Rockford, illinois Posts: 55	Mk3 Thermostate Question i have a 89 supra 7mgte 5 speed targa top. i find that my car is way quicker off the line and in the long run when my car reaches between 100 to 160 degrees. my car normally heats up to between 190 and 220. im woundering if i take out my thermostate is there any reason that would be a bad idea. i dont need my heat but i want my car to run cooler. Way cooler. Is there any Bad Longterm effects from pulling out the thermostate. If anyone has experience with this please let me know. __________________ Zuni www.myspace.com/toxicskin www.originalskintattoo.com

06-13-2007, 08:34 PM	#4
f00g00 12psi boost Join Date: Aug 2005 Location: Kuwait Posts: 292	A better idea Running a lower temp thermostat will not make the car run at that temp. It will still run at normal operating temp but the lower thermostat will probably just let it take a little longer to warm up. The reason your getting more power is cause your running a little richer fuel mixture while its still warming up. Is that what you really want? If your running rich all the time then your fuel economy will suffer. But if you must have this extra power all the time without playing with your cooling system there is a mod you can do electrically that will get you what you want without sacrificing the cooling system efficiency. You can read about the mod here. http://www.supras.com/06/techcenter/display.php?QID=23 I tried it years ago but to try and make mine run leaner for better fuel economy. That was before I found out that leaner on these cars is a no no.

06-14-2007, 04:43 AM	#7
btwilson86 Super Moderator Join Date: May 2007 Location: Billings, Montana Posts: 1,034	I've read that running with no thermostat will cause your ECU to run in an open loop, giving incorrect A/F mixtures and ignoring some of the sensors (such as MAF, IAT, etc.) until the car (finally) reaches it's proper operating temperature. This is because the computer thinks it's alot cooler than it is (since the engine takes so long to warm up)... In any case, it's worse for emissions (if that matters) and is very likely to cause premature wear on your engine. I wouldn't recommend it. Found out the hard way that it's bad (destroyed the cold start system on my 92 Jetta) __________________ 1989 7MGTE R154 Targa Top White Package w/Blue Interior Driftmotion 57trim CT26, Upgraded Intercooler, 2.25" Hard Pipes, 3" Turbo Back Exhaust with Test Pipe, HKS VPC w/GM 3 bar MAP sensor, APEXi S-AFC, Walbro 255lph fuel pump, ProSport EVO Series Boost / Fuel Pressure / AFR gauges, Lotek a Pillar Gauge Pod, HKS Type 0 Turbo Timer, Eibach Lowering Springs, Tokico Illumina II TEMS struts, custom powder coated Motegi Racing TrakLite wheels

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06-13-2007, 02:15 AM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	I wouldn't recommend running without a thermostat. If anything find a lower temp thermostat. Running without a thermostat can actually cause your engine temp to fluctuate, this is bad. You might also want to check and see if there's any correlation to engine bay temp. It's possible that the heat of the engine bay is saoking some of the electronics, or that (if you've got an aftermarket air filter) your car doesn't like sucking warmer air into the intake.

06-14-2007, 02:54 AM	#6
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	A cooler temp thermostat will reduce the engine's operating temps a bit. It's not going to change the temp of the incoming fuel mixture which is more important. Forget about running without a thermostat, hell, most of the race cars I've seen still use them and for a reason. There are a lot of reasons why automotive engineers choose a specific operating temperature range for an engine. I'll keep it simple, they did the thinking for you, take advantage of it. I highly doubt you'll find a 120? thermostat that'd fit, and I wouldn't recommend it either. If you want to see the car run better when it's up to temp, do it right. Fix what's broken, make sure the engine is getting the coolest air possible, make sure the ignition system is in good order, adjust the timing to suit your driving style, make sure the engine is breathing well (intake and exhaust restrictions minimized), and make sure the vacuum system is in good shape and free of leaks and obstructions. Do it right or don't do it... otherwise it'll just bite you in the ass.

06-14-2007, 08:14 PM	#9
supramacist 1000whp postwhore Join Date: Apr 2007 Location: Escape from the Prison Planet Posts: 1,356	Don't remove the t-stat. Don't play with your timing after you get it set to where you want it. If you run rich all the time you'll be removing the entire intake to maintain your plugs. Do Not remove the thermostat. Listen to what these guys are saying to you.

06-14-2007, 08:39 PM	#10
IHateHacks 20psi boost Join Date: May 2006 Location: New Haven/Hamden Posts: 793	Yeah don't remove that thermostat. The thermostat not only regulates minimun operating temperature, but flow also. You will totally screw up your cooling system by running without one. Use a 160 or 180 degree thermostat. How do you know it runs as hot as 220? Do you have an aftermarket gauge? My aftermarket gauge ran at 190 all day today, actually I couldn't get it above 190 even under boost. Mine normally runs around 195-200 at its hottest with a 180 degree thermostat, stock radiator, new waterpump and a new fan clutch.