I have an 88 mk3 7mgte. I have after market gauges. Just wondering what the official on what my coolant temp should be for street and what it should b for the track (road racing) Thank you.
What should my coolant temp be?
- Thread starter 1-2clutch-u
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mine bounces from 160-180 on the street. it will go to 180, then drop to 160, go back to 180 etc. am running a 180 themostat
225*F is warmer than I would run the car, but on the stock gauge still shows in the "acceptable" range. So basically, Toyota thought it was ok, but they also thought the head gasket torque was good too 
. You have to remember that 212*F is boiling for water, so if you're going that warm you're adding more pressure to the system. All it takes is one pin hole leak for a hose to explode at that point.
ECU happy range is 180 - 210. Under 180 it goes in to a rich warmup mode and above 210 it tries to do things to prevent the engine from getting warmer. 210*F is when the extra electric fan(s) beside the mechanical clutch fan will engage. A stock system with the stock thermostat (190*F) on a relatively stock motor should keep it between 180 and 195 for most regular driving. If I'm driving on a warmer day and pushing the car a bit, I might see 200 or 205, but not really any higher. If you let the car sit after being warm for 5 - 10 minutes, you'll get some heat soak that will show higher on startup but it should drop down within 10 seconds of starting the car.
My car has an upgraded 57-trim CT26 @ ~10psi, 3" turbo back cat delete exhaust, 2.5" IC hard pipes, and I'll stay within those numbers.
. You have to remember that 212*F is boiling for water, so if you're going that warm you're adding more pressure to the system. All it takes is one pin hole leak for a hose to explode at that point.ECU happy range is 180 - 210. Under 180 it goes in to a rich warmup mode and above 210 it tries to do things to prevent the engine from getting warmer. 210*F is when the extra electric fan(s) beside the mechanical clutch fan will engage. A stock system with the stock thermostat (190*F) on a relatively stock motor should keep it between 180 and 195 for most regular driving. If I'm driving on a warmer day and pushing the car a bit, I might see 200 or 205, but not really any higher. If you let the car sit after being warm for 5 - 10 minutes, you'll get some heat soak that will show higher on startup but it should drop down within 10 seconds of starting the car.
My car has an upgraded 57-trim CT26 @ ~10psi, 3" turbo back cat delete exhaust, 2.5" IC hard pipes, and I'll stay within those numbers.
212 will only boil water at sea level pressure of one BAR. Toyota puts a pressure cap on at .9 BAR, raising the boiling point so the coolant can absorb more heat. I changed my 13 psi cap for a 16. And have a huge fan clutch on it. I have my high pressure A/C switch disabled and a toggle plugged in. I can turn on my A/C and not the electric fans and the guage won't budge, even in our ridiculous heat this summer.
edit: your car will run just fine at 190.
edit: face palm...
edit: your car will run just fine at 190.
edit: face palm...
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mine sits at 190 in 95 degree heat driving 70mph to work
it rises up to 210 when i run it hard
i have aluminum radiator, a/c condensor removed, 190 degree tstat, stock fan with no fan shroud, no small electric fans either
it rises up to 210 when i run it hard
i have aluminum radiator, a/c condensor removed, 190 degree tstat, stock fan with no fan shroud, no small electric fans either
radiod;1741848 said:
That is not correct. ECU enrichment ends at 60C (140F). Timing is retarded above 95C (203F) reaching a max reduction of 4 deg at 105C.
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Hmmm, my bad on that. I'll have to find the post that was mentioned in and see if they had a source. Thanks for correcting though, now I know too
EDIT: Where can you find those figures? I've taken a quick look through TSRM and can't seem to find it.
EDIT: Where can you find those figures? I've taken a quick look through TSRM and can't seem to find it.
Its from the ECU firmware. :icon_bigg You won't find it in any book I know of.
http://www.supramania.com/forums/showthread.php?73379-3P-s-TCCS-Disassembly-Analysis&p=1712465&viewfull=1#post1712465
http://www.supramania.com/forums/showthread.php?73379-3P-s-TCCS-Disassembly-Analysis&p=1712465&viewfull=1#post1712465
It's in the factory TCCS manuals as well as some aftermarket ones although the numbers are slightly different. I'll defer to the code though because it doesn't lie...
Doesn't the ECU actually advance the timing at idle to help cool things down, and retard off idle to prevent detonation when there is an overtemp situation?
Since we're on the topic of timing stuff, I just noticed this in the "troubleshooting" section of the TSRM cooling system.
Engine Overheats, possible cause is ignition timing retarded. I thought pulling some ignition timing was better for temps???
source: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=CO&P=4
Engine Overheats, possible cause is ignition timing retarded. I thought pulling some ignition timing was better for temps???
source: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=CO&P=4
It does adjust the idle timing +/- 3 deg, but only to stabilize rpm. There is no idle timing adjustment with temperature, only rpm and AC on/off (and for A/T cars if the car is in gear or not).
Ah ok. I think I read the info in one of the Autoshop 101 articles a little while back, but it must not pertain to all vehicles/models. Thanks for the precise info yet again 3p. And radiod, I believe advancing timing actually reduces engine temperature (to a point) and retarding has the opposite effect, but the ECU retards timing not to cool the engine, but to prevent damaging detonation which is much more likely to happen with an overheating engine(someone correct me if I am wrong).