DIY thermostat delete
04-22-2012, 12:04 PM
#41
most cars today dont even have the t stat set to open to 190 and operating temp of 220 is for emissions purposes, oil temp is kind of important but thats seperate from what hes talking about, hes talking about coolant temp which you should go as low as possible. the lower you go the lower the temp is going to be around your cylinders and heads promoting less detonation and if you can tune for it you can throw a bit of extra timing in IF the engine stays that cool and never gets beyond a certain point.
oil temps will be seperate and can be higher since they come into alot of hot parts that coolant dosnt, as long as its around 160ish your fine. the car taking longer to heat up dosnt hurt it in the least the significantly more wear they see on start up only last until oil starts moving since the system has to re pressurize each time you restart it.
edit obviously did not see a few responses here.
one thing everyone needs to remember that the engineers ARE NOT trying to make the best performing engines, they arnt trying to make the most effecient engines, or most powerful, or any of that. what they ARE trying to do is make a engine that is balanced, and fits into set parameters established by the government. one of those is decreased emissions, which is a very very hard balancing act. temp has a huge role in this i can tell you that because 90% of the work we did at the first shop i worked at was emissions work since the echeck station was like 1 mile away and recommended us. running a engine at 200 degrees operating temp vs 220 will make emissions skyrocket and look like a bad cat, i can tell you right now i had several cars fail just from a low temp thermostat(they had other things done to them but the combo of things the thermostat was the ice breaker.) mostly bigger radiators, bigger fans, huge oil coolers, and low temp thermostats all combined to make it run to cold for emissions, there was nothing wrong with the cars though the engineers just need it to pass emissions.
hell even my grandfathers 88 jeep commanche longbed failed echeck barely from a stuck open thermostat despite being bone stock, replaced and everything dropped about 4 or 5% and we went and passed it.
Last edited by jerryd87; 04-22-2012 at 12:13 PM.
04-22-2012, 12:22 PM
#42
will have to respectfully disagree, while lower temps wont do anything if you just achieve them they do allow better timing. if they dint we wouldnt be running aluminum blocks and heads now. the increased cooling around the heads and cylinders allows more extreme set ups, thats why you can run 10.3:1 compression on a aluminum block aluminum head engine on 91 octane, and heck we can even boost it. try that with a iron block iron head engine running at the "operating" temp for these engines and your not going to be able to get much higher then 9.2:1 before you hit detonation and you wont be boosting at all unless you want a huge boom.
the only temp that matters is oil temp, and as long as thats around 160ish, although you dont want it much lower then that, your good. coolant temp you want the lowest that you can stabilize and then tune to that or use coolant temp corrections because you will be able to squeeze some extra power out if you know what your doing.
this whole thing came about in old school engines when heat retention was alot more noticeable, people discovered that if they took the thermostat out they ran 20-30 degrees cooler and where able to run 1-1.5 degrees more timing without detonation. 5.0 guys claim its bad but my old manager at the Cadillac dealership had a fox body with a vortech and was able to run a extra 3 lbs of boost before detonating with no thermostat.
some engines wont benefit however as had been said because they dont have enough time in the engine and radiator but you cant determine that until its tryed a good number of them do. personally im running mishimoto(same temp as nismo but alot cheaper) with a couple small holes drilled in it and see how it goes.
i honestly have no idea how i missed this thread till now =/
the only temp that matters is oil temp, and as long as thats around 160ish, although you dont want it much lower then that, your good. coolant temp you want the lowest that you can stabilize and then tune to that or use coolant temp corrections because you will be able to squeeze some extra power out if you know what your doing.
this whole thing came about in old school engines when heat retention was alot more noticeable, people discovered that if they took the thermostat out they ran 20-30 degrees cooler and where able to run 1-1.5 degrees more timing without detonation. 5.0 guys claim its bad but my old manager at the Cadillac dealership had a fox body with a vortech and was able to run a extra 3 lbs of boost before detonating with no thermostat.
some engines wont benefit however as had been said because they dont have enough time in the engine and radiator but you cant determine that until its tryed a good number of them do. personally im running mishimoto(same temp as nismo but alot cheaper) with a couple small holes drilled in it and see how it goes.
i honestly have no idea how i missed this thread till now =/
Some people are under the opinion that if its cooler, its automatically better. Not sure how that all got started exactly.
On older cars with primitive ecu's, coolant temp was a reference point for things like head temperature sensors (ie early fuel injected Z's). Doing a colder thermostat made the car run richer. These cars are smarter though, because look how quick AFR stabilizes even after a cold start in the dead of winter - its what, maybe 30-45 seconds before it starts oscillating around stoich? Not only that but the ecu moniters how quickly things get up to temperature, including the coolant. So, perhaps in a summer climate, something like this "works", in a colder one it won't. I remember on my own Z, I did the NISMO thermostat - and every single winter, my car would throw random CEL's that had an unspecified code, and some that had a coolant related code. Eventually I tossed the thermostat out, went back to a stock one, and problem solved. Car never ran worse or better with the NISMO stat, and aside from it opening earlier, it didn't even change the net coolant temps by any meaningful amount (maybe 20 degrees).
While the colder is better theory holds true for intake temperatures, on NA or FI cars, it doesn't hold true for things like coolant and oil. These fluids are designed with certain operating temperatures in mind. Exceeding their limits is bad, as they aren't able to perform their job as intended (nor as the components they service are intended). Go too far the other direction and the same thing happens - bad stuff.
How on earth coolant temps that are now 10% lower than before helps anything, god only knows. I mean, it's cool and all that you did it, but it would be beneficial for someone else looking at the thread to say why you it and what benefit you realized yby doing it. At least if the OP had some sort of datalogs to show any sort of net change - timing, fuel, torque, hp, something. But no such data exists. So it's one of those things that is somehow better because it's different than it was before, absent empirical data showing it's different and better
On older cars with primitive ecu's, coolant temp was a reference point for things like head temperature sensors (ie early fuel injected Z's). Doing a colder thermostat made the car run richer. These cars are smarter though, because look how quick AFR stabilizes even after a cold start in the dead of winter - its what, maybe 30-45 seconds before it starts oscillating around stoich? Not only that but the ecu moniters how quickly things get up to temperature, including the coolant. So, perhaps in a summer climate, something like this "works", in a colder one it won't. I remember on my own Z, I did the NISMO thermostat - and every single winter, my car would throw random CEL's that had an unspecified code, and some that had a coolant related code. Eventually I tossed the thermostat out, went back to a stock one, and problem solved. Car never ran worse or better with the NISMO stat, and aside from it opening earlier, it didn't even change the net coolant temps by any meaningful amount (maybe 20 degrees).
While the colder is better theory holds true for intake temperatures, on NA or FI cars, it doesn't hold true for things like coolant and oil. These fluids are designed with certain operating temperatures in mind. Exceeding their limits is bad, as they aren't able to perform their job as intended (nor as the components they service are intended). Go too far the other direction and the same thing happens - bad stuff.
How on earth coolant temps that are now 10% lower than before helps anything, god only knows. I mean, it's cool and all that you did it, but it would be beneficial for someone else looking at the thread to say why you it and what benefit you realized yby doing it. At least if the OP had some sort of datalogs to show any sort of net change - timing, fuel, torque, hp, something. But no such data exists. So it's one of those things that is somehow better because it's different than it was before, absent empirical data showing it's different and better
Last edited by jerryd87; 04-22-2012 at 12:28 PM.
04-22-2012, 01:47 PM
#44
with modern fuels and oils shouldnt have any issues with carbon build up. everything has cleaners and detergents in it now adays. oil is going to wash anything out of the crank case especially with synthetic, and the only potential problem i see could be the plugs getting fouled, but ive never heard of anyone having issues from running cold. poor fuel yes but never temp related, quality fuel will have more of a impact then your coolant temps any day of the week.
the only reason im even running the mishimoto thermostat is because i need the defroster in the mornings when i first go to work. cars so damn loud i dont wanna idle any longer then needed so ill sacrifice a little bit of power from timing or boost to cut idle warm up times down 5 or 10 mins. if i run into temp issues then ill rip it out but considering it stays right about 85 degrees for the high year round here i dont see it being a problem.
the only reason im even running the mishimoto thermostat is because i need the defroster in the mornings when i first go to work. cars so damn loud i dont wanna idle any longer then needed so ill sacrifice a little bit of power from timing or boost to cut idle warm up times down 5 or 10 mins. if i run into temp issues then ill rip it out but considering it stays right about 85 degrees for the high year round here i dont see it being a problem.
Last edited by jerryd87; 04-22-2012 at 01:49 PM.
04-22-2012, 02:06 PM
#45
with modern fuels and oils shouldnt have any issues with carbon build up. everything has cleaners and detergents in it now adays. oil is going to wash anything out of the crank case especially with synthetic, and the only potential problem i see could be the plugs getting fouled, but ive never heard of anyone having issues from running cold. poor fuel yes but never temp related, quality fuel will have more of a impact then your coolant temps any day of the week.
the only reason im even running the mishimoto thermostat is because i need the defroster in the mornings when i first go to work. cars so damn loud i dont wanna idle any longer then needed so ill sacrifice a little bit of power from timing or boost to cut idle warm up times down 5 or 10 mins. if i run into temp issues then ill rip it out but considering it stays right about 85 degrees for the high year round here i dont see it being a problem.
the only reason im even running the mishimoto thermostat is because i need the defroster in the mornings when i first go to work. cars so damn loud i dont wanna idle any longer then needed so ill sacrifice a little bit of power from timing or boost to cut idle warm up times down 5 or 10 mins. if i run into temp issues then ill rip it out but considering it stays right about 85 degrees for the high year round here i dont see it being a problem.
04-22-2012, 05:34 PM
#46
which hemi? because the older ones most certainly do not suffer from sludge due to improper heat range. ive NEVER seen a engine sludge up from different temps what is so magical about the temp ranges your promoting that stops sludge? please if you can show some type of science how somehow temperature has anything to do with sludge buildup ill believe it but everything i have ever dealt with says your wrong. there is absolutly nothing about a temp range that stops carbon deposits and sludge.
prove to me it had anything to do with temp ranges and not the oil being used, fuel being used, or other systems. the new hemis your talking about has a egr valve which dumps exhuast into the intake which is known to cause sludge and one of the reasons manufacturers are trying to do away with them.they do this because to burn off remaining fuel in the exhuast, it also drops actual combustion temps since the carbon absorbs a large amount of heat downside is it dumps all kinds of carbon into your intake track, on valves, and into the combustion chamber. what is on the valve stems gets pushed into the head after a long period of time and some of what is sent into the combustion chamber is scraped off the walls by the rings and sent into the oil. i guarantee its not from improper hear ranges especially since the 3mz and the new dodge hemis(im making a educated guess that its new since the only old ones that had sludge problems where ones that ran quaker state and similar early oils made from Pennsylvania crude but all the engines running these oils had bad sludge problems thats why its a much better formula now.) BOTH run at a operating temp of 220 which is the standard for most cars now.
kinda hard to say sludge formation is caused by temp mismatch when the engines you point out run in the same temp range as 95% of vehicles on the road.
you must also look at the intervals, "on time" dosnt mean anything now adays since depending on the oil used some oils recommend a oil change interval of up to 15,000 miles. ive seen horrid sludge creation at 10k when using "15k" oils despite the fact the oil maker will warrenty a engine if thats the fault and that is technically "early" and considering a fox body mustang is one of the car that is rumored to have this magic formation of sludge from too low of temp yet i know personally of ones that never experienced this so called problem and actually where able to take advantage of less heat just goes to show its obviously something else.
prove to me it had anything to do with temp ranges and not the oil being used, fuel being used, or other systems. the new hemis your talking about has a egr valve which dumps exhuast into the intake which is known to cause sludge and one of the reasons manufacturers are trying to do away with them.they do this because to burn off remaining fuel in the exhuast, it also drops actual combustion temps since the carbon absorbs a large amount of heat downside is it dumps all kinds of carbon into your intake track, on valves, and into the combustion chamber. what is on the valve stems gets pushed into the head after a long period of time and some of what is sent into the combustion chamber is scraped off the walls by the rings and sent into the oil. i guarantee its not from improper hear ranges especially since the 3mz and the new dodge hemis(im making a educated guess that its new since the only old ones that had sludge problems where ones that ran quaker state and similar early oils made from Pennsylvania crude but all the engines running these oils had bad sludge problems thats why its a much better formula now.) BOTH run at a operating temp of 220 which is the standard for most cars now.
kinda hard to say sludge formation is caused by temp mismatch when the engines you point out run in the same temp range as 95% of vehicles on the road.
you must also look at the intervals, "on time" dosnt mean anything now adays since depending on the oil used some oils recommend a oil change interval of up to 15,000 miles. ive seen horrid sludge creation at 10k when using "15k" oils despite the fact the oil maker will warrenty a engine if thats the fault and that is technically "early" and considering a fox body mustang is one of the car that is rumored to have this magic formation of sludge from too low of temp yet i know personally of ones that never experienced this so called problem and actually where able to take advantage of less heat just goes to show its obviously something else.
Last edited by jerryd87; 04-22-2012 at 05:36 PM.
04-22-2012, 05:45 PM
#47
also if too low of temps cause magic sludge formation how come the people on here running 170-180 degrees arnt having issues? thats 40-50 degrees colder then most vehicles on the road. or pretty much any vehicle from the 60s when cars came from the factory running 180 degrees?
04-22-2012, 08:44 PM
#48
Aren't sludge and carbon deposits unrelated? I'm talking about the baked on carbon on valves, etc.
Handy tip: If you want to make the degrees° sign, hold [Alt] and type [0176] on the number pad. I don't know why, but it doesn't work if you use the numbers above the keyboard.
Handy tip: If you want to make the degrees° sign, hold [Alt] and type [0176] on the number pad. I don't know why, but it doesn't work if you use the numbers above the keyboard.
04-22-2012, 09:24 PM
#49
sludge is alot of things, is mostly oil thickened with carbon deposits and broken down oil so it dosnt actually lubricate anymore as well as metal shavings and various other things. mostly its broken down oil and oil oversaturated with carbon deposits though.
oil dosnt break down from low temps though it breaks down from excessively high temps, it gets so thin that it looses its lubricating propertys(please dont turn it into a "oil isnt thin when its hot arguemen"), anti shear, ect, when it cools back down it gels partly more it happens the more it gel's age is also a huge determining factor in gelling.
remember most of the parts coming into contact with coolant are receiving little to no contact with oil. for instance coolants main purpose is to cool the cylinder heads and top of the cylinders, the hottest parts of the engine. other parts are cooled by oil though crank, rods, pistons(on some cars like ours directly, others indirectly through oil on the wrist pin.) hence why you can have a 180 degree oil temp and 170 degree coolant temp.i would def say oil needs to be above 160 though but thats simply so its performing in the range of the thicker side(ie 30 in the 10w30) since 10 weight would be far to low. but keeping it under 180 will keep it thicker so it performs like a cold 30w vs 180 and above it will perform like a hot 30w and thus actually wind up being thinner.
oil dosnt break down from low temps though it breaks down from excessively high temps, it gets so thin that it looses its lubricating propertys(please dont turn it into a "oil isnt thin when its hot arguemen"), anti shear, ect, when it cools back down it gels partly more it happens the more it gel's age is also a huge determining factor in gelling.
remember most of the parts coming into contact with coolant are receiving little to no contact with oil. for instance coolants main purpose is to cool the cylinder heads and top of the cylinders, the hottest parts of the engine. other parts are cooled by oil though crank, rods, pistons(on some cars like ours directly, others indirectly through oil on the wrist pin.) hence why you can have a 180 degree oil temp and 170 degree coolant temp.i would def say oil needs to be above 160 though but thats simply so its performing in the range of the thicker side(ie 30 in the 10w30) since 10 weight would be far to low. but keeping it under 180 will keep it thicker so it performs like a cold 30w vs 180 and above it will perform like a hot 30w and thus actually wind up being thinner.
Last edited by jerryd87; 04-22-2012 at 09:34 PM.
04-26-2012, 09:44 PM
#50
Aren't sludge and carbon deposits unrelated? I'm talking about the baked on carbon on valves, etc.
Handy tip: If you want to make the degrees° sign, hold [Alt] and type [0176] on the number pad. I don't know why, but it doesn't work if you use the numbers above the keyboard.
Handy tip: If you want to make the degrees° sign, hold [Alt] and type [0176] on the number pad. I don't know why, but it doesn't work if you use the numbers above the keyboard.
Last edited by Andrei; 04-26-2012 at 10:05 PM.
04-26-2012, 09:48 PM
#51
This is true. Many times here I've seen tuners rent the dyno at Dyno Proven LLC to tune customer cars and they are limited to how much timing they can run because of coolant temp. I told them to take out the t-stat but they don't listen.
Last edited by Andrei; 04-26-2012 at 10:05 PM.
04-27-2012, 08:52 AM
#52
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also if too low of temps cause magic sludge formation how come the people on here running 170-180 degrees arnt having issues? thats 40-50 degrees colder then most vehicles on the road. or pretty much any vehicle from the 60s when cars came from the factory running 180 degrees?
So you take a 350z with a stock thermostat (180*) and one without a thermostat and go normal city driving and they will both run about the same temps. The only time they will vary is when it's open highway with little to no load. Then the non-tstat car will drop temps down lower than the car with the thermostat. How does that help? it doesn't since it's on the highway with low load.
Now take it to the track. Race both cars. Both stock cars run at the track one with and one without. They will both release the same amount of heat through their stock cooling system. The thermostat will not be an issue because both cars in a high load situation will be producing well over 180* of temperature.
The only way a car is going to actually run lower temps with no thermostat is to upgrade the radiator and additional cooling mods that will actually allow them to release the energy built up during high load situations.
I don't give a crap what my car's temp stays out when i'm on the highway with little to no load.
And yes, i have tested tstat in and out when i was having bleeding issues. I gutted a cheapo and used it since I thought that was the issue to not being properly bled. On the dyno with high load and the same fans both cars ran at the exact same engine temps. They stayed between 200-210 while doing full pulls. So basically having none, 160* or 180* thermostat would have done nothing for me under boost since the car runs at 200-210 under boost and load.
So, again, thermostat delete does NOTHING for a car under high load unless the thermostat from the stock vehicle is higher than what the car would run during high load. If you want to lower temps while boosted you have to upgrade the cooling system to include a larger heat exchanger(radiator) to eliminate the heat generated. I have yet to see a boosted vehicle running coolant temps under 180* while boosting. People can argue all day long about cruise temps blah blah blah but what does that matter? who races at cruise speed?
EDIT: this is not an argument for or against the temp range being safe or not safe. I'm only stating that a thermostat does not lower temps of a vehicle while under load (which is what we are talking about when discussing boosted vehicles). It is merely a regulator of a temperature.
If you find me a car that can stay under 160* while under heavy boost then yes, a lower thermostat will stay open then and allow full coolant flow which is good. I have yet in my entire lifetime to see a single engine run that cool on a standard cooling system though. A few down around 180's with extreme mods and huge cooling systems but as long as the thermostat is below their operating temps it will have the same outcome on performance as having no thermostat at all.
This is also assuming that the heat from the combustion chambers is properly transferred to the coolant. You can drop coolant numbers without actually helping the engine. The best choice for seeing if combustion temps are dropped due to a better cooling system is having a pyrometer (egt) on every cylinder to watch. If the temps are being transferred to the cooling system properly then the egt temps will go down as well.
Last edited by binder; 04-27-2012 at 08:59 AM.
05-01-2012, 04:54 AM
#54
So, a thermostat is only useful during cold weather?
Why don't we email one of the Nissan engineers and ask about their opinion on this? lol.
Perhaps do a proper research with logged temperature data in different situations (daily, road racing, autoX, etc) to finally conclude all claims.
My mechanic said he's had a customer who had been running without a thermostat and his Z was fine.
As for me, I'd still run the thermostat.
Why don't we email one of the Nissan engineers and ask about their opinion on this? lol.
Perhaps do a proper research with logged temperature data in different situations (daily, road racing, autoX, etc) to finally conclude all claims.
My mechanic said he's had a customer who had been running without a thermostat and his Z was fine.
As for me, I'd still run the thermostat.
05-01-2012, 06:43 AM
#55
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So, a thermostat is only useful during cold weather?
Why don't we email one of the Nissan engineers and ask about their opinion on this? lol.
Perhaps do a proper research with logged temperature data in different situations (daily, road racing, autoX, etc) to finally conclude all claims.
My mechanic said he's had a customer who had been running without a thermostat and his Z was fine.
As for me, I'd still run the thermostat.
Why don't we email one of the Nissan engineers and ask about their opinion on this? lol.
Perhaps do a proper research with logged temperature data in different situations (daily, road racing, autoX, etc) to finally conclude all claims.
My mechanic said he's had a customer who had been running without a thermostat and his Z was fine.
As for me, I'd still run the thermostat.
07-07-2012, 06:07 PM
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For people that are getting lower temps without a thermostat. That's an easy answer. With the thermostat in place it is difficult to properly remove all the air from behind it causing it to not function correctly. When you remove the thermostat it becomes very easy to bleed a system.
So your change is due to the fact that your cooling system is now properly bled when before you probably had trapped air. Pressure bleeding or using a spill free funnel over a period of time is the only way to remove all the air. Until you have done that you will have suboptimal cooling. I know because i always had poor cooling until i properly bled it WHILE STILL KEEPING THE SAME THERMOSTAT and magically I now am 652hp and can do dyno pulls for 2 hours with coolant temps never breaking 200*. On the same thermostat before proper bleeding i was up in the 230's only at 540hp. More hp, properly bled cooling system and my temps went down.
So your change is due to the fact that your cooling system is now properly bled when before you probably had trapped air. Pressure bleeding or using a spill free funnel over a period of time is the only way to remove all the air. Until you have done that you will have suboptimal cooling. I know because i always had poor cooling until i properly bled it WHILE STILL KEEPING THE SAME THERMOSTAT and magically I now am 652hp and can do dyno pulls for 2 hours with coolant temps never breaking 200*. On the same thermostat before proper bleeding i was up in the 230's only at 540hp. More hp, properly bled cooling system and my temps went down.
07-07-2012, 08:08 PM
#57
those temps are rediculous, i know the mishimoto thermostats(nismo replica.) and i think the nismo as well have a little plunger in the fact. you pull it apart and cut that out and you will have a 1/8th hole for coolant to constantly pass through to bleed the system. i was able to bleed my system without a funnel or pressure because of this, you definitly have some issues though i would try bleeding the system and go from there. that oil temp is ridiculous and i would highly encourage you to change your oil every time you take it to the track if it sees that high a temp.
by comparision i have to do stop and go traffic to hit 180 oil temp and it takes awhile, after 5 20 psi pulls tuning i would spike to 185-190 degrees but only for a second till the oil went through the cooler. if bleeding the coolant system dosnt work i would look into other things. possibly clearances too tight and causing high oil temps
by comparision i have to do stop and go traffic to hit 180 oil temp and it takes awhile, after 5 20 psi pulls tuning i would spike to 185-190 degrees but only for a second till the oil went through the cooler. if bleeding the coolant system dosnt work i would look into other things. possibly clearances too tight and causing high oil temps
07-08-2012, 04:21 AM
#60
I wouldn't remove my thermostat as it is critical for the engine getting up to temp to where the bearings and valve train are worn in at. It seems that those of you who are removing your thermostat are dancing around your real problems related to cooling. There are plenty of close to 1000whp Z's that have zero issue with maintaining reasonable temps.
There are plenty of things that could be causing some of the higher temps people are seeing. It could simply be a bad thermostat. Calcification in the system that is insulating the thermal transfer. Bent radiator fins not allowing air through. Crucial panels such as the top panel and the under body panel being removed which are designed to control air flow. A different front bumper which allows air to roll out or around the radiator rather than forcing it through. An improperly bled coolant system. The list goes on but removing your thermostat is a bandwidth that could actually do damage to your car long term.
There are plenty of things that could be causing some of the higher temps people are seeing. It could simply be a bad thermostat. Calcification in the system that is insulating the thermal transfer. Bent radiator fins not allowing air through. Crucial panels such as the top panel and the under body panel being removed which are designed to control air flow. A different front bumper which allows air to roll out or around the radiator rather than forcing it through. An improperly bled coolant system. The list goes on but removing your thermostat is a bandwidth that could actually do damage to your car long term.
