Let's argue about 160 degree thermostats
05-23-2008, 12:49 PM
#1
Junior Member
Thread Starter
iTrader: (1)
Join Date: Oct 2006
Location: Cincinnati, OH
Posts: 375
Total Cats: 0
Let's argue about 160 degree thermostats
From searching, I found that most of you think 160s are a bad idea. 160s are pretty common for people to install on boosted cars, no matter the model, why would Miatas be any different? Spec Miataers like 160s as well.
It might not be the best idea with a stock ECU but with Megasquirt or something there shouldn't be a problem. What floors me is that people say there's no benefit at all but it's common sense that lower temp coolant running through the system keeps the cylinder walls slightly cooler and would help with knock.
It might not be the best idea with a stock ECU but with Megasquirt or something there shouldn't be a problem. What floors me is that people say there's no benefit at all but it's common sense that lower temp coolant running through the system keeps the cylinder walls slightly cooler and would help with knock.
Reply
0
0
05-23-2008, 01:17 PM
#3
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,024
Total Cats: 6,591
I'm running 180° on mine.
BenR pretty much said it. A lower-temp thermostat will start to open sooner (thus slowing initial warmup) and if your cooling system is not overtaxed, then your average operating temperature will go down.
On the other hand, if you are overheating with a 180° or 195° thermostat, it signifies that your cooling system is not adequate, and lowering the thermostat temp will not fix this. You need to add the capacity for more heat transfer from the engine to the atmosphere- big aluminum radiator, reroute, intake ducting, etc. Or it could be something really simple like a bad radiator cap.
BenR pretty much said it. A lower-temp thermostat will start to open sooner (thus slowing initial warmup) and if your cooling system is not overtaxed, then your average operating temperature will go down.
On the other hand, if you are overheating with a 180° or 195° thermostat, it signifies that your cooling system is not adequate, and lowering the thermostat temp will not fix this. You need to add the capacity for more heat transfer from the engine to the atmosphere- big aluminum radiator, reroute, intake ducting, etc. Or it could be something really simple like a bad radiator cap.
Reply
0
0
05-23-2008, 01:19 PM
#4
Junior Member
Thread Starter
iTrader: (1)
Join Date: Oct 2006
Location: Cincinnati, OH
Posts: 375
Total Cats: 0
OK, simplified scenario. Say you were cruising and your stat opened at 160. Your system temperature would be 20 degrees cooler than if it opened at 180. Lets say you average 200deg WOT on full boost.
At those temps the stat doesn't matter. But it takes longer for those temps to reach 200, so it DOES matter. Also, tip-in knock is a problem, and if you're cruising at 160, you're running cooler than you would at 180 so it helps with that.
Edit: even if your cooling system is overtaxed, it will benefit you some as long as your system is capable of cooling to 160 while cruising. Starting from a base of 160 rather than 180 would help somewhat.
At those temps the stat doesn't matter. But it takes longer for those temps to reach 200, so it DOES matter. Also, tip-in knock is a problem, and if you're cruising at 160, you're running cooler than you would at 180 so it helps with that.
Edit: even if your cooling system is overtaxed, it will benefit you some as long as your system is capable of cooling to 160 while cruising. Starting from a base of 160 rather than 180 would help somewhat.
Reply
0
0
05-23-2008, 01:21 PM
#5
Boost Czar
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,493
Total Cats: 4,080
It would just take longer for it to reach normal operating temperatures. consider from 70° to 160° takes me maybe 2 minutes and stabilizes at 190, why do i care if it takes an extra 5 seconds to reach 190?
Reply
0
0
05-23-2008, 01:38 PM
#7
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,338
Total Cats: 573
first you need proof that engines running 20 degrees below operating temp are better. I doubt that claim can be universally made.
second, more important than temperature they open is how much they open. the regular (NOT SUPERSTAT) stant t-stats open far wider than most. test them sometime in boiling water. you want flow area for better flow, not lower temp opening.
second, more important than temperature they open is how much they open. the regular (NOT SUPERSTAT) stant t-stats open far wider than most. test them sometime in boiling water. you want flow area for better flow, not lower temp opening.
Reply
0
0
05-23-2008, 03:09 PM
#9
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,024
Total Cats: 6,591
This is an interesting observation, as I recently bought a 180° SuperStat (45868) in preparation for my upcoming reroute. I wonder if I ought to purchase a regularstat instead, or if the additional opening of the regularstat might actually cause greater instability of the system owing to the increased flow in the re-routed configuration?
Decisions, decisions... I guess at a minimum I'll buy a regularstat and boil them both.
Decisions, decisions... I guess at a minimum I'll buy a regularstat and boil them both.
Reply
0
0
05-23-2008, 04:49 PM
#11
Elite Member
iTrader: (22)
Join Date: Dec 2006
Location: Sunny Spanish speaking Non US Caribbean
Posts: 3,224
Total Cats: 3
first you need proof that engines running 20 degrees below operating temp are better. I doubt that claim can be universally made.
second, more important than temperature they open is how much they open. the regular (NOT SUPERSTAT) stant t-stats open far wider than most. test them sometime in boiling water. you want flow area for better flow, not lower temp opening.
second, more important than temperature they open is how much they open. the regular (NOT SUPERSTAT) stant t-stats open far wider than most. test them sometime in boiling water. you want flow area for better flow, not lower temp opening.
Thanks
Reply
0
0
05-23-2008, 05:02 PM
#12
Boost Pope
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,024
Total Cats: 6,591
Hell...
http://stant.com/brochure.cfm?brochure=5024
That list seems to have been truncated at "M". Pep Boys also carries them.
Reply
0
0
05-23-2008, 05:54 PM
#14
Elite Member
iTrader: (22)
Join Date: Dec 2006
Location: Sunny Spanish speaking Non US Caribbean
Posts: 3,224
Total Cats: 3
http://stant.com/brochure.cfm?brochure=5024
That list seems to have been truncated at "M". Pep Boys also carries them.
first you need proof that engines running 20 degrees below operating temp are better. I doubt that claim can be universally made.
second, more important than temperature they open is how much they open. the regular (NOT SUPERSTAT) stant t-stats open far wider than most. test them sometime in boiling water. you want flow area for better flow, not lower temp opening.
second, more important than temperature they open is how much they open. the regular (NOT SUPERSTAT) stant t-stats open far wider than most. test them sometime in boiling water. you want flow area for better flow, not lower temp opening.
Sorry but I need to buy a thermostat asap.
Reply
0
0
05-23-2008, 07:03 PM
#15
Shoot, I thought DID take a picture of them in the water, but I guess I didn't. Ah, well. I'm supposed to be able to host video, too, but I haven't messed with it yet.
Anyway, here's the one pic I do have:
And here's the other one I have.
They don't tell much, but I can say that the NAPA one opens at LEAST twice as far. Probably more. My guess at the time was that the flow would be 4x through it. The leftmost is my original thermo, the middle a new one from mazda, and the right the napa part.
Only I think it's a 160. If I had it to do over again, I'd get the 180, my car is always cold and my poor bearings probably don't like it.
Also, I remember somewhere in my deep dark past hearing in thermodynamics that you want the 'ambiant' temperature to be as high as possible for peak efficiency. Then again, that's a close cycle heat engine. :-P Nonetheless, the longer they make cars, the higher those temps get. I doubt you'll find a modern ferarri with a 140* in it. More like 200 or 205.
Anyway, here's the one pic I do have:
And here's the other one I have.
They don't tell much, but I can say that the NAPA one opens at LEAST twice as far. Probably more. My guess at the time was that the flow would be 4x through it. The leftmost is my original thermo, the middle a new one from mazda, and the right the napa part.
Only I think it's a 160. If I had it to do over again, I'd get the 180, my car is always cold and my poor bearings probably don't like it.
Also, I remember somewhere in my deep dark past hearing in thermodynamics that you want the 'ambiant' temperature to be as high as possible for peak efficiency. Then again, that's a close cycle heat engine. :-P Nonetheless, the longer they make cars, the higher those temps get. I doubt you'll find a modern ferarri with a 140* in it. More like 200 or 205.
Reply
0
0
05-23-2008, 07:25 PM
#16
yeah but modern engines need to worry about super low emmisions. i've been toying with getting a 160* thermostat myself, never thought about one flowing more. in my mind if you can stay stabilized near 160* with normal cruising then it would be just a little bit more of a margin of safety.
Reply
0
0
05-23-2008, 07:47 PM
#18
Junior Member
Thread Starter
iTrader: (1)
Join Date: Oct 2006
Location: Cincinnati, OH
Posts: 375
Total Cats: 0
From the pic above, the answer seems to be NAPA, not Stant.
Anyway, if you're a hi rev toona and you can make your car run perfectly, then, yeah, you're gonna be better off with a higher temp in your motor. I'd personally like the extra headroom.
Anyway, if you're a hi rev toona and you can make your car run perfectly, then, yeah, you're gonna be better off with a higher temp in your motor. I'd personally like the extra headroom.
Reply
0
0
05-23-2008, 07:59 PM
#19
I had a 160 in mine, until we installed my MSPNP and noted that temps usually stayed under 159* and didn't make it above ~165* unless I flogged it hard. In this scenario I was in warmup mode for the overwhelming majority of my drive, wasting fuel.
I put a 180* back in and it works fine, Jerry at DIYautotune (Foundsoul here) even commented during my dyno session that the car managed heat really well. Only cooling mod is GS rad from the groupbuy and a $40 cooling plate.
The spec miata angle is a moot point IMO, there's only so much they're allowed to do, plus the cars in SM see much more abuse than a street car.
I put a 180* back in and it works fine, Jerry at DIYautotune (Foundsoul here) even commented during my dyno session that the car managed heat really well. Only cooling mod is GS rad from the groupbuy and a $40 cooling plate.
The spec miata angle is a moot point IMO, there's only so much they're allowed to do, plus the cars in SM see much more abuse than a street car.
Reply
0
0
