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Cooler thermostat?

ntreftz

ntreftz

Too broken to be broke $$
hopefully scottydoggs, stealthee and bio get a chance to read this.

we had a conversation on NINTEYEIGHTGTP's post http://www.grandprixforums.net/showthread.php?t=83297

I spoke with a buddy that's been building and racing IHRA blown alcohol funny cars for 20 years and I asked him about it. "why would you want to cool the air charge coming into the block without cooling the block as well to maintain the ability to keep the air contact surface cold as well?"

3800's are meant to run between 195* and 210* to keep the manifold temperature up as keeping the fuel from condensing and turning in to a wet puddle of un-burnable fuel sitting on top of the piston. I was running my car at 172* thinking I was helping and I thought my plugs were bad because I could always smell un-burnt fuel in the exhaust, but all it was is the "puddle of fuel" finding its way out of the system.

if you run the motor any lower than about 180* you risk wasting fuel and performance by not keeping the fuel atomized, even with fuel injection.
- more of an issue with throttle-body injection and carbureted fuel systems.

with adding NO2 you are basically freezing the fuel that comes to the cylinders but maintains the atomization which supercharges the air to fuel ratio adding power and efficiency,
with a no2/fuel ratio of 28/28 you can gain tremendous power
if you go with more fuel than no2 like 28/36 you will be lucky to make a clean pass without scorching hole in a piston or 2.
if you run a highrt no2 to fuel you can make more power without risking detonation like running a 32/28 if too much no2 the engine just wont fire.

any and all comments are welcome
 
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that's why i keep telling people to stop running colder thermostats, but everyone is so engrained with the terrible advice that was spewed for over a decade.

gains: none.

losses: fuel mileage, engine wear, performance, etc.
 
Bio, I actually paid attention to what you said in the past about this and have never questioned your point of view. Just saying lol. Just so you know I am one of the few that don't find it necessary
 
Now I know, and knowing is 1/2 the battle... lol I didn't mean to doubt what was said just no one could tell me exactly why so until I found out why I was not going to agree nor disagree. I hope the explanation is complete enough so other will understand as well. My buddy David runs mid 4's in the 1/8th and he's the one who explained it to me though about a 2hr long discussion, took awhile because we were going through about 18 beers or so
 
What's stock temperature anyhow? I think I installed a 180 a long long time ago and my car actually seems to run warmer than normal. Might be time to swap that back to stock and do a coolant flush while I'm at it.
 


Yeah a long time ago when I was a n00b still I thought it would make rainbows shoot out of my grand prix's ass.
 
drunken crash course check... but he was ahead of me by about a twelve pack
I was just annoyed by stealthee and others that I couldn't get a real answer so beer plus IHRA veteran equals knowledge lol
 
My only comment/concern with this post is that last time I checked a blower car (specifically a blower car without an intrcooler ) had no issues keeping manifold temps high. I can't imagine that the ~15* change in coolant temp would effect the manifold temps enough to counter the zillion degree heat coming out of the blower.
 
180* Thermostats don't make the car run 180*. You should see temps of 195, which will still make the engine happy.

If we were talking 160* thermostats, it would be a whole different story.
 
A 180F t stat and a good cooling system should keep engine coolant temps right in the ballpark of 180F. Although..it's not the manifolds we are trying to keep at a temp, it's more the cylinder temp.
 


Even with a stock 195, ive found that on the colder mornings (below 40F) with the heat on, my engine runs between 185-193 according to scangauge. This morning for example, the warmest i saw it was 198 idling in traffic. During winter I imagine it would be harder to keep it between 195-210, especially when your commute is mostly rural areas (45-65 mph limits)

I know the stat is good, installed it in March and all summer it ran between 198-206 at speed and up to 216-220 idling to less than 25mph on the real hot days.
 
Even with a 180* stat and an upgraded radiator my car would almost immediately head up to 215* or so if I was sitting still in traffic, and bounce around there indefinitely, and trans temperature wasn't far behind.

I'm much more aggressive about keeping coolant temp down because I want to keep trans temps down. With a 180*, I'm currently in the 175* range when on the highway, and 185* in town - because I had the car tuned and the fans come on at that point.
 
I have a 180* stat and a tune for it. Car is always between 180 and 190. Never more or less under normal driving conditions. Plus it keeps my trans temps down too, having the fans set that way.
 
hensleya-

What did your trans run before you had the fan retuned? Im stock, and during the summer on the highway my trans will get as high as 210. I saw it up to 228 once, 98 degrees outside, AC cranked, in stop and go Boston traffic, engine was in the 210-220 range.


One thing that has always bugged me about these cars is the fact that the fan on point is so much higher than the stat open point, and the fact that the gauge normally goes a tick past the middle line. To someone who has never driven these cars, they could appear to be having a problem. With the notable exception of many euro imports, 99% of the cars on the road have temp gauges that read at or just below half. In a Honda Civic for example, if you are running just over the halfway mark, you know that there is trouble brewing. Youre not full on overheating, but its still disconcerting.

I use the Civic example because thats my grandmother's car, which I borrow when taking long trips. You can sit for hours at idle and that gauge will not budge. I drove right up a mountain during the summer in that car, the gauge got to half, that was it. If the thermostat is a 180, the fans come on at 187 and off at 185. The tolerance is less than ten degrees.

In the stock GP, the stat opens at 195 and the fans come on at 218, a full 23 degrees and three notches higher.

Sidebar: I shuffle cars around New England for Enterprise car rental. The Cruze eco has an "electronic thermostat" that allows the engine to run hotter if there is no heavy load on it. I had a Cruze eco one day that had both the regular temp gauge and the electronic readout. The gauge remained two ticks below the middle for the entire trip. In town (stop and go) it was running just over 180, once I set the cruise control on the highway it climbed to 225. It clearly had one of those dummy gauges.
 
Pretty sure the stock 195* tstat only cracks open at 195*... It doesn't fully open till 210*.


I run a 180* tstat and am tuned for it .. My operating temps range between 179*-195* depending on weather.
 


Chad--

I saw the trans fluid temperature rise more slowly to whatever the coolant temperature was, give or take a few degrees. Meaning that it would slowly rise to 215 or so, but take twenty minutes to get there. Trouble is, anything above 175 or so shortens the life of your trans fluid by half for each 20 degrees it goes up. Eventually it breaks down, giving you that "burnt" smell. Much more of that and the trans will begin to break down, and it's all downhill from there.

Running a hotter block will help your mileage, but make you more prone to predetonation if you're pushing boost. In short, I'd run a stock tstat if (1) you have no KR and (2) you install an independent trans cooler.

Since I don't have the $ to replace a trans anytime soon and in any case intend to pulley down, no stock tstat for me.
 
You wonder why things like gaskets, o-rings, vacuum lines, plastics, etc. dry rot.

Oh...hi heat.

180* is fine. Proven time and time again there is a 10-15* le-way on what the t-stat is rated. I didn't care for boiling things in my engine bay with the 195*.

You all can keep the stock T-Stat and enjoy. This is by far the worst topic on this forum, ever.
 
Also realize, when you guys mention temperature, just because the coolant is at 200°, the pistons are a LOT hotter than that. Don't think that coolant temp = all engine internal part temps. Not even close.
Also, I really don't see the OP's claim possible. [Running a 180 keeps me in the 190 area all summer without a tune and 185 in the freezing cold winter, so sill not below his temp claims] So he is mentioning temperatures below the most common lower temp t-stat. A 180 t-stat should never see temps much below 180, so this really only applies to people with a 160 t-stat which although many here disagree with the OP, they still wouldn't use a 160 for other reasons, not unburnt fuel. So I agree people really shouldn't run a 160° thermostat, but disagree with the claims you're making as to what WILL happen if you do.

When I start my car in very cold winter temps, wait a minute or so, the engine is still at like 50° and I smell 0 unburnt gas in the exhaust. You would have to combine to low temps with mods or other issues to have any ill effects like that.

Also, I agree with hensleya1 about the transmission temp. My trans was running cooler with a 180 thermostat over a 195. I am now running a trans cooler so I can gladly go back to the stock thermostat temp.
 
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the guy he was talking to was talking about an alcohol fueled blower motor that needs to be hot or it just won't burn the fuel. it has it's merit as an overall statement, but doesn't apply directly to the 3800 motors.

however, i still think the colder thermostat thing is a waste of time. it doesn't help anything.
 
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