Keeping the viper cool in all this upcoming hot weather. Need ideas

[Qualitywires.com]

I guess this thread would apply to people who have front mount intercoolers....my temp gauge hits right around 200-220 and maby hovers above that when I get on the car...it will climb steadily if I don't have some fast moving air coming in.... I hear people say that is normal temp for vipers...but I don't think it really is. I know the front mount intercooler does block a lot of the moving air...but maybe I need to think about ducting the front of the car...I tried diluted solution of antifreeze and water..plus water wetter...but still didn't see that big of an improvement.

So any suggestions? Kicking on the fan early seems like a good idea, but I think...eventually the engine gets to a point where it gets heat soaked...soo the fan does little...unless you have mass amount of air hitting the car...

so give some ideas and suggestions...I think ducting will do the trick...back to the drawing board.

 

[Bill Pemberton Woodhouse]

That is the normal operating temperature.

 

[Qualitywires.com]

I guess mine stays around the 225-230 area..most of the time...hwy driving it gets to 220-225...under boost...it climbs to maybe 230...which seems a bit hot.

 

[DG Viper]

AB... I thought you ran cooler than that before? Is the new setup running warmer than the previous one?

As you probably will recall... I'm usually at about 200-215 on any given day. Your help got my car running down to 200, where before I was barely able to even get to 205 or so.

 

[GTSnake]

wait a second. you mean your Ron Davis radiator doesn't help?

 

[Qualitywires.com]

The Ron Davis Radiator or any larger one will help in cooling the car down while TRAVELING, but at a stand still...it can get heat soaked...also remember...I have a big front mount intercooler that is blocking my radiator also...if I didn't have that, my car would run real cool.

I did some minor duct work tonight and got the car temp down a bit...so ducting seems to be everything in cooling.

 

[viperkraz]

Temps. sound normal to me. Anybody ever try Evans waterless coolant? Pretty good idea behind it. Eliminate the water, eliminate steam pockets that form in the engine. I will be changing to this when I rebuild the motor this winter.

 

[Qualitywires.com]

Temps. sound normal to me. Anybody ever try Evans waterless coolant? Pretty good idea behind it. Eliminate the water, eliminate steam pockets that form in the engine. I will be changing to this when I rebuild the motor this winter.

any information on this?

 

[Qualitywires.com]

I found this....

Evans NPG Waterless Coolant is the original waterless coolant. NPG is recommended for racing engines that run on tracks or in series that have a “no ethylene glycol' rule. NPG is also a stand-alone coolant. NPG is not recommended for street use or cold weather vehicles. A free test strip is included with purchase as a guide to successful conversion.


NPG is not recommended for street use or cold weather vehicles

 

[joe117]

What do you mean by "heat soaked"?

The radiator is going to transfer coolant heat to the air at some rate.
The quantity of air flowing over the radiator and the temperature of the air will determine how much heat gets transferred out of the coolant.

There isn't any point where anything gets heat soaked and stops this transfer.
After the thermostat is full open, the amount of heat that the engine makes and the amount of heat that the radiator looses to the airflow, will come to a balance, and that's where the temperature of the engine will stabilize.

If you get more air flow by running the fan, you will get more heat transfer out of the coolant.

Blocking air flow and adding heat to the incoming air, with an AC condenser or SC cooler will cause less heat transfer from the coolant.

As the measured temperature of the coolant rises there is more chance for hot spots in the head, near the exhaust valves, to form steam bubbles. These bubbles will stop heat transfer to the coolant at these points and this will make the engine run even hotter.

I think the only thing you can do to make the car run cooler is to increase air flow by running the fan and make sure the system is well burped.

I don't know abut removing the thermostat on the V10, but removing it from many engines will make for more coolant flow and cause the engine to run cooler.
Someone else may have done this on the V10 and they can say if it works.
Just don't let anyone tell you that the coolant flow needs to be restricted "to give it time to cool down" in the radiator.
That is a common myth.

But again, you can't think of the radiator as some kind of container of coolant that somehow gets heat soaked and stops working.

 

[agentf1]

I don't know abut removing the thermostat on the V10, but removing it from many engines will make for more coolant flow and cause the engine to run cooler.

I have seen in alot of cases that when you remove the thermostat the coolant will flow to fst through the radiator not allowing it to actually remove the heat and the engine will run hotter.

 

[Tom F&L GoR]

ab,
Don't do anything. The coolant temperature is the water jacket around the cylinders. People put lower thermostats in because in the good old days with carburetors, the intake was married to the heads and block such that intake charge temperatures were affected greatly by coolant temperature. That is no longer the case - as you can stick your hand under the intake runners.

Even in modern engines there's supposedly power to be gained or saved by cooler coolant; if there is, it's because the fuel map runs richer, not because anything is more efficient. Frankly, I'll argue that cooler coolant leads to cooler oil, which then robs some of the power you gain.

Yes, you want cool intake air for a denser charge, and you have your intercoolers. You also have to have some feature already that lets you tune air-fuel ratio, so you aren't chasing the fool-the-ECU game. I think you're done on the intake side. You want moderate coolant temperatures; cooler sounds good, but cooler walls will **** more heat out of the combustion chamber and take a little bit of energy (power) away. As long as you are not detonating or feel you are spark limited, theory says you should go hotter (to take less energy away).

You want oil temperatures to be above 212F to boil off water and the light ends of the fuel (dilution.) Water combines with acids, fuel, additives and degrades the oil almost as quickly as extremely high temperatures do.

I think your recipe should be: cold air, moderate coolant, higher oil temps, tune your A-F.

(Not meant to sound like a know-it-all, just a textbook geek with a little bit of experience, and always ready to listen to those with lots of experience.)

 

[GARY J]

Mine never goes over 180. Even at the dragstrip, in 90 degree weather, one pass after another, I think the car saw 200 degrees. Call Jason Heffner.

 

[Russ M]

Ab,

Get an AEM unit if you want to lower the temps, its in the tune not the hardware. But your temps are normal for Vipers, stock mine would see 220-230 at a prolonged stop or long hard acceleration.

***,

I bet you already have an AEM unit, that is why your temps are so low.

 

[Anaconda]

Your percentage of coolant as opposed to water also effects temperatures. Most people tend to use entirely too much coolant.

 

[joe117]

"I have seen in alot of cases that when you remove the thermostat the coolant will flow to fst through the radiator not allowing it to actually remove the heat and the engine will run hotter."

Agentf1,
this is not the case. Many people think that slowing flow through the radiator will give more time to cool the water, but it just isn't so.

There was a time when cars did not have cross flow radiators and the restriction posed by a thermostat helped keep the water pump from pulling a low pressure in the radiator and causing boil over.
Stock car catalogs even sold restrictor rings.

The fact is, faster flow will keep the hot spots inside the head from boiling. Faster flow will bring hotter water to the radiator. the heat transfer will be better with a higher temp delta between the air and water.

There is no science to the idea of giving the water time to cool in the radiator.

 

[Qualitywires.com]

I think I will go with the AEM route here soon...just need to find a person who offers a great price and support on it. I agree that the tune makes a big difference.

 

[95Viper]

ab, Have you tried Zerex Super Racing coolant? I read about this in Car/Driver a year ago. It's basically corrosion protection without ethylene glycol. Since more distilled water is used with this product it naturally would be cooler. No freeze protection.

 

[Qualitywires.com]

I can't find it anywhere....looked at autozone and pep boys...

I am running water wetter and distilled water...with maybe 35% antifreeze mix (Preston green stuff)

 

[95Viper]

He called Prestone and they directed him to a place to order it online. Small bottle, like 1/3 of the size of a regular gallon of antifreeze, mix with distilled water.

I'd try it if I were you but you might need to remove your block plugs and cycle once with just distilled to really get rid of anything currently in there first.

 

[DG Viper]

AB... let me see if I can come with some more. I might have a full bottle in my garage that I would be happy to give you.

I'll have to check tonight and I'll let you know.

 

[WOT!]

I too ran hot. Until recently when I replaces the thermostat with a 180 degree, and flushed and replaced the coolant. Now I think I might be running too cool. When moving I hit 180 - 185. In traffic (slow) I hit 200 on 90+ days with high humidity.

 

[Gerald]

hate to tell u Adam, mine will stay in the 170 to 190 range in the HEAT of summer. Only time it gets warmer is stop and go traffic and even then it MIGHT see 200, perhaps a tickle more. Once I get moving, back down to 175-180'ish... Only thing I can tell u is burp, burp, burp. that $1.75 prestone radiator flush kit is the key for me. I use it about every other day to keep air out and top off....
Doesn't adding timing create more heat?

Good Luck..
Gerbil

 

[Qualitywires.com]

Gerald...that's because Gerbil Powered Vipers don't give off a lot of heat.

 

[GR8_ASP]

"I have seen in alot of cases that when you remove the thermostat the coolant will flow to fst through the radiator not allowing it to actually remove the heat and the engine will run hotter."

Agentf1,
this is not the case. Many people think that slowing flow through the radiator will give more time to cool the water, but it just isn't so.

There was a time when cars did not have cross flow radiators and the restriction posed by a thermostat helped keep the water pump from pulling a low pressure in the radiator and causing boil over.
Stock car catalogs even sold restrictor rings.

The fact is, faster flow will keep the hot spots inside the head from boiling. Faster flow will bring hotter water to the radiator. the heat transfer will be better with a higher temp delta between the air and water.

There is no science to the idea of giving the water time to cool in the radiator.

Joe, mostly good points. A few different perspectives to ponder. First you have 2 things at work. Pressure and temperature. It is true that pressure does not have a significant impact on heat transfer rates and thus an open thermostat with a higher flow rate should increase heat transfer. However, and doesn't there always seem to be a however, the increase in flow is coupled with a reduction in pressure. Not at the cap but within the engine. The thermostat acts as a restriction allowing higher internal pressure within the engine than the pressure cap would normally allow. That pressure (circa 30 to 40 psi) raises the boiling temperature of the coolant in the engine.

The other aspect that did not appear to be correct is that when boiling occurs, which may be enhanced by reducing the pressure, heat rejection goes up. Nucleate boiling actually increases the heat transfer rate INTO the coolant, thus when a car starts to boil internally the rate of coolant temp increase goes up considerably. Therefore I would hazard that vehicle with a thermostat removed may actually attain a higher coolant temperature, if the open flow's related pressure drop allows for nucleate boiling. If boiling does not occur the temperature will drop. But if nucleate boiling does occur the coolant temperature will rise and probably exceed the pre t-stat removed temp. Note this condition would probably exist only under load as nucleate boiling is doubtful under low load operating conditions.

 

[Qualitywires.com]

This is some good information...

 

[acrdakota]

AB, which fan do you have on your car? I'm not sure which year the made the change but the newer (maybe 99+) got the 2spd fans which on high flow a considerable volume of air. If you already have it, are you sure it's coming on high, and at what temp?

 

[Neil - UK]

slap in a GTSR centre louvre/vent

 

[Tom F&L GoR]

Ron, the water pump is not a positive displacement pump, so I have a question. Does the thermostat restriction then create 30psi on the upstream side in a 16psi system or does it add 30 psi? And what is the pressure on the downstream side - cap pressure?

Seems the upstream pressure would vary with engine speed (pump speed) and I wouldn't want to be standing near it after you run hard, get lots of heat rejection to the pressurized coolant, and then suddenly turn the engine off. Or even run at high speed (with high pressure) and then shift to a lower speed or idle or braking (creating low pressure.)

 

[GR8_ASP]

Tom,

You are correct it is not a positive displacement pump. The pressure produced by the pump is directly related to the pressue drop or resistance in the system. During open thermostat periods the primary resiatances in the cooling system are the head gasket, thermostat and radiator. The head gasket pressure drop is fairly low. Just enough to direct coolant in the proper direction and make sure block bore coolant areas are not stagnant. The thermostat restriction, which has been fairly consistent for decades, is roughly equivalent to a 5/8 inch hole. Head gasket opeings try to be twice that size in total opening area to keep the cylinder head at the highest possible pressure.

Radiator pressure loss is generally less than 10 psi at maximum flow, in keeping with providing a water pump inlet pressure on the positive side. In effect the pressure in the engine is cap pressure + t-stat pressure drop + head gasket pressure drop (assuming the cap is on the upstream side of the radiator as is the case in most modern cars).

The end effect is that the maximum poressure observed is around 40 to 50 psi, of which 30 to 40 remains in the cylinder head and 15 in the upper radiator tank/hose (and yes I realize the rad is really cross flow). That means the t-stat provides around a 15-25 psi pressure drop, or about 2-3 times the radiators pressure drop. Note that these are maximum values. The pressure curve is generally not linear as the water pump efficiency drops off due to speed - efficiency curves and cavitation. This normally plateaus the flow curve at 4000-5000 rpm for most engines.

I digress and the wife is telling me I have to go to a 4th of July fireworks party. So tah tah for now.