How can I make this BEAST run cooler?

[05 Venom]

Just passed the "break-in" period and have started to gas it. Seems the coolant
temp hovers around 200 degrees. The fan kicks on soon after. Any way to turn the
fan on sooner with an aftermarket kit.(no use in a lower thermostat if the fan
kick on temp isn't lowered). Chris

 

[Skip White]

This is another on of those $64,000.00 questions.

These cars all run around 205 to be exact, in heavy traffic, but will cool down to around 185 in fifth gear at highway speed. This tells me the car has a 185 thermostat in it, but the cooling system is unable to maintain that in traffic. As many of you know, most temp sensors, that being the device that kicks the fan on, will go through a cycle and kick the fan on at around 205 or more, then run till the temp drops to a certain level. The SRT's fan when running at full speed, still can't bring the temp down on the car as well as high gear at highway speed can. One or more of the components in the SRT cooling system, are just not able to cool the beast as it should. I don't like the car running that hot, as I know it's only about 20 more degrees over that, and you've killed the engine. It's gotta be ******* it. Kills horsepower also.

Some people will say we need a higher volume water pump. They think that's the weak link, well I think not, because the car cools right down, on the highway, at 1600 rpm, and the water pump is really turing slow at that speed. Kick the car into forth gear, watch the temp go up. The Viper creates a huge amount of heat at higher rpm, and I just don't know what it's going to take to cool it down. The radiator may possibly be to big, and not create enough water velocity. Big rads. are good when the going gets really tough, but they are lousy for normal sporting about. I really don't know where to start.

Let's all give some input on this, and maybe we can come up with an affordable way to get this car to run at 185 all the time. If you could get the fan to come on sooner, that would not bring the car down to 185 in traffic.

As I said on the highway it falls, and it's because of two things, lower rpm, and much needed forced air. I say both of these things, because I did a test and loaped around town at about 40 mph, in a gear that kept my rpm down to around 1600 and the car still ran hot. So this proves it takes air volume and low rpm to keep it cool. Maybee that hydro fan is not cranking out enough cfm. Maybe a set of dual electric fans, and a lighter smaller radiator would do the trick. When I was in Texas, summer heat around 104 the car would not even drop to 185 on the highway, only come night time, did it cool down. Winter really brings some cool air into the front of the rad. The car runs cool even at 40-45 mph. Archer has a $1,000.00 mechanical water pump with increased volume. For that much you could device the best electric water pump system made, and run the best dual electric fans on the market. Then for around $600.00 we should be able to have a custom light weight rad.

Skip White

 

[Viper Specialty]

Lets not forget, on an SRT the fan speed is entirely variable. I doubt 99% of you have ever even seen that fan run at 100%. Want to try? Go out, warm up your car, and pull the connector off the temp sensor. It will go into safety mode and kick the fan to 100%. After seeing how much air one of those Hydraulic fans can move at max speed, tell me that fan doesnt have the ability to cool to 185 all the time. Trust me, it can. (I cant remember if this action will pop a code, so make sure you have a scanner or know someone with one before you try it.)

I have yet to see an SRT in any temp I have been in run over 205 or so in ANY condition, even with the AC cranking away. If you are seeing temps higher, you may have an underlying cause.

 

[Skip White]

Yes Daniel, the fan is variable, as I've heard and felt it when it kicks on high, but the temp still stays the same.

Your right about the car not going over 205 no matter what, thats one good thing about the big radiator, it won't let the car overheat, but I really think, this is one of the reasons, it's unable to bring down the temp, due to lack of coolant velocity. I would like to have an overide on the fan, or a shorter cycle.

Big radiators have some drawbacks, but they also keep things from getting to hot.

Tommy Fudge's car, ran an inline electric pump, along with the oem pump, and he said his car never ran over 180 no matter what. His car was putting down about 750 HP on the natural. This pump did infact increase coolant velocity.

I may try one. They only cost around $450.00 for the system, and looks like a day's work to install. The SRT has an acre of room in front of the engine, so that's a plus.

Skip

 

[treynor]

> The SRT has an acre of room in front of the engine, so that's a plus.

Yes, that's to leave room for the supercharger

 

[Skip White]

yes, this is the only car I've ever seen that you can remove the air intake system, and stand between the engine, and radiator. Paxton must of loved tooling up for this car.

Skip White

 

[Herc]

Isn't a "hot" engine more efficient than a "cold" engine? Seem to remember
this from Thermo.

RD

 

[STUGOTS]

Fluidyne??

172 Degree thermastat??

Water wetter additive??

 

[Skip White]

Yes a hotter engine is more efficiant than a cold one, BUT NOT THAT HOT! Colder therm. is not going to do anything, as the car rarly achieves the 185 temp. 185 is perfect if the rest of the system could maintain that.

I wonder about water wetter. I'd like to try it, and see.

The SRT would be a good car to test it on, as it is allways changing temp under different conditions.

I just think the radiator is to big, and the water flow to slow.

Skip

 

[GR8_ASP]

I have stayed out of this but I will state the SRT keeps the engine temperature the most constant of any car I have ever owned. The thermostat starts to open at 195 and is fully open at 210. I have never witnesssed mine reaching the full open temperature.

Do not compare the gauge readings with other cars as the other cars generally have desensitized readings in the normal range. Hook up a DRB and see the actual temperature. Once you do your concerns will disappear.

The SRT exhibits none of the tempermental aspects shown by the Gen I/II. I have not even heard of any of the highly modified cars indicating a temperature concern.

To the original question. The only way to have the fan come on sooner would be to also lower the thermostat opening temperature. The system needs hysterisis to prevent being in a perpetual on condition. trying to cool the car below the thermostat opening temp would be fruitless as the coolant is no longer passing through the radiator.

 

[DSR207]

Quote:

" I have not even heard of any of the highly modified cars indicating a temperature concern."

Good point, my car runs between 185 and 200, even when stuck in traffic and with all the added HP...Same temp it had before all the mods.

 

[Chuck 98 RT/10]

There has been an obsession with Viper temps as far back as I can remember. I think those concerns are unnecessary. The motor is designed to run at or near the 200 mark. I'll trust the million-dollar research of Dodge.

Unless your Viper sees more track duty than street, or you drive like an idiot when you go to the grocery store, I don't see any reason to fool with the cooling system.

If it's the overall heat of the car that bothers you, then you need to sell your Viper. With more cylinders and C.I. than the average motor the extra heat has to go somewhere. Removing the cats will help but a modified cooling system won't.

IMO live with it. You won't get any HP gain by lowering the motor temp, and if preserving the motor is the goal lower RPMs will do more to accomplish longevity than any cooling mod.

 

[Skip White]

Well I lived in Texas where it's 100-106 all summer long, and the sun blazes. My SRT's have never ran as well in that temp, but then again, I never really liked driving them in the heat of the day. The car did run better in the cooler evening temp. Heat soak took a bit longer when the temp fell. Iceing down the intake at the track, seemed to help.

I really like the idea of trying to get the car to run at the 185 temp it does on the highway. I don't really like the 205 temp. As our cars age the temp may rise a bit more. They usually do, then we really need to do something to bring it down. After one good sprint, the car rises, and seems to not want to come back down.

If you live in Texas, you know what I'm talking about.

No ones saying the car is overheating, just running a bit hotter than we like. Who wants there car on the border line of overheating.

Skip

 

[Chuck 98 RT/10]

Motors run better in cool air because cool air is more dense which allows more air in the cylinders, which in turn acts like higher compression or a blower. The engine however, still needs to be at operating temp. To illustrate, take your bone cold motor for a run without letting it warm up. You will notice that it doesn't run as well until it warms up.

I don't know what optimum performance temp is, 185 might be just fine but stock temps are not high on my worry list.

BTW 205 is not the borderline of overheating. 250 is.

 

[rubbersidedown]

EMISSIONS. Hydrocarbons burn out at higher temps, which allows the viper and every other car in production to run hotter. C5 vettes fans don't kick on until 220. It won't hurt anything, but some power is generally left on the table. If you go much lower than 180, extensive tuning is required as enrichment is added because of ECT (gradually reduced from cold to about 168)

 

[05 Venom]

Some very goods point made. Let me just clarify that I don’t want to considerably drop temps,
just keep in the range of 185-190 under most driving situations.
Chuck. The overall heat doesn’t bother me, in fact the cabin is quite cool. Even the door sills I have no problem. Maybe they addressed these issues with the ‘05 model. I just feel a difference when flooring the car after it’s been in traffic compared to exiting from highway drivingOnly difference is lower temps after highway driving.
Everyone on the forum knows high -po cars run better when cooler/cooler air temps.
My ‘02 Z06 has a 178 therm and fan controller . The fan kicks on at 190 and the car never gets above 192-195 even in heavy summer traffic. (This also helps when sitting in the staging lanes
waiting for your run, without these mods the temps would hit 230 in a ‘heartbeat’(no pun intended)).
I plan on installing the K&N setup along with removing the plastic piece in the hood scoop. Hopefully this will increase cooler air. Maybe I will notice a difference.

Chris

P.S. Anyone attending the Northeast Rendezvous May12-15

 

[Chuck 98 RT/10]

a ‘heartbeat’(no pun intended)).

LOL.

I'm sure motorheads know about the cool air, I just mentioned it for anyone reading that might not understand. I guess I was in one of those "teacher" modes.