Running Too Hot 280F Oil 250F Coolant

[GTS Dean]

I can overheat my viper on track in 3 laps by winding the shit out of the car in 2nd and 3rd gear when it's 80+ degrees.

Since I had a nice flashing light at 240 for coolant when romping in it, i can now taper coolant temps by changing up driving style.

That's pretty much my experience when in Time Attack mode - just drive it like my Sprint Shifter kart. When I'm out practicing, I put together track segments to use max effort, then cool it on other sections. Otherwise, I just gear up, throttle back, use the torque and work on smoothness.

[Arizona Vipers]

Take your valve cover off?

This is excellent advice as well

[ViperGeorge]

This is excellent advice as well

Come on AZ, be honest. You took yours off to save a couple of ounces not because of temps.

[ViperSRT]

Hopefully the decorative covers and not the actual valve covers. That would be quite a mess.

[Arizona Vipers]

Come on AZ, be honest. You took yours off to save a couple of ounces not because of temps.

hehe that too. Actually prefix had to take them off due to the solid cam valvetrain requiring spacers on the valve covers. I weighed them and was surpsied, heavier than I thought but I forget now. They are pretty thick/dense

[sadil]

Thanks for all the comments folks.

I will go ahead and remove the radiator to blow it off and give it a good clean and will get some fresh coolant inside. Will report back with what I find.

As for driving on the track and overheating, seems like it is common when sticking to second gear as often as I do on our short Michigan tracks. The car is just geared that way and I need to start targeting hot laps instead of running race style for 15-20 mins. I am glad I asked the question before having a failure. I will back off and drive faster for a shorter amount of time. Brakes and tires will be happy too.

Regarding some of the suggested cooling modifications, I might not need them if I change my style. Will try to find something wrong with the rad first. I have also reached out to Prefix for a 160F t-stat adjustment but not sure I want that all the time since I street the car. I won't come up to temp fast enough. The 160F might help me for sure to keep things cool before going out.

Regarding coolant, I am running how it came from the factory.

Regarding the high pressure coolant reservoir cap, what have people upgraded to?

[ellowviper]

I put a cooler t-stat in my Dakota and now I get a P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature). Just saying....

[Tamvette]

Changing the thermostat will just delay it and you can damage your car if you drive in street significant miles. I thought we had slow tracks around here, 75% 2nd gear is crazy but sounds fun. For the tracks around here l, I almost always hit 240-250 oil temps and 200 - 208 coolant temp at race pace with ambient temp being 40 to 80 F.

What engine oil do you use? The thickness plays a huge role as well. As you suggested, I would change coolant mixture as well. Do you have aftermarket headers installed? I would go back to stock on that if you do.

Next step could simply be changing the gearing to suit this track better but that is obviously an extreme step. Or you could always hunt down cooler days, do you know what under what conditions the record was set?

[Arizona Vipers]

Thanks for all the comments folks.

I will go ahead and remove the radiator to blow it off and give it a good clean and will get some fresh coolant inside. Will report back with what I find.

As for driving on the track and overheating, seems like it is common when sticking to second gear as often as I do on our short Michigan tracks. The car is just geared that way and I need to start targeting hot laps instead of running race style for 15-20 mins. I am glad I asked the question before having a failure. I will back off and drive faster for a shorter amount of time. Brakes and tires will be happy too.

Regarding some of the suggested cooling modifications, I might not need them if I change my style. Will try to find something wrong with the rad first. I have also reached out to Prefix for a 160F t-stat adjustment but not sure I want that all the time since I street the car. I won't come up to temp fast enough. The 160F might help me for sure to keep things cool before going out.

Regarding coolant, I am running how it came from the factory.

Regarding the high pressure coolant reservoir cap, what have people upgraded to?

Since you drive it on the street a lot, maybe go with a 180*? And still have Prefix change the fan speed to 180* as well. You'll be 30* cooler on your first lap. And correct I think all fast drivers on 2nd gear mostly short tracks will run hot. 3rd gear these cars run ice cold.

[sadil]

Changing the thermostat will just delay it and you can damage your car if you drive in street significant miles. I thought we had slow tracks around here, 75% 2nd gear is crazy but sounds fun. For the tracks around here l, I almost always hit 240-250 coolant temps at race pace with ambient temp being 40 to 80 F.

What engine oil do you use? The thickness plays a huge role as well. As you suggested, I would change coolant mixture as well. Do you have aftermarket headers installed? I would go back to stock on that if you do.

Next step could simply be changing the gearing to suit this track better but that is obviously an extreme step. Or you could always hunt down cooler days, do you know what under what conditions the record was set?

Thank you for the insight. I am a little more comfortable now knowing that other people are also hitting these temperatures. You definitely have to drive hard to get there. I only got to this point after going to used slicks, brembo htc brake fluid, and raybestos ST47 brake pads. Arrow tune is there too but some have said it doesn't matter and I am starting to believe it. Its a big motor that will overheat with the excessive 2nd gear usage. Funny thing is that this was me actually strategically using more 3rd in the twisties!

Here is Ralph running a super quick lap in Storm. On Hoosiers he was 1:22.5 (ACR record is 1:22.1)

You can see him running 2nd for a majority of the lap along with the rev limiter jump.

https://www.youtube.com/watch?v=autrPigRodw

I only run 15W50 on the track. I am a development engineer at GM so oil is my life and it was easy to notice the advantage of going to 15W50. Cant beat the price too with Walmart Roll Back! 5Qt for $22!

I dont have my headers installed...yet! Hopefully its an issue I can solve without avoiding my header install. That would be bummer

Since you drive it on the street a lot, maybe go with a 180*? And still have Prefix change the fan speed to 180* as well. You'll be 30* cooler on your first lap. And correct I think all fast drivers on 2nd gear mostly short tracks will run hot. 3rd gear these cars run ice cold.

Agreed, its Grattan Raceway specifically due to the tight turns for more than half the track. Gingerman is another track I am going to in a few months. Will be great to see how the car does there at my current pace. I am thinking I won't have any issues due to more time in 3rd.

And I will definitely inquire about the fan. I actually had a typo in my post,

I have also reached out to Prefix for a 160F t-stat adjustment but not sure I want that all the time since I street the car. I won't come up to temp fast enough. The 160F (meant to write FAN SETTING) might help me for sure to keep things cool before going out.

Will try to get the fan to come on earlier for sure!

I put a cooler t-stat in my Dakota and now I get a P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature). Just saying....

Makes sense. System would recognize it as a potential issue if you just put the t-stat in without updating the sensor alarm for t-stat opening temperature.

[ViperGeorge]

Thank you for the insight. I am a little more comfortable now knowing that other people are also hitting these temperatures. You definitely have to drive hard to get there. I only got to this point after going to used slicks, brembo htc brake fluid, and raybestos ST47 brake pads. Arrow tune is there too but some have said it doesn't matter and I am starting to believe it. Its a big motor that will overheat with the excessive 2nd gear usage. Funny thing is that this was me actually strategically using more 3rd in the twisties!

Here is Ralph running a super quick lap in Storm. On Hoosiers he was 1:22.5 (ACR record is 1:22.1)

You can see him running 2nd for a majority of the lap along with the rev limiter jump.

https://www.youtube.com/watch?v=autrPigRodw

I only run 15W50 on the track. I am a development engineer at GM so oil is my life and it was easy to notice the advantage of going to 15W50. Cant beat the price too with Walmart Roll Back! 5Qt for $22!

I dont have my headers installed...yet! Hopefully its an issue I can solve without avoiding my header install. That would be bummer



Agreed, its Grattan Raceway specifically due to the tight turns for more than half the track. Gingerman is another track I am going to in a few months. Will be great to see how the car does there at my current pace. I am thinking I won't have any issues due to more time in 3rd.

And I will definitely inquire about the fan. I actually had a typo in my post,

I have also reached out to Prefix for a 160F t-stat adjustment but not sure I want that all the time since I street the car. I won't come up to temp fast enough. The 160F (meant to write FAN SETTING) might help me for sure to keep things cool before going out.

Will try to get the fan to come on earlier for sure!



Makes sense. System would recognize it as a potential issue if you just put the t-stat in without updating the sensor alarm for t-stat opening temperature.

If you put headers on send them to Swain for their coating first. Amazing how cool the primaries are with their coating. Coming off track and checking primary temps with a laser Pyrometer I haven't seen temps above 175 degrees on the primary tubes. That's plain crazy low for exhaust primary pipes. My friend and I both have 9 liter motors with ARH headers and we both Swain coated them. Both of us have similar readings on the primary pipes coming off track.