Cooling Mods for Towing

mitchely03 · October 15, 2019

As the title states, looking for cooling mods I can do for my 2015 5.3l. I am towing my track car about once a month, sometimes twice and I find myself getting hot. This pass weekend i towed my car to Laguna Seca from Socal, and it got fairly hot going up the grapvine. Around 230 coolant and 230 trans temps.

What cooling mods can I do? Whats out there?

1SLOW1500 · October 15, 2019

Thermostats delete, better fluid, deeper pan.
But the best mod is get the lines out of the radiator and get a large trans cooler in the grill.
Better if it is stack and plate. Bigger the better. There are guys with 1000hp and 195 or less temps.

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greatmizzou · October 15, 2019

I need to take a picture of this setup, it might be relevant, but my trans shop installed three aftermarket coolers with one Giant high flow in the front. I barely get over 150 now!

He supposedly fabricated some stuff to get it to work

CamGTP · October 15, 2019

If you've never done it before, remove the fan assembly ( it's a little tricky but not that bad) and back flush the radiator fins with a hose/compressed air to clean them out. Lots of crap gets stuck in there over time and will cause poor cooling system function.

1SLOW1500 · October 15, 2019

I need to take a picture of this setup, it might be relevant, but my trans shop installed three aftermarket coolers with one Giant high flow in the front. I barely get over 150 now!

He supposedly fabricated some stuff to get it to work

3 coolers WoW like to see pictures of that.
Most truck guys go with the tru cool max with side ports. There is even a guy that sells the brackets to bolt it to the support behind grill. Then just rubber hose clamped to the stock trans line. Easy install.

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mitchely03 · October 15, 2019

9 minutes ago, CamGTP said:

If you've never done it before, remove the fan assembly ( it's a little tricky but not that bad) and back flush the radiator fins with a hose/compressed air to clean them out. Lots of crap gets stuck in there over time and will cause poor cooling system function.

not a bad idea.

mitchely03 · October 15, 2019

11 minutes ago, greatmizzou said:

I need to take a picture of this setup, it might be relevant, but my trans shop installed three aftermarket coolers with one Giant high flow in the front. I barely get over 150 now!

He supposedly fabricated some stuff to get it to work

wow that would be awesome if i was getting that cold of temps.

Grumpy Bear · October 15, 2019

50 minutes ago, mitchely03 said:

As the title states, looking for cooling mods I can do for my 2015 5.3l. I am towing my track car about once a month, sometimes twice and I find myself getting hot. This pass weekend i towed my car to Laguna Seca from Socal, and it got fairly hot going up the grapvine. Around 230 coolant and 230 trans temps.

What cooling mods can I do? Whats out there?

Question. Do you ever expect to see ambient air temperatures under 33F?

Edited October 15, 2019 by Grumpy Bear

Grumpy Bear · October 16, 2019

Assuming you haven't any need for sub zero freeze protection in SoCal.

A 25% EG based antifreeze (Dexcool) solution will increase the specific heat capacity from .865 to .953 BTU/Pound per degree F. (water is 1.00). Add one ounce per quart of Red Line Water Wetter. You could run as low as 20% but below that running the AC could cause some freeze problems. BOOM!! The Red Line not only improves the heat transfer rate but adds back the lost additives due to the lower solution percentage. (Use a refractometer to adjust).

At 25% you will have freeze protection to @ + 12.7 F. Burst protection to @ 0 F. Boil over to @ 218 F at 0 PSIA, @ 255 F at 15 PSIG.

The lower viscosity of the solution will increase the pumping rate roughly 12-15%.

This is a bit more than a 10% increase in cooling capacity with just the chemistry. It will not cool below the thermostat setting however. You have a 207 F water thermostat. I would expect it would run a few degrees over that but under 212 F at 15 PSIG. that is your pressure cap setting. It is also the factory fan tip in point if I remember correctly.

You can gain more with a cooler thermostat from a Camaro (mid 190's F). The stat is a drop in. You could also use a Katech 174 F as a drop in. (1SLOW1500 runs one) IPSCO makes an upper hose splice in that allow use of any GM style 54 mm Stant with really opens things up. But don't go below 170 F.

This is all good and fine as long as road speeds stay over 50 MPH. Below that the fan settings will need some adjusting to kick in at a lower set point than the factory 212F. If that is not adjusted slow traffic and city water upper limits will be at the mercy of the fan setting. That is it would not make any difference how low the thermostat setting is if there is little air through the radiator. Jon A has done allot of research on fans settings while hauling. Look him up.

The transmission has thermal bypass set at around 192 F. Flipping the pill up side down bypasses it fully. That should bring your transmission temps down under 200 F. If not....you need more cooler as others have replied. If fact staying below 180 F would be what you would hear from the major trans rebuilders.

PML has an 8 quart alloy pan with a drain plug that picks up 2 quarts of capacity. Slows the rate of temp increase and shortens recovery time.

Red Line D6 trans fluid (I'm assuming you have the six speed) has a slightly higher specific heat capacity and a higher heat tolerance. Just information, not an endorsement.

:seeya:

Chevor · October 16, 2019

Easiest thing would be going up the hills slower and in lower gears.

mookdoc6 · October 16, 2019

3 hours ago, Grumpy Bear said:

Assuming you haven't any need for sub zero freeze protection in SoCal.

A 25% EG based antifreeze (Dexcool) solution will increase the specific heat capacity from .865 to .953 BTU/Pound per degree F. (water is 1.00). Add one ounce per quart of Red Line Water Wetter. You could run as low as 20% but below that running the AC could cause some freeze problems. BOOM!! The Red Line not only improves the heat transfer rate but adds back the lost additives due to the lower solution percentage. (Use a refractometer to adjust).

At 25% you will have freeze protection to @ + 12.7 F. Burst protection to @ 0 F. Boil over to @ 218 F at 0 PSIA, @ 255 F at 15 PSIG.

The lower viscosity of the solution will increase the pumping rate roughly 12-15%.

This is a bit more than a 10% increase in cooling capacity with just the chemistry. It will not cool below the thermostat setting however. You have a 207 F water thermostat. I would expect it would run a few degrees over that but under 212 F at 15 PSIG. that is your pressure cap setting. It is also the factory fan tip in point if I remember correctly.

You can gain more with a cooler thermostat from a Camaro (mid 190's F). The stat is a drop in. You could also use a Katech 174 F as a drop in. (1SLOW1500 runs one) IPSCO makes an upper hose splice in that allow use of any GM style 54 mm Stant with really opens things up. But don't go below 170 F.

This is all good and fine as long as road speeds stay over 50 MPH. Below that the fan settings will need some adjusting to kick in at a lower set point than the factory 212F. If that is not adjusted slow traffic and city water upper limits will be at the mercy of the fan setting. That is it would not make any difference how low the thermostat setting is if there is little air through the radiator. Jon A has done allot of research on fans settings while hauling. Look him up.

The transmission has thermal bypass set at around 192 F. Flipping the pill up side down bypasses it fully. That should bring your transmission temps down under 200 F. If not....you need more cooler as others have replied. If fact staying below 180 F would be what you would hear from the major trans rebuilders.

PML has an 8 quart alloy pan with a drain plug that picks up 2 quarts of capacity. Slows the rate of temp increase and shortens recovery time.

Red Line D6 trans fluid (I'm assuming you have the six speed) has a slightly higher specific heat capacity and a higher heat tolerance. Just information, not an endorsement.

I would add another aux cooler than DON'T deviate from 50/50 getting high concentration of Coolant next thing you know it's frozen. Cold snaps, mountains etc. nah........Aux Cooler!

Edited October 16, 2019 by mookdoc6

Nitrousbird · October 16, 2019

There is a long, in-depth thread about this on here.

The best solution:

- Slightly lower thermostat

- Reprogram fans

Logging data proved that a more aggressive and earlier fan ramp-up will significantly reduce coolant AND transmission temps even at highway speeds.

1SLOW1500 · October 16, 2019

Yes I forgot about the engine coolant.lower thermostat like the katech. And reprogram the fans. There is a LOT to the fans as the are a.progressive speed control and there are two. I would look more at your IAT(inlet air temps) I understand the air is warm however there is also some heat soak with hours of driving and hot engine.
Also stay out of the tow haul if possible and and keep the cruise at a reasonable rpm. I day this with in reason as the tow haul is nice when needed just need to understand where that is.

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flyingfool · October 16, 2019

i've been running the Katec for 2 weeks now at 175 I run 180-185 in the city and hwy, the trans temp dropped 8-10 degrees plus i deleted thermostat in trans so i'm at 135 cool city driving-150 on a hot day doing 85 mph on the highway for 100 miles, no need to reprogram fans, it runs fine without going into the ecu. do it!!! I will be pulling a trailer out to El Mirage this month so i'll let you know if i over heat. i doubt i'll go over 160 on the trans and NO Aux cooler needed on an 18 foot toyhauler with the 1500 silverado

Edited October 16, 2019 by flyingfool