CSF vs OEM radiator

[ZIOI]

I forgot that I'd shot this short comparison video contrasting CSF radiator with OEM. It's not a subtle difference. The CSF is over half again thicker, and is physically far more robust. Sorry, icloud link is all I have for now. I hope it works.

iCloud Photos - Apple iCloud

View, organize, and share photos and videos with iCloud Photos on the web. Changes will sync across your devices with iCloud.

www.icloud.com

 

[jeremy j]

Looks nice. I just replaced my radiator less than a year ago with OEM or I'd definitely get one of these.

What did it cost? I am not finding it on their site.

 

[llm]

Did it fit without any modifications? I'm looking to get this done and have no experience replacing radiators.

 

[ZIOI]

Looks nice. I just replaced my radiator less than a year ago with OEM or I'd definitely get one of these.

What did it cost? I am not finding it on their site.

I got it from Summit Racing for $550 or so.

CSF Racing Radiators 2019 LEXUS GX460 | Summit Racing

Find 2019 LEXUS GX460 CSF Racing Radiators and get Free Shipping on Orders Over $109 at Summit Racing! CSF racing radiators feature the most advanced and efficient radiator cores in the industry. Offered for both vehicle-specific and universal applications, they use innovative tube and fin...

www.summitracing.com

 

[ZIOI]

Did it fit without any modifications? I'm looking to get this done and have no experience replacing radiators.

Zero mods.

 

[Rednexus]

Thanks for posting this. I'm gonna get one for my 470 in the spring. I have found that my engine will get up to around 205F on long 4LO climbs at lower speed, which to me indicates the radiator isn't keeping up as well as I'd like (it being nearly 18 years old probably does not help).

 

[Chronicle]

I have the CSF in the box still waiting to install it in the spring. I'm curious to know how much it will affect the trans temp since the cooler is built into the radiator or if it will still be stuck at whatever the coolant temps are.

 

[Rednexus]

Heat flows from warmer to colder, and the amount of heat flow is based on the gradient (i.e., temperature difference, with a bigger temperature difference meaning more heat flow). Under light throttle/cruising conditions, the TCC is locked and the trans will generate very, very little heat. At this period the engine should be running around 195F, resulting in the coolant transferring heat to the ATF and warming it up to around 195F as well. I don't think the CSF would change trans temps under this conditions the engine temp is controlled by the thermostat and should not be affected by the size of the radiator.

When the ATF exceeds engine temp (which usually happens when the engine is working hard), if the coolant temp were lower than it would be with a OEM radiator, due to more radiator capacity (i.e., the thermostat is wide-open as the system temperature is controlled by the radiator/fan cooling capacity), the trans temp should be lower with a CSF radiator as the temperature gradient between the ATF and radiator will be higher - thereby allowing the ATF to shed more heat to the radiator.

I still recommend an aux trans cooler on any of these rigs. Mine is installed after the OEM radiator/trans cooler (OEM location for a GX470, though I have a larger-than-stock cooler). The aux cooler is not combined with the radiator, so it allows the ATF to shed additional heat directly to the atmosphere, which will always be cooler than the 195F coolant temperature. In theory this should also help with engine temp as aux cooler shedding heat to the atmosphere means less heat is being transferred to the engine coolant.

 

[jeremy j]

I got it from Summit Racing for $550 or so.

CSF Racing Radiators 2019 LEXUS GX460 | Summit Racing

Find 2019 LEXUS GX460 CSF Racing Radiators and get Free Shipping on Orders Over $109 at Summit Racing! CSF racing radiators feature the most advanced and efficient radiator cores in the industry. Offered for both vehicle-specific and universal applications, they use innovative tube and fin...

www.summitracing.com

Dang. My OEM was over $450.

 

[ZIOI]

Heat flows from warmer to colder, and the amount of heat flow is based on the gradient (i.e., temperature difference, with a bigger temperature difference meaning more heat flow). Under light throttle/cruising conditions, the TCC is locked and the trans will generate very, very little heat. At this period the engine should be running around 195F, resulting in the coolant transferring heat to the ATF and warming it up to around 195F as well. I don't think the CSF would change trans temps under this conditions the engine temp is controlled by the thermostat and should not be affected by the size of the radiator.

When the ATF exceeds engine temp (which usually happens when the engine is working hard), if the coolant temp were lower than it would be with a OEM radiator, due to more radiator capacity (i.e., the thermostat is wide-open as the system temperature is controlled by the radiator/fan cooling capacity), the trans temp should be lower with a CSF radiator as the temperature gradient between the ATF and radiator will be higher - thereby allowing the ATF to shed more heat to the radiator.

I still recommend an aux trans cooler on any of these rigs. Mine is installed after the OEM radiator/trans cooler (OEM location for a GX470, though I have a larger-than-stock cooler). The aux cooler is not combined with the radiator, so it allows the ATF to shed additional heat directly to the atmosphere, which will always be cooler than the 195F coolant temperature. In theory this should also help with engine temp as aux cooler shedding heat to the atmosphere means less heat is being transferred to the engine coolant.

Doing a bit of investigation, it appears that the "oem trans cooler" isn't much of a cooler at all. It's basically just a section of tubing inside the end tank of the radiator. Which means that it's probably contributing very little actual cooling.

I'm going to call CSF and see if they can enlighten me as to how the trans cooler function is integrated in the radiator.

 

[Rednexus]

Doing a bit of investigation, it appears that the "oem trans cooler" isn't much of a cooler at all. It's basically just a section of tubing inside the end tank of the radiator. Which means that it's probably contributing very little actual cooling.

I'm going to call CSF and see if they can enlighten me as to how the trans cooler function is integrated in the radiator.

The OEM radiator is set up the same way, which is why these rigs all need the OEM integrated cooler plus a aux cooler add-on after the radiator.

The trans would run way too cold in the winter without the integrated cooler. Do it is important to have it.

 

[ericm979]

The main OE transmission cooler is the trans fluid to coolant heat exchanger bolted to the transmission. Part #1 in this diagram:

 

[ZIOI]

An add-on trans cooler is moving up the priority list by the hour.

 

[Rednexus]

An add-on trans cooler is moving up the priority list by the hour.

I highly recommend a Hayden 678 or equivalent-sized aux cooler. The OEM aux cooler on my 470 was far too small - I'm guessing the 460 equivalent is also under-sized. The 678 (which was around $55) is around 3X the size of my OEM aux cooler.

 

[Cold Iron]

You can get an OEM radiator for $255 delivered from Bell Lexus. But I suspect that when most people need one they need one now, not wait for one to be delivered. The good news is the OEM radiator lasts 8-10 years. The bad news is the OEM radiator lasts 8-10 years.

If I was going aftermarket and I've looked, CSF would be first on my list. I should have a few more years to decide

The main OE transmission cooler is the trans fluid to coolant heat exchanger bolted to the transmission. Part #1 in this diagram:

Part #1 is often called cooler in parts department diagrams but in the Factory Service Manual it is called ATF Warmer, sometimes heater.

The function is to warm ATF when it is cold, because you don't want your ATF too hot OR cold. Once it warms up the wax poppet thermostat sends it to the radiator where the built in transmission cooler cools it. In warmer climates you can pin the T-stat open so that it is always going to the radiator cooler. Not sure if anyone has figured out the temp that it fully opens can't find it in any documentation.

I run OBD Fusion on a dedicated phone that I leave in the rig all year. Below zero the screen freezes solid so can't use it. At 14° above zero it works fine, this is after warming up for 10 minutes and before putting it in gear. Obviously, as Torque Converter temp is lower than ATF pan

I've only seen it hit above 230° three times in a year and only one of those was towing (2.5K pounds). But it is enough that I am putting a Hayden 698 cooler in, it is sitting in my garage. But I'm not in a hurry given temperatures this time of year in Minnesota.

 

[ZIOI]

Great Post, Cold Iron. As I posted in the other thread, I'm mulling over the tradeoffs of post-OEM or pre-OEM aux cooler plumbing. Seems to me that there's a good reason to prefer putting it after that OEM unit (downstream, as it were). That way, you make best use of the 195F temp of the OEM radiator for cases where trans temp is above that point while adding a bit of cooling below 195. No need to worry about over-cooling with the small stat on the trans side.

 

[Cold Iron]

Great Post, Cold Iron. As I posted in the other thread, I'm mulling over the tradeoffs of post-OEM or pre-OEM aux cooler plumbing. Seems to me that there's a good reason to prefer putting it after that OEM unit (downstream, as it were). That way, you make best use of the 195F temp of the OEM radiator for cases where trans temp is above that point while adding a bit of cooling below 195. No need to worry about over-cooling with the small stat on the trans side.

Personally I am going post OEM downstream as well but also went with the Hayden 698 internal bypass cooler. It has a thermostatic bypass that only cools the ATF once it needs to. My train of thought is to let the OEM cooler do its job then let the Hayden pick up when it needs to.

I'm getting ready to hit 50K miles and will install it in a couple of months when it warms up. Along with several ATF drain and fills. And coolant flush. Once I get to 80K-90K miles (~4-5 years) it will be time to do preventive maintenance and will do a complete water side job including replacing the radiator. TBD which one. At that time will likely replace the Hayden 698 also as they aren't that expensive.

Hayden 698