Aluminum Radiator

[bloc]

That said, I will be upgrading the tranny cooler before summer. At a scaled 15,620lbs, I've been able to trip the auto transmission hot temp logic at 266F on more extreme grades, where it goes into a more regimented torque converter lock-up strategy to reduce heat. It's managing okay to prevent from tripping the overtemp at 302F. But I'd like to help it out with a larger tranny cooler.

Any thoughts on getting a small but powerful fan for the factory cooler? It is ducted such that some of the radiator fan airflow will be drawn over it, but this is only a small portion of the radiator and even more restrictive than the flow path through the rad alone. And this may be easier than installing a different core and building effective ducting.

I guess you could also run temp probes on the inlet and outlet of your existing air/fluid unit to see how effective it really is. Same for the one in the radiator, now that I think about it.

 

[borfoo3]

In Kuwait, we see much higher temps than anywhere in the US, nobody ever has issues with the stock radiator on the 200 series.

However, some mods do help in certain cases:

1- For heavy rigs doing lots of dune bashing, we keep an eye on transmissions temps. Going with a bigger trans cooler can help remove some thermal load on radiator.

2- Some people add an electric fan in front of the A/C condenser (turns on by switch or with compressor cycle), mainly to help sustain cold A/C air during heavy traffic stops. This is a common mod for the Nissan Y61 Patrol guys, but honestly never felt the need for it in the 200 series.

In short: Keeping the stock 200 series radiator in good working order is good enough to handle whatever you can throw at it

 

[TeCKis300]

Any thoughts on getting a small but powerful fan for the factory cooler? It is ducted such that some of the radiator fan airflow will be drawn over it, but this is only a small portion of the radiator and even more restrictive than the flow path through the rad alone. And this may be easier than installing a different core and building effective ducting.

I guess you could also run temp probes on the inlet and outlet of your existing air/fluid unit to see how effective it really is. Same for the one in the radiator, now that I think about it.

I did think to maybe add a fan. The only time I'm seeing elevated tranny temps is at speed on the freeway when lugging up hills. Fan likely won't do much there and I probably just need more radiator surface area but still noodling. I'll start another thread soon but haven't landed on how much larger or which radiator. The Tundra units are about 20% larger so that may be a candidate.

In Kuwait, we see much higher temps than anywhere in the US, nobody ever has issues with the stock radiator on the 200 series.

However, some mods do help in certain cases:

1- For heavy rigs doing lots of dune bashing, we keep an eye on transmissions temps. Going with a bigger trans cooler can help remove some thermal load on radiator.

2- Some people add an electric fan in front of the A/C condenser (turns on by switch or with compressor cycle), mainly to help sustain cold A/C air during heavy traffic stops. This is a common mod for the Nissan Y61 Patrol guys, but honestly never felt the need for it in the 200 series.

In short: Keeping the stock 200 series radiator in good working order is good enough to handle whatever you can throw at it

Great input. Any insight into which larger tranny cooler they fit?

For #2, interestingly, the later model year 100-series got rid of the aux A/C condenser fan. It was very noticeable on hot days transitioning from stopped at the light to moving again, how the A/C worked that much better. Probably cost saving and I was thinking to re-fit the factory condenser fan. The 200-series doesn't exhibit this issue and has a electric condenser fan. Still maybe something to do and add another fan combined with the tranny cooler...

 

[borfoo3]

I did think to maybe add a fan. The only time I'm seeing elevated tranny temps is at speed on the freeway when lugging up hills. Fan likely won't do much there and I probably just need more radiator surface area but still noodling. I'll start another thread soon but haven't landed on how much larger or which radiator. The Tundra units are about 20% larger so that may be a candidate.



Great input. Any insight into which larger tranny cooler they fit?

For #2, interestingly, the later model year 100-series got rid of the aux A/C condenser fan. It was very noticeable on hot days transitioning from stopped at the light to moving again, how the A/C worked that much better. Probably cost saving and I was thinking to re-fit the factory condenser fan. The 200-series doesn't exhibit this issue and has a electric condenser fan. Still maybe something to do and add another fan combined with the tranny cooler...

I've had decent experience with B&M Super cooler for the 4runner transmission. If I decide to run something for the 200 series I'd run the same radiator but with better connections at the hoses (had 2 leaks before, mainly from the hose clamp area).

Once again, I'm really impressed with the stock 200 series cooling setup and don't see the need to preemptively upgrade anything.

 

[Boston Mangler]

Our cooling systems are very robust.. I don't think having that mesh grille guard would cause any real temperature concerns, but my gut is telling me it will have an impact and the fan is going to have to pick up the slack. Edit: whether this is a significant amount of slack pickup or not probably has to do with other elements of a build.. how much harder is the vehicle having to work to go 75mph from front bumper, rack, tires, etc.

Agreed

 

[bjowett]

The VDJ diesel radiator is the next step, IMO, which is the same core as the gasser, but has different header tank w/ bleed port and degas tank mount. Let the coolant do the job by keeping steam and dissolved gasses out of it. Also run more water in the coolant, 60/40 or even 70/30 water to ethylene glycol.

 

[bloc]

The VDJ diesel radiator is the next step, IMO, which is the same core as the gasser, but has different header tank w/ bleed port and degas tank mount. Let the coolant do the job by keeping steam and dissolved gasses out of it. Also run more water in the coolant, 60/40 or even 70/30 water to ethylene glycol.

If someone were to change the EG:water ratios would that mean more frequent changes?

And I like the idea of the pressurized reservoir but is all of this really necessary? I keep going back to virtually zero reports of problems outside of the common crack and in rare cases the heater Ts.

 

[bjowett]

Yes, more frequent changes will likely be required.

Necessary? No. It’s just further up on the cooling system performance ladder.