FWIW the trans passage in the factory radiator is actually a preheater for the trans fluid, not a cooler. There is a separate stand-alone cooler as well. That is a great price on the radiator from tuner sports as well.
Mike

 

Good point Mike. Exactly why I don't get any heartburn over losing that part with a new radiator install.

 

So would you just loop the lines then?
any temp issues?

 

You would bypass the connection through the stock rad core. One of my customers was the first to test this in CA and given the weather he has not experienced any issues for the last 2 years daily driving.
Mike

 

Sorry, i mean. if i replace the oem unit with this koyorad. on the transmission side, do you just loop the lines that would go to the radiator or plug em somehow?

 

 

The radiator loop is there to stabilize the temperature. If the transmission fluid is hotter than the engine coolant - which is more often than you might want to believe - the radiator will dissipate heat from the transmission. If the transmission fluid is cooler than the coolant, it will absorb heat from the coolant. In either case, once this happens, the fluid goes through an air/oil heat exhanger (looks like a small radiator in front of the radiator), so no matter what, heat will be extracted from the transmission fluid. If you bypass the radiator portion entirely, you might experience a wider range of temperatures in your ATF. Depending on where you live it might present service life issues for your ATF.

There is small benefit to removing the radiator from the circuit - you'll have a little more capacity to remove heat from the coolant because you won't be loading it with heat from the transmission too. And, if you are super worried about your ATF temperatures, you can just buy a Tundra transmission cooler and stuff it in the same spot the OEM cooler is for added capacity - or something else.

My only concern with putting any bigger heat exchanger in front of the radiator is reducing the radiator's ability to shed heat from the coolant at full load. I seriously doubt you'd ever have a problem on a street driven vehicle, but at the track it might be problematic.

If it were my choice, I'd bypass the radiator loop in a heartbeat, and monitor ATF temperature at the track just to be sure all is well.

 

FUNNY YOU SAY THAT!

I was just looking at tundra coolers lol!

 

Does anyone know why the koyorad hh012170 says 2008-2011 ISF and doesn’t include 2012+? Is there a difference and it won’t fit?

 

I have the koyo radiator but RR-Racing installed it . What I would do is a comparison before buying it . Try to get pictures of both radiators make shure all the fittings and piping fits or where they should be . Good luck

 

The overflow hose is larger on the late model. We offer an adapter with our kit to make it work on all model years. Mike
https://www.shopfigs.com/v3/index.ph...ch=IS-F%20koyo

EDIT: Sorry realized it did not make it to the options although we have sold the solution to customers.
listing options added and attached pics.

 

This would replace the OEM external cooler as per Setrab/Mocal/whatever in the RRR kit, right? Could you share the Tundra cooler P/N? Thanks.

 

Tundra P/N is 32910-0C010. Might take some clevering to make it fit and work, but it's way bigger. I did a quick eyeball with a friend's Tundra and it looked pretty likely to work, but I can't say I've actually fit one.

 

Good catch Mike...!!!

This thread discusses the IS F radiator differences in depth.

Thread link below.

Radiator Differences


Joe Z

 

Thank you for the clarification! I wondered why no one asked this.. is that because the 2012 and up radiators are not as likely to fail?

So far mine seems good but I just ordered a Koyo to keep aside just in case. They’ve recently been sold out almost everywhere I checked online but saw them back in stock this morning and bought one. Thanks again for your reply.

EDIT: no option to buy it separately on the website, will it be added soon if I want to buy it?

Also I guess I can always measure it but do you know what the measurements of both ends are?