So I recently just picked up an S4 TII.

I was looking into getting a Koyo radiator since I plan on keeping everything relatively stock and just upgrade some of the cooling.

I was told to go with the kouki model Koyo radiator over the zenki Koyo radiator. Can anyone tell me if this is true that that the zenki one is single pass while the kouki one is dual pass?

What would it take to run a kouki model Koyo in my zenki?

 

anyone?

 

well i kind of found the answer..

one of the kouki Koyo radiators are dual pass while the zenki one is single pass.

now the question is how to mount the kouki dual pass Koyo into my zenki?

 

The s4(zenki) will have a place for a sensor at the bottom of the rad.
I don't think the s5(kouki) has that.( I know that the aftermarket s5 koyo N flow would fit an s4 but had no placement for the sender)
also you should look at Rad cap placement..I think some of the s4 rads had no cap on the rad.But had a cap on the thermostat neck.
...
the stock rads are switchable and need no mod to mount it on the car.

 

thanks, that does help!

I am definitly looking into the S5 Koyo N Flow radiator for my S4. As you said, it bolts right up?

Do I use S4 radiator hoses?

I really need to start doing more research into this.

 

If you use an S5 replacement radiator, it will have the awkward filler neck next to the battery. S4 fan shrouding will interfere with it.

Radiator hoses are all the same.