Quick question. Yes, I did a quick search, and checked the archives.

I'm swapping a J-spec S5TII motor into my S4 NA Base. After looking around at some aftermarket radiators, a bunch basically say S4 only, or S5 only.

Would I be able to run my stock radiator from my S4 NA with the S5TII engine, or will I have to upgrade? If I have to upgrade, would I need an S5 radiator, or an S4? The inlet/outlet pipes for each radiator look very similar (placement)

If the only differences are mounting/ the radiator switch or other electrical connections, it's not important. I am not using stock harnesses or ECU's, and would not have much trouble making brackets to mount a different rad.

Thanks a lot guys,
James

 

I think some modifying would be involved to use the S4 radiator with the S5 JDM TII engine. If you did go aftermarket though... you would need a S5 radiator. What company did you get your engine from?

 

No idea, picked it up with tons of other parts from a guy in Pennsylvania.

Thanks for the quick reply.

James

 

Oh, alright... just wondering. - n/p

 

There's no difference between NA and Turbo radiators, so you don't need to upgrade it unless you plan on making a lot more power than the stock 13BT.

The only problem with using the S4 radiator with an S5 enigne is that you loose the filler cap on the thermostat housing. The radiator cap becomes the only fill point, but it's not the highest point in the system. The S5 radiator has an extended filler neck to avoid this problem. I can't speak from experience but you might have trouble getting all the air out of the system.

 

^Thanks!!

That was a huge help.