Originally Posted by
jonwepa Ok, guys here is the deal. The stock se-r radiator is 5/8ths thick, the stock nx rad is 15/16ths(1"), and the gtir is also 15/16ths(1"), but the fin count is different and set-up for high speed while the nx is set-up more for stop and go.
It's true that adding fins eventually falls victim to the "law of diminishing returns" because you lose some airflow, but after increasing surface area by 33% it seems like it would take a severe loss of airflow to negate the gains. I've never seen any testing, but I have to assume the Nissan engineers know what they are doing. I've never heard of anyone running a GTIR radiator having cooling issues in stop and go traffic (without other issues at least).
Originally Posted by
jonwepa Listen if you just want a upgraded rad over the stock 5/8ths se-r then just get a nx it will be more then enough.
I am running a gtir with a gt28r @ 18-20psi and I am having no problems at all. I'll be upgrading to a holset hx35 in feburary and still am going to us the same rad. Koyo's are overrated IMO. I don't think there needed unless your road racing or something where your not going below 6k.
To say the Koyo is "overrated" implies that it doesn't perform as well as it should. That's not really accurate. I would say it's "overkill" and I agree that most folks would do fine with an NX rad.
BTW, have you ever price checked a brand new Nissan radiator? The Koyo isn't much more expensive than a plain-jane SER radiator. I would argue that makes the Koyo a bargain.