Johnny

not only is it better constructed...but it has more capacity also....

Kahren

iTrader: (13)

have u guys heard of teh air entrapment issue on some koyo rodiators? i think i am gonna go with fluidyne because of this

Import Convert

for the cost you might as well go with Fluidyne. It's $415 at Rotor Motor Sports compared to $375 for Koyo. It's worth the extra money to me to get a drop in replacement.

WhtRocket

Yes, it definately helps. My coolant temps dropped about 7-8 degrees on average with the Koyo.

No I had not heard about an air entrapment issue with the Koyo but it does heat up as much or more than the stock plastic on.

A BIG advantage is your stock radiator will crack and likely kill the motor if it's running. Somewhere around 80k-100k is typical. I replaced mine at 82K and it was starting to crack under the top inlet hose and the top tank next to the inlet hose.

Finally, One thing to consider about the larger Koyo is the increase in coolant you have to carry around. It's not a big increase but ever little bit hurts. Being fast is a lot of little things combined, right? If it's not much better thatn the Fluidyne, why bother. Of course I thought about that after I installed the Koyo.

user 84205

Ya there is on the KOYO. They are the only company
known right now, to still be selling that type. With a lot of modifications, like air vents in that radiator it would be kick ***. BUT to save the trouble, make sure you find out the flow or the radiator. Usually if it start in the most far left corner, if your in the seat, and it comes out at the most far right corner, dont get that one. MOST companies know not to sell that radiator if your a street driver, but sometimes they will. Just make sure the flow is not up down up down up. GOOD LUCK

I have the KOYO Comp Radiator, and I put the extra hose on, now no troubles, I have a pic in the gallery, under canman6969, with all the blue haha

WhtRocket

Thanks for the info canman6969. Sorry to be dense. I don't quite understand the problem. Can you or anybody else clue me in on the problem with the Koyo? I still don't get it.

Thanks in advance

spooledUP7

people say that the Koyo is too thick for a street driven car since the flow rate is reduced and may cause the coolant to reach higher temps than the Fluidyne. I have a Fluidyne. Once you see the stock unit out in the open, you will see that anything is better than it. The fluidyne is a very well built radiator, and at the current price of 375, you cannot go wrong. I don't really understand how they used to cost $500 8 months ago, but I am not going to argue. Jason at the RX-7 store sales the Fluidyne if you want to go that route.

user 84205

Ok not all radiators flow the same. I wish I had a picture to expalin it, it would be much easier. Slow flow from bottom to top, some flow in a sideways horse shoe shape, and some flow in an up down up down snake pattern.

The RX-7 Bandit

I might be wrong, but i think the koyo is a drop in, but the fluidyne you have to make a slight alteration to the mounting area to get it to fit.

redrotorR1

You have it backwards. The Fluidyne is a straight drop-in fit; the Koyo has some slight fitment issues.

Fluidyne has been a proven high quality radiator for a number of cars (not just RX-7's). The extra $30 is worth your peace of mind.

redrotorR1

I didn't notice any difference in warm up time after the Fluidyne was put in. I don't think there are many disadvantages to going to an all-aluminum radiator ... maybe weight, but it's not that much heavier than the stock radiator. And as far as winter, you live in Houston, dude ... winter, what's that?

ApexRX7

anybody have any info on the Apexi radiator? How does it compare to Koyo and Fluidyne? I understand it has copper endtanks. I know anything is better than the plastic tanks on the stock radiator, but is copper better or worse than aluminum?