Stock FD fans 5blade vs 4blade
 

I'm modifying the top tank to go completely across my Koyo Radiator since it's not longer in the stock position but vertical instead. After taking off the fans I noticed that one fan is 5 blade (passenger side) and one is 4 blade.

My question is which fan flows more? I have two sets of fans and was wondering if I should make both fans a 5 blade.

Has anyone had any experience with two 5 blade fans?

I've researched on this and other forums but haven't seen a thread dealing with this question. I'm surprised this question hasn't come up before

I figure the 5 blade pulls more because it's placed on the inlet side of the radiator.

Interesting find.

FYI 99+ spec radiator fans are alot smaller and have more blades.

Would you mind posting a pic? I woudn't mind seeing them.

The configuration you have is normal. Here is more info on newer FD fans. https://www.rx7club.com/showthread.p...ighlight=blade

It is well known that the reason for two different blades is to stop the noise from the harmonics . The four blade fan is known to flow more air so use two four blade fans .I run two and some of my customers have with out any noise ( wa wa wa wa ) When I last bought one from the dealer they were about $ 32 each .

Thanks Garco for the info.