Ok.. This has been done somewhere I'm sure. Just thought I'd share. I have no data yet, but am more than willing to take numbers with both these and the stock units to see if there is a real difference as soon as the car is back on the road... As you can see, the 4/5 blade stock setup was swapped with a 5/7 blade setup. Opinions?

 

keep us updated

 

where did you get them?

I'm gona need new blade soon.

 

Well, I'll have to ask because I'm not sure if where I got them is offering them to the public yet.

 

I just put on some Perma Cool industrial strenth fans ... about 3200-3400 cfms on my Fluidyne. My temps barely push 185 up here in PA.

Monitor your temp! It should sound pretty smooth since both would emmit a different noise frequency (-> #blades).

 

Looks nice man.

 

were u having temp problem with the stock fans???

 

A friend of mine put upgraded fans on his RX7 and they didn't blow near as hard as the stockers. He got his from summit.

 

You will find your new fans pulling a good bit LESS air than before, garanteed. Many others including my self have done extensive research into improving the stock cooling capacity. It turns out that with the given surface area of the stock cooling system, there is NO after market cooling componenets that moves more air. The ONLY way I and some others have found to increase the air flow is to replace the stock 5 blade with the stock 4 blade, making both 4 blade fans.
Final note, having more blades doesn't mean you're moving more air. The blade pitch, depth, surface area and speed all account for total cfm. Nice try though.

 

You will find your new fans pulling a good bit LESS air than before, garanteed. Many others including my self have done extensive research into improving the stock cooling capacity. It turns out that with the given surface area of the stock cooling system, there is NO after market cooling componenets that moves more air. The ONLY way I and some others have found to increase the air flow is to replace the stock 5 blade with the stock 4 blade, making both 4 blade fans.
Final note, having more blades doesn't mean you're moving more air. The blade pitch, depth, surface area and speed all account for total cfm. Nice try though.

 

You don't know where these fans came from to make that assumption. I know where he got them...and they do pull more.

 

And you have actual controlled testing with confirmed factual data to back up this statement?

 

a nice cheap upgrade to the fans is to put two stock four blade fans on the unit. it doesnt make any noise either. . . strangely. haha.

paul

 

I understand all that. I got them free for testing and I plan on posting #'s. If they work, great. If not, I'll go back to stock. 5 minutes work. No biggie. I'm always up to try something new..

All the aftermarket fan setups I've seen have had different motors.. (I could be mistaken) I didn't lose any surface area. More blades, but less area each. I'd imagine the worse would be no change in temperature..

I'm not trying to reinvent the wheel or anything. I know vosko had aftermarket fans. FAL or something.. He never had any heating issues. Not saying that he had better airflow over stock, but he didn't hurt anything. I guess we'll see when I turn the key. I'll keep you guys posted.

 

Nope. Didn't have a problem with the stock twins either.

 

Mazda engineers didnt like the overheat problems during the past years on the 93-98 versions so during 99-02 they put these fans in and a few other minor things and shazam..... we have no overheating or even temp problems on the 99spec and up, well nothing like the 93-98 thats for sure..

 

I dont think Jspec would right off hand, but im sure with a few kind words to Mazda we could get it hehe

 

so are those the actual 99 spec fans?

 

i think they 're strait from mazda japan. correct me if i'm wrong.

 

Not me. Mazda.

 

Also Jason, you forgot to mention that the fans draw less amps than the stock '93 - '98 FD's. Those motors draw 17 amps(or 18...can't remember now) whereas the earlier models pulled 25 amps.

 

Yeah that was the other minor mod hehe

I just didnt want to mention it since those are some COIN.

Im working on them though.

 

Which could mean that the '99 fans spin at a slower speed than the '93-'98 fans. Mazda engineers probably wanted to cut down on the alternator's current load. This means that they wanted to get the same cfm, but with less current draw.

There's more to a fan's cfm capacity than just the number of blades on the fan, or even how fast it spins. As has been pointed out, blade pitch, overall curvature, surface area, and depth play a crucial role in how much air a fan can move. If simply adding more blades was the solution, you would've seen WWII fighters with 8 or 10 blades on their props.

Also, if Mazda engineers were so concerned with overheating issues, they'd be concentrating on improving the efficiency of the radiator and airflow through the engine bay at speed, not increasing the radiator fan cfm. You can't depend on radiator fans to cool the engine.

Let's see some info from Mazda regarding these fans before we go jumping to the conclusion that they are better than the stock fans.

 

Well we have a couple people being testers too, so we will see their findings too.

Im working on Mazda but the work car is at the shop getting fixed so no way to get around right now.

 

So if what your saying is true(that the '99 fans spin slower than the '93-'98 fans because of the fan motor), wouldn't putting the '99+ fan blade onto a '93-'98 fan motor make them spin faster, thus increasing cfm?

Or is my logic wrong.

I'm no engineer, but the fact remains that putting the whole '99 fan assembly(cage, motor, fan blades) still yields less current draw on your alternator, even if that's the only benefit.