RB25 clutch fan upgrade

[Matej]

Hello,
After hearing that an RB25 clutch fan is a decent cooling upgrade due to it having one extra fin and more clutch resistance than the KA fan (two extra fins over SR), I finally acquired one.
However, after comparing the two, it turns out the RB25 fan is also bulkier, and quite a bit heavier, 0.5 kg (1.1 lbs) heavier to be exact.
Would it still be a worthwhile upgrade, or would any benefits it gives be sacrificed elsewhere?

Also, I am curious if anyone happens to have actual numbers proving how much more air the RB25 fan pulls.

Thank you for any information.

[airhead]

ive been thinking about trying that

[mysharonna]

I am in the same boat. My rb25 fan will be here Monday. I will be mounting it on a redtop sr so ill update when it is installed.

[eklips3]

its probably heavier and bulkier due to the extra fins.

and if you think about it , more fins = more air being pulled

[godrifttoday]

U might lose 1-2 hp do to the weight, but in my opinion that's fine since ur car would be cooled better, I don't think it matters much to turbo cars than to all motor cars

[Jeezy240]

Its one pound.. go to the gym and loose one pound. over all it isnt that big of a deal. your car will make the same power longer if you are beating on it, because it stays cooler.

[airhead]

i think he means heavier on the pulley/belts will cause some what of a HP loss. kinda like if your running AC on you feel power loss soon as you turn it on.

What about if you change out this? will this make a difference?
http://www.turnermotorsport.com/image/engine/engine_fan_clutch_e36_z3_e39_e46_11521719269_lg.jp g

[Matej]

Tried swapping to the KA fan clutch which is much lighter, which was actually what I was originally planning on. However, the RB one is slightly larger in diameter, so the bolt holes are farther apart.
I installed the fan after all. I decided I might as well since I bought it already. Better cooling is always nice, plus the fin design looks neat in the engine bay. :)

Still would like to see a performance comparison of all the stock clutch fans though. That could be interesting.

[mysharonna]

Well I am ditching my altima/dif controller setup. This has to cool better and more reliably I would think.

Also, I read a post where Dousan was saying that you should cut the top of the shroud and I sent him a pm asking why and havent heard back. I would assume that it lets the air escape better from the fans.

Matej you got a pic of the setup?

I did a lot of searching about the rb25 fan swap and couldn't come up with any really good info so it would be nice for the future to have this thread with some good info.

[Touge Noob S13]

Well I am ditching my altima/dif controller setup. This has to cool better and more reliably I would think.

Also, I read a post where Dousan was saying that you should cut the top of the shroud and I sent him a pm asking why and havent heard back. I would assume that it lets the air escape better from the fans.

Matej you got a pic of the setup?

I did a lot of searching about the rb25 fan swap and couldn't come up with any really good info so it would be nice for the future to have this thread with some good info.

I think it was so the hot air could escape easier if you were running a vented hood.

[mysharonna]

I think it was so the hot air could escape easier if you were running a vented hood.

That is kinda what I was thinking. I need to get on the d-max hood program lol.

[Matej]

Also, I read a post where Dousan was saying that you should cut the top of the shroud and I sent him a pm asking why and havent heard back. I would assume that it lets the air escape better from the fans.
It is slightly larger in diameter, and sits farther away from the engine. Maybe the shroud does not fit over it. I cannot say for sure though, I do not use the shroud.

[!Zar!]

The reason you cut the top of the shroud is so that air can escape through the top of a vented hood.

It is pointless if you don't have a vent.

As for loosing power, I figure the loss is minute, and you might help free up some power since the engine isn't running as hot.

Who knows. I'd rather have less power and a reliable engine at the track, than one with more power that is struggling to keep temp.

[Matej]

All my pulleys are lightweight, so that should offset the extra weight. :)

[codyace]

Trust me when I say, the HP losses on modern engines going from fan to efan is in the 0-5 hp range...which for the most part I write off as 'negligable' to 'no difference' as you can get that much fluctuation between runs in general.


What happened to your EFAN idea? I've put in and used mayn Altima E fan setups over the years without issue, and across different platforms...I'd never run a Mechanical fan again, simply for the fact it is in the way.

[fliprayzin240sx]

I'm coming from the other side of the fence. Car has had E-fans for the last 3 yrs, Pulsar fan, FD fan and then FAL twins. Car would slowly creep up to 100 sitting with the AC on. Had an extra R33 pusher fan in front of the condenser, did not help much.

Changed back to stock shroud, clutch fan, left the R33 pusher fan on a switch and a stock S14 overheat fan inside the shroud that's hooked up to my old fan controller (turns on at over 80). I've drifted the shit out of my car with the AC on and the car has yet to hit over 90 degrees. I was out there for 45 mins straight, heat index of over 100 outside and car held up rock steady at 90-92 max.

[Matej]

What happened to your EFAN idea? I've put in and used mayn Altima E fan setups over the years without issue, and across different platforms...I'd never run a Mechanical fan again, simply for the fact it is in the way.
Ended up not wanting to put another electrical device in my car. I decided to make it as simple and mechanical as possible.
The wiring in my car is in bad shape. I actually just started reducing my harnesses today to only the necessary wires, so it will be easier to troubleshoot.

Plus I think visible moving things in the engine bay look neat. :)

[ShawnHalu]

can anyone give me a part no. for the fan clutch & shroud of the r34 fans. as i need it to order..

ps/ i only need this 2 parts right?