Air scoops and fans

[DesperateSP2]

Just out of curiosity... I have Durbahn airscoops installed and since I still use the bike on the road I left the fans on.
Yesterday I got stuck in a colossal traffic jam and saw temperature climb to 108°C. Nothing to worry about since as soon as the road opened up it dropped down to 84°C in a breeze and stayed there despite the heat.
But I am thinking about improving the fans efficiency to help them work better with the air scoops.
I've read topics both suggesting and advising against inverting fans polarity and I am a bit confused.
I would need the fans to move air from the inner side of the radiator to the outside but I am not so sure just inverting the polarity would work well given the fans conformation.
Thanks.

[JBs_SP3]

I'm running the Durbahn scoops with 1 x fan removed and have similar issues. I'll be installing some front mount rads I bought a while back but if I was keeping the side mounts I would definitely stay with the air scoops but bin the OEM fan and mount 1 x 5" SPAL push fan instead.

[RVTMAVERICK]

WHOLEY SHIT!.. This is so Old guys.. (NO attack agaisnt you 2)


I came up with this 4+years ago! WHY does no one else think of it... Go to the friggin' store (I bought mine from Radio Shack) you guys and buy a switch... "DP DT Center OFF" switch, pick a spot and install the bitch as I did!

This is what I do and it works Perfect!
One position, You have them runinng "OEM direction in traffic"
Onces you get moving, (I wait until approx.30to40mph) switch to the "center position" which then shuts the fans OFF....
wait acouple seconds and flip the switch to the "next position which reverses the fans"

My temps. drop like a rock! And Since I have installed My switch,.. my temps have NOT gone over 221degs. in 4 years!!

Yes, there is some work involved with paying attention to speeds and where your switch is positioned and you have to work it... but to me... it is My Best mod. for controlling temps. Period!

Thorstens Scoops are the best for dropping temps. quicker with My Switch installed!

No dicking around with different fans and fan blades and this and that..

Peace

[Luck Runs Out...]

I have Thorsten rad scoops on my SP1. When I got the bike, the PO had reversed the polarity on the fan, and as long as I did 40 MPH or more, the bike was rock solid at 175-182 degrees. Below that on a hot day, it would begin to overheat, and on one occasion, it hit 252 and the flashy light came on (don't worry- I shut it down immediately and didn't start it back up 'till it was at 190).

I jumpered the fan to stay on all the time in reverse polarity and held my hand over the outside of the right rad to feel if air was going in or going out... felt like it was coming out just a little, and the inlet of the scoop was the same way... then I jumpered the fan to run the correct way, and could feel a strong pull from the outside of the radiator and a lot of wind coming out of the rad scoop.

I figured I'd try the bike like this with the idea that at low speeds, the fan running the correct way would pull cool air through the radiator and overpower any ram air effect, but at high speeds, the ram air would overpower the fan, dropping the temp and causing the fan to turn off, improving airflow through the radiator.

It didn't quite work out like that. In conditions that would cause the bike to overheat, I was seeing 230ish, but once I hit the highway, it took about 15 miles to drop it down to 195, but wouldn't go any lower.

Sooooooo... When I return from my current deployment, I'll be ordering this here fan and be done with it: SPAL USA

[Biaggi]

Ok Jeff, I desperately need you to PLEASE write up the DPDT switch install instructions.

I dug up all the old threads but need the exact wire setup....

TIA

[DesperateSP2]

Jeff, the only problem I see with your instruction is that it works well with the SP1 (which has an old style fan switch) but the SP2 activates them through the ECU (via a relay, of course). Of course if you could tell me how to bypass this problem I'd be very grateful.
On the issue of Spal fans, the factory's a little over 100 miles from here, I'll drop them a line and see what they have to say about this product.
Thanks.

[RVTMAVERICK]

Hey Boys,

Mine's an SP2, all's I did was to tap directly into the fan wires... I set Mine up, to have control in only direction(s) And OFF... at the RC51s pre-set temp of 218degs.
So then when the fans kick on... I've got control until they shut off... again, OEM Pre-set temp.

So, I don't have full control, as another guy here I know does.... Where he can start his fans at whatever temp. & or time he wants.. just by turning on the key,.. he can flick his switch and start the fans... Although, I don't think he has direction control like I do...?

[mrgrn]

wastabb did the 2000 manual fan switch in 2000 i think and i have not worried since coupled with a richer map

[Vitza]

colder is NOT always better

normal operating temps on the RC are 190-220

i also noticed that by bike runs best and healthiest around 210.

[mrgrn]

Originally Posted by Vitza

colder is NOT always better

normal operating temps on the RC are 190-220

i also noticed that by bike runs best and healthiest around 210.

i think it auto richens at 223

yes, 200ish works the best that is why i like to ride the 51 in thr spring and fall in the morns

[onebadrc51]

Somebody drop a link for me if you will for some SP-1 rad scoops if there is any? Thanks!

[RAZR51]

My bike rads are bone stock, no fins. My fans kick on at 221 but never rise above that. Even in 95 degree heat and sitting still my fans always cool the bike down to 210. SP2 with water/wetter. I must be lucky.

[ZeroGara]

On the fireblades RC51 forum there are plenty of information for both the SP1 and SP2. There is a great SP1 solution that works without a switch.
The SP2 fans are controled by the ECU not by a thermal switch as in the SP1.
The signal from the ECU goes to the tail to a relay that turnes the fans on. It is better to tap on the input wire ground of the relay than the higher Amp. output cirquit where an adequate switch is necessary.
There is a black wire going to the relay that when is grounded it turns the fans on.
Although on an other thread here someone brought up the point of where the fuse would blow if the fans have already been turned on and automatically and you flip the switch.

[DesperateSP2]

In the end I think I'll probably buy a couple of SPAL "push" fans and fit them over the winter... does anyone have the parts number for those?
Thanks!

[selfinfliction]

you only need one spal fan, don't worry about buying two of them, unless you're running 130+hp and don't worry about wiring in a toggle switch or any other crap. just cut the connectors on the old fans and splice them onto the spal.

search for spal in this forum under my username, i have the part # listed somewhere in that thread

[b.miller123]

Don' know about a part number (the auction has one), but here you go: SPAL 5.2" Paddle Blade Push 12V Fan, Motorcycle & ATV:eBay Motors (item 200366867993 end time Aug-24-09 15:41:38 PDT)

I think these are the ones that people have been using and that it is also the cheapest you'll find them. Somebody correct me if I am wrong on this.



I was going to order one, after I get around to making my scoops.....

FWIW, I have a switch set up to turn on the stock fans, whenever I want and it works pretty good, up until it's about 95-100 degrees outside. Then it starts getting a little scary when it never drops below 205 on the freeway (15/40 with no pc and slip-ons), then immediately starts going up unless the fans are running 100% of the time while below 40-50mph. I'm thinking scoops, returning to 16/40, ditching the stock fans for one spal, and adding a powercommander will fix it just fine.

[dadrc51]

Originally Posted by DesperateSP2

Just out of curiosity... I have Durbahn airscoops installed and since I still use the bike on the road I left the fans on.
Yesterday I got stuck in a colossal traffic jam and saw temperature climb to 108°C. Nothing to worry about since as soon as the road opened up it dropped down to 84°C in a breeze and stayed there despite the heat.
But I am thinking about improving the fans efficiency to help them work better with the air scoops.
I've read topics both suggesting and advising against inverting fans polarity and I am a bit confused.
I would need the fans to move air from the inner side of the radiator to the outside but I am not so sure just inverting the polarity would work well given the fans conformation.
Thanks.

overheating rc51? how about a fix? must read.

i posted this a while back...i can see nobody listens...as usual ...the info is their for a cheap fix...the scoops only work if your moving...doesnt do much good in the real world when traffic comes to a stop. and yes rc51's will over heat on a hot day!..hope this helps

[DesperateSP2]

Thanks for the tip but...
Problem is you have no idea how much Honda spares are around here (SP2 fuel filter 64 €... two years ago! )...
I'll ring a couple of breakers after the August break to hear if they have any VTR-F fans available but I am not holding my breath since lately used Honda parts are in very short supply. Mr Honda really pulled a fast one on us by increasing spare prices at a steady and alarming pace over the past four years.
SPAL fans may be a cheaper (and I am not kidding) alternative since the factory is a mere 100 miles away and auto spare shops usually have good pricing policies.
Anyway if I'll be able to save money this way I'll let you know, that's always a good thing.

[selfinfliction]

Originally Posted by b.miller123

Don' know about a part number (the auction has one), but here you go: SPAL 5.2" Paddle Blade Push 12V Fan, Motorcycle & ATV:eBay Motors (item 200366867993 end time Aug-24-09 15:41:38 PDT)

that's the one, they're just using the wrong pic, this is what it looks like compared to the stock

[borislav]

SPAL pusher fan is the best and cheapest way to go!