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JES_VFR

Tired Of Having A Hot Vfr?

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I just did this mod too. I does work rather well. My bike stayed pretty low in temp. Never went above 220. And it was 95 degree's out. Plus I do use water wetter in the bike too. A cheap mod and improves air flow. Highly recomended.

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I've been corresponding with Jes on this issue on the STN forum and wanted to share my findings with you regarding this fan mod for the 6th gen model VFR's

<.....>

After switching back to my bike I did some further testing up and down the mountain. I discovered that in a situation when the bike is under a load the fan is unable to get the temp down low enough to turn off. However,the fan is able to maintain the temp in the 215 225 range (depending on the load) as opposed to getting into the 230's such as my friends' 07 and higher (240s) as seen previously on my bike.

At idle with the temps above 90 degrees the fan can hold the temp around 215 - 218 but it was unable to get the temp down low enough to shut off. However, once under way under normal riding conditions the temps dropped 210 or so and the fan remained off.

On my way home I saw a high of 106 on the interstate and decided to push the bike hard by running 90+. At those speeds the temps rose to 223 and the fan engaged. Once again the fan could not cool sufficiently to turn off but It did maintain the temps at a range of 218-221 consistently. This is where I had my most severe problem with the temps creeping into the 240 range. Also, I observed that when getting within 100 feet of another vehicle that the temp rose slightly but once back into the air stream it would fall back into the same levels.

Finally, In traffic at speeds up to 50mph with temps in the mid 90's the VFR ran consistently in the 209-213 range with the fan OFF. At a traffic light or in slow heavy traffic the temp would quickly spike to 222 and the fan would kick in slowly reducing the temp to 218 or so. But once moving at around 20 mph the temp dropped steadily down to 210 and the fan could disengage. In the past the fan would not have had enough time before the light changed to cool down below it's cutoff point. Once under way it was stuck on and the temps hovered around 220's in traffic. The only way it would shut off is if I were to pull over and wait for a few minutes but that was useless because the temp would climb back to 222 at the next stop anyway. Hmm... Let's see, Fan off bike runs cooler, Fan on Bike runs hotter.... Makes sense to me Headscratch....

I ran the VFR under some of the most demanding conditions that most people will likely see and it performed much better than it ever has. The highest temp it ever got to was 225, hot but tolerable. I am now comfortable taking the bike out on my upcoming 3800 mile journey through the 4 corners states. I can also go on record to say that this mod seems to work better than the stock setup for the 6th gen model VFR.

Jes,

Thanks once again for your detective work figuring out that a VTR fan blade is compatible with the VFR fans.

Oh yeah, I forgot to mention that after the fan had been running for about 5 minutes while the bike sat on the driveway the bike (especially the clutch) was pretty hot to the touch as hot air works it's way up between the side fairing and the gas tank. However it was no big deal as it cooled off quickly once the bike was in motion.

This might be one of the reasons that Honda designed the fan to pull inward.

You, and everyone else are welcome.

As far as the fan not being able to cool below a certain point under load and/or ambient conditions, I have seen that as well (and reported it). However these were conditions that prior to my changing the blade would have had the bike up in the 240 range and me searching for a way out.

I have been looking at more ways to cool the VFR and have a few ideas, but as Vern points out, the heat has to go somewhere and unfortunately its going to have to pass close to you guys the riders. And by that I mean either out the left side and past your leg or up along the left side near your clutch hand, or out the back under the naughty bits.

That is just the facts when it comes to riding in the summer heat, the engine heat has to go somewhere?

So until I get the next step sorted out, try and stay cool

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Guest forrer13

So, just out of curiosity, what is the next step? Bigger radiators? thermo switch that turns the fan on sooner? Addition of a second fan on the right radiator? or a manual fan on/off switch?

Enquiring minds want to know....

PS my new fan is on order, should arrive late this week.

Edited by forrer13

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I am truely amazed at the temperatures that you are all seeing. But, I have yet to see the highway, at rushhour, in the scortching heat. Hell, it's not even 80 here yet. :beer:

So, just out of curiosity, what is the next step? Bigger radiators? thermo switch that turns the fan on sooner? Addition of a second fan on the right radiator? or a manual fan on/off switch?

Enquiring minds want to know....

I would suggest a fan on the right side. In fact I would go so far as to suggest a computer fan on the right side. They are small, lightweight and move a good amount of air. I would wire in a manual switch controled but keep it controlled by the other fan. In the heat of the summer, turn the switch on, and when the temps drop back to liveable, turn it off.

I hear that 6th gen rads are bigger, but you are looking at a big expense there as well as some possible machine work. Just move the air past the heat exchangers faster. :goofy:

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Guest forrer13

http://cgi.ebay.com/25-Nidec-Beta-V-12-Vol...1QQcmdZViewItem

I am thinking about mounting one of these to the inside of the other radiator. Hard wire to the battery through a simple fuse and toggle switch. Its only .11 amp so no relay would be needed.

When I install the new fan I will look at this for clearance.

Has anyone tried this before? Mayby I will make a DIY.

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Guest onedowneaster

Howdy Forrer 13; That little fan only pulls 10 CFM, I am not sure that would make a difference. I know

Radio Shack has a couple 12 volt fans and one is considerably larger than your 10

cfm unit, that may be a better option. Anyway I am not trying to supress your

creativity.

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Guest forrer13

Does anyone know how many CFM the OE fan pulls?

I pulled two fans from an old computer I have at home and was going to hook them both up together, they are about 4" square each. I should be able to attach them with some zip ties through the radiator fins.

The previous owner installed heated grips on my bike, which I have never used, and probably never will, so I was thinking about using the heated grip switch to manually turn on and off the computer fans. Plus there is already power run to that switch.

So my thought is riding around, bike reaches 200 F, turn on computer fans. One of two things will happen. Bike will stay around 200 F and drop off when I start moving. Or temp will continue to climb to the point at which the factory fan will switch on.

This is gonna be a fun project, and should be totally reversible if it doesnt work.

Edited by forrer13

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So, just out of curiosity, what is the next step? Bigger radiators? thermo switch that turns the fan on sooner? Addition of a second fan on the right radiator? or a manual fan on/off switch?

Enquiring minds want to know....

PS my new fan is on order, should arrive late this week.

I went to my dealer to order the SH fan and they say they are on back order. Meaning no way can they tell when I would get one if I ordered.

Just curiuos - how many of us jumped out and ordered one? New demand - new shortage?

MD

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So, just out of curiosity, what is the next step? Bigger radiators? thermo switch that turns the fan on sooner? Addition of a second fan on the right radiator? or a manual fan on/off switch?

Enquiring minds want to know....

PS my new fan is on order, should arrive late this week.

I went to my dealer to order the SH fan and they say they are on back order. Meaning no way can they tell when I would get one if I ordered.

Just curiuos - how many of us jumped out and ordered one? New demand - new shortage?

MD

Order one after I hit 249 on a run a few weeks ago. Also burped the system which seems to have helped a lot. Still hitting over 230 very often.

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I'm pretty comfortable with my bike temps (I only ride with it set to ambient, and ignorance is bliss on this issue for most), but I was thinking of a small/computer fan to assist in exhausting the engine compartment with the stock sucker fan....somewhere other than at the rads. It seems to me the aerodynamic design comes into play with the rads and does somewhat different things at different speeds, so why not vent some of the hot air out another direction? It's just a thought and I may tinker with it.

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Guest forrer13

I think blowing the air out through the other (unused radiator) is the way to go. After all the radiator is a heat exchanger, and a heat exchanger works much better with air blowing through it as opposed to just sitting there in stagnant air. Simple physics, no?

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So, just out of curiosity, what is the next step? Bigger radiators? thermo switch that turns the fan on sooner? Addition of a second fan on the right radiator? or a manual fan on/off switch?

Enquiring minds want to know....

PS my new fan is on order, should arrive late this week.

Lets see the next step could involve anyone (or all of the following).

1 a second pusher fan moving air out the right side rad.

2 a set of ducts that will keep the heat from the headers and the engine block from 'pre-heating' the cooling air that get flows through the rads.

3 more efficient non honda fan blade.

4 a special ambient temperature sensitive black box to alter the engagement temp of the left fan.

5 custom radiators.

ps do not forget the locktite in the gluestick form for the nut.

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So, just out of curiosity, what is the next step? Bigger radiators? thermo switch that turns the fan on sooner? Addition of a second fan on the right radiator? or a manual fan on/off switch?

Enquiring minds want to know....

PS my new fan is on order, should arrive late this week.

Lets see the next step could involve anyone (or all of the following).

1 a second pusher fan moving air out the right side rad.

2 a set of ducts that will keep the heat from the headers and the engine block from 'pre-heating' the cooling air that get flows through the rads.

3 more efficient non honda fan blade.

4 a special ambient temperature sensitive black box to alter the engagement temp of the left fan.

5 custom radiators.

ps do not forget the locktite in the gluestick form for the nut.

I prefer Gold BondTM for my nuts... no seriously, are you referring to the nut holding the fan blade on?

The problema with a second fan on the inside of the right-hand radiator is there is very little room in there, due to the eccentric positioning of the motor in the chassis... There is just a very squeezy bit of room for a 10 cm PC style fan on the forward lower corner of said radiator. Otherwise, you could do like a friend of mine and zip-tie two PC fans on the plastic mesh on the outside of the radiator. I did the same but noticed no difference whatsoever as a PC fan doesn't create much more airflow than a human fart. In the end I removed them as the mechanical benefits did not outweigh the eyesore factor... in the end I removed bothe black plastic meshes as mines a silver VFR and I like the way she looks more w/o them... I hope that doesn't cause any problems... they don't hold anything together do they? I figured they were just for protecting the delicate radiator fins.

26062008wq3.jpg

So, anyways, I now am the proud owner of a VTR fan blade, my question is... can you post up step-by-step instructions on how to install... I'm wondering if there are any shortcuts, or ways to avoid bleeding the coolant... any special things I should keep in mind besides the loctite?

Thanks a million in advance...

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I don't read shematics well so this is not a knock Tightwad. :blush: Just simpfied.

I set up my switch as a closed ground (-) SoThe fan is switched on as a ground loop so no positive wire is required.My fan is swiched on manualy and or by the thermo couple.

This way I can't forget to turn it on. It also shuts off with the key if left on.

David

Please explain how I can do this... but, explain for electronical idiots if you would be so kind...

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Guest Davidlong
I don't read shematics well so this is not a knock Tightwad. :biggrin: Just simpfied.

I set up my switch as a closed ground (-) SoThe fan is switched on as a ground loop so no positive wire is required.My fan is swiched on manualy and or by the thermo couple.

This way I can't forget to turn it on. It also shuts off with the key if left on.

David

Hi CP; could you send us any photos, pleaseeeee? :biggrin:

Edited by Davidlong

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More along the lines of why does the VFR get so hot so quickly.

I was thinking about the plastic front panel of the lower fairing the other day.

I have an idea that I think will improve the cooling.

I need to get my hands on the black lower fairing inner panels to modify.

Does anyone here have one that they can part with?

Edited by JES_VFR

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I don't read shematics well so this is not a knock Tightwad. :rolleyes: Just simpfied.

I set up my switch as a closed ground (-) SoThe fan is switched on as a ground loop so no positive wire is required.My fan is swiched on manualy and or by the thermo couple.

This way I can't forget to turn it on. It also shuts off with the key if left on.

David

Hi CP; could you send us any photos, pleaseeeee? :fing02:

Hey David... fancy seeing you here!!! I want to stick a switch on mine as well, in the same way, hopefully Combine Pilot can give us a run down for the electronically cchallenged...

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The 5th gen the themo couple closes the ground loop.

There for to add ain a switch all that needs to be done is.

Find wire theat goes to the fan motor tap into it with a wire of the same size or bigger. Run that wire to a switch tha you can reach while ridding. Then find a suitable ground to attach a wire to on the frame and run that wire to the other side of the switch.

Switch in closes position closes the ground loop an walla fan runs.

Switch in open position opens the groud loop and no fan.

Thero couple closes the ground loop at 104 and fan runs all on its own when it is supposed to.

Just dont forget to shut it off. And for added protection I put in a fuse to protect from over load.

Use a quality switch as I broke the first one with my big mitts>>>>>>>>>>>>>

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2 a set of ducts that will keep the heat from the headers and the engine block from 'pre-heating' the cooling air that get flows through the rads.

Probably the best (but not the cheapest or easiest) way to keep header heat out of the engine compartment is to have the headers ceramic coated. I know JetHot coats the inside and outside of the tubes, so you get a double wall of insulation.

Alternatively, you could use asbestos header wrap tape to insulate the headers and keep the heat out of the engine compartment, but I wouldn't recommend it. Several people have told me of their header wrap experiences that ended badly. Basically, the pipes get eaten from the inside out since the heat can get into the pipe but can't escape to the outside, which drives up the temperature of the pipe wall. Ceramic coating prevents this by having an insulating layer on the inside of the pipe.

Of course, either method requires pulling the headers off your bike, which would make it a winter project for me.

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Just ordered my new fan blade smile.gif Hope it works well. I don't usually have a problem, but don't like the potential. I realized reading this thread that the reason they used a "puller" fan as opposed to the RC51/superhawk/whatever pusher is probably "rider comfort" of not having the fan blowing out hot air thru the radiator up at you or on your leg. The race bikes won't have the same level of expected comfort. I know we see that as a fault, but I guarantee it was intentional. I rode a Sportster. If HD doesn't give a crap about rider comfort (sitting on a furnace) I can live with the fan actually cooling the water.

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Just ordered my new fan blade smile.gif Hope it works well. I don't usually have a problem, but don't like the potential. I realized reading this thread that the reason they used a "puller" fan as opposed to the RC51/superhawk/whatever pusher is probably "rider comfort" of not having the fan blowing out hot air thru the radiator up at you or on your leg. The race bikes won't have the same level of expected comfort. I know we see that as a fault, but I guarantee it was intentional. I rode a Sportster. If HD doesn't give a crap about rider comfort (sitting on a furnace) I can live with the fan actually cooling the water.

Actually the RC51 uses the same puller style fan as the VFR. the superhawk is the only one that got a proper pusher fan.

the fan mod double part I is on the list of stuff to try with my New to me RC51 sp2

But I'm still looking for a spare inner fairing panel for an 98-2001 VFR?

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2 a set of ducts that will keep the heat from the headers and the engine block from 'pre-heating' the cooling air that get flows through the rads.

Probably the best (but not the cheapest or easiest) way to keep header heat out of the engine compartment is to have the headers ceramic coated. I know JetHot coats the inside and outside of the tubes, so you get a double wall of insulation.

Alternatively, you could use asbestos header wrap tape to insulate the headers and keep the heat out of the engine compartment, but I wouldn't recommend it. Several people have told me of their header wrap experiences that ended badly. Basically, the pipes get eaten from the inside out since the heat can get into the pipe but can't escape to the outside, which drives up the temperature of the pipe wall. Ceramic coating prevents this by having an insulating layer on the inside of the pipe.

Of course, either method requires pulling the headers off your bike, which would make it a winter project for me.

Did the header wrap thing when the bike was down. Cant say anything negative yet. Its a wait a see thing. Temp wise I've seen 230 degrees in 90 degree stop and go. Dunno if the header wrap plays a part or not. The main reason I did it was to insulate the heat baking the Penske shock. Also supposidly there is a bit of a power boost. (Hotter exhaust gases = higher gas viscosity = faster flow = more go)

Maybe I should start saving pennies for a Motad.

MD

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Guest Davidlong
Hey David... fancy seeing you here!!! I want to stick a switch on mine as well, in the same way, hopefully Combine Pilot can give us a run down for the electronically cchallenged...

I'm glad too. Shall we meet in "A ver que os parece: SurVfr"? I am not so sure they could deal with...

Edited by Davidlong

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Well the 2000 and 1997's use the same fan blade part #'s (67875-001)....Hmmm........? I wonder if it the VTR fan blade 19020-MBB-003 will help my Gen 4 / 97.......................?

Gen 4 Radiator

Gen 5 Radiator

I'm thinking no cause the fan on my 97 faces forward compared to the side on 2000. Anyone have two cents to offer on this?

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