Fan Switch Temperature Options

[mello dude]

I had posted this question while most of you were at the summit - so this is kinda of a repost .............

The stocker fan switch comes on at about 219 F degrees - when your sitting in traffic, - that seems a little late since the bike will crept up to about 230 F and bounce around 225 - 230. It would be nice to kick that fan on sooner. (I know I could stick a manual switch on it) I'm wonderin what optimum would be?

So just out of curiosity, for 5th and 6th gen, if you could have the perfect fan switch, it would kick on at ______________ degrees F and then shut off at ______________ degrees F, what would your 2 numbers be?

I'm thinking 205 and 190, too low?

MD

Edited August 26, 2009 by mello dude

[mello dude]

This will be the first full season on my '98 with the VTR fan swap. I did it last year in June and our summer here was the 2nd coolest on record, so I didnt really get a good read on liking or disliking the VTR fan. - I'll see how it goes for this season.

The bike does get hot fast in stop n go traffic and sitting still. The ambient temp really doesnt matter.- My fan does kick on at 219F, but still kinda drives me nutz. It's probably fine, but still would like to screw with bit lower temp fan switch. - Never really got a good wish list on/off temps from the gang here so it the idea kinda died.

Edited May 4, 2010 by mello dude

[Auspanglish]

The fan has a problem, sort of. Honda decided that it would be better that the fan pull cold air in from the outside, which is the opposite of air movement when the bike is in motion. The theory is that the outside air is cooler, which would be true, if the bike isn't moving. The problem comes when you're seating at a light, the temp gets to 220, and the fan kicks on. If the light than turns green with the fan still running, when you get up to 30-40 miles an hour, the fan is actually working against the air flow caused by your movement. I've noticed my fan will cool the bike down from 220 to 210 pretty quick while waiting at a light but if I'm moving 30-45 mph, it'll just hang around 220.

Just today, I picked up the pieces to make a module to kill power to the fan when bike speed hits 30 mph. I believe this will actually make the bike run cooler plus save wear and tear on the fan motor trying to buck natural air flow. I did think about actually making the fan run backwards above 30 mph but the fan is really designed to move air just one way and I don't think it would add much, if any, above 30 mph.

I should have the module done and tested by the end of the week, I'll post my results.

I think on the part that I highlighted in bold, you are off on the direction of the airflow when the bike is in motion. The aerodynamics of the bike cause the air to flow around the outside of the fairing. The fairing is open behind the wheel allowing the bike to breath from inside. Therefore, in stock form, when moving at speed, the fan is rendered useless. The natural flow of air around the bike and over the hole that the radiator is placed inside causes air to be drawn from inside the fairings outward. When at speed however, the fan is not required. There is enough natural airflow over the engine, headers, and through the radiator that a fan is not needed anyways and will turn off when temperatures drop in range. Honda did this intentionally.

When at a stop, I couldn't agree more. I would rather leave the fan alone and allow it to draw cooler air from the outside in. Naturally this will do better when at a stop. I can see the VTR fan being beneficial only when moving, it will just assist the natural draw of air that Honda decided to come inside to out. But I also feel Honda knows that when moving the temperatures will not require a fan. That is why they have it pulling from outside.

For those of you questioning my theory on the air flow around the fairings drawing air out, have you ever taken two straws, placed one in a drink, then blown over the top of the straw with the second one? It will create a vacuum drawing the drink up.

Coderighter and Jess... interesting debate... all of those factors and possible mods have been discused here before in great detail...

Based on my experiments with the VTR fan I can safely say the following:

It rocks when the bike is in motion. Very effective.

It sucks when the bike is stationary. So much so that if you enter into a slow speed zone, like going through a small city/large town on your way somewhere, travelling on say, secondary highwyas (don't know the US term)... and the bike is already close to climax (hehehe)... you stop at a red light (one that lasts a while cause it's like a 6 way intersection or something, or for whatever reason)...maybe you've had to stop at several intersections, but the frame and all the other bits and air immediately surrounding the motor and bike are hotter... and the ambient temp is high... the VTR fan will not get the coolant temp down to the lower cut-off point... it will just keep coming on until it stays on unless you get to run the bike at about 70 km/h for a good run...

More later, gotta go to a Microbiology exam and I'm running late ...

I commute in traffic daily, so the current configuration makes more sense. With that said, I wouldn't mind it coming on at an earlier temperature due to the heat I get here. I see 225 a lot with an occasional 230 which makes me uncomfortable.

I for one don't doubt the vacume effect you describe, although I can guarantee you some air also flows straight into the engine bay between the forks and thus flows through the radiators from the inside out, this complements the vacume effect you mention and the degree to which both are in play would depend on forward speed I guess.

Where I would differ is in the fact that, I have experienced umpteen times just how the inflowing air makes the fan rendered useless when it's on to the point where (at lower than 70 km/h) the bike does not cool down... I'm talking really hot summers and half an hour in stop&go traffic for example... & thus the fan would labour on continuously until, A: you get on a freeway/highway & at speed +80 km/h & the force of the oncoming air overcomes the fan, or B: you go so slow (or stop) that the fan can do its job.

The VTR fan worked (for me) when I didn't spend too much time stopping and going... on my 5th gen I've had to pull over and turn it off cause it just wasn't capable of cooling the thing down enough... I often found myself longing for a stretch of freeway to get up to speed.

With the OEM fan, I figured out how to wire up a switch to turn the fan off for when I'm moving forward and the fan is on... so the air can do it's job...

Having the fan running continuously is putting the VFR's fairly dodgy charging system under extra load for longer... same would happen if you drop in a thermoswitch with lower activation values... it'll come on more often... it is a fairly hot running bike by design as far as I can figure...

But hey... every VFR is a little different... some fry stators some don't... some run that bit hotter than others... and the weather here is extremely hot over summer... +40ºC is extreme... and the asphalt and surrounding buildings are radiating even more heat.. like at MotoGP... the track temp is always way higher than ambient...

I'm glad the VTR fan works so well for others...

Experiment I say, and find out what works for you....

[Guest]

The fans on both my 5th and 6h gens come on at 104ºC and turn off at 96ºC... religiously...

96= 204.8 degree Fahrenheit

104= 219.2 degree Fahrenhe

THANKS

I let the bike sit until it got up to 219, and bingo, on came the fan

I feel so much better knowing when it is supposed to come on, and of course, that it does indeed work and come on

[JES_VFR]

As someone who has swapped out to the VTR fan all I can say is that it was a simple swap and it just WORKS.

No messing around with a manual switch, no messing around re-wiring anything. It just WORKS.

The only downside is that the bike throws out some serious HEAT onto your left leg and if you are wearing something other than real moto pants or a 1-piece moto suit it becomes uncomfortable. I did some test riding around the block with my new fan and OMG HOT AIR ON MY LEG! But when I put my 'stich suit on it's not even noticed.

So, if you want to wear shorts or a light pair of cotton pants you might not like the bike actually COOLING ITSELF by throwing heat OUT of the engine compartment rather than right back inside it. I guess Honda made a decision that having a bike that ran way too hot in Stop & Go traffic and sometimes overheated was better than having the squids who rode without proper gear bitching and complaining about hot air hitting their leg when they rode in shorts and flip-flops.

That's just how I see it.

I'd rather have a radiator and cooling system that WORKED. The VTR fan swap works. I'm a bit insulted that Honda would sacrifice an effective system to keep a few squid's leg's cool because they weren't wearing decent leg protection that would insulate their knee/upper leg from the isolated blast from the left radiator. The only way I can feel it is if I pull off my glove and feel the outside of my 'stich at my knee. Yeah, it's warm (not melting hot -but quite warm). But I can't feel it through the fabric inside.

Thick abrasion-resistant and insulating clothing works both ways.

DUDE, if you think that the VFR can warm your one bare leg, you should try my RC51 with it's reversed fans. It will toast both your legs when the fans are running, but that is still better than just hearing the fans kick on and then just watching the temps still rise to 245.

Oh, yeah one other thing. And I discovered this with my one piece Infinity suit. The suit will insulate you up to a point and then it will match ambient temperatures, so you still need to have a layer on that can insulate you from the outside temp enough. So if its hot better plan on something that will just keep the suit off your bare skin or you will swear it burning you.

I don't know what Auspañol is saying about it his VTR fan is not cooling enough, In fact he's the only one that I know of that has tried the fan swap and says that it doesn't work well enough.

Auspañol, What did your VFR do before you swapped the fan blade? I mean if you are still having issues with the VTR fan, then I hate to think what heat issues you were having with the stock fan. And just to clarify, you did just install a new VTR fan blade on the VFR honda's fan motor correct?

I'm asking this because the VFR/VTR fan swap was like nothing compared to changing the direction of airflow on the rc51.

Hey Mello Dude, any chance of getting you to make those switches after all?

How many interested parties or wanted switches would you need to make it worth the effort?

[JES_VFR]

As someone who has swapped out to the VTR fan all I can say is that it was a simple swap and it just WORKS.

No messing around with a manual switch, no messing around re-wiring anything. It just WORKS.

The only downside is that the bike throws out some serious HEAT onto your left leg and if you are wearing something other than real moto pants or a 1-piece moto suit it becomes uncomfortable. I did some test riding around the block with my new fan and OMG HOT AIR ON MY LEG! But when I put my 'stich suit on it's not even noticed.

So, if you want to wear shorts or a light pair of cotton pants you might not like the bike actually COOLING ITSELF by throwing heat OUT of the engine compartment rather than right back inside it. I guess Honda made a decision that having a bike that ran way too hot in Stop & Go traffic and sometimes overheated was better than having the squids who rode without proper gear bitching and complaining about hot air hitting their leg when they rode in shorts and flip-flops.

That's just how I see it.

I'd rather have a radiator and cooling system that WORKED. The VTR fan swap works. I'm a bit insulted that Honda would sacrifice an effective system to keep a few squid's leg's cool because they weren't wearing decent leg protection that would insulate their knee/upper leg from the isolated blast from the left radiator. The only way I can feel it is if I pull off my glove and feel the outside of my 'stich at my knee. Yeah, it's warm (not melting hot -but quite warm). But I can't feel it through the fabric inside.

Thick abrasion-resistant and insulating clothing works both ways.

DUDE, if you think that the VFR can warm your one bare leg, you should try my RC51 with it's reversed fans. It will toast both your legs when the fans are running, but that is still better than just hearing the fans kick on and then just watching the temps still rise to 245.

Oh, yeah one other thing. And I discovered this with my one piece Infinity suit. The suit will insulate you up to a point and then it will match ambient temperatures, so you still need to have a layer on that can insulate you from the outside temp enough. So if its hot better plan on something that will just keep the suit off your bare skin or you will swear it burning you.

I don't know what Auspañol is saying about it his VTR fan is not cooling enough, In fact he's the only one that I know of that has tried the fan swap and says that it doesn't work well enough.

Auspañol, What did your VFR do before you swapped the fan blade? I mean if you are still having issues with the VTR fan, then I hate to think what heat issues you were having with the stock fan. And just to clarify, you did just install a new VTR fan blade on the VFR honda's fan motor correct?

I'm asking this because the VFR/VTR fan swap was like nothing compared to changing the direction of airflow on the rc51.

Hey Mello Dude, any chance of getting you to make those switches after all?

How many interested parties or wanted switches would you need to make it worth the effort?

[JES_VFR]

I'm glad I found this thread, I'll have to keep an eye on it

As I have only 203 VFR miles under my belt and it is clearly anything but hot here yet, I'm not sure what to expect

One thing though, I will not give up the way I ride, I will not lumber through a 30-mph zone shifted way up into a higher gear to keep the rpms/temps down

If I can't rumble my Staintune through town at 30-mph at 5,000 rpm's without overheating, I will indeed have to make some kind of change

The rpm's are not the big deal, and if you are moving at 30mph, then you should be just fine.

at that speed you should have enough air flow even with the fan trying to run to keep the cooling system working and the bike running right.

This fan issue is really more something that rears it's ugly head when you hit stop and go traffic.

The the OEM fan just doesn't move the heat away from the bike, so it quickly hits the point where the fan is running 100% of the time and the coolant temp keeps on rising.

[JES_VFR]

Based on my experiments with the VTR fan I can safely say the following:

It rocks when the bike is in motion. Very effective.

It sucks when the bike is stationary. So much so that if you enter into a slow speed zone, like going through a small city/large town on your way somewhere, travelling on say, secondary highwyas (don't know the US term)... and the bike is already close to climax (hehehe)... you stop at a red light (one that lasts a while cause it's like a 6 way intersection or something, or for whatever reason)...maybe you've had to stop at several intersections, but the frame and all the other bits and air immediately surrounding the motor and bike are hotter... and the ambient temp is high... the VTR fan will not get the coolant temp down to the lower cut-off point... it will just keep coming on until it stays on unless you get to run the bike at about 70 km/h for a good run...

Again, this makes me wonder what you VFR's were like with the oem fans. I have had my VTR fan kick on in stop and go traffic on an UBER-Hot day, cycle on and off couple of times and then not shut off again until the I cleared the traffic. If the heat index is high enough that is normal. But I've never had it kick in at 223-224, cycle a couple of times then run continuously and still have the temperature keep rising until its 240+ (which the VFR did all the time with the oem fan blade) The most I've ever seen was 234 after a twenty minute delay on a day that I later learned the ambient heat index as 158. The asphalt was so hot you could see the oils and tars rising through the aggregate.

That oem fan never cycled in traffic, it would come on and just stay running 100%, with the temps just rising.

Where I would differ is in the fact that, I have experienced umpteen times just how the inflowing air makes the fan rendered useless when it's on to the point where (at lower than 70 km/h) the bike does not cool down... I'm talking really hot summers and half an hour in stop&go traffic for example... & thus the fan would labour on continuously until, A: you get on a freeway/highway & at speed +80 km/h & the force of the oncoming air overcomes the fan, or B: you go so slow (or stop) that the fan can do its job.

Its more like a).you speed up to a speed where the air flow through the right radiator does enough of the job that the bike cools down and shuts off the fan or b). You pull over and stop and wait for the bike to cool down on it's own.

The VTR fan worked (for me) when I didn't spend too much time stopping and going... on my 5th gen I've had to pull over and turn it off cause it just wasn't capable of cooling the thing down enough... I often found myself longing for a stretch of freeway to get up to speed.

Well, hang on a second, are you saying that the VTR fan did could not hold temperature or that it could not necessarily bring it back down below the fan cut off temperature.

If the fan ran and held the temp at 223, then it was working just fine. Just like the ac compressor in a car, conditions are often such that it cannot cycle on and off. As long as its running and the temperature does not just keep climbing then the fan is working.

With the OEM fan, I figured out how to wire up a switch to turn the fan off for when I'm moving forward and the fan is on... so the air can do it's job...

Having the fan running continuously is putting the VFR's fairly dodgy charging system under extra load for longer... same would happen if you drop in a thermoswitch with lower activation values... it'll come on more often... it is a fairly hot running bike by design as far as I can figure...

If the fan is running and the bike is not moving then its true its a load on the charging system. However it is a necessary evil as the alternate is the bike overheats.

But with the VTR fan once the bike is moving the electrical load from the fan drops to almost nothing as the natural air flow through the radiator wants to spin that fan like pinwheel. In fact the fan motor almost generates power at that point. So it's sort of a win/win.

Now while the fan would run more often if its switch's temperature thresholds were changed, I don't think that it would be bad. I think it would cycle more and run continuously less.

The whole bike would be cooler and that is a pretty serious mass of metal we are trying to cool. It is a hot running bike by design, but that doesn't mean that keeping it in its sweet spot is a bad idea.

But hey... every VFR is a little different... some fry stators some don't... some run that bit hotter than others... and the weather here is extremely hot over summer... +40ºC is extreme... and the asphalt and surrounding buildings are radiating even more heat.. like at MotoGP... the track temp is always way higher than ambient...

I'm glad the VTR fan works so well for others...

Experiment I say, and find out what works for you....

That is why I keep thinking about building a fan controller to make the fan more effective. Sort of a cross over from an automotive electrical cooling fan adventure.

Edited May 28, 2010 by JES_VFR

[vfrjim2002]

The reverse fan works for you, OK. When I had the 157 degree reading, the ambient was 90 (inside / outside thermo). The difference of 67 is pretty big. The stock fan actually does a pretty good job under 15-20 mph and I don't ride between 20-30 mph. By 30 mph the fan will be off, so I should do pretty well from then on.

I checked and by the time I pay for the reverse fan with tax and/or shipping, I'm looking at close to $40. I had most of the parts on hand to build the module. I think I got about $5 into it, maybe $10 if you count the stuff I had on hand.

The reverse fan worked for you, I think stopping the fan will work just fine for me.

CR,

I came to the same conclusion several years back, but lack the wherewithall to pull off what you're doing. I don't know if you're interested in putting another module together, but I'd be interested if you are.

thanks,

Jim

[mello dude]

Hey Mello Dude, any chance of getting you to make those switches after all?

How many interested parties or wanted switches would you need to make it worth the effort?

- I do have a vendor in mind to give it a shot, they make automotive fan switches for a living. I still like this heat discussion and kinda wonder if we go too low on the temp on/off, would we get to a point where the fan wont shut off? Then what happens with the system electrics? Something to think about.

- Another curve ball in this thing is there seems to be a wide variance of vfr heat issues. Some seem to be totally fine stock, and others are a problem child. Theres something going on there and I dont know what it is.

- If I had enuff interest, I suppose I would ask the vendor to quote me a batch of 50 and 100 to see where the price tag would go. For the moment I couldnt guess what they would charge. I'm willing to work with you guys if I get some interest.

[JES_VFR]

Hey Mello Dude, any chance of getting you to make those switches after all?

How many interested parties or wanted switches would you need to make it worth the effort?

- I do have a vendor in mind to give it a shot, they make automotive fan switches for a living. I still like this heat discussion and kinda wonder if we go too low on the temp on/off, would we get to a point where the fan wont shut off? Then what happens with the system electrics? Something to think about.

You make a valid point that If we go to low the fan won't ever stop running, but I do think that it stand to be triggered a few degrees (say 15-25) earlier than the stock one.

- Another curve ball in this thing is there seems to be a wide variance of vfr heat issues. Some seem to be totally fine stock, and others are a problem child. Theres something going on there and I dont know what it is.

I think this is two things, one some of us ride everywhere and must deal with traffic issues frequently and often. Where as others don't. That along with lots of variations in temp and humidity, not mention conditions and concentration of coolant have to effect, results. If we took 15 vfr's from three generations and rode them all in the same conditions for a week in hot conditions (say 95F and over 85% humidity, at rush hour in the city traffic), I bet that we would see some heating issues in several of the bikes. Not all, but quite a few.

Also there are several different expectations when it comes to the performance of the fan. Some think that its only working if it can drop the coolant temp back down to the cutoff point no matter what the ambient conditions are. Some think that if the fan comes on that the temp should at least freeze exactly where the fan kicks on and if it doesn't then it isn't working either (again the conditions don't matter. The last group recognizes that the fan is working if it stabilizes the engine temp in a range that is less than boiling the coolant, but that the ambient conditions may push the temp higher than they normally expect (like on a day when the heat index hits 165 at rush hour)

- If I had enuff interest, I suppose I would ask the vendor to quote me a batch of 50 and 100 to see where the price tag would go. For the moment I couldnt guess what they would charge. I'm willing to work with you guys if I get some interest.

Well I would take several, to install on my current bikes and to have on hand for replacement and other projects.

So you can count in for 5 or 6

[enzed_viffer]

My experience is that when I'm riding in traffic, the temperature will gradually creep up, because the column of traffic entrains the air, so instead of there being a positive pressure in front of the engine and low pressure either side of the bike, there's little air movement. Once the traffic's doing more than say 40mph, that changes. This is worse in summer than winter. On the open road, I've never had problems with the bike getting hot.

I fitted a manual switch that I trigger whenever I'm stationary and the temperature gets above about 90C. Originally I was going to fit another thermoswitch that I found that was set to go on at 95 and off at 85C (IIRC). I decided against this, as there would be too many times when it would be on and I'd be moving. So far, apart from forgetting to turn it off, the manual switch has worked out well. I may add a red light on the dash to remind me to turn it off.

[AndyJ]

I'd be interested in a lower temp fan switch as well MD. I had a nice 1.5hr commute at walking pace Thurs due to some massive accident. Stop & go traffic on the highway, bailed off onto secondary roads, which were also all creeping stop & go. Fan was running constantly, to the point where the battery drained & it died on me on the highway. Fortunately I unplugged the headlights and a guy stopped to help me bump start it (uphill, of course).

The fan was running the entire miserable ride, and never cooled below about 210, even on a few stretches where I got up to 55-60 for a mile or so.

[dogman]

Interesting discussion.

I have fitted the VTR fan and it works for me. I also have fitted a manual override switch so I can turn it on when ever I want, say when I know that I will be in slow moving traffic.

Its also interesting that Honda should bring out 2 bikes (VFR800 and VTR1000) with almost identical radiator setups and choose to have one fan sucking and the other blowing.

I have owned several of both bikes and the VTR1000 setup makes more sense to me.

If I could change the on / off temp of the thermoswitch, it would be to 95deg C ON and 90 deg C off

[enzed_viffer]

I have owned several of both bikes and the VTR1000 setup makes more sense to me.

I owned a VTR1000 before my current bike, a '90 VFR750 before that, and a '85 VF500 before that. All of them got hot in traffic, but the VFR800 is the least uncomfortable. The VTR tended to blow more eat out onto my leg, and all the bikes were somewhat uncomfortable on hot days due to heat from the rear headers. I think however that the current bike is the least worst.

[JES_VFR]

I'd be interested in a lower temp fan switch as well MD. I had a nice 1.5hr commute at walking pace Thurs due to some massive accident. Stop & go traffic on the highway, bailed off onto secondary roads, which were also all creeping stop & go. Fan was running constantly, to the point where the battery drained & it died on me on the highway. Fortunately I unplugged the headlights and a guy stopped to help me bump start it (uphill, of course).

The fan was running the entire miserable ride, and never cooled below about 210, even on a few stretches where I got up to 55-60 for a mile or so.

I think this clearly illustrates a couple of points.

#1, Honda did not build an excess of cooling potential into the fan, In fact this case is argument that the factory suck fan is a epic sucking failure.

#2, It also proves that there us much more to the cooling issues that just atmospheric temperatures, there is "local" ambient temps, humidity and even other local conditions.

Now would the swapped fan blade and/or a lower temp switch have saved him? I don't know, I do think that those two items would have reduced the possible overheating, and perhaps reduced the electrical load a bit. Perhaps that would have been enough for him to keep bike charging and get to his destination without the joy of it quitting on the road.

[JES_VFR]

Interesting discussion.

I have fitted the VTR fan and it works for me. I also have fitted a manual override switch so I can turn it on when ever I want, say when I know that I will be in slow moving traffic.

Its also interesting that Honda should bring out 2 bikes (VFR800 and VTR1000) with almost identical radiator setups and choose to have one fan sucking and the other blowing.

I have owned several of both bikes and the VTR1000 setup makes more sense to me.

If I could change the on / off temp of the thermoswitch, it would be to 95deg C ON and 90 deg C off

Don't forget the RC51, it as twin fans in suck mode where the VTR doesn't

Makes you wonder if Honda designers ever look at which past designs were successes.

[mello dude]

Interesting discussion.

I have fitted the VTR fan and it works for me. I also have fitted a manual override switch so I can turn it on when ever I want, say when I know that I will be in slow moving traffic.

Its also interesting that Honda should bring out 2 bikes (VFR800 and VTR1000) with almost identical radiator setups and choose to have one fan sucking and the other blowing.

I have owned several of both bikes and the VTR1000 setup makes more sense to me.

If I could change the on / off temp of the thermoswitch, it would be to 95deg C ON and 90 deg C off

Don't forget the RC51, it as twin fans in suck mode where the VTR doesn't

Makes you wonder if Honda designers ever look at which past designs were successes.

The RC has twin fans? Thats a new one on me. --Another goofy data point is that Gold Wings have the same issue with the radiators on the sides, and do the overheat thing on occasion too. Sometimes I wonder about Honda. On the one hand they are brilliant and on the other hand - idiots.

Wish numbers - I'm thinking 207deg F on, 194deg F off. -Better add a backup off switch on the fan just n case.

btw - I know the stocker on is 219, but what is stock off?

[JES_VFR]

Don't forget the RC51, it as twin fans in suck mode where the VTR doesn't

Makes you wonder if Honda designers ever look at which past designs were successes.

The RC has twin fans? Thats a new one on me. --Another goofy data point is that Gold Wings have the same issue with the radiators on the sides, and do the overheat thing on occasion too. Sometimes I wonder about Honda. On the one hand they are brilliant and on the other hand - idiots.

Wish numbers - I'm thinking 207deg F on, 194deg F off. -Better add a backup off switch on the fan just n case.

btw - I know the stocker on is 219, but what is stock off?

Yup my RC51-SP2 had twin fans, one on each rad sucking in. To call it a hot bitch was an understatement when I got it.

So I did the usual things,

changed the coolant,

checked the thermostat,

confirmed that the fans were kicking in at the right temperatures and together.

I replaced a mis-sized and dying battery, and it solved a problem I had initially with bike dying at lights as soon as the fans switched on, but the bike would still roast at a traffic light.

I cut the coolant down to less than 5% of the mix and added lots of water wetter and still it would just get hotter when the fans were running.

finally I did some work on the fans (flipping the blades and reversing the fan motor rotation) and now it cools down. I can sit at a traffic light or in traffic and the hottest I have ever seen was 229 (and I was just about melting behind a NJT bus).

Sure I feel the heat on my lower legs for few minutes when the fans kick on, but that better than everything that touches the bike roasting for as long as you have it running and the bike overheating to boot.

Hey did you know that Honda had a recall on the early gl1800's to replace the tractor fan blade (the suck in fan) with a pusher fan blade to cure overheating issues.

[spud786]

As someone who has swapped out to the VTR fan all I can say is that it was a simple swap and it just WORKS.

No messing around with a manual switch, no messing around re-wiring anything. It just WORKS.

The only downside is that the bike throws out some serious HEAT onto your left leg and if you are wearing something other than real moto pants or a 1-piece moto suit it becomes uncomfortable. I did some test riding around the block with my new fan and OMG HOT AIR ON MY LEG! But when I put my 'stich suit on it's not even noticed.

So, if you want to wear shorts or a light pair of cotton pants you might not like the bike actually COOLING ITSELF by throwing heat OUT of the engine compartment rather than right back inside it. I guess Honda made a decision that having a bike that ran way too hot in Stop & Go traffic and sometimes overheated was better than having the squids who rode without proper gear bitching and complaining about hot air hitting their leg when they rode in shorts and flip-flops.

That's just how I see it.

I'd rather have a radiator and cooling system that WORKED. The VTR fan swap works. I'm a bit insulted that Honda would sacrifice an effective system to keep a few squid's leg's cool because they weren't wearing decent leg protection that would insulate their knee/upper leg from the isolated blast from the left radiator. The only way I can feel it is if I pull off my glove and feel the outside of my 'stich at my knee. Yeah, it's warm (not melting hot -but quite warm). But I can't feel it through the fabric inside.

Thick abrasion-resistant and insulating clothing works both ways.

Yeh , whats the problem, The bike is designed to keep the heat off the rider and the cooling system does that very well .

The bike works as its supposed too, keeps the heat off the rider , Id rather have a warmer running engine than hot legs. I also ride in high heat post 100, the bike holds up great in stopped trafic the fan is extremely effective. I dont understand all the heat issue complaints at all.

so now your bike is cooler but you have to wear fire proof clothes, thats Funny!

[coderighter]

The reverse fan works for you, OK. When I had the 157 degree reading, the ambient was 90 (inside / outside thermo). The difference of 67 is pretty big. The stock fan actually does a pretty good job under 15-20 mph and I don't ride between 20-30 mph. By 30 mph the fan will be off, so I should do pretty well from then on.

I checked and by the time I pay for the reverse fan with tax and/or shipping, I'm looking at close to $40. I had most of the parts on hand to build the module. I think I got about $5 into it, maybe $10 if you count the stuff I had on hand.

The reverse fan worked for you, I think stopping the fan will work just fine for me.

CR,

I came to the same conclusion several years back, but lack the wherewithall to pull off what you're doing. I don't know if you're interested in putting another module together, but I'd be interested if you are.

thanks,

Jim

If I could get 5-10 people, I just might. If I do, I'll let you know.

[Serenity_VFR]

Yeh , whats the problem, The bike is designed to keep the heat off the rider and the cooling system does that very well .

The bike works as its supposed too, keeps the heat off the rider , Id rather have a warmer running engine than hot legs. I also ride in high heat post 100, the bike holds up great in stopped trafic the fan is extremely effective. I dont understand all the heat issue complaints at all.

so now your bike is cooler but you have to wear fire proof clothes, thats Funny!

Yeah, when the bike belches out all the coolant and you are stuck at the side of the road waiting for it to cool down and either have to find some coolant and refill it (after pulling off the bodywork) -or call a truck to come tow you.

But at least you can wear your shorts and flip-flops instead of proper ATGATT...

Works like it is supposed to! :fing02:

[biobiker]

Yeh , whats the problem, The bike is designed to keep the heat off the rider and the cooling system does that very well .

The bike works as its supposed too, keeps the heat off the rider , Id rather have a warmer running engine than hot legs. I also ride in high heat post 100, the bike holds up great in stopped trafic the fan is extremely effective. I dont understand all the heat issue complaints at all.

so now your bike is cooler but you have to wear fire proof clothes, thats Funny!

Yeah, when the bike belches out all the coolant and you are stuck at the side of the road waiting for it to cool down and either have to find some coolant and refill it (after pulling off the bodywork) -or call a truck to come tow you.

But at least you can wear your shorts and flip-flops instead of proper ATGATT...

Works like it is supposed to! :fing02:

My Y2K with 30K miles had no problems with cooling. Fan would come on around 218-220 and drop temps back to the low 200's. Never saw temps over 230. Once up to speed, temp dropped dramatically to running around 185. So...I had a tip over on the clutch side in the garage, nothing broke but it was on its side for several minutes while I collected myself and got it back on the side-stand. Now I heat up much faster and run hotter 210-225 (about 20 degrees) than before. I'm thinking air in the lines/system so I will change coolant this week and bleed the system as per manual and will go from there. Just an interesting side bar since I had no cooling issues before the tip-over.

[spud786]

Yeh , whats the problem, The bike is designed to keep the heat off the rider and the cooling system does that very well .

The bike works as its supposed too, keeps the heat off the rider , Id rather have a warmer running engine than hot legs. I also ride in high heat post 100, the bike holds up great in stopped trafic the fan is extremely effective. I dont understand all the heat issue complaints at all.

so now your bike is cooler but you have to wear fire proof clothes, thats Funny!

Yeah, when the bike belches out all the coolant and you are stuck at the side of the road waiting for it to cool down and either have to find some coolant and refill it (after pulling off the bodywork) -or call a truck to come tow you.

But at least you can wear your shorts and flip-flops instead of proper ATGATT...

Works like it is supposed to!

I never seen that happen on my 06 at all, I still say Honda's coolant is causing issues with metals in the VFR system, like the thermo. and then there are the water wetter guys, which it cant handle over 200 degree temps.

I can just tell you I have no cooling issue at all, never have on the vfr

I dumped that stuff when new to prestone mixes with anything 60 to 70 mix, I am in south texas, so it sees alot of heat

Edited May 31, 2010 by spud786

[Guest]

FYI.. my 2000 RC51/ SP1 had a single fan on the left side.. I think the twin fans were 02 and newer RC's only but I'm not 100% sure. I am 100% sure my 2000 RC had only 1 fan and it was stock. It ran just as hot as my VFR.. I personally haven't seen the temp on my VFR get higher than 232 deg but that's dangerously close to overheating IMO. I leave my gauges set to show my temp at all times becuase it at least gives me a chance to save the motor if it does get too hot. I plan to shut my bike down if I ever see the temp hit 236. I've been thinking about doing the VTR fan swap but I'm not totally convinced it will work. It makes sense to me but I do find myself sitting at long red lights around here. If the hawk fan doesn't work well when stopped, it may not help.

[JES_VFR]

Yeh , whats the problem, The bike is designed to keep the heat off the rider and the cooling system does that very well .

The bike works as its supposed too, keeps the heat off the rider , Id rather have a warmer running engine than hot legs. I also ride in high heat post 100, the bike holds up great in stopped trafic the fan is extremely effective. I dont understand all the heat issue complaints at all.

so now your bike is cooler but you have to wear fire proof clothes, thats Funny!

Okay you live in texas so I get that you see hot days,

But how long are you in stopped traffic, and what is the heat index behind that city bus at rush hour.

As for heat on my leg, heat on the outside of one leg beats feeling the heat off the frame/tank/bars/seat roast most of the tender parts while in stopped or creeping traffic.

Then, if you really are luck and the traffic breaks up before the bike boils but doesn't get back to full speed, you get to roll along with the 240+ temps not changing because the fan is bucking the normal and natural airflow pattern. Even if some miracle happens and the traffic suddenly disappears in front of you, its miles before the bike cools down enough to shut down the fan and really cool off.

I meant think about this if while you are moving with the fan off the bike consistently cools to say 190, but in a traffic jam the fan starts running and the temperature after 15 minutes is 240 and climbing, plus when the jam ends and your riding at 40 mph with the fan running it doesn't cool back down for miles. It cools painfully slow until you get down to 210 where the fan kicks off and in less than a minute your back at 190..

What more proof do you need that the fan design is flawed.

I mean Codewriter agrees that the fan design is flawed, he just thinks that there is a different solution to the problem (he wants to switch it off as soon as there is some natural airflow through the bike from the front). I think that having the fan supplement the natural airflow when stopped and at low speeds better than having it fight nature.

Thanks but no thanks, I'd rather have one slightly warm leg versus baked thighs, groin, abdomen, chest and one boiled VFR motor. I know that my own core temp stays lower when the sh fan blade is running even though I can feel the heat on left calf. So the bike and rider are cooler in the end as the VTR fan pushed the heat out of the bike, instead of trying to hold it in.

FYI.. my 2000 RC51/ SP1 had a single fan on the left side.. I think the twin fans were 02 and newer RC's only but I'm not 100% sure. I am 100% sure my 2000 RC had only 1 fan and it was stock. It ran just as hot as my VFR.. I personally haven't seen the temp on my VFR get higher than 232 deg but that's dangerously close to overheating IMO. I leave my gauges set to show my temp at all times becuase it at least gives me a chance to save the motor if it does get too hot. I plan to shut my bike down if I ever see the temp hit 236. I've been thinking about doing the VTR fan swap but I'm not totally convinced it will work. It makes sense to me but I do find myself sitting at long red lights around here. If the hawk fan doesn't work well when stopped, it may not help.

I think that the sp1's did only have a single fan, and the sp2's got two. It doesn't matter two fans trying to blow air the wrong way doesn't work any better than one fan blowing it in instead of out.

As for the super hawk fan working or not, I can only tell you this.

For me it works and I did have issues from the day I bought the VFR until the day I yanked out that VFR fan blade, Now I have none.

To me that tells me that it did not matter what condition my coolant was in or what type I was using. It did not matter what the local conditions were particularly.

The heating issue was there until I swapped out the fan.

Also after I figured out how to reverse the airflow on the RC51, It also cools just fine moving or standing still now

What I would love is to have two bikes brought together, checked on a reasonably cool day for temperatures after idling and while waiting in traffic.

then swap out the fan blade on the hotter running of the two bikes and repeat the test on a nice 95+ degree day at rush hour.

I'd bet that the unchanged bike has cooling issues, both while stopped and while slowly moving. I'll even bet that when they both get an opportunity to run faster, the unchanged bike can't cool down as quickly as the Hawk fanned bike.

In fact it's like this, your not that far away.

Order the fan. If you want I'll ride out and help you install it. If Your not happy, after trying out, I'll buy the superhawk fan from you.

That is how much I'm convinced that it works.