semperfire Posted September 6, 2017 Share Posted September 6, 2017 The stock Radiator fan on the VFR is intended to pull fresh air from outside as to cooling the radiator down on the left side. It also is meant to blow the cooler air across to the other radiator disseminating heat. I bring up this topic because some where I read about changing the the fan to a puller with a VTR fan. In my opinion this is not a good idea because when your mostly moving the bike never really breaks past 210 DEG . but at a dead stop is really when you need the fan sitting so question is would you rather suck hot air near the engine and pipes blow that onto an already hot radiator, or cooler fresher air from outside. Ask yourself that question because that is the difference. Link to comment Share on other sites More sharing options...
Member Contributer Marooncobra Posted September 6, 2017 Member Contributer Share Posted September 6, 2017 Sempfire I think most people swapped over to a VTR fan as it complements the flow of air whilst the bike is moving forward. Agree in static traffic the air being blown across the radiator is warm air off the exhaust etc. I know a fan is at its most effecient when drawing air across the radiator rather than blowing but a fan trying to pass air against forward motion is not effecient either. Link to comment Share on other sites More sharing options...
Rogue_Biker Posted October 6, 2017 Share Posted October 6, 2017 I've found my VFR's cooling system to be very efficient when the bike is moving forward. Once stopped it relies on the fans to bring it down to a reasonable temperature, but not until it hits 220 degrees coolant temp before the fans start up. I've had my bike in traffic in 105+ degree heat with the fans running and keeping coolant temp at 221 degrees for long periods. It bothered me knowing it's hot down there. But the engine never missed a beat. The solution was to get the hell out of town and get the speed up to get the forward airflow going again. I used to know someone who obsessed over his VFR running near 220 degrees while climbing up a mountain in summer. We would compare notes while riding this mountain and both our bikes ran the same temps under the same conditions. I also rode another bike up same mountain under same conditions and guess what? It ran at similar temperature as my VFR. So I stopped thinking about it. If my VFR800 got too hot it just means I need to get the hell out of town! Link to comment Share on other sites More sharing options...
Member Contributer KevCarver Posted October 7, 2017 Member Contributer Share Posted October 7, 2017 If VFRs had a bar graph temp gauge instead of numbers no one would ever think twice about it. Link to comment Share on other sites More sharing options...
Auspanglish Posted October 7, 2017 Share Posted October 7, 2017 Yes and no. If you are thorough and consistent in your maintenance regime and know your coolant is not old, thermostat and radiator cap are good, air bled, etc, then probably you'll never need to worry. A few fellow VFR owners always say just to swap the display to ambient temperature and "faggedaboudit"!! Then there's Sod's law. If something can go wrong, it will, and if it does, I'd rather know about it. The OEM fan is more efficient when stopped. If it comes on at speeds between, roughly, 40 - 100 Km/h it is rendered useless and will see your electrical system overworked and we all know the 5th and 6th gens' weak points lie in (different) components of their electrical installations. So I think it's good to know what's going on to avoid any possible untoward event becoming catastrophic. Still, it's good to know how it works, what different factors affect it and what those numbers mean and how to avoid overstressing the system. Ignorance is not bliss when you find out the hard way. Read your manuals. Honda, and they're not always right even about their own bikes, has decided the VFR will tolerate up to 120°C. Then the display starts flashing. I have personally seen this at the racetrack on my 6th gen. This is time to stop subjecting the bike to whatever it is you're doing and stop somewhere in the shade, for example, don't switch off immediately, and see if the fan indeed will lower that temperature a bit without the opposing wind from moving forward hindering its flow. Either that, or try easing off the throttle or getting out of bad traffic and out on open roads. The bike is not very proficient at city commuting. Install a manual override, to turn the fan off when you know the incoming air is defeating the fan, try installing it with a timer to revert back to OEM function (to avoid any forgetfulness leading to further disaster). A VTR fan blade will probably only be useful if you use the bike mainly at the racetrack, which few do as it's not exactly the most effective race bike. So, in summary, don't be paranoid, get informed about what's normal and take it as a hot runner. There is a point, at 120°C where you are likely to develop an oil ooze at the header gasket and I do believe the bike shuts down at 125°C but I have no confirmation of this. Thus, temps of 110-112°C which I frequently saw in mixed-use situations were not reason for panic but could, if stuck longer in the aggravating situation, lead to undesirable temperatures and wear and tear on the electrical components like stator, reg/rec, connectors, etc. Knowledge will set you free!! Link to comment Share on other sites More sharing options...
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