can i make it run cooler?

i have a new to me 07 vfr that i am quickly falling in love with. problem is that she is running at around 225 degrees most of the time. PO says that thats just how she runs in this heat at this time of the year so im not really concerned for the bike. my real concern is for my... how can i put this? ill just be blunt, this thing is roasting my nuts!!! i dont like roasted nuts!!! is there any tips or tricks/mods for cooling these things down? i do a lot of riding in traffic so i would be willing to go the expense of aftermarket/donor radiators. or try a different coolant. as much as i like the bike i will deal with the heat if need be, its not that bad. but it sure would be nice to cool this thing down a few degrees. thanks in advance

 

Drain the coolant, refill it with distilled water and Water Wetter (or the Royal Purple stuff, just depends on what you want to spend). Just remember to put antifreeze back in before winter.

Search for the VTR fan swap mod. The fan blade of the VTR's are 180deg from the VFR's, so it blows air out instead of sucking air in.

Also popular to make a manual override switch when you do the fan swap, it’s convenient since you’re in there digging around any way. That way you can turn it on as you please, say if you are coming to a stop light and you’re already at 210deg.

Another option is to look into buying the aftermarket CAT-less header and wrapping the pipes with exhaust wrap. Try and keep the radiant heat out from under the bike and keep it in the exhaust.

Just some food for thought.

 

What Guj said is all good.
What is the ambient temp where you are riding?
I have done all the mods mentioned, and will add that if I fit my exhaust baffles ( I have leo vince pipes and motad headers) the engine runs about 5degC hotter than without them, so a consrictive exhaust does retain a lot of heat.
The thing with doing the VTR fan swap is that the cooling efficiency while the bike is stationary is actually worse than the OEM fan, because it is blowing air through the radiator that has been preheated by the engine and headers, but once you get moving, the cooling efficiency is better than the OEM.
I use the override switch to turn on the fan whenever I'm in traffic, when the engine gets to about 90 degC (sorry not sure what that converts to in degF) to stop the engine getting really hot in the first place.
Otherwise, are you sure the thermostat is opening properly and there are no airlocks in the radiator/hoses, and the radiator is topped up?
You could also try fitting a fan override switch with the OEM fan but be aware that you need to turn it off once you get up to speed or cooling would be worse due to the airflow stalling in the left radiator.

 

All good ideas, but what's the circumstances you are riding in? If your at 225 doing 65 down a highway, you may have t-stat issues.

If you're at 225 sitting in traffic in 95* F, that's kind of normal, and making the changes above would probably help.

 

My 07 RWB is pretty typical from what I've read, 175-200 on the road and then when I get into traffic it creeps up to 224-225 and then the fan kicks on and brings the temp down to about 210 or so and cycles off. What I've been wondering is, Isn't there a way to have the fan kick on at a lower temp, say 210?
John

 

An old radiator cap that won't hold pressure can be one cause for excessive heating.

 

thanks for the tips guys. all good advice and i will do all the things that guj suggested. 90-95 degrees here, and humid. pretty sure the bike is functioning properly. just looking for ways to make a great bike even better. i will post up the results after i do the mods. prob be a couple weeks cause i just bought a house and it is being remodeled so i am busy right now. thanks

 

Hey Tinkerin, I had read your info about the manual switch in a previous post (and thank you) but I was just thinking there might be a way to change the thermetic trigger (word) to trip the fan on sooner automatically.
John

 

the temps that you say is typical for my 2006. I don't ride when it's that hot..been upper 90's to low 100's and I just seem to like my A/C in traffic.

 

Re the original post - I guess the answer is - well possibly.

Things like changing the coolant to a medium which is able to transport/dissipate more heat may help with any bike. A decent motorparts outlet will stock various propriety water wetter concoctions designed to improve summer coolant performance. The downside is they might not have the same anti freeze capabilities.

Living and working in the mountains I often see temperatures soar on my basically stock 6thGen when storming up steep climbs especially on hot summer days. Hence I too have been trying to find ways to either fire up the fan at a lower temperature or somehow discretely improve heat disposal.

As other have said the VTR fan swap on its own is not ideal - if you want to know more try this link Sport-Touring.Net - Tired Of Having A Hot Vfr?, Sick of Honda's short sighted fan design.. The thread gives a fairly honest assessment of what you gain/loose.

Hence I have been wondering if the answer may lie elsewhere. Even in ridiculously hot conditions once the bike is making real progress - eg +60mph then the natural flow of air around the bike seems to do enough to mean the fan is not needed. Inherently at that speed most of the cooling comes from three routes all of which involve in heat ultimately being dumped into the surrounding air. 1 the fairing shape behind the front wheel acts as a ram air duct which funnels air between the engine and fairing providing direct air cooling, 2 quite a lot of that funneled air exits the side of the fairing passing through the radiators taking heat from the engine coolant, and 3 some passes through the oil cooler. I suspect that despite its size, the oil cooler may be the most significant heat dissapation route, as oil has the potential to carry more energy than water.

Hence I have been wondering whether a combination of the VTR fan swap and fitting an auxilary slimline fan on the oil cooler would help ensure that even when stationary - some air continued to flow in the route it normally follows around the bike when its moving.

It does seem strange that the OEM VFR fan is set up to actually fight against the normal airflow experienced when the bike is moving at speed. I guess this interaction will actually reduce the engine cooling - especially when the bike is moving at relatively low speeds but under heavy loads - so riding up a steep twistie mountain pass.

Inherently the trade off seems that when you are stuck in a traffic jam, the VTR fan fix will actually make things even more uncomfortable for the rider, but may make life less extreme for the engine. Sort of your choice what gets fried. Certainly I think protection from excess heat is another good reason to always wear decent motorbike trousers.

I will be back in the UK next month aiming to round up a VTR fan and source a low amperage motorbike fan from a breakers to mount on the the oil cooler. If I can find a fan with a low amp demand, I plan to wire it to the standard fan circuit so both fans come on at the same time, otherwise I will need to run it via a relay. Suffice to say knowing my luck, by the time I get over, typical Summer weather will have set in, so I can be certain the VFR will never get hot enough for the fan to fire up at least until I head back for winter in the Alps. hey ho.


Skimad4x4
Proud member 6th Gen Militia # 218 - European 1st Division.

 

Apparently the oil cooler from an RC51 isn't too difficult to install (although I'm not sure about the double o-ring part).

Honda VFR oil cooler swap. - TWT Forums

 

Since the fan runs with a DC motor, wouldn't it be possible to reverse + and - on the fan and have it run "backwards" like the VTR setup ??

Make sure not too many radiator fins are bent or distorted and that imbedded bug guts haven't blocked airflow.

 

You're right Tink, it is really close. I don't know why anybody would go through that much effort and not just drill some 1/4" aluminum to shift it back to center.

How difficult is it to get the ends that bolt to the block? If you could get a pair of those I would imagine that a decent shop could make a hose that would mount pretty much any cooler that you would want.

 

The curvature of the fan blades would mean that running in reverse would make it very inefficient, but if you took it off and reversed it, it would be OK, if that is possible due to the mounting consraints.

 

Does anyone ever have the safety mechanism shut the engine down due to reaching the temperature threshold? I'm kind of thinking (not that Honda would ever get anything wrong) that the bike runs the temperatures that it does is by design. That is that this is an efficient operating temperature range. It may be a bit uncomfortable for us when the fan comes on and all that excess hot air comes pouring out of the fairing but Honda has certainly had the time to redesign the VFR if this was a durability or performance issue. I have not been riding in 110 degree plus temps yet but when I'm in traffic and the bike reaches 224 d. The fan kicks on and always brings the temp down, so seems to work as designed. Just thinking out loud.
John