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Got a question and looking to see what some of you other guys are getting for normal highway temps. I know the Sp2's run hot but my 06 tends to run alot hotter than my 00 RC does.

I rarely see above 200 on the highway (60-70 mph) on the 00. On the same type of day (approx 80 deg) the temp will eventually climb up to 220 and then the fans kick in and take it back down to 210. As long as I'm running that speed with those outdoor temps the operating temperature will bounce between 210 and 220. My 00 is all stock, the 06 has Wibbly brkts and dual pusher Spal fans, 15 and 41 gearing, and Moriwaki carbon fiber rad opening fins (not sure if that could be an issue).

I guess what I'm wondering is those of you who own Sp2's run a similar type of temp when on the highway? When the evening temps cool down the 06 will run at 200 or below but the 00 always runs consistently cooler (at least by 10 degrees)

Coolant is fresh Honda factory coolant and no leaks in the system.

Looking for input from some of you other guys.

Thanks,

Nick
 

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Here in Florida, I see my '02 SP2 hit 221 F in traffic, with the fans kicking on at 218 F (as did my ex-FZ1).
Once the fans kick in, the temps drop down to 205 F.
On the freeway, the temps drop down to 185 F or so. The lowest running temp I've seen was 175 F while cruising in the country, away from the hot city air.

It's interesting to note how sensitive the system is, as while traveling down a country road around mid-day, I've passed under a shade tree and watched the temp drop 1 F then bounce back to to prior temp.
 

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Discussion Starter #3
Here in Florida, I see my '02 SP2 hit 221 F in traffic, with the fans kicking on at 218 F (as did my ex-FZ1).
Once the fans kick in, the temps drop down to 205 F.
On the freeway, the temps drop down to 185 F or so. The lowest running temp I've seen was 175 F while cruising in the country, away from the hot city air.

It's interesting to note how sensitive the system is, as while traveling down a country road around mid-day, I've passed under a shade tree and watched the temp drop 1 F then bounce back to to prior temp.
That's pretty much how my '00 acts. The '06 runs alot hotter. In traffic or running down the interstate during the day it's well over 200 but never above 221.

I did also forget to mention that I have a dyno tune from Schnitz on a Powercommander V and the Pair is pulled along with the flapper being deactivated.
 

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That's pretty much how my '00 acts. The '06 runs alot hotter. In traffic or running down the interstate during the day it's well over 200 but never above 221.

I did also forget to mention that I have a dyno tune from Schnitz on a Powercommander V and the Pair is pulled along with the flapper being deactivated.
My 05 runs the exact same. constantly bounces 209-220f; SPAL fans kick on and back down to 209.

all the usual mods, engine ice etc.

some of my friend's RCs run cooler when moving (~185) some SP1 and SP2. Idk its a bit odd.
 

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The extra fan on the SP2 blocks more of the air flow at speed and reduces cooling effectiveness while in motion. If you remove one of those fans or both even you will see much cooler running temps while in motion.

The flipside of that is that extra fan helps keep the engine a lot cooler when stuck in stop & go traffic with you idiots that actually commute on an RC51 which was one of the chief complains from SP1 owners about the bike getting too hot in bumper to bumper traffic congestion.
 

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Discussion Starter #6
The extra fan on the SP2 blocks more of the air flow at speed and reduces cooling effectiveness while in motion. If you remove one of those fans or both even you will see much cooler running temps while in motion.

The flipside of that is that extra fan helps keep the engine a lot cooler when stuck in stop & go traffic with you idiots that actually commute on an RC51 which was one of the chief complains from SP1 owners about the bike getting too hot in bumper to bumper traffic congestion.
Sounds like I'm kind of stuck with it running as hot as it does. Don't want to take the fans off because I do get stuck in traffic during in town riding even though I don't commute on the bike.
 

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Even in track only trim I kept my Dussault undertail installed on the SP1 and I would occasionally slap a license plate on it, connect the brake wires and ride it to the local Honda shop to pick up parts and lean it against the wall. It does not take much traffic at all to get those temps up when you don't have any fans installed. I mean just sitting at a normal stoplight for a minute or less in humid Southern heat will have you staring at that temp gauge and praying whether you are a believer or not...
 

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I'm a chickenshit so I when I installed the Spal fans I also installed an override switch beside the cluster so that I can turn the fans on manually. When I am in traffic and see the temps creeping over 200, I hit the switch and the fans keep the temps out of danger. Once I am back on the road, I turn off the switch and the temp sensor takes over again.
 

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I'm a chickenshit so I when I installed the Spal fans I also installed an override switch beside the cluster so that I can turn the fans on manually. When I am in traffic and see the temps creeping over 200, I hit the switch and the fans keep the temps out of danger. Once I am back on the road, I turn off the switch and the temp sensor takes over again.
If you were going to be proactive like that anyway by monitoring the temps you would have had the exact same results with the OEM fans as long as you are willing to flip the switch before the engine gets too hot...
 

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The factory fans collectively weigh 100 lbs (only slight exaggeration) and flow against the normal air flow path. The Spal pushers match the normal air flow path and move more air. They bring the temps down really quick and make me feel that they are not fighting the flow of air through the fairing.
 

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Considering the money I have wasted, this was a mere drop in the bucket. It was more of a PITA to fab the brackets than money.

In the end, it did save a few pounds (worth something right?), and they blow in the same direction as the natural air flow, so I am not worried about running them at low speeds.
 

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Have an 04, speeds 50 and above always around 185 to 190, in traffic fans do what they are supposed to and it doesn't take long to drop back down once I start moving again.Bike is mostly stock though
 

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Just got my 04 RC51 not long ago. I've had same questions. In stop/go on a hot day mine gets well above 200(need to check) and one of the cylinders will start to miss when I take off from a stop, then it comes alive. With ??Fall temps now there is no problem.
 

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The flipside of that is that extra fan helps keep the engine a lot cooler when stuck in stop & go traffic with you idiots that actually commute on an RC51 which was one of the chief complains from SP1 owners about the bike getting too hot in bumper to bumper traffic congestion.
Mike, you crack me up dude. I mean, anyone who races or tries to race an RC51 is an idiot simply because it wont measure up to modern I4s. Now I'm an idiot because I commute on my RC51. haha...

I guess maybe the bike has lost all value except for sitting in the corner of a garage with either a Nicky Hayden or Joey Dunlop poster above it so the owner can day dream about how great it was in the good ol' days. Any other application of the bike simply makes it's owner idiotic.

Crazy world.


As far as temp goes, here in New Mexico, temp can get to 115 pretty regularly in the summer which makes for a miserable ride especially with riding gear on. While I haven't owned the RC yet during the summer, Im sure the fan will be constantly running to cool the engine.

My first bike was an SV1000s and my fans would never kick on. Sitting at stop lights, the temp would sky rocket to the point of steam billowing from under the fairings. I was new and dumb to motorcycles so I had no idea of how much damage I was allowing. Unless my bike becomes a designated track bike, I couldn't image willingly taking off a fan. lol... Of course if those fans are as heavy as people joke about, I can really see the benefit removing them from a track bike!
 

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Mike, you crack me up dude. I mean, anyone who races or tries to race an RC51 is an idiot simply because it wont measure up to modern I4s. Now I'm an idiot because I commute on my RC51. haha...

I guess maybe the bike has lost all value except for sitting in the corner of a garage with either a Nicky Hayden or Joey Dunlop poster above it so the owner can day dream about how great it was in the good ol' days. Any other application of the bike simply makes it's owner idiotic.
I have zero problems with someone wanting an RC51 on static display with a Joey Dunlop poster above it. That is truly one of the best uses for one and if ever there was a reason to reminisce for the sake of nostalgia of motorcycling in the modern age the RC51 is definitely a central theme to that. While it may be a poor facsimile of a racebike to us mere mortals it did bring with it a lot of technology that benefits us today.

All that being said the RC51 is a terrible racebike without the millions of dollars the Factory put into them to make them competitive which basically replaced every single part of the bike. Additionally with it's slightly less than medieval ergonomics and limited range per tank of fuel it's also a terrible touring bike and with the heavy flywheel, small side mounted radiators and propensity for running hot at slow speeds that also makes it not the best choice for a commuter bike. There is no shame in doing any of those tasks with an RC51 and yes I have done them all at one point or another including 550 mile days in the Arkansas Ozarks, but anyone that doesn't admit those shortcomings would be dishonest at best.

What the RC51 does do well is carve up twisties. Tearing up canyons for an hour between gas stops or 20 minutes at a time during a trackday suits it just fine and when you are done you can still put it back on display below the Dunlop poster.
 

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Very well said LDH! Sadly, I live in the worst part of New Mexico (thanks USAF) where most people around here have no idea what a twisty road is. I've never been so bored on a bike! All the same, I'm happy to be on a bike again and want to enjoy this awesome machine the most I can.

Sandia Speedway is about 3.5 - 4 hrs away and I'm looking forward to jumping into track days so I can open this bike up and really stretch her legs in a way she was meant to. Having twisty roads or a canyon near by would be amazing!

So, getting back to the original subject, I believe I read that the RC51 looses performance around 220F. What kind of performance loss can be expected at that temperature? Is it minimal or pretty noticeable?
 

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It's noticeable , but minimal and the motor cools down when going above 45. My '04 runs at 172 if I can stay over 45. I first tried Engine Ice and dropped it several degrees , Redline Supercool dropped it several more.
 

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I would commute to work on my RC51 no problemo. Filtering is legal, Leave early for work and arrive home a little bit late, racking up a couple of extra twisty miles! All I need now is to find my next job..
A Dutch fellow SP2 rider does commute (probaby some 20k miles/year) and recently put heated grips on as winter is coming.... He used to race old, underpowered Laverda's..... He now enjous racing his SP2
It is not the miles per gallon but the smiles per gallon methink.


I will eat glass before ever buying a KYMCO.... :)





2 brothers from the same mother Honda!!!
 
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