Speedzilla Forums banner
1 - 18 of 18 Posts
G

·
Discussion Starter · #1 ·
Now that the ambiant temp has been firmly entrenched in the triple digits, my bike is accelerating dog slow, and the coolant (water/water wetter) regularly sees the 240's at anything below 60 mph. Anyone else living in the southwest have any luck or solutions? would it help with the higher altitude and higher temperature to remap, or is this just the way it is?
 
G

·
Discussion Starter · #2 ·
Re: hot weather slow bike (RCLinc)

I know what you mean and experienced it in Tucson, AZ a few weeks ago and it's pretty much the way it is. It was 110* in AZ...bike felt doggy, but back up here in WA on a 65* morning a few days later, it felt much better.

To put it short: hot air is less dense than cool air--hot air makes less power...cool air will net more power. YMMV
 
G

·
Discussion Starter · #3 ·
Re: hot weather slow bike (ZJumper)

take the lowers off and it'll run cooler. we had a couple mid-90 days and i rode around without the lowers (with good results).

also, do you have a PC? it's probably not mapped for the high temps.
 
G

·
Discussion Starter · #4 ·
Re: hot weather slow bike (entropy)

yes, pc3r, sorry, i should have been more specific. more to the point of it would be how much do the baro and temp sensors affect the injection at higher altitudes and/or extreme temperatures? (if at all?) and does it make any improvement to performance in these conditions to find or build an area specific map?
 
G

·
Discussion Starter · #6 ·
Re: hot weather slow bike (entropy)

Thanks,
I understand the theory, and the lower air density also from being 2000ft above sea level, I was looking more to find out if there was anything that I could do to remedy the power loss...
 
G

·
Discussion Starter · #7 ·
Re: hot weather slow bike (RCLinc)

I run water and water wetter. I see temps 200 to 214 in dallas.
 
G

·
Discussion Starter · #8 ·
Re: hot weather slow bike (sherrc51)

hotter weather = less dense air = you need to lean the bike out, it's sluggish because it's too rich, when i lived in phoenix i hotwired my fan to be constant on, it's pretty easy, just ground the single wire that leads from the fan to the thermal switch in the radiator, it will keep the fan on anytime the key is on...

try using the buttons on the powercommander to lean out the mixture and see if it helps...
 
G

·
Discussion Starter · #9 ·
Fuel injection has the ability to optimize the air/fuel ratio as the enviroment changes. It does this by monitoring both air temperature and barometric pressure. The one issue that Honda EFI motorcycles have and perhaps some of the other manufactures as well has to do with the ECU enriching the air/fuel ratio as a function of engine temperature. This has been implemented in order to prevent premature detonation which it is more likeky at higher engine temparature. If you take an exhaust gas analizer you will noticed how the air/fuel mixture becomes richer and richer with increasing engine temperature. Many of the fuel maps developted for the Power Commander are done within "normal" (around 190 - 200F) engine operating temperatures. The maps work great as long as the engine temp remains close to this temp but as the temp increases the ECU enriches the mixture and you are no longer in the optimum range. The Power Commander has not the ability to compensate for this factor. There are ways to dissable the ECU from doing this but it requires making changes to the wiring and the one engine sensor.
I leave in the Phoenix area and have done a few trackdays when the air temperature is around 110F and normal operating engine temperature is around 230-240F for my RC.
LDH at RC51.org talks a little bit about this issue when talking about engine tunning with the Power Commander.
 
G

·
Discussion Starter · #10 ·
Re: hot weather slow bike (entropy)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by entropy »</TD></TR><TR><TD CLASS="quote">air effects performance --> hotter=less dense=less air.</TD></TR></TABLE>

Certainly true. But I've never owned a bike this sensitive to air temperature.

I rode last week when it was 59 degrees and it was a no doubt, obvious difference. I loved it, and couldn't stop grinning. The throttle response and power difference was incredible. Oh if the RC could be like that everyday.

Maybe I'll put it away and take it out again in September.
 
G

·
Discussion Starter · #11 ·
Re: (andres)

so, would it be feasable to run a hot weather map that was further leaned out than required if the bike were running at optimal engine temperature? I might see 200-210 on the temp when i'm riding home at midnight, but during the day, (117F here last week) not a chance. Obviously getting the engine temperature down would be the preferred method. KYA rads....?
man, did not have this issue in New York....did have winter though!
 
G

·
Discussion Starter · #12 ·
Re: (andres)

I just read the info at RC51.org you reffered to on the ecu richening at higher temps, it explains and answers a lot. Thanks.
 
G

·
Discussion Starter · #13 ·
Re: hot weather slow bike (RCLinc)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RCLinc »</TD></TR><TR><TD CLASS="quote">Now that the ambient temp has been firmly entrenched in the triple digits, my bike is accelerating dog slow, and the coolant (water/water wetter) regularly sees the 240's at anything below 60 mph. Anyone else living in the southwest have any luck or solutions? would it help with the higher altitude and higher temperature to remap, or is this just the way it is?
</TD></TR></TABLE> seems with all of the brilliance at honda,you'd think they could at least get the cooling on the rc(as well as the vfr800,superhawk,also side mounted rad)done right. lets face it,they run too hot! im guessing the reason for the fans being pullers instead of pushers is to keep as much heat as possible off of the rider.instead what they've created is a convection type oven.when your traveling down the road at lets say 75mph,the air is forced into the front,then its met by 2 fans trying to pull air(yes if my rc is showing 225 the fans are on and running)into the engine compartment,all of that air and no place to exit it! seems to me they would have made the fans pushers to exit the air inline with the flow of air already present.robs already flamed me on this one(just what you need,more air on your legs so you'll have something more to complain about)i still say all that is needed to make the rc51 run much cooler is a pair of fan blades that have the blades pitch reversed,thus making it a pusher,thus making it much cooler!if anyone knows a company that custom makes this type of fan blade(muzzy does but not for the rc)then please share the info....
 
G

·
Discussion Starter · #14 ·
"seems to me they would have made the fans pushers to exit the air inline with the flow of air already present.robs already flamed me on this one(just what you need,more air on your legs so you'll have something more to complain about)i still say all that is needed to make the rc51 run much cooler is a pair of fan blades that have the blades pitch reversed,thus making it a pusher,thus making it much cooler!"

The problem with that is the fact you would then be pushing hot air throught the rad instead of cool air. Also I believe the air pressure behind the rad where the fan is is most likely lower pressure while at speed than the air "outside" the bike, the fan would have to push against that. The net effect might actually be LESS air being moved throught the rad. (Caution, this theory may be full of #[email protected]% but that is what I surmise.)
 
G

·
Discussion Starter · #15 ·
Re: (RCPhil)

It's amazing how the same topics continue to emerged on this forum. It seems like people hibernate

LRLinc, all you have to do is pull the two pins out of the electrical connector at the fans and reverse them (reverse polarity) and reconnect. The fan will now blow from inside to outside and YES it makes a significant difference specially when moving with the fans running. Has been tested over and over again.

dadrc51, this is no longer a theory it has been tested and found to work.
 
G

·
Discussion Starter · #16 ·
Re: (andres)

Hibernate....work...wife...kid...it's all good.
regardless, i'll try tomorrow. Thing is, i generally shut off the fan completely at highway speeds, and turn it back on when speed is unachievable (stoplights) I have an adjustable thermostatic switch in place, ('00 and '02 radiators are not exactly alike!), so without a major radiator change, i'm not hopefull. Hot air is hot air. I was more interested in mapping changes to compensate, but it looks like honda took care of that for us. maybe carbs weren't so bad....
 
G

·
Discussion Starter · #17 ·
Re: (andres)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by andres »</TD></TR><TR><TD CLASS="quote">It's amazing how the same topics continue to emerged on this forum. It seems like people hibernate

LRLinc, all you have to do is pull the two pins out of the electrical connector at the fans and reverse them (reverse polarity) and reconnect. The fan will now blow from inside to outside and YES it makes a significant difference specially when moving with the fans running. Has been tested over and over again.

dadrc51, this is no longer a theory it has been tested and found to work.
</TD></TR></TABLE> actually i never said it was a theory
one problem though with switching the polarity,the pitch on the fans are made to work in one direction and not the other,thus the need for different blades. ive tried this change of direction with little change,meaning that it didnt really work.i was hoping with all of the knowledge on this board someone could point to a company that makes or could make a blade assy with a reversed pitch,i can deal with the extra heat on my legs,id just like the bike to run at a more conservative temp...cooler engine means more hp and lots more fun!!!
 
G

·
Discussion Starter · #18 ·
Re: (dadrc51)

Sorry dadrc51, I meant to direct my comment regarding the reverse fan theory to RCPhil.
Anyway, I have tested reversing the motion of the fans on '02 model several times in order to verify that it does bring the temperature down faster once the fans are active and moving at highway speeds. I did all my testing while living in PA where ambient temperatures are much lower compare to AZ.
Then again keep in mind that if the ambient temperature is way above 100F like it gets here in AZ, hot airflow will not make much difference at that point when it comes to cooling the engine. I've done a number of trackdays in AZ when the temperature was above 100F without the fans installed and running water wetter and 230-240F engine temp seem normal.

my
 
1 - 18 of 18 Posts
Top