| Author | Message | ||
     Mountainstorm |
http://www.badweatherbikers.com/buell/messages/290 431/557540.html?1271957725 I found 11F above ambient from the IAT in the airbox and 3F above ambient from the IAT in the snorkel inlet. This is at 45+ mph with the inner cover in place. Bottom line is relocating the IAT to the airbox may make it "read correct" but it will also read a higher air temp and that will make less power. Just a heads up before you drill a hole and wish you hadn't. | ||
| Fresnobuell |
I think it's safe to say if you spend most of your time at speed, you really shouldn't worry about the IAT as it will be close. For those doing city driving, could it be that the airbox is actually warmer than the the radiator heat blown at the snorkel? | ||
| Mountainstorm |
I live in rural VA so my idea of a traffic jam is three pick up trucks at the BoJangles' take out window. As much as I love road testing  I refuse to find city traffic and get stuck in it for science  (Message edited by MountainStorm on April 22, 2010) | ||
| Fresnobuell |
PS-3 degrees over AT at the snorkel at speed seems pretty close to what I have noticed over time. | ||
| Captain_america |
Fingerless Captain Types! Mountain, you misunderstood the reason for me relocating the sensor it seems.... Kevin_Stevens said it correctly... I am NOT trying to fool the ECU, I am trying to make it accurately see the correct temp of the air being ingested into the motor. I think that the location at the snorkel reads too hot when not moving and too cool while moving. Air passes by the IAT sensor at the snorkel while moving but does NOT necessarily go into the intake or motor. Example: Stock... we know the radiators blow hot air towards the intake. This is reflected by the stock IAT location. With my mod this is not show by the IAT because the motor is not actually ingesting all of that hot air, some yes, all... no I think the air box in it entirety heats soaks slightly which is shown by my mod which shows what the motor is taking in. Whatever temp air happens to be by the stock location is show and is what the ECU thinks is going in but is not true. | ||
| Fresnobuell |
WELL, it stands to reason if the sensor in the airbox is reading higher (correctly or incorrectly) than the same sensor by the snorkel and the ECM thins out the fuel as temps get warmer, then you will be reducing fueling. Isn't it already lean per the EPA? Isn't the goal to richen the mixture? Yes, you could be 100% right about the temperature being more accurate with the sensor being inside the airbox, but if the resulting temperature leans out the mixture more, what's the point again? | ||
| Captain_america |
Well it seem as though different bikes read differently.... My IAT always read extremely hot no matter if i was sitting still or going 100mph. That is why I moved my sensor, regardless if it reads a little warmer than ambient, its still a hell of a lot cooler than when it was in the stock loc. In Mountainstorm's case, his read accurately all the time it seems, so there wasn't really a reason for movement of his? | ||
| Freezerburn840 |
I agree with Captain on this havent got around to doing mine yet. But 80 degrees outside for instance my bike is at 185 degrees inside and the fans kick on and now the IAT reads 120 degrees now because of the false hot air for cooling the bike. I think that will effect the ECU to some degree. | ||
| Fresnobuell |
Freezer, that might be a true statement while stopped. However, I think there's some initial proof that at speed the airbox will read higher than the snorkel inlet. | ||
| Mountainstorm |
I think I'll drill a hole in an ice-cube to slip over the sensor. I figure the cube won't melt for at least 20 minutes in this weather. Think of the power gains! Plus free water injection. Or I could pack the intake with dry ice...hmmm maybe all that CO2 would be a bad thing. | ||
| Captain_america |
Mountain, save the effort dude! just run the bike with the sensor unplugged and it will read minimum temp which is usually -30 degrees F | ||
| Mountainstorm |
REALLY? That's going to kill my whole industry of IAT accessories  Dammit man. | ||
| Ratsmc |
I am starting to think that the issue with the IAT sensor reading high may be particular to warmer climates. | ||
| Fresnobuell |
I don't think so. I think it has everything to do with clean air hitting it from forward movement of the bike. | ||
| Freezerburn840 |
I kid you not when moving at freeway speeds its off like Captain says. Maybe there is a way to mount it under the headlight and above the front wheel somewhere away from the hot air generated from the fans. To ratsmc. Me and Captain experience the same climate. I ride in the morning at 5:30am and then 4:00 p.m. in the afternoon The sensor does better on accuracy in the morning but it is still off just not as much as the afternoon time. I know when summer really hits here in California the dry heat we will hit the high 90s and low 100's. It will throw the IAT way out of wack. | ||
| Fresnobuell |
Well, I live in toasty Central California and I see fairly accurate temps at speed. That being said I have never been one to pay much attention to the AT reading. I have always been more attentive to the CT temperature. Gee remember when both were on the SAME cluster screen?!?! I wonder how much heat radiating from the searing black roads affects the AT in the heat of a summer day? | ||
| Freezerburn840 |
That might have something to do with it as well Fresno just about to post that or maybe my IAT is just faulty. I just know its off at a stop and while moving anywhere from 15 to 30 degrees higher. I know it definitely increases and its at its worse when the fans kick on. (Message edited by freezerburn840 on April 22, 2010) | ||
| Sportster_mann |
Before moving the sensor why not fit something like this into the airbox - http://cgi.ebay.co.uk/DIGITAL-AQUARIUM-THERMOMETER -ALARM-Vivarium-Incubator_W0QQitemZ280486816259QQc mdZViewItemQQptZUK_Pet_Supplies_Fish?hash=item414e 512a03 it has a separate temperature probe so the readout can be mounted near the IC and the two temperatures can be seen and compared. (Message edited by sportster_mann on April 22, 2010) | ||
| Ratsmc |
Fresnobuell, it has very little to do with clean air hitting the sensor. Mine reads wrong (+15) over the entire 2 hour ride to Tucson when I am doing 85MPH the whole way. | ||
| Fresnobuell |
Fresnobuell, it has very little to do with clean air hitting the sensor. Mine reads wrong (+15) over the entire 2 hour ride to Tucson when I am doing 85MPH the whole way. Then I guess the question you have to ask youself is the airbox cooler or warmer than +15 degrees? I bet warmer. | ||
| Ratsmc |
Wow. I am having a hard time. It doesn't appear that anyone actually read Captain's topic and my following responses. To state with absolute clarity: Before the mod - IAT sensor ALWAYS showed +15-30 higher than actual airtemp. After the mod - IAT sensor ALWAYS shows less than +4 degrees over actual airtemp. Does that help? | ||
| Fresnobuell |
Wow. That makes little sense. Especially after mountainstorm found the exact opposite. Do you have a theory as to why this huge change is occuring? | ||
| Captain_america |
Go Jerry! | ||
| Mountainstorm |
I just took a ride to see the IAT temps in the airbox with the inner cover off. It was about 3-5F cooler than with the cover on, which I would say is because of the gap around the outer cover allowing fresh air in. But it still read higher than the Digital Aquarium Thermometer sensor I have tucked in the fairing. I tested this in a few hours with an inexpensive temp probe you can get at any pet shop or online. Rather than do the typical internet dog and pony show anyone that doubts my report or wants to verify it or whatever should just buy one of the lil dinguses and stick it wherever they like. In fact buy a half dozen digital thermometers and stick them all over the bike...what the heck. If I had thought Captain America's IAT mod was a bad thing I sure as hell would not have drilled a hole in my airbox and snipped the IAT off the harness. But I also have to test things for myself. For me the factory location is fine. So I just spent the past few minutes undoing my modifications and putting the sensor and harness back to stock. I stuck a lab-grade black rubber cork in the hole I drilled, snapped the inner cover back in place and called it a night. If it improves your ride do it, if it doesn't all you have to do is undo your work and move on. It's not a life or death event. | ||
| Dannybuell |
If you know that the IAT sensor signal has the ECM richening the fuel with cooler weather why not make the darn thing think it's on the North Pole? | ||
| Mountainstorm |
I think anything too far one side or the other of reality is a bad thing. As Rat and Capn have said they performed the mod to correct what they saw as an error on the intake temp. If you don't see an error leave well enough alone. And more interestingly Lampo posts that IAT won't make any difference in power (most of the time) since the 02 sensors are all the ECU pays attention to in closed loop. I can't verify that information but he seemed to know stuff we apparently don't. So even if you see high temps for the IAT it apparently does not matter. | ||
| Fdl3 |
Has anyone considered the possibility of IAT sensor variances between bikes? Possibly even a faulty IAT? It seems one would want to verify a good, working IAT before modding? How much does a new IAT sensor cost? | ||
| Fresnobuell |
Having quite a bit of riding experience in HOT weather, I really think there is something to the radiant heat coming from the road. That's maybe why the hot weather guys are experiencing such a high reading--even at speed. Or then it could be a faulty sensor, but then the reading inside the airbox would be wrong too? | ||
| Mountainstorm |
Maybe it's because the bikes are born in Wisconsin Bad Weather Bikes don't like perfect sunny days. Just do what Froggy does and only ride when it's awful weather. | ||
| Freezerburn840 |
Fresno I think that is part of the equation. I would still want it more accurate. In the stock location there is too many variables screwing up the reading by 15 degrees or more. (Message edited by freezerburn840 on April 23, 2010) |
