[robsch]

The dashboard on the 2007+ FZ6's will display air temperature (reset button toggles between coolant temp and air temp). The air temp sensor is inside the air filter housing, as I understand. It displays the correct ambient temperature when the bike is cold, but as the engine warms up, the heat from the engine warms up the filter housing and what is displayed can be 10-15 degrees higher than ambient air temp.

I was wondering if this sensor & reading is used as an input into the fuel injection computer, or if they just chose a sub-optimal place to mount the sensor. I'm thinking it's probably the former, but if not, it would be nice to relocate the sensor to some place not affected by engine heat, and actually display the ambient air temp. This would be particularly useful in the winter months, when I'd like to know how close to freezing it really is.

Anyone know?

 

[RJN2112]

The same 'feature' is available for the previous generation wiht more button flipping..... it's the intake air temp, which is needed for the FI mapping. If the intake temp goes up by 10+ degrees as the engine warms at idle, I wonder what it does when the bike is in motion? I'd expect the change to be a lot less dramatic when there is air circulating around the bike......

 

[04Fizzer]

The same 'feature' is available for the previous generation wiht more button flipping..... it's the intake air temp, which is needed for the FI mapping. If the intake temp goes up by 10+ degrees as the engine warms at idle, I wonder what it does when the bike is in motion? I'd expect the change to be a lot less dramatic when there is air circulating around the bike......

Once in motion, the intake temp is within about 5 degrees of ambient, but that's because new air is being pulled in. It's the sitting out in the sun, or idling, that will cause a pretty big temp jump in the air box.

 

[rennsport]

The same 'feature' is available for the previous generation wiht more button flipping..... it's the intake air temp, which is needed for the FI mapping. If the intake temp goes up by 10+ degrees as the engine warms at idle, I wonder what it does when the bike is in motion? I'd expect the change to be a lot less dramatic when there is air circulating around the bike......

So what does the engine management do with this information?

The pre 07 bikes run in open loop mode. This is a limited system.

The later 07 models have an O2 sensor and run in a closed loop mode. So any changes made to the mixture, are based on the O2 sensor.

 

[04Fizzer]

So what does the engine management do with this information?

The pre 07 bikes run in open loop mode. This is a limited system.

The later 07 models have an O2 sensor and run in a closed loop mode. So any changes made to the mixture, are based on the O2 sensor.

Cold air requires more fuel because it's more dense. You don't need a closed-loop system to adjust for that.

 

[rennsport]

Cold air requires more fuel because it's more dense. You don't need a closed-loop system to adjust for that.

As I understand open loop mode, it just dumps the max amount of fuel, all the time. That is how it works on my Miata. If the engine goes over 4000 rpm, it is open loop time, and the FI just squirts the max amount in. So much for controlling pollution...

 

[RJN2112]

Open loop simply means there is no feed back to fine tune the pre set mix...... there is still 3D mapping for air density, engine temp, RPM, and load. The amount of fuel injected also relates to the TPS, and how hard the rider yanked on the wires.... rate of change as well as position.

Closed loop adds the O2 sensor in the exhaust to ensure the charge is consuming all of the available oxygen. (That strikes me as odd, given the air injection into the exhaust on the CA models..... )

A carbureator is an example of an open loop system; but it does a worse job adjusting for altitude than any FI system.... which is analagous to air temp.

I'd think the sensor being used by the FI that is also giving us the intake air temp is a hot wire anemometer -- in auto terms a mass airflow sensor. You hang a sensor in the air stream that changes resistance with temp, and pump a calibrated current through it. The sensor is part of a regulated voltage circuit. As air flow cools the sensor it's resistance changes, which requires a change in current to maintain the voltage. That current is 'mapped' to equal a specific air density. The density is affected by altitude, temp, humidity -- doesn't matter to the engine which, the only factor that is relevant is how much fuel the avialable air can 'carry'.

 

[RJN2112]

Once in motion, the intake temp is within about 5 degrees of ambient, but that's because new air is being pulled in. It's the sitting out in the sun, or idling, that will cause a pretty big temp jump in the air box.

'stagnant' air, then. That would be pretty easy to goof up the FI with, making an over rich mixture at idle.... It has struck me in the past that the FZ intake is in a pretty lousy spot. Doesn't seem to be a big issue though, only at idle.

An intercooler would change that, but there doesn't seem to be any room for all the plumbing.

 

[04Fizzer]

'stagnant' air, then. That would be pretty easy to goof up the FI with, making an over rich mixture at idle.... It has struck me in the past that the FZ intake is in a pretty lousy spot. Doesn't seem to be a big issue though, only at idle.

An intercooler would change that, but there doesn't seem to be any room for all the plumbing.

An intercooler is relatively pointless without some compressed air (turbo/supercharger).

 

[robsch]

Once in motion, the intake temp is within about 5 degrees of ambient, but that's because new air is being pulled in. It's the sitting out in the sun, or idling, that will cause a pretty big temp jump in the air box.

Yesterday evening, it was about 55 degrees out, and with the coolant temp at 164, the air temp gauge read 63. This summer, when running around the mountains and giving the engine a chance to get up to around 200 degrees, the air gauge would read 97 degrees on an 80 degree day, while still in motion.

It sounds like this is different from others' experiece -- I'll have the sensor checked out the next time I take my bike in, since it's still under warranty.

 

[rc5695]

Mine will read in the 40's while riding on those balmy 20 degree F mornings in the winter. The engine temp must have a HUGE affect on the air in the airbox I guess...

I'm just noticing that my 2bro nets me much worse gas mileage than the stock exhaust in the colder temps... Still way better than my car or truck though

 

[RJN2112]

So is there any way to direct cooler air to the intake?

Considering it's right above the radiator, on top of the head, adjacent to the exhaust header...... doesn't seem like it could be in much worse of a spot......