what to do with the air pressure sensor?

[ArtD]

Hey guys, hope everyone had a happy T-day! And if your not in the USA, that you found an excuse to party anyway Ok, if one wanted to install pod type/K&N air filters on a 2004 V11, where does the Air pressure sensor go? What do you do with it? Btw, this is NOT starting a "why would you want to do that" thread, lets just treat it as a hypothetical Thanks

[richard100t]

If its what I think it is, just zip tie it out of the way of anything too hot.

[Skeeve]

Hey guys, hope everyone had a happy T-day! And if your not in the USA, that you found an excuse to party anyway Ok, if one wanted to install pod type/K&N air filters on a 2004 V11, where does the Air pressure sensor go? What do you do with it? Btw, this is NOT starting a "why would you want to do that" thread, lets just treat it as a hypothetical Thanks

 

This comes up periodically; I think there's a sticky on it somewhere? Anyway, one solution has been to imprison it in on old 35mm plastic film can (suitably ventilated, to keep the majority of weather & grime & cr@p off the sensor) and just zip tie it out of harms way.

[ArtD]

If its what I think it is, just zip tie it out of the way of anything too hot.

 

 

Its that little sender thingie with a couple of wires mounted in the air filter box, right? What does it do? If I tie it out of the way in an area of somewhat calm air, will it still do whatever it is supposed to do?

[Ryland3210]

Its that little sender thingie with a couple of wires mounted in the air filter box, right? What does it do? If I tie it out of the way in an area of somewhat calm air, will it still do whatever it is supposed to do?

 

It is intended to sense the temperature of the air entering the engine, so somewhere within the airbox would be ideal. To the extent it monitors temperature different from that, it will affect mixture ratio governed by the ECU.

[coz1100]

I was running pods on my V11 for about a year. Nice sound out of them and as long as I kept up on keeping them clean I never had a problem with water or gunk getting into the motor. As for the air temp sensor I first just zip tied it up to the frame. After some time thinking about it though ( the sensor looks a bit fragil) I opted for 35mm film case. After market exhuast, PCIII, dynoed. Bike ran nice......... till some *&^% slamed on his brakes. Then things started to go down hill.

 

 

 

Ciao

Z

[Ryland3210]

Why the hell would you want to put K&N pods on your bike? You're sure to suck water inside that way. I wonder how well the injectors will like that? Those K&N filters don't work worth a dang, anyway. Sorry, couldn't resist.

 

I think there is both an air pressure sensor and ambient air temp sensor, but I don't know where each of them are. Seems like the air temp sensor used to be on the frame near the front. If the barometric sensor is in the airbox, would it be calibrated for intake air pressure while the engine is running? If memory serves it's at the top RH side of the airbox. It probably stays fairly clean in there, since only filtered air enters. You definitely want/need it because otherwise you'll lose any altitude mixture compensation.

 

The injectors would not be affected, since they inject at relatively high pressure.

A little water in the engine is OK as well. Quite a lot of water is used in systems to deliberately inject water to boost power. It cools the intake charge, thereby increasing its density, and acts as an antiknock aid as well. Military piston engined airplanes in WWII used it to boost power by 20-25% for heavy load takeoffs.

 

The best place to monitor absolute air pressure is inside the airbox. That way, it can compensate for filter element pressure drop. It's not only a matter of keeping it clean. However, I'm not sure where it is actually located. It may even be located in the ECU.

[Guest ratchethack]

FWIW, there is an ambient air pressure reference in the FI. It's the open vacuum line stub facing forward on the fuel pressure regulator under the RHS of the fuel tank. Many (including myself) have experimented with it by connecting it to intake vacuum thru the charcoal canister/balance reference barbs, with no discernable effect on performance wotsoever.

[docc]

My understanding is that the barometric (atmospheric) air pressure sensor is in the ECU. The sensor mounted to the airbox is for temperature.

 

I just had my airbox off to install a power cable for the Garmin Zumo and service all the connectors under the tank. Those side covers are such a pain the %$^ to get back on, I couldn't stop thinking about using pods instead.

[nose2wind]

It is a air temp sensor.

 

I run pods and like them alot.

I wouldn't change them for a performance increase.

For looks and ease of maint. they are a plus.

 

I located the temp sensor to the frame and then moved it later

due to possible heat saturation in the summer.

 

I put it inside a pvc cap you buy for irigation pipe and moved it up

behind the headlight with zip ties.

 

MPH replaced it once as it was bad. He said there is a set %

it alters the mixture. It is not that much if it were not working

you might hardley notice.

 

Ok

 

d

[ArtD]

It is a air temp sensor.

 

I run pods and like them alot.

I wouldn't change them for a performance increase.

For looks and ease of maint. they are a plus.

 

I located the temp sensor to the frame and then moved it later

due to possible heat saturation in the summer.

 

I put it inside a pvc cap you buy for irigation pipe and moved it up

behind the headlight with zip ties.

 

MPH replaced it once as it was bad. He said there is a set %

it alters the mixture. It is not that much if it were not working

you might hardley notice.

 

Ok

 

d

 

Thanks!! I'm doing all sorts of mods, etc at this moment, hopefully this will be one of the + things. If it does not run right, and that will be with Todd's computer tuning software used to set the TPS , and the brass fitting for the temp sensor installed with thermal grease, then I can always put the box back on, and drill the holes in the back of it as per several past threads. I know that I'm violating the axiom of "don't change more than one thing at a time", but when I pulled the box off, there was raw fuel in the inlets, the mileage sucks, and I'm fouling Iridium plugs. This is with the factory Ti cans and the racebox control unit. My thoughts are that getting more air in can't hurt. I figure that I will not have done anything that can't be "undone"

[Dan M]

FWIW, there is an ambient air pressure reference in the FI. It's the open vacuum line stub facing forward on the fuel pressure regulator under the RHS of the fuel tank. Many (including myself) have experimented with it by connecting it to intake manifold vacuum thru the charcoal canister/balance reference barbs, with no discernable effect on performance wotsoever.

 

The vacuum operated regulator is used to increase fuel pressure upon throttle opening. Of course it must be attached to manifold vacuum to operate so why it is installed on our machines but unused is a bit of a mystery to me. They typically reduce fuel pressure by 5 or so psi when 10 or more inches of vacuum is applied (closed throttle). I experimented with it as well and found that with it hooked up to manifold vacuum the CO% with closed throttle is reduced somewhat which would make for very slightly more efficient running but I too could not see a performance difference. It theoretically could be made to make a difference with extensive mapping because the instantaneous rise in fuel pressure as the throttle is opened will have sort of an accelerator pump effect; and when the throttle is closed the lower pressure will make for leaner running to save a slight amount of fuel. The down side is when in operation this type of regulator fails with some regularity. Leaving it static will certainly reduce the likely hood of the rubber leaking and flooding the engine. I now have mine open to atmosphere as it came from the factory.

 

So far as the intake air temperature sensor is concerned it should be mounted in an area that will be the same approximate temperature as the air being drawn into the throttle bodies. Don't let it lay in the valley where things are considerably warmer.

[Ryland3210]

So far as the intake air temperature sensor is concerned it should be mounted in an area that will be the same approximate temperature as the air being drawn into the throttle bodies. Don't let it lay in the valley where things are considerably warmer.

 

I take it you also agree with docc that the absolute pressure sensor is in the ECU?

And that the temperature sensor should also not be mounted in the windstream where it is coupled to the ambient air instead of the somewhat warmer air being drawn into the throttle bodies?

[Hardy Hawaii]

Aloha, I was gonna do the same thing but one of my good friends told me not to do it... Curtis from Harpers mentioned the abnoxious noise... a guy did a dyno test... 17 more horsepower with a stock air box versus after market cross over and K+N slip on. I ended up buying a K+N filter cartrigde for the stock box... only 40 something $.... runs good.... it's so funny to see MG enthusiast squeeze a few more horse power.... I am one,... got a love it,.... good luck Hardy

[v11cafe]

My manual says air temp sensor, so I agree with people who already mentioned that.

I have not installed pods on my bike, but a friend with V11 sport /2000, who loves KN pods gave the following solution

after many trials.

After installing the pods , the V11 didn"t run Ok, maybe the sensor gave the ECU wrong data...

He wrapped the air temp sensor completely in plastic tape, and then with the engine running opened small holes with a needle,

until the idle was OK.I remember that after 3-4 holes ,the idle was almost good

Then tied it up somewhere close to the frame.

 

I don't say this is the best solution, but at least it"s easy enough to give it a try...