IAT Relocation Kit

[rbabos]

Anybody know of a source for twin cams for this item? Have them for vrods but no search results for tc's.
Ron

[FSG]

For those interested in the VRod stuff check the Instruction Section

-J03017    VRSCA INTAKE AIR TEMPERATURE SENSOR RELOCATION KIT,   29541-03
-J03016    VRSCA INTAKE AIR TEMPERATURE SENSOR RELOCATION KIT,   29540-03
-J02673    VRSCA INTAKE AIR TEMPERATURE SENSOR RELOCATION KIT,   29434-01A

there is nothing for the TC's.

[rbabos]

Thanks for confirming no kits.
Ron

[glens]

Isn't your IAT part and parcel with the MAP?

What are  you trying to accomplish that you can't get done already with the tuning interface?

[rbabos]

Isn't your IAT part and parcel with the MAP?

What are  you trying to accomplish that you can't get done already with the tuning interface?

glens: IAT sensor is a seperate unit on the tb. I'm looking for a more stable tune . I'm picking up iat temps around 180F at times, which leans the afr out way too much, especially in traffic.  Besides, sticking it into a heat soaked tb is not where it should be in the first place. It should only be reading ambient inlet air. Logging shows this never to be the case, with it at best 40-50F over. If the sensor change was reduced the afr would be more stable too. Remember my post on crappy running when starting after sitting for a while. It turns out to be leaner than normal causing it to run this way until driven for a while to cool things down a bit. The iat heat soaks and when started the afr is leaner than normal. That's what the iat does, as in add or remove fuel depending on intake air temp but it shouldn't be influenced from hot air blasting the tb or cooking inside the tb when engine is shut down. Iat reloacation is also a performance upgrade in many other circles as well.
Ron

[glens]

ahem... Yeah, I know.

Don't you think air getting sucked into a 200+ degree manifold is going to heat up a bit over ambient, especially from where the ambient is it's getting sucked from?  Are the ECM's calculations incorrect with the temperatures it's getting from the IAT?

So you move the IAT and get it sending cooler signals.  The ECM will figure the fuel too high and it will be removed while closed-loop.  Then you'll be exactly where you are again right now.  Except where you're open-loop-only...

[hrdtail78]

That mode in other circles?  Is it to lie to the ECM?  When you can control the ECM you dont need to lie to it.

[rbabos]

ahem... Yeah, I know.

Don't you think air getting sucked into a 200+ degree manifold is going to heat up a bit over ambient, especially from where the ambient is it's getting sucked from?  Are the ECM's calculations incorrect with the temperatures it's getting from the IAT?

So you move the IAT and get it sending cooler signals.  The ECM will figure the fuel too high and it will be removed while closed-loop.  Then you'll be exactly where you are again right now.  Except where you're open-loop-only...

You just validated my reason for doing so. Areas that I must remain in open loop need to be more stable by eliminating faulse input from this sensor and closed loop areas will require less adjustment as a side benifit.
Ron

[BVHOG]

Buy an extra sensor and mount it in the A/C backing plate, then you can swap the plug back and forth and see what the difference is while data logging. I read a few years back in an AIM article about relocating the sensor and the author (DP I believe) claimed that the IAT sensor got hot and leaned out the mixture making things hotter and basically feeding off itself, like most AIM articles it came with very little hard data.

[rbabos]

Buy an extra sensor and mount it in the A/C backing plate, then you can swap the plug back and forth and see what the difference is while data logging. I read a few years back in an AIM article about relocating the sensor and the author (DP I believe) claimed that the IAT sensor got hot and leaned out the mixture making things hotter and basically feeding off itself, like most AIM articles it came with very little hard data.

This is exactly what I think I'm experiencing. While the when head temp increases some, extra fuel is added beyond normal engine heat. This is ok in my book. The fact that the iat pulls fuel at a higher rate than what the slight increase in head temp can add is not equalled out. While my testing is not hard data it goes like this. Start a cold engine an let it warm up. Throttle body is luke warm at this stage and it runs perfectly in all conditions. Drive as far as you want as long as the engine is being cooled normally. Get into city traffic and eventually the light load areas drivabilty start to exibit a lean condition. I know it's lean because I had to make these areas rich to make it run smooth. Get out of the city and drive at highway speeds for about 15 minutes the light load areas are once again running smoothly because the tb has cooled off.  If the iat was in the breather and not being heat soaked from the tb I'm quite sure this leaning would not occur to this extreme. I don't know exactly what % of fuel this sensor pulls with an increase in heat, but at 180F, Id be guessing it would be close to 10%
I mean, let's face it, the brain childs at HD could only have placed this sensor in the exhaust pipe to have a worse location for it.
Ron

[hrdtail78]

So what temps are being indicated while moving and what is it indicating after a ride when your at a light?

[rbabos]

So what temps are being indicated while moving and what is it indicating after a ride when your at a light?

About 120-140 on the road and this is likely lower on cooler days. All testing was done on 80-90 days. I've seen it as high as 180 on a heat soak after stopping for a smoke. In traffic it will sneak up to 180. It will follow the head temp. Throttle body and the elbow on the SE Heavy Breather are really hot at this point as well from radiant heat off of the front head or hot air from cooling blowing it in the general area. Once hot, it takes a long ride to bring it back to a cooler 120F.  Logging shows both head and iat temps matching prior to startup. I have a new iat coming and will relocate it to the back of the SE element and compare. If I can get through town and retain my light load lower rpm afrs with smooth running, and get better mixture during the first few minutes after a hot start, that should prove to point, at least to me.
Ron

[Rider57]

I experimented with this idea about 2 or 3 years ago.
It worked but was somewhat cumbersome.
I posted some info on another forum but cant remember where.
Basically, I left the OEM in place and added on into the air box.
Ran a little richer and smoother. Got rid of the stumble. Extending the harness and having it look neat was the only big issue, if you want to call it that.

[hotroadking]

should be able to get the HD connector for it when you get the sensor

Be interesting to see what the results are by moving it.  Wonder if it's placed
where it is in order to help meet EPA... Otherwise if it improved power
by being in the backing plate you'd think it would be there anyway..

[rbabos]

That mode in other circles?  Is it to lie to the ECM?  When you can control the ECM you dont need to lie to it.

For the hell of it let's look at this from a tuning standpoint. When a bike is tuned, what is the iat at when the calibation is done. Is the afr set when the iat is heat soaked or cooled some or is one area set when cool or another area set when the iat is hot? Does anybody actually look at what temp this sensor is running at when tuning? Would you get a much more exacting tune if the iat was located in an area that sees constant ambient air rather than the up and down temps it sees in the tb? Would this not also reduce the amount of adjustments needed by the ecm to maintain this tune? Something to think about, isn't it?
Ron

[glens]

I'd be inclined to think the Delphi engineers who designed this system know what's happening when and have accommodated it in the programming.  You likely could save yourself some time and expense by locating a datasheet from Delphi showing how the mounting surface temperature of the unit affects its readings.  If any appreciably at all...

[BVHOG]

That mode in other circles?  Is it to lie to the ECM?  When you can control the ECM you dont need to lie to it.

For the hell of it let's look at this from a tuning standpoint. When a bike is tuned, what is the iat at when the calibation is done. Is the afr set when the iat is heat soaked or cooled some or is one area set when cool or another area set when the iat is hot? Does anybody actually look at what temp this sensor is running at when tuning? Would you get a much more exacting tune if the iat was located in an area that sees constant ambient air rather than the up and down temps it sees in the tb? Would this not also reduce the amount of adjustments needed by the ecm to maintain this tune? Something to think about, isn't it?
Ron
[/quote
I have watched this on the real time data display while tuning and it has struck me at how  high it reads. Doesn't seem to correlate with the ambient air temp at all. I would assume in most conditions if the calibration was made with the high reading than it should stay consistent in all but the worst of operating conditons.

[FLTRI]

I'd be inclined to think the Delphi engineers who designed this system know what's happening when and have accommodated it in the programming.  You likely could save yourself some time and expense by locating a datasheet from Delphi showing how the mounting surface temperature of the unit affects its readings.  If any appreciably at all...

Also consider the IAT sensor is sensing the air temp the engine is seeing.....which is exactly what is required to maintain proper AFR.....it is a tuning issue.
Now when you lie to the ECM by telling the ECM it is seeing air temp cooler than reality, the entire system will react and maintain a richer than expected or wanted AFR.....an old trick we used BEFORE tuning devices and software was available. IME, no need to lie or trick the ECM when tuning adjustments are in fact, available.
JMHO,
Bob
PS - IAT is directly affected by the surrounding heat sources, such as cylinders so IAT can be as high as engine temp for a while until the bike has been ridden long enough to cool the intake tract down. The system knows how to handle it...if tuned properly.

[glens]

So you move the IAT and get it sending cooler signals.  The ECM will figure the fuel too high and it will be removed while closed-loop.  Then you'll be exactly where you are again right now.  Except where you're open-loop-only...

You just validated my reason for doing so. Areas that I must remain in open loop need to be more stable by eliminating faulse input from this sensor and closed loop areas will require less adjustment as a side benifit.

I differ with you on this, Ron.  First, you've not proven the sensor is providing false output.  Second, you've not proven the ECU is coming up with the wrong fueling while using this data.  Lastly, you don't know whether or how well-contained your "lower" open-loop area is.  What AFV factors have you eliminated from the equations, if any, and are they affecting only that area or is the effect further-reaching than you'd like if you knew what that effect was?

Post-lastly, I submit that the closed-loop corrections would become greater, not lesser.  Unless you v-tuned it the "new" way, in which case you'll be exactly where you are now, all over again.  Only this time the ECU programming will factor temperature changes incorrectly, probably.  But maybe that's just what you're looking for.

You've got something wrong with your build.  Some way, some shape, some form of some kind of wrongness; even if it''s only an unhappy combination of otherwise good parts.

[rbabos]

So you move the IAT and get it sending cooler signals.  The ECM will figure the fuel too high and it will be removed while closed-loop.  Then you'll be exactly where you are again right now.  Except where you're open-loop-only...

You just validated my reason for doing so. Areas that I must remain in open loop need to be more stable by eliminating faulse input from this sensor and closed loop areas will require less adjustment as a side benifit.

I differ with you on this, Ron.  First, you've not proven the sensor is providing false output.  Second, you've not proven the ECU is coming up with the wrong fueling while using this data.  Lastly, you don't know whether or how well-contained your "lower" open-loop area is.  What AFV factors have you eliminated from the equations, if any, and are they affecting only that area or is the effect further-reaching than you'd like if you knew what that effect was?

Post-lastly, I submit that the closed-loop corrections would become greater, not lesser.  Unless you v-tuned it the "new" way, in which case you'll be exactly where you are now, all over again.  Only this time the ECU programming will factor temperature changes incorrectly, probably.  But maybe that's just what you're looking for.

You've got something wrong with your build.  Some way, some shape, some form of some kind of wrongness; even if it''s only an unhappy combination of otherwise good parts.

Well, find me another sensor in the tb that makes the engine run like "Potty mouth" when it gets heat soaked and runs smooth until it does.  I'm happy with my testing so far and the observations I've made.
I'm sure the ecm will reset the afrs again or vtune it again.  What I'm trying to eliminate is starting a heat soaked iat, leaning my idle out on a hot start and keep me from leaning out in city traffic. Both of these conditions occur with me and I can't come up with a single reason why I would want either of these conditons. You are not allowed to insult my engine. Only I can call it fkg junk.
Ron

[FLTRI]

Ron,
Are you thinking the IAT is producing erroneous readings due to heat soaking?
My experience is the intake temperature really gets as hot as the engine as measured with my infrared temp gun that I had calibrated by the mfg. Raytek before I used it to measure the intake temp on the outside of the T/B and manifold as well as the inside T/B temps both with the engine off for less than 5 secs, then after it had heat soaked for 5 mins.
My findings pretty much back your data log readings. The intake actually gets that hot so why lie to the ECM?

Have you tried increasing the fuel in the warmup enrichment @ the applicable temps for your hot starts?
The enrichment lasts for quite a while, depending on the calibration used for base mapping.

Just a thought before you toss out the baby with the bath water.
Bob

[rbabos]

Ron,
Are you thinking the IAT is producing erroneous readings due to heat soaking?
My experience is the intake temperature really gets as hot as the engine as measured with my infrared temp gun that I had calibrated by the mfg. Raytek before I used it to measure the intake temp on the outside of the T/B and manifold as well as the inside T/B temps both with the engine off for less than 5 secs, then after it had heat soaked for 5 mins.
My findings pretty much back your data log readings. The intake actually gets that hot so why lie to the ECM?

Have you tried increasing the fuel in the warmup enrichment @ the applicable temps for your hot starts?
The enrichment lasts for quite a while, depending on the calibration used for base mapping.

Just a thought before you toss out the baby with the bath water.
Bob

Bob: I'll give that a shot and see how it behaves. It is a touch low at the moment.
Ron

[glens]

That's what the iat does, as in add or remove fuel depending on intake air temp...

I was just reviewing the thread before closing out the tab when I saw this and remembered I'd wanted to comment on it.  I believe it's stated rather like that a time or two subsequently in the thread by other folks, too.

The IAT sensor doesn't add or subtract fuel any more than an O2 sensor does, or than a TPS does, or than a CKP does.  They're only reference devices which the ECU uses to decide upon fuel quantities.  The sensors don't care what the ECU does.  They just report what they're seeing at the moment.

I'm not suggesting we use such tediously precise language as a lawyer might use, but it's pretty important to get the proper mental image across.  Don't you agree?

[Jamie Long]

That's what the iat does, as in add or remove fuel depending on intake air temp...

I was just reviewing the thread before closing out the tab when I saw this and remembered I'd wanted to comment on it.  I believe it's stated rather like that a time or two subsequently in the thread by other folks, too.

The IAT sensor doesn't add or subtract fuel any more than an O2 sensor does, or than a TPS does, or than a CKP does.  They're only reference devices which the ECU uses to decide upon fuel quantities.  The sensors don't care what the ECU does.  They just report what they're seeing at the moment.

I'm not suggesting we use such tediously precise language as a lawyer might use, but it's pretty important to get the proper mental image across.  Don't you agree?

Glens, you are exactly correct with this information. Sensors are simply a reference, the lookup tables determine how this information is used and applied as an end result

[1FSTRK]

For the hell of it let's look at this from a tuning standpoint. When a bike is tuned, what is the iat at when the calibation is done. Is the afr set when the iat is heat soaked or cooled some or is one area set when cool or another area set when the iat is hot? Does anybody actually look at what temp this sensor is running at when tuning? Would you get a much more exacting tune if the iat was located in an area that sees constant ambient air rather than the up and down temps it sees in the tb? Would this not also reduce the amount of adjustments needed by the ecm to maintain this tune? Something to think about, isn't it?
Ron


I think I follow what you’re saying and think you’re on the right track. Most new autos gather a temp reading from the mass airflow sensor as well as the iat in the manifold. Because we can add or subtract warm-up enrichment and the O2 will tune in the closed loop area then tuning the open loop base map to the area you’re having trouble with and letting the ecm tune the rest makes sense.
The only difference should be that with the way it is set up now you have the correct tune in open loop at normal riding temps and go slightly lean in traffic when the iat sees heat soak.
  With the relocation you should have correct tune in open loop when in traffic because the iat won’t heat soak as much and you might go slightly rich at normal riding temps.
You might loose a little fuel mileage around town if you have a lot of open loop cells but the bike should run cooler and smoother in traffic. Might also have to retune once to correct the closed areas for the new air temp readings and center the CLBs but once tuned it sounds like it would be better in any slow in town traffic. Please post how this works. If you have any luck I think I’ll give it a try.