Hotrodding the GS

Thank you JJ for the idea. But I don´t have any contacts in the States.

I believe postage costs to Europe fur such a device will be around 15$ to 25$ (with and without insurance), because it is not an heavy gadjet.

I buy books from US amazon and ebay, and books are heavier.

And I have paypal.

<table border="0" cellpadding="5" width="650"><tr><td>I have been waiting for that question "Does the location of the air temperature sensor make a difference?" The short answer is, no, it doesn't.

When the bike is moving, the sensor always sees the ambient air temperature.

It's easy to imagine that putting the sensor up near the steering head gives it a supply of cool air. Though just because it's easy to imagine doesn't make it true. I admit I wanted it to be true.

Seems like a reasonable question. I mean, seeing as how some of the competitor products have the sensor mounted up near the steering head/instrument cluster. Of course I had to find out.

It was a mild evening last August. The plan was to make a high speed run on the freeway, then take some temp measurements while the bike was idling. Ambient temperature was 70°F, and since it was evening there would be no influence from solar radiant heating.

I set up for the test and took off on a run up the 405 freeway from Long Beach to UCLA/Westwood. The 28 miles of freeway in 19 minutes, so the motor was good and warm.

I pulled off the fwy and quickly pulled into a waiting garage. The door was shut to eliminate any breeze, and the bike was left idling on the centerstand while we started logging measurements.

In preparation for the experiment, I had relocated the original Intake Air Temp sensor from the airbox to the area in front of the steering head.

First thing after pulling into the garage the bike is put on the centerstand, then pull off the saddle and connect to a waiting GS-911 and laptop to take temp readings. No cooling fan was used.

The setup process took no more than 30 seconds. The ambient temp in the garage was 70°F but already the IAT reading was 86°F. Remember, this was the ECU's reading from the relocated IAT sensor, mounted in front of the steering head.

The motor idled along happily with the headers turning red while the ECU gave these temp readings via the GS-911.

&#8200;INTAKE
AIR TEMP&#8200; OIL TEMP
&#8200;&#8200;&#8200;86.0&#8200;&#8200;&#8200; 228.2
&#8200;&#8200;&#8200;87.8&#8200;&#8200;&#8200; 230.0
&#8200;&#8200;&#8200;91.4&#8200;&#8200;&#8200; 230.0
&#8200;&#8200;&#8200;93.2&#8200;&#8200;&#8200; 231.8
&#8200;&#8200;&#8200;93.2&#8200;&#8200;&#8200; 233.6
&#8200;&#8200;&#8200;95.0&#8200;&#8200;&#8200; 235.4
&#8200;&#8200;&#8200;96.8&#8200;&#8200;&#8200; 237.2
&#8200;&#8200;&#8200;98.6&#8200;&#8200;&#8200; 239.0
&#8200;&#8200;&#8200;98.6&#8200;&#8200;&#8200; 242.6
&#8200;&#8200;100.4&#8200;&#8200;&#8200; 242.6
&#8200;&#8200;100.4&#8200;&#8200;&#8200; 244.4
&#8200;&#8200;102.2&#8200;&#8200;&#8200; 244.4
&#8200;&#8200;102.2&#8200;&#8200;&#8200; 248.0
&#8200;&#8200;104.0&#8200;&#8200;&#8200; 248.0
&#8200;&#8200;104.0&#8200;&#8200;&#8200; 249.8
&#8200;&#8200;105.8&#8200;&#8200;&#8200; 249.8
&#8200;&#8200;107.6&#8200;&#8200;&#8200; 253.4

I shut it down at that point, figuring 250 degrees was hot enough for the oil.

So there it is. Ambient air temp was 70°, and after a few minutes the relocated sensor was reading 38 degrees higher at 107.6°

For comparison, I did this experiment 2 more times. Once with the IAT sensor in the factory location in the airbox. And once more with the sensor resting on top of the airbox, with the saddle in place.

Result: The ECU sees the same temperature regardless where the sensor is mounted.

Wait, that's not entirely true. With the sensor placed on a table 5 feet away, the ECU always reads the same intake temperature. (I actually did that with an extension wire on the sensor.)

Conclusions: No matter where you put the sensor, there's no way to escape the heat when you come to a stop.

And once the bike starts moving, the hot air that collects when stopped is immediately replaced by moving ambient air.

When the bike is moving, the sensor always sees the ambient air temperature.

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Lucky for us we don't ride at a stop!

Will a wet air sensor (more efficient cooling) affect how it runs?

........there has to be a way around this

I am very interested in your product however the timing is all wrong for me as we just had a baby girl, the question is will you be doing a second batch of these or is this a one time only offer:huh.
Thanks

See post # 559

JJ

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Thanks, I forgot to mention. I somehow thought it was obvious.

When the bike is moving, the sensor always sees the ambient air temperature.

No matter where the sensor is, it always gets ambient air temp. No matter if it's under the seat, behind the fuel tank panel, inside the airbox, or up in front of the steering head. It's all the same temp when the bike is moving.

Once the bike starts moving, the hot air that collects when stopped is immediately replaced by moving ambient air.

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If it's under water, yes.



Hey JD, did you order one of these yet?

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It's a good 'universal enclosure'.

I don't care if you see what's inside, it just needs to be sealed, and held in place. In this case, epoxy is just the ticket.

I guess I could have used a NEMA 4X enclosure. But it would be 12 times the size, and cost much more.

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The sensor may see ambient air temps immediatly, but the ecu certainly dooes not. Have you had the opportunity to measure the AIT temp to ECU temp reading delay? Have you done this in hot weather at a stop light, or going over a mountain pass?

There are compelling reasons why your competitors are using external sensors.

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I get how compelling beliefs are...

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Why do you make light of my my questions? Are you afraid of dialog?

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You'll notice the greatest performance increase where you actually use the engine most.

You may twist the throttle a little more because it's more fun, so you might use a little more gas when doing that.

It won't change your mileage during cruise.

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That was dialog. The temperature difference thing is only a belief system. And I conducted tests to prove it, and that included proving it to myself since I was believing it too. Are you afraid of facts?


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It is apparent to me that the patience required to delve into this project may be exceeded by the patience required to put up with the "dialog" that has occurred here at times.

It's more patience than I have, and I have the patience of a Saint.

No matter what my wife says.

Good on you...

What if you're riding in a buttload of rain, and it's consistently wet?

And no, I haven't. Few other priorities above it on the "to buy" list.

Is this the test you're referring to? In your garage?

Let me add a thought or two to this.
One way to look at what these modifications are doing is they will shift the way the fuel injection system operates DURING ACCELERATION. These mods change the EFI's response from its 'stock' efficiency mode to a power mode of operation.

And what I have observed when this is achieved is, the fuel economy can actually increase because you don't need to use as much throttle to get the same rate of acceleration.

This may seem counterintuitive but when the engine makes power as optimally as it is capable, then the overall efficiency ESPECIALLY DURING ACCELERATION is improved.

And it should be noted that most of the time when we are running down the road (ie. touring) in a steady state condition, (aka closed loop operation) and not accelerating nor decelerating to any great extent these mods will have no effect.

Now if you get overly enthusiastic with the go fast handle, then yes your mileage will be reduced, but that is true with or without these mods in place. Only with the mods, the fun factor is considerably enhanced.

As for the 'butt dyno' effect. Where you'll notice it is in the directness and immediacy of the response of the engine to throttle inputs. A good deal of vagueness and delay will be replaced with an immediate torque reaction from the engine.

JJ

Actually if anything, having that remote sensor probe encased in metal will slow down the response. What with the added mass of the metal that would need to be cooled down after getting hot while at a stop light. So I'm not sure if that is a benefit or a hindrance at least in terms of the immediacy of response to ambient temp changes.

JJ