278 replies to this topic

[Catteeclan]

I've got open exhausts to and I like the popping. 

 

Just contacted Unifilter about the filter kit. Can't find it on any other site so asked about postage from Australia. 

Edited by Catteeclan, 16 May 2016 - 07:18 pm.

[Kelpie]

Are there no concerns over running those lovely engines too lean?

[celticbiker]

Must admit I have been wondering about that but the lambda sensor should sort that out.

Not sure about at higher revs though.

Bought an air box and going to give it a try but as I have no sensor I'll have to get it dyno'd to make sure the power commander has a good map for the increase in air.

[fixitsan]

Are there no concerns over running those lovely engines too lean?

 
Not really.
 
The CO adjustment affects revs below 3000, at throttle openings of less than about 10%...light load cruising and overrun
 
In the mid range and cruising range the O2/lambda sensor keeps the mixture where it needs to be.
 
Under heavy load, - this is where it gets tricky, because the ECU selects a map based on a combination of throttle position sensor  output and intake manifold pressure (throttle body sensor)....but to be honest, mixture ratios under heavy load are programmed to be so rich that you probably couldn't lean it out .Like carbs used to have an acceleration fuel pump - the 900 ECU enrichens the AFR under heavy load to enable good acceleration.
 
I was thinking of trying the addition of a 820 Ohm resistor in series with the air temperature sensor, just to force the ECU to enrichen the mixture, if it became evident there was a problem (it will assume an air temperature a few degrees lower than actual)




And at roughly this point in the conversation.... 850 owners with carbs go 'Awwwwwww', because dont have fuel injection

Edited by fixitsan, 16 May 2016 - 11:29 pm.

[frits44]

 
Not really.
 
The CO adjustment affects revs below 3000, at throttle openings of less than about 10%...light load cruising and overrun
 
In the mid range and cruising range the O2/lambda sensor keeps the mixture where it needs to be.
 
Under heavy load, - this is where it gets tricky, because the ECU selects a map based on a combination of throttle position sensor  output and intake manifold pressure (throttle body sensor)....but to be honest, mixture ratios under heavy load are programmed to be so rich that you probably couldn't lean it out .Like carbs used to have an acceleration fuel pump - the 900 ECU enrichens the AFR under heavy load to enable good acceleration.
 
I was thinking of trying the addition of a 820 Ohm resistor in series with the air temperature sensor, just to force the ECU to enrichen the mixture, if it became evident there was a problem (it will assume an air temperature a few degrees lower than actual)




And at roughly this point in the conversation.... 850 owners with carbs go 'Awwwwwww', because dont have fuel injection

 

Good morning fixitsan,

 

Your story is the truth.

 

CO only works under 3000 rpm , after that ECU takes over with the sensors.

 

About the 820 Ohm resistor you want too try, it is too low in value.

 

You need a resistance of  5K Ohm, 0,25 watt, 5 volt on bikes before 2007 because of the richer ECU, 

 

and 6 K Ohm, 0,25 watt, 5 volt on bikes after 2007 because of the leaner ECU.

 

A mechanic and tuner  told me this he uses it too on the race track for hobby racing. ( cheap trick too fool the ECU )

 

It gives you a better acceleration, a little bit more torque and horse power.

 

Too try it start with a potentiometer and use a multimeter, that is the way I did it.

 

You will notice the difference, I used it before not any more.

 

My machine is running very nice now with my modifications.

 

Thanks for the advice with the AIS, I took it of completely.

 

Have a nice day,

 

Greetings, Frits from holland

[fixitsan]

Thanks for the advice Frits, but I did measure it myself

 

At about 15 Celsius the sensor measured 4.7k. Left in the sun and warming to 28 degrees the resistance dropped to 3.8k. A difference in resistance therefore of 900 Ohms for 13 degrees Celsius temperature difference.

 

At lower temperatures, due to the NTC curve, an increase of 820 Ohms should be the equivalent of between 8 to 12 Celsius lower

 

Adding 5k to the existing 4.7k would more than double the resitance at 15 Celsius - I bet the ECU thinks the temperature is well below freezing !

[frits44]

Are there no concerns over running those lovely engines too lean?

 

Good morning,

 

The sensors will correct the lean on fuel or air.

 

Nothing can go wrong, in my case I am trying too make my machine better because of all the restrictions that are on the bike

 

because the law wants it that way.

 

In my country the law is not so bad, we can do a lot before we get a ticked from the police.

 

Greetings, Frits from Holland

[fixitsan]

Your value of 6k additional resistance is too much for my bike, I only need to adjust the AFR by a small amount, so adding only a small amount of resistance is the answer

 

 

 

EDIT - Have you added the resitor in series with the temperature sensor - OR - have you added the resistor in place of the temperature sensor ? (the recommendation is to replace the sensor with the resistor) ?

Edited by fixitsan, 17 May 2016 - 09:03 am.

[frits44]

Thanks for the advice Frits, but I did measure it myself

 

At about 15 Celsius the sensor measured 4.7k. Left in the sun and warming to 28 degrees the resistance dropped to 3.8k. A difference in resistance therefore of 900 Ohms for 13 degrees Celsius temperature difference.

 

At lower temperatures, due to the NTC curve, an increase of 820 Ohms should be the equivalent of between 8 to 12 Celsius lower

 

Adding 5k to the existing 4.7k would more than double the resitance at 15 Celsius - I bet the ECU thinks the temperature is well below freezing !

I think a have an other sensor??????

 

Because with 10 celsius I measured  3.5 K ohm and with minus 20 celsius  I measured 8.5 K Ohm.

 

There are different brands of  sensors in  air box of a TDM 900.

 

Greetings, Frits from holland

Your value of 6k additional resistance is too much for my bike, I only need to adjust the AFR by a small amount, so adding only a small amount of resistance is the answer

 

Oke I get it.

[fixitsan]

Here's the results of somene's very accurate tests.....different bike, but a temperature sensor which has the same characteristics as ours does, and an ECU which is trying to do exactly what ours does

 

http://www.vulcangad...nce-fueladd.xls

 

 

You can see from that spreadsheet how a different resistance value affects the AFR differently based on temperature, IE it is a non-linear change

 

I know that my bike is unlikely to see an air temp of more than 20 Celsius, so I only need to focus at the lower end of the temperature scale

 

(Extracted from the spreadsheet)

[attachment=8058:rgraph.gif]

 

Two specific examples below...

Example 1. Ambient temperature is 10 deg.C, engine inlet is 20 deg.C. The sensor/ECU is reading 2560 Ohms, air pressure 0.06813 lb/ft3. Added 500 Ohms - the ECU is now reading 3060 Ohms, corresponds to 15.4 deg.C = air pressure 0.06925 lb/ft3. Air pressure increase is 1.7% the ECU adds 1.7% more fuel.

 

Example 2. Ambient temperature is 30 deg.C, engine inlet is 40 deg.C. The sensor/ECU is reading 1210 Ohms, air pressure 0.06245 lb/ft3. Added 500 Ohms - the ECU is now reading 1710 Ohms, corresponds to 30.4 deg.C = air pressure 0.06530 lb/ft3. Air pressure increase is 4.5%, the ECU adds 4.5% more fuel.

 

 

I can see that adding 820 Ohms is going to give me a mildly richer mixture up to 20 degrees, and quite a bit richer beyond that.

 

Perhaps I only need a 470Ohm resistor, or a 680 Ohm resistor instead.... just a small tweak is needed. 6k would be massive !

[frits44]

fixitsan,

 

Do not forget that the plastic material of your air box holds on to heat 

 

The plastic becomes very hot  around the place were the A.I.T sensor is located .( engine heat )

 

So isolate the bottom of the air box with aluminum thin plate , it will be cooler.

 

I just did a test ride, and looked in my display for errors and I notice that the out temperature is 44 celsius. Diag code number 05.

 

With slow drive it becomes even hotter. 

 

The sensor takes over the head from the plastic air box.

 

Test it do a  test ride and look at your Diag code number 05.

 

Greetings, Frits from holland

[fixitsan]

Yes I'll look at it.

For information purpose, do you have a 6k resistor in series with the sensor....or have you disconnected the sensor and inserted a 6k resistor in it's place.


Also, any temperature measurement must be made with the bike being ridden, receiving eexternal cooling air....and at 3000rpm getting over 20 litres of cold fresh air per second through the airbox ....do you see what i mean ?

Edited by fixitsan, 17 May 2016 - 04:47 pm.

[frits44]

Yes I'll look at it.

For information purpose, do you have a 6k resistor in series with the sensor....or have you disconnected the sensor and inserted a 6k resistor in it's place.


Also, any temperature measurement must be made with the bike being ridden, receiving eexternal cooling air....and at 3000rpm getting over 20 litres of cold fresh air per second through the airbox ....do you see what i mean ?

 

fixitsan, I see what you mean

 

I did not disconnect the sensor, I just cut the brown/white wire and placed the resistance between it

 

Brown/white is the signal wire. Do not use the black bleu wire just the brown/white wire.

 

I also did this: on top of the oil tank there are a lot of wires it is a mess. I took some tire ribs  and clean it little bit.

 

so the air comes free in and not over  all those wires , to the air inlet of the air box.

 

I hope you understand what I mean.

 

Greetings, Frits

I do not use the resistance any more but you new that

[fixitsan]

Ok Frits thanks for that explanation

[Jole]

Hi all ,

 

I must say that I was not really happy with my TDM at low revs and speeds too . I did not play with CO settings much (added + 4 on each cylinder) , but I disconnected the wire for Air flap solenoid .

I solved my problems with low speed riding by replacing front sprocket .I put 15 teeth sprocket forward.

[frits44]

Hi all ,

 

I must say that I was not really happy with my TDM at low revs and speeds too . I did not play with CO settings much (added + 4 on each cylinder) , but I disconnected the wire for Air flap solenoid .

I solved my problems with low speed riding by replacing front sprocket .I put 15 teeth sprocket forward.

 

Jole try next time this,

 

Do a test ride without the cover of your air box, you will than now what I mean.

 

Tape your air filter.

 

You can drive now in low rpm in every gear you want.

 

Simple test and it is free.

 

After the test you put the cover back. ( cover air box modification )

 

Greetings, Frits from Holland

[Jole]

I 'll try it after this riding season Thnx . TDM is serviced and ready,side cases mounted , so no more jobs for this summer . Last year I did a trip to Slovenia & Austria and sometimes was very annoying to drive on curvy roads / passes . I had a feeling that TDM was dead under 4000 rpm, so very often I was forced to use first gear . I hope that now TDM will do the same job in 2nd gear . I am planning to visit Transalpina & Transfagarasan in Romania so low revs torque is something I will need.

 

Edited by Jole, 22 May 2016 - 02:46 pm.

[fixitsan]

You can see from this table, that below 4000rpm the timing is retarded considerably compared to above 3500-4000rpm

 

The values across the top are the throttle opening %

 

Top left corner shows the timing very advanced for starting (normal)

 

But what is clear is that between 2500 - 4000 there is a huge change in ignition timing, in gears 1-4

 

 

Apologies for low quality, it is a copy of someone else's screenshot

 

[attachment=8080:900timing.png]

 

 

[frits44]

I 'll try it after this riding season Thnx . TDM is serviced and ready,side cases mounted , so no more jobs for this summer . Last year I did a trip to Slovenia & Austria and sometimes was very annoying to drive on curvy roads / passes . I had a feeling that TDM was dead under 4000 rpm, so very often I was forced to use first gear . I hope that now TDM will do the same job in 2nd gear . I am planning to visit Transalpina & Transfagarasan in Romania so low revs torque is something I will need.

 

 

Jole, I had the same problems and I solved it with help from this site.

 

Here are same pics you can use if you want too.

 

http://s1175.photobu...iypeei.png.html

 

Have a nice holyday.

 

greetings, Frits from holland

You can see from this table, that below 4000rpm the timing is retarded considerably compared to above 3500-4000rpm

 

The values across the top are the throttle opening %

 

Top left corner shows the timing very advanced for starting (normal)

 

But what is clear is that between 2500 - 4000 there is a huge change in ignition timing, in gears 1-4

 

 

Apologies for low quality, it is a copy of someone else's screenshot

 

900timing.png

 

 

 

 

fixitsan,

 

Did you measure your IAT sensor already ??

 

This is what I found.

 

http://www.apriliafo...ake-temp-sensor

 

Greetings, Frits 

[fixitsan]

I don't see the point to moving it Frits....what if the results are not how you like after moving it....you need to move it a little bit more, and so on. Resistors can do that job quite well. I think the sensor is in a near optimum position, but then again at the moment I am running with two long snorkels, so the air isn't moving over the sensor as much as if the snorkel next to it was an original shorter one.

 

Anyway, the timing diagram I posted, 10 degrees of static timing at low revs - I cannot think of another engine I have seen which runs such retarded ignition values. by 1200rpm most are over 15 degrees, some are nearly at 20. This is why I feel that advancing the timing is a step in the right direction