TPS range too small

[chasmon]

My TPS only gives me a range of around 130 I have adjusted it to give me different readings at closed throttle but I still only get a range of 56-186 which isn't great for tuning low throttle openings in Alpha-N mode. I'm GSXR TB's so the first few degrees of opening change the flow dramatically. My concern is that I'm not getting the resolution here.

IS this range low compared to what others have experienced?

Is there a way of increasing this or even making it non linear as I oly really need the resolution low down?

Thanks for any thoughts.

C

[loren]

Mine is 178-865.

But, yours doesn't sound unusable. You've got 1% resolution.

As long as you set the Alpha-N TPS table to give you the resolution you need at low TPS and low RPM, I think it should work.

Haven't been able to get anyone to confirm, but I believe the TPS table interpolates date just like the fuel table does. So, if you set it up like I did, with your lowest bin at 10% (or if your throttle is REALLY touchy, maybe even 3-5%), but make that bin represent a fairly high kPa number... something about the middle of your range, that first 10% can account for 4-5 bins of resolution. The first 2% would be in the bottom kPa bin, and on up to 10% actually being the specified kPa.

Keep tinkering with it. I've found Alpha-N to be a wonderful thing when configured properly.

[chasmon]

I'm guessing you're talking about an MSII installation right as in MSI you just put the raw values of TPS on the Y axis of the table...

My concern is that I can't get the resolution I'd like at low openings as a small change low down makes a big difference and the MS won't be seeing it... For instance a small change in throttle opening but the TPS might not actually see a change as the resolution isn't high enough on the ADC. Ideally I'd like to use a bigger portion of the 0-254 range.

[Heribert]

An electronic solution which involves analog stuff is possible.

Use a simple opamp in noninverting mode and run it off of the 5 V supply in the MS

Put in a couple of resistors to get the gain right and another resistor to get the amplifier output close to
0,2 V at closed throttle. This way you will have control and adjustability and can use the entire 0/5V// 0-255
capability of the MS CPU

Certainly not elegant but with 8 bits of resolution it is worthwhile trying to use as many as possible


pm me with an email if you need further info, analog signal conditioning stuff on the MS forums
may be a bit rankling


Heribert

[loren]

You're talking about the Alpha-N TPS map, not the TPS itself. I've been playing with this recently.

Yes you can set the table up so that at low RPM you have more resolution at small throttle openings.

I set mine so that the first 10% of throttle gives "60 kPa". With my VE table set linlearly from 10-120 kPa, that effectively gives me SIX bins (10, 20, 30, 40, 50 and 60 kPa) of resolution for the first 10% of throttle.

On the higher end, I use fewer bins for small throttle openings and more in the mid-range and wide-open area.

[chasmon]

You're talking about the Alpha-N TPS map, not the TPS itself. I've been playing with this recently.

Yes you can set the table up so that at low RPM you have more resolution at small throttle openings.

I set mine so that the first 10% of throttle gives "60 kPa". With my VE table set linlearly from 10-120 kPa, that effectively gives me SIX bins (10, 20, 30, 40, 50 and 60 kPa) of resolution for the first 10% of throttle.

On the higher end, I use fewer bins for small throttle openings and more in the mid-range and wide-open area.

I'm guessing you are talking about some functionality thats in the MSII code but not MSI...

It is the ADC value of the TPS signal I'm concerned about ie the ADC range should be 0-255 (8 bits) but I'm only covering 130 out of the range ie about half the potential resolution I could have.

[chasmon]

An electronic solution which involves analog stuff is possible.

Use a simple opamp in noninverting mode and run it off of the 5 V supply in the MS

Put in a couple of resistors to get the gain right and another resistor to get the amplifier output close to
0,2 V at closed throttle. This way you will have control and adjustability and can use the entire 0/5V// 0-255
capability of the MS CPU

Certainly not elegant but with 8 bits of resolution it is worthwhile trying to use as many as possible


pm me with an email if you need further info, analog signal conditioning stuff on the MS forums
may be a bit rankling


Heribert

I may well need to pick your brains at some point but I follow your solutiona nd think I shouldbe able to implement it on the proto area in my MS... Just need to change where the TPS signal come in to and construct the op am circuit.

Many thanks I'll follow up in here how I get on.

Cheers