I know I am at 100% throttle but overlay shows 50%

[llan981]

Harry,

At Watkins Glen on the straight and back straight, I know I must be at 100% throttle. I am using GoPoint BT1A on an Iphone Ios8.3 with HLP GP 19.07 but as you can see in the video, it seems I never hit 100% throttle. I am sure on both straights I am hitting the throttle hard. Solution?

https://youtu.be/xNi_N5YmrC0

[Harry]

Throttle values delivered by OBD should show value between 0 to 255 - which is mapped to 0 to 100%. In reality, throttle sensor deliver a smaller range, e.g. 10 to 123. LapTimer monitors this values. It starts with a fictive range of 10 to 60 and enlarges it whenever bigger or smaller values are received (and maps this range to 0 to 100 ...).

Now to what you observe: it seems your car is delivering a range even smaller than the starting range, e.g. 0 to 30. As 60 is set from the beginning (to not show completely wrong throttle values while not calibrated), you will never get 100%.

As a workaround, please try to use one of the gas pedal PIDs for throttle display. It can be selected in Expert Settings / OBD Tweaks. Try position D first.

Harry

[llan981]

is there a guide on advanced setting definitions? I will set to 'D" first but what does this value or other values do?

[Harry]

Please search Wikipedia for "OBD" and "PID". It gives you a list of all standardized PIDs. Which pedal PID to select depend on your car.

Harry

[llan981]

Harry,

Any thoughts to order of precedence I should try if "D" still does not fix the issue?

Thanks you in advance of a track weekend.

[gplracerx]

One of GoPoint's apps, BT1 maybe, will show you all the throttle outputs, and lots of other data besides, while you're sitting in the car with the engine running. Pick one that works and try that with HLT.

[Harry]

In Sensor List, select the GoPoint Bt1 and press Info. This will show you all PIDs available for your car - including throttle.

Harry

[gplracerx]

It's the GoPoint app. Knowing what's available is necessary, but not sufficient. The advantage of the GoPoint app is that it shows you a measure of the response range. If you turn on scanning and scroll down to the different throttle PID's, touch the arrow to the right and you can see a running graph from 0-100%, which I assume is 0-255 digital. Blip the throttle and see where it sits at idle and how far up it goes. Throttle PID E on my Mustang, for example, only goes to 40%. Default (0111), B and D go to ~90%. And zero isn't 0 for several, it's more like 15%. Commanded throttle actuator, 014C, which isn't available to HLT, unfortunately, goes 0-100%. You can see the effect that the ac compressor cycling has on that, for example.

Even though HLT corrects for the actual range, the resolution suffers for a PID that doesn't give you the full range from 0-255. Once again, it would be nice if HLT stored the measured range for an individual car based on the VIN.

[Harry]

Didn't know the GoPoint app shows the ranges, very interesting!