Gear Depended boost

[AVP]

Hi,

does anyone has any idea of the values of the speed sensor for an Audi S2/RS2? i know the kms for each gear but unless i calibrate the speed sensor properly im not going to be able to use this feature!

Thanks!

[AVP]

http://www.vems.hu/wiki/index.php?page=MembersPage/MarcellGal/PowerAndTraction/SpeedoMeter

according to this post by Marcel i have calculated that the speed sensor would need to have 115hz @ 100km/h for my car judging by the circumference of the wheels i use.

So how do i tackle the minimum period time now?

[GintsK]

AVP, first you have to sort out why you have not any signal. Then calibration is quite easy if you have GPS.

[AVP]

no i thought i mentioned to you that i do have a signal.

wheel speed dial is operative and changes on different values i put on the speed sensor. Obviously different values made the sensor think i am moving although being stationary etc.

But so far, i have been using different values on the speed sensor area and i was getting different reaction.

What i wasnt registering was fuel consuption, but this has also been fluctuating in the log and i assume it also has to do with a wrong speed sensor signal

Marcel did give me an answer.

What do you mean excactly by using the GPS? My wheel circumference is identical to stock at the moment so speedo calculations are not far off. I can use a GPS, no problem but the issue here is not the GPS reading to match the wheel speed, but the fact that this does not correspond to different Hz values. So that is when the minimum period time comes in. Is that what i have to modify with the GPS? is that what you mean?

[GintsK]

You had "signal" also on stillstanding vehicle, right? I mean your log file about we discussed.
If so - it is failure.  Speed value must be strongly proportional to engine speed in given gear.  Speed changes in log file should be even until wheels aren't blocked.
It was not so in your file. Or now it is solved?

[AVP]

on the log file i had something like 255hz/10km and 16320us

that could not possibly be right in calculating any speed. Also once i started changing those values, i noticed that there was a delay in reaction at some times, and an overaction at others depending on HZ input. However because i had no idea what to use for minimum time period, it was left to 16320us. BUT i did see a change in wheel speed measurement on tha wheel speed gauge which sort of corresponded to actual speed at times. Also when stopped it did go to zero and at other times it delayed going to zero.

all these reactions to wheel speed, dont they show that the sensor is there, and it needs calibration? ECU was sent to me with a proper speed sensor installed.

[AVP]

Right, here are the results of my tests today.

anything between 112-114hz works and it is pretty close to the GPS wheel speed.

Problem is that whenever the car accelerates (mostly) the gauge needle on the wheel speedometer jumps up then down before it settles to the proper speed. If speed is maintained for a few moments, then it is ok.

I tried different minimum period times as well as both and rising edge and didnt have any good effect. most of the times it was better with period time close to 400-1600us.