AX-22 HP runs ??

[stevieturbo]

What is required to plot a graph of rpm, vs estimated HP when making an acceleration run ?

Does the AX-22 just need a tacho input ? ( signal and ground ? )


And assuming the input parameters for weight/drag stayed the same, you used the same section of road etc.

Would the results of a graph of say a 4th gear 40-140mph run produce a reasonably repeatable HP graph ?

[Support]

The AX22 needs an rpm signal of 5-15 volts, which is normally just one wire.
The the AX22 should produce a reasonably accurate horsepower figure, provided the test environment is consistent.
It is worth noting that ambient conditions can have a measurable effect on rolling resistance, engine power output and aerodynamics hence also the measured horsepower figure, there is a compensation for pressure, temperature and humidity in the software which goes some way to eliminate these discrepancies but there will always be some errors.
For some further reading on horsepower measurements please see our Knowledge Base here: http://www.race-technology.com/wiki/ind ... asurements

[stevieturbo]

The AX22 needs an rpm signal of 5-15 volts, which is normally just one wire.
The the AX22 should produce a reasonably accurate horsepower figure, provided the test environment is consistent.
It is worth noting that ambient conditions can have a measurable effect on rolling resistance, engine power output and aerodynamics hence also the measured horsepower figure, there is a compensation for pressure, temperature and humidity in the software which goes some way to eliminate these discrepancies but there will always be some errors.
For some further reading on horsepower measurements please see our Knowledge Base here: http://www.race-technology.com/wiki/ind ... asurements

5-15v ??

I did try a few years ago connecting my tacho output to the AX-22, but never did get a rpm reading logged.

Obviously thats a pulsed earth signal though ??

How would I obtain a 5-15v signal in order to give the unit an rpm reading ?

( I do have a DTA-S80Pro CAN interface, and the Dash2. ) Although as yet, I cannot get the CAN interface to display the information I want reliably to the Dash,. so ended up just using the actual rpm trigger for the Dash2 instead )

As far as weather etc.

Im simply looking to do 4th gear pulls, same day, same time, same weather, whilst altering ignition timing.
I dont care what the actual numbers are, just whether any gains have been achieved

[Support]

The AX 22 can only accept a low level rpm input, so a signal from an ECU, hall effect sensor or from an injector.

The AX22 can detect a few horse power difference, provided you document all the ambient conditions and the environment is the same.
So it can be used to optimise ignition, I will how ever say that ideally the ignition should be optimised on a dyno, where you can monitor knock, head temperatures etc. So be very careful with that one.

[stevieturbo]

So the tacho output from the ecu should work ??

Dyno isnt an option for me. There are no suitable facilities here. There are some dynos, but my car wont be near them.

[Support]

The tacho output from an ECU should work indeed.

[stevieturbo]

I'll give it a try again..


Now where did I put that little orange plug for the back of the unit....2-3 years ago lol