2011 Mazdaspeed 3 | HFS-4 Install

[Richard L]

I am curious to know, what is the limiting factor of this engine producing higher power?

[skeurton]

Originally Posted by Richard L

I am curious to know, what is the limiting factor of this engine producing higher power?

Fueling and engine internals. There is someone out there with a custom build making over 700hp.

[paveltol]

I'd like to do something with part throttle knock. On 91 fuel I have 1-2 knock retard according to the Dashhawk gauge. It is very common issue with these engines, when moving in city traffic or cruising on highway. It can be false knock - the ECU may be adjusting the timing. But it can be real knock as well.
Have you thought of any solutions for that? Is there any way to trigger the system when the ECU sees knock at loads when IDC is not reached? Richard, chime in please!

[Richard L]

Do you have an output from dashhawk, it may be possible to use it to active the HFS. I am sure I can find a way to do it.

[paveltol]

There is a miniUSB slot on Dashhawk - it was made to connect Dashhawk to PC. This device is no longer produced.
However, there is another powerful tuning&diagnostic tool - AccessPort by Cobb tuning.
Both these devices read signals from oem OBD2 port.

Can't it be easier wiring up to knock sensor?

[Richard L]

knock sensor needs to be processed differently with an algorithm that suits a particular engine. Ideally includes infos such as ignition timing, load and knock spectrum. On top of all that, sharp cut-off filters has to be employed or noise will dominate.

Assuming the dashawk possesses all those abilities, how does it translate it visually? It may be easier to splice into the final stage of knock signal internally. Provided they exists in some analogue form.

Porting a usb requires more work and if it unlikely we will do it an an one-off. If you haver a circuitry of the dashawh or let me open it up to take a closer look.

[paveltol]

Probably I can source and send you a used Dashhawk.
I am not sure Dashhawk can help with finding a clean Knock Retard signal - it displays multiple parameters at the same time. Also user can adjust the quantity and type of these parameters displayed.

The only thing I can think of now is as follows: Dashhawk allows you to adjust visual and sound alerts for the parameters displayed, so you can probably connect to sound alert. But the alert frequency and volume are not progressive with the growfth of Knock Retard. And the user will have to set only one alert for KR so that the system would not trigger because of any other alert.

[Richard L]

The sound alert is a good output to use, tell me more about it? Does it change pitch of just blips faster.

[paveltol]

Neither of these - with the KR increase it just keeps on blinking and ticking(sound) with the visual increase of KR value.
KR normally happens at part throttle when the Engine Coolant Temp reach 99+C and Boost Air Temp reach 70+C.

[Richard L]

It is probably a single/train of pulses send to a piezo sounder. It might work. The HFS4 has a secondary PWM input that may be used to spray based on the pulse. Need some modification.