Nistune Forums

i am interested if there is a simple way to force the ECU to read the knock timing map from a push button ! ground the knock wire or something similar ?

i need this for setup the launch control . at this moment i am at 4500rpm when l/c is active and i make 0.16 bar of boost standing at the line. logging the timing in this situation i get about 40deg. if lowering the timing to 5deg i can get even 0.5bar of boost standing. but if i alter the regular timing map in that area in real world driving condition i hit it and the car doesn't act normal.

so i was thinking about switching to knock timing map modified for the launch bigger boost ...i don't need the knock map because i have headcans to monitor the knock and doing 2.1bar(30psi) boost without a ping !

the car si skyline r33 rb25det with z32 ecu

thanks and any help is greatly welcome !

Interesting!

Fudging the voltage on the knock sensor will result in it flaggging a knock sensor fault code. Which you definitely don't want. It'll jump to knock maps but also do a heap of other bad things that you do not want.

But seeing you're running a Z32 ECU you may have another option. They have separate maps for top gear. So just wire up a switch so that it'll access the top gear maps ad then you can have a separate LC map.

I'm not sure if there are any other conditions that need to be met before they access the top gear maps (like speed above xxx etc.) but hopefully it'll just switch to the top gear maps as soon as it sees a switch input.

I'm assuming that's how it works. If they sense top gear purely on speed input then you're sunk.

Eric will know. He's replaced his own brain with a Z32 ECU!

PL

thanks pl

first of all from my understanding to read the high gear fuel map you need to play with one parameter. in my case this is set to 0 , because i have the z32 ecu and the rb25 transmission and from this reason the stock value doesn't work in my case and i need to play with it. in the future i want to work on this subject too , but i need to find that value to "crack" the gears between the 2nd and 3rd because i want to map 1st and 2nd different for better launching.

back to topic: the problem is that in high gear there is only fuel map which indeed if going very rich in that area is helping to boost more , but not as much as the timing . so from my testing timing modulation is the most effect . i know that knock sensor is sending some pulsing signal back to the ecu and if that signal is faster or has higher spikes it triggers the knock map...something like that. so i am thinking if sending a fixed volt value to the ecu , will this trigger the knock map ?

That wont work. I've had troubles triggering the knock sensor on Z32 ECU so far and it uses pulse counts etc to determine when to use those maps (also pulling out timing etc in the process)