This might be a stupid question but I searched and did not see anyone post about it. After reading, it is apparent that the Zeitronix is considered a quality failsafe for their meth kit. My question: would it be possible to use the stock ecu to act as a failsafe in the same way? Would it be possible to have a unused pin on the ECU trigger a solenoid to cut boost based on a set of conditions? If there are enough unused pins would it be possible to input a wideband AFR reading, use the jdm map sensor for boost, and then the other parameters already monitored by the ECU. So basically all you would need is two unused pins (AFR and trigger for solenoid) and some programming? This might be far fetched but is it possible? Thanks

 

Bez has done the closest thing to this out there. I think he is using the output for the EVAP solenoid to control his meth kit. I am not sure what he has in the way of a failsafe.
Check out aktivematrix.com - look at posts by BEZ - basically this site is the cutting edge of ECU work, so whatever you want to know you can read about there.


For the most part it is doable, but maybe not yet. It is a lot of work and a lot of coding. Also this issue is how fast the ECU can deal with everything as it does not have the most powerful processor.

 

Thanks for the information, i'll look into what he has done so far.

Does anyone else think this is a feasible idea? It would make meth kits safer and cheaper not having to buy a zietronix.

 

I'm working on tephra's patch which will limit boost to 19psi if knocking - rom is complete, mechanical portion all ready in effect, will flash today and try it out.

Is not incorporated into methanol system, but maybe it's better keeping it separate or redundant

 

Could this be used as an adequate meth failsafe by itself? Possibly if it is bundled with the Aquamist DDS-3. How does the ECU go about limiting the boost? GM solenoid?

 

Why 19lbs?? Can't we get it so the ECU can WG boost on high knock count

 

I am guessing that the 19psi would be adjustable, so it could be tailored to specific setups.

 

you can never really cut the boost. your always mechanically limited to the spring tension of the wastegate. if its a stock wastegate, the boost will drop to 11psi. but some people with meth have aftermarket wastegates, that will only drop down to 19psi.

 

The minimum boost is mechanically set at the wastgate pressure, however you are not limited to that. Couldn't you just set a lower duty cycle for the fail safe to use? So it would be less than your normal boost but not as low as 11 psi if you are one the stock wastegate.

 

right, that can be done.

 

19 isn't low enough though....


Most people with meth switch systems will have it turn on at 10-15 You would need to have the boost set lower than that maybe to wastegate and have the kits turn on after that. That way the car sees the lower "stockish" portion of the map and gets rid of the risk...

Itll definetly be a step ahead of the snow kit since it would be in the flash versus another part that could possibly fail.


Keep us updated


Cheers!

 

On my setup I was going to have the meth come on at or a little above wastegate spring pressure. This is on a 35r with external wastegate.

So in case the meth does fail it would revert to the spring pressure which the car would be tuned for.

Does this sound like a plausible plan?

 

The patch I got from tephra works like a charm, I logged the differences. I also have logs of my WM failsafe system working as well, which seems to work more abruptly. I haven't had a chance to log both systems working at same time since I would need both knock and failure of spray but I would guess it would be a great degree of low boost
Even though I can set it to failsafe to 15 psi as a default, it will cost me about a peak normal boost of 25 psi, where I run 28 psi.

19 psi is all the failsafe I need without spray - the load is 200% compared to 300%, airflow is 1300hz at redline compared to 1850hz. Furthermore this is a second safety feature on the car not as a backup, but to work at same time if need be

Nevertheless, with unnecessary amounts of timing, there would be very little room for a failsafe boost pressure

 

Is this a patch or a rom swap? I swapped roms for the "FLASH CEL ON KNOCK" thing and would like to add this functionallity but don't want to loose the previous hacks in the process.

 

It's just the patch but modified somewhat so the IC relay DE-ENERGIZES (instead of energizes) when knock. For me this patch vents boost when knocking due to the configuration and modification of my diverter valve.

In order to get the patch to do the same for someone else you need to rig the following mechanical portions:

1. Use a stock nylon diverter valve and drill a port through the inner chamber on manifold side of diaghram
2. Place a 3 way, two position solenoid (I used and extra FP solenoid) in line.
3. Tap that side into the highest pressure source on charge (turbo outlet is about 5 psi higher than plenum)
4. Tap the top diaghram where it normally is (vac source, plenum).
5. Wire the solenoid into IC relay controlled motor output
6. Set IC relay parameters to energize at 2 volts TPS always
7. Now the flash will undue the energize if knock happens

Fairly simple but DV holds solid if TPS over 2 volts (holds better than the rs valve I used), drives like OEM while under 2 volts, and most important, vents boost at knock