VICS open earlier
- Thread starter Fade
- Start date
I bet if you checked the resistance of the solenoid and replaced it with a resistor the ECU wouldn't know the difference, then you could just use your original 'noid'. Just make sure you get a resistor that will handle the correct wattage. It would probably end up being a bit cheaper as well.
jersey_emt
Member
- :
- 04 MSM #1089
Fade said:
That would be my assumption. PCM sees 5250rpm, and sends power signal to solenoid.
I'm not sure what you mean. Yes the wires going to the solenoid are what powers it. I'm pretty sure the connector to the solenoid is simply two wires, signal and ground. When the ECU wants to open VICS(yes this is based on rpm), then it sends turns on the signal, powering the coil in the solenoid.
Disconnecting the solenoid connector completely would probably throw a cell, because I think the ECU checks if the circuit is complete.
But if you replace the solenoid with a resistor on the ECU side of the connector, I don't think the ECU has any way to tell the difference. Then on the solenoid side of the connector, you can attach your rpm switch.
Disconnecting the solenoid connector completely would probably throw a cell, because I think the ECU checks if the circuit is complete.
But if you replace the solenoid with a resistor on the ECU side of the connector, I don't think the ECU has any way to tell the difference. Then on the solenoid side of the connector, you can attach your rpm switch.
twilightprotege
Member
- :
- 2001 323 Astina SP20 (P5)
it will work. all you need is something like a VTEC controller and it'll be fine. just have the stock wires working on something else so the ecu thinks it is still working fine
Why do you want to change it? You're messing around with something Mazda engineers probably spent a week to figure out. If you modded your engine, and your torque/power curves are different than stock, then you might want to change the VICS opening point. But to do it properly, you need dyno time. You do a run with the VICS held open, then a run with the VICS held closed. You then plot both runs together, and where the curves meet is where you want the VICS to open.
If nobody has changed it, then how do we know it won't do any good? Trial and error.
Not like I can't put it back to the stock setting. I left it open to see what it was like. Low end suffered as everyone knows but at about 4000rpm it seemed to help. I may be able to tune it in better with my MPI.
Not like I can't put it back to the stock setting. I left it open to see what it was like. Low end suffered as everyone knows but at about 4000rpm it seemed to help. I may be able to tune it in better with my MPI.
You will gain a couple hp at peak, but the loss in low and midrange just isn't worth it. We had problems with my VICS changeover conflicting with my cam timing when I first installed my exhintake cam, so we disconnected the VICS to see if it smoothed it out. It did, and it gained a couple hp at peak. This graph shows you the amount you lose in the bottom and midrange. This shows the before/after my exhintake cam. With the cam, and the VICS open, I got way more at peak, but the loss in midrange and torque just isn't worth it, The second chart shows the cam tuned some more and with the VICS functional(as well as my original baseline. sorry it's so big). Next time I'm on the dyno, I'm going to do runs with the VICS held open, then again closed.
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I'm not sure where it opens on the FS, but on the BP it opens at 5300RPM. If it were to open at 3500, there would be a HUGE dip in power from from 3501RPM to 6000RPM where it would start to gain velocity again. And it's not just about the lost in velocity at 3500RPM, there are resonance issues too, because everything changes when the butterflies open.
