mscdman

Im am really hoping you s2000 guys/gals can help me out. Can you tell me how VTEC works from an ECU standpoint? It is my assumption that the ECU reads the RPM from the RPM sensor wire. When it hits the ECU's programmed level for VTEC operation, the ECU tells VTEC to "start" Is this correct?

Now, if this is correct how does the greddy e-mange allow the user to change the VTEC level? Please help.

Wesmaster

Any piggyback that can change VTEC engagement just sends the signal to the VTEC solenoid to go ahead and do it's thing (I'd get technical but I'd get it slightly wrong) at a given RPM. It doesn't actually tell the ECU to change the VTEC engagement, it just sends the signal to the solenoid. This is where the VTEC fuel fix, a feature on most piggybacks that can control VTEC, comes in. Since the ECU won't know to modify the map it's running on if you lower VTEC, you need to modify the fuel in the area where your sending a signal to the solenoid but th ECU is still on the non-VTEC map. I believe that you must add fuel in that area, but I don't remember since with the turbo it's better to raise than lower VTEC.

For a VTEC reference visit http://auto.howstuffworks.com/question229.htm

mscdman

so the e-manage just sends a singal to the vtec solenoid to begin then?

mscdman

by the way when you talk abotu piggy backs sendding a dinal to the VTEC solenoid - is it a voltage? is so is it constant and what is the voltage?

Wesmaster

[QUOTE]Originally posted by mscdman
[B]by the way when you talk abotu piggy backs sendding a dinal to the VTEC solenoid - is it a voltage?

mscdman

becuase I want to use the VTEC control on the greddy emanage on my car (not a honda) to control the powering of a nitrous solenoid (kinda like an RPM window switch)

RazorV3

yeah the vtec solenoid is responsible for engaging vtec, its that gray thing in your engine bay that looks like a camera film cynlinder thingy near the valve cover.

AusS2000

I'd hazard a guess that it's 12V.

You should be able to trigger it and monitor it with a multimeter.