Heres my question, if you have a Vtec motor like say a B16, D16z6, H22, can you operate vtec on their corresponding NONVTEC ECUS (LS/PR4, D15, H23) with just a VAFC? IE, if you dont have a VTEC ecu can you make the NON vtec ecu activate Vtec with just a VAFC. I say no because a VAFC is just a piggyback correct, doesnt it have to have the program, signal to modify from the ECU in the first place? In other words , you can modify vtec engagement, but you cant creat it if the ECU never has it to begin with right??

 

i think the vtec lead out will turn vtec on.. but will vtec still operate with out the pressure sensor hooked up?

 

No, it won't work. I was considering trying this at one point.

The problem lies in that the AFC is just a piggyback; it only alters the signals going into the ECU., and the ECU still uses its stock maps.

When you run the AFC on the non-vtec ECU, it will get VTEC to kick in, but it will not have a map that ranges into the VTEC's RPM's; after you get to the non-vtec redline, there's no map to read from.

Also, even though VTEC will be engaged for a little bit, it will not have the VTEC's timing maps, which means you will be making a LOT less power while in VTEC.

There's no cheap way around it; get a VTEC ECU.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VtecKiDD &raquo;</TD></TR><TR><TD CLASS="quote">Heres my question, if you have a Vtec motor like say a B16, D16z6, H22, can you operate vtec on their corresponding NONVTEC ECUS (LS/PR4, D15, H23) with just a VAFC? IE, if you dont have a VTEC ecu can you make the NON vtec ecu activate Vtec with just a VAFC. I say no because a VAFC is just a piggyback correct, doesnt it have to have the program, signal to modify from the ECU in the first place? In other words , you can modify vtec engagement, but you cant creat it if the ECU never has it to begin with right??</TD></TR></TABLE>


This will work (and I know a few people who've done this)...just to solely activate the VTEC solenoid and nothing more.

The problem with this is that you will still be running on your stock non-vtec fuel & timing maps which & you won't be running at optimum power on the VTEC engine, because a VTEC ecu's programming has 2 pairs of fuel & timing maps; one pair used BEFORE vtec crossover point (which are actually non-vtec maps), and another pair of maps while your IN VTEC (which are incidently not the same as the maps before VTEC crossover).

but like LudeyKrus says, its best to use a VTEC ecu with a VTEC engine (whenever you can find and/or afford one).

 

settles an argument i was having, good info. I was thinking about the timing and ignition maps also. thanks guys. Side question, you have a vtec motor, Vtec isnt engaging, you still rev to redline (as much as you can) , what damage an you cause. debate

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VtecKiDD &raquo;</TD></TR><TR><TD CLASS="quote">settles an argument i was having, good info. I was thinking about the timing and ignition maps also. thanks guys. Side question, you have a vtec motor, Vtec isnt engaging, you still rev to redline (as much as you can) , what damage an you cause. debate </TD></TR></TABLE>

There shouldn't be any damage because of the fail-safe mode the ecu has in its programming if a certain a sensor or sensors are not working right such as the VTEC solenoid; btw safe mode allows you to rev up to 7500rpm max, if VTEC isn't engaging.

..and even if you are you able to rev past 7500rpm with no vtec, its pointless because your powerband dies off for the primary & secondary cam lobes somewhere around 5300-5500rpm (and then the MID (vtec) lobe takes over). As far as damage goes, I dont see what damage could be caused though...maybe..(and this is far fetched)...mess something up in the valvetrain...but I doubt it..