Ok today I was talking to someone from here about getting a VAFC. I was told that it can actually damage your engine even when tuned correctly. Something about the X-over point set with the VAFC not matching what the ECU is reading? I kinda got lost but it was something like that. And something also about the engine not getting damaged with a VAFC only when your at WOT. When your not at WOT your car is in a "deadzone" and it is dangerous. Can someone please shed some more light on this cause I didn't find anything on it. Thanks in advance.

Is a VAFC with a Vortech Kit any good? What can I use to safely tune the kit?

 

yes. if you set hi->lo different from hi<-lo then in the rpm range between if you don't tune it properly u can hurt the engine. kinda complicated, kinda confusing...RT lead a long discussion about it a while back. basically, if u hold rpm in that "deadzone" and you hear popping it's bad and you need to tune the mismatch settings.

 

tune it with a dyno and wideband O2

 

If you set hi->lo the same as lo->hi will you be ok then?

 

Not exactly, remember you are only modifying signals relating to Air/Fuel mixture. The problem is that you are not making modifications to the Ignition Map. The issues really come to a head if you have modified VTEC engagement/disengagement. Imagine running the high cam fuel map but the low cam ignition map - Snap Crackle Pop.

"Use the SEARCH Luke!"

 

Tried vafc + damage under search couldn't find anything. What should i use for search parameters?

 

Could you be a pal and do a search for us and post the links? I did a search like I stated in my post and didnt find anything.

 

search: vafc mismatch
https://www.s2ki.com/forums/showthread.php?...?threadid=37329
https://www.s2ki.com/forums/showthread.php?...?threadid=46939
https://www.s2ki.com/forums/showthread.php?...?threadid=33471
and a few more

 

Yes, a VAFC can most certainly cause damage to your engine if it's not tuned properly, or is tuned on the "edge", where a change in conditions could push the A/F mixture too far into lean (e.g. a high IAT caused by it being too warm outside).

Ignition retard has very little to do with it. The reason you gain power on with a AFC is that it lets you tune your fuel mixture more precisely than the generic, emissions-happy fuel map currently does. Most performance-oriented hondas run very rich from the factory in the open-loop mode. If you lean that out a bit - by modifying the MAP signal to fool the computer into thinking there is less air, causing it to use a different point on the a/f map, you gain more power. The closer to 14.x (14.7? 14.3? forget), or an ideal stochiometric combustion mix, you will gain power, and your combustion temperatures will also rise. Remember nothing is free, and the engine runs rich from the factory for a reason.

The problem is if you lean too far for a given condition, the computer can no longer correct properly in all cases, as you've put a pair of sunglasses over it's sensors. Run too lean for too long, and you WILL cause engine damage.

How lean is too lean? That's what the guy who runs the wideband o2 can tell you (and what you should discuss here). Mindlessly plugging in VAFC settings is bad news. I live in Canada, i might get away with very agressive settings in the winter, and need to readjust in summer. If you try my "safe" winter settings in someplace like Florida, you may very well cause damage from excessive combustion temperatures and even detonation.

The risk isn't great, but it is there. Many, many people are using them so they're pretty safe, you gain power and mileage with a proper wideband dyno tune. Win win win. Just be conservative if you don't want to hurt your engine.

In-car wideband and EGT meters are never a bad investment. Nor are proper oil and coolant temperature guages.

Hope that helps.

Steve

 

very much thank you. Does that wide band O2 sensor tell or measure the ideal combustion mixture? Pardon my ignorance.