Well my cousin and I just finished the VAFC install in my 99 Si. I must say it looks pretty nice. Anyway, everyhing went well, but it seems that my Vtec doesn't engage as sudden or pull as hard as it used to? Also the setting for Vtec Lo-Hi is set @ 5800 and Hi-Lo is set @ 5400 (default) I can't remember where it should be set @? We bumped it down to 5600 and it still didn't seem like it helped....any suggesetions?

Thx all....

 

i am pretty sure that the default should be L>H 5300, H>L 5200. i have a 2000 civic si, and thats the way mine came. hope it helped a bit

 

i will try that out...thx buddy....

most appreciated ...

thx again.

 

Did you do all the seatings correctly?

 

confused.....seatings? u mean settings....? i did follow the manual and did exactly. i am going to look into the vtec settings when i get off work.

 

Yeah there are settings, in the settings mode. Such as sensor 6 in-6 out, throttle settings etc.....there could be more but i can't remember. But take a look at it might help.

Question for anyone else who may know since we're on the subject. With the sensor in and out setting on the VAFC is it possible to make the VAFC ignore, lets say the out vtec signal and just use the stock vtec crossover point from the ecu (Making it 6-in 5-out on that particular setting) or ignore any of the other sensors used for the VAFC's function for that matter.

 

I have a si also and wasn't the stock vtec engagement at 5700rpm? Also you will notice that the vafc screen will display the rpms lower then what they read on the stock tach....that is because the stock tach is off and the vafc is right.

 

If you read the Helms guide, the ecu doesn't always crossover into vtec at the same rpms everytime. The ecu constantly monitors the changes in engine status such as load, rpm and vehicle speed. Vavle timing change conditions are: Rpm=over 5,300 rpms, Vehicle speed=over 30 km/h, and Water temperature=over 60 C.

On my VAFC i have seen the ecu put out the vtec signal at 5400 rpm all the way up too 5800, all depending on engine load, throttle postion, and vehical speed. So there is no exact rpm for when vtec changes over from the ecu vtec signal, that is with in the specs mentioned up. But with the VAFC it will always engage vtec at what you set it at, whether or not your ignition timing has changed (from the ecu) from the low ignition timing to the high ignition timing (but thats a differeent story all together). Good luck with future tuning

 

That helps alot buddy, thanks. I went ahead and bumped it to Lo-Hi --> 5,300 & Hi-Lo --? 5,200. Its seems ok....still keeping an eye on it. Also to answer the above question I double checked all the settings and everything looked ok, I followed the steps in setting it up straight off the manual. Wish me luck...