I say lets have a discussion on electical tunning. I really dont know much so I will sit back and learn. what are some pros and cons about this tunning device, the Vafc? what other mods do you need to support it and get the most HP?

 

Well we can discuss the VAFC compared to other tuning devices such as the HKS AFR and Field Fuel Controller which are a few other piggyback controllers. We could also compare to other units such as Hondata, PMS, GReddy e-manage, Apexi Power FC, AEM, Motec, Haltech, and Electromotive which are all little more complex as far as tuning. Usually it all depends on the application and how much tuning capability you want. Also price is usually a factor involved when people are looking to add any type of moification.
Piggy back computers(i.e. VAFC) are usually the best bang for the buck for most people. They range, usually from $250 to $500 depending on which one and where you bought it from. Whereas some of the other systems can go up into the $1000,
$2000, and $3000 range. Don't get me wrong.....the expensive systems can do a lot of other things besides control fuel and VTEC engagement and depending on the application it may be well worth it. For instance if you add 2 or 3 piggy back controllers to you car you may have well spent over $1000, but spent it over time instead all at the same time.
I will write more in a little bit after I take a break. I know a lot of other people probably have opinions also though so this will probably go on for a while.

 

Here we go again.

Piggy back computers are widely used mainly because they are easy to adjust. I recommend that you don't unless you understand the consequences if you do it wrong. But from a tuning standpoint they are still not too difficult because the processor inside the unit does the computing for you. AN example would be telling it to increase fuel by 10% at 6000rpm. That is all you have to enter in. The processor inside the unit does the rest. That is a crude explanation because there is more involved but you get the idea. On the other hand some of the more advanced controllers or stand alone units have to be programmed more precisely by hand. This is an advantage from the aspect it gives you more tuning capability but it is more complex and only someone who has vast expertise in all the parameters should be tuning with it. If you look around most places that do tuning have one or two favorite systems that they use and recommend.
As far as the VAFC is concerned it is a great controller. It gives you access to the VTEC cross over point which can be maximized to work best with your set-up. This comes in really handy if you are changing cams which may have a different powerband than stock. You also get 8 points of fuel adjustment on the low cam side and 8 points on the high cam for a total of 16. The HKS Super AFR only has 11 points of adjustment. The Apexi AFC has 8. I have not tried to use a VAFC on a non VTEC car yet to see if it will still function properly and get all 16 adjustment points. It may or may not but like I said I have not tried. On the other hand the HKS AFR has an idle adjustment feature which comes in handy for those large injector upgrades that sometimes seem to make the car run extremely rich at idle. This is like the feature in the HKS VPC for cars with air flow meters( not the Hondas obviously)...just a fun fact. ........more later