VAFC and VTEC? - Tuner-Junction

ltlblkcvc · #1 (**permalink**) March 9th, 2006, 09:02 PM

Will the vafc operate the vtec if the ecu doesn't have vtec? in the instructions it shows to run the vtec through the vafc then back to the ecu. does it have to run back into the ecu? I'm thinking to just get a small turbo and use the vafc to control everything important and just use the p2e and sell the p2p I have.

Johnlude85 · #2 (**permalink**) March 9th, 2006, 09:09 PM

yes it does have to run back to the ecu, and yes you do need an ecu that has vtec.

njn63 · #3 (**permalink**) March 9th, 2006, 09:25 PM

i'd look at using crome/uberdata/neptune/hondata instead. For the price you could sell the VAFC for you could pretty much have that setup and it'll allow you much better control over the tune.

Quote:

Why piggybacks (vafc, emanage) "suck" by pgmfi.org:
Piggy Back controllers allow stock ECUs to do things that they normally can't do, like run larger injectors or deal with boost. Remember that piggyback controllers work by altering sensor signals before they get to the ECU.
Most of the time, the primary signal being messed with is the Map Sensor. This is critically important in a Speed Density car. The Map Sensor is used by the ECU to guess how much air is going into the car, and therefore how much fuel to supply in order to match airflow. When you "lean" out a car with an AFC, you are simply decreasing the Map Sensor signal - the ECU responds to the decrease in manifold pressure by supplying less fuel. When you "richen" a car with an AFC, you are simply increasing the Map Sensor signal - the ECU responds to the increase in manifold pressure by supplying more fuel.
The change in fueling happens for a reason: if you look at a fuel table, Map Sensor values correspond with columns. When you increase or decrease the signal from the Map Sensor, you are simply making the ECU use a different column than it originally would have used. (see Understanding Maps if you need some help understanding reading Fuel and Ign tables)
But wait, isn't the Map Sensor used for determining ignition requirements too? When you "lean" out a car with a Piggy Back, you also in all likelyhood advanced timing. When you "richen" a car with a Piggy Back, you also in all likelyhood retarded timing. Look at trends horizontally (as MAP changes) in an ignition table, and you will see why this happens. This helps explain why so many boosted cars running on the "AFC hack" have issues due to excessive ignition advance.
The bottom line: Piggy Back Controllers suck because you cannot independently adjust fuel and ignition. Any changes to fueling will produce a change in ignition too, and often this is undesirable.

ltlblkcvc · #4 (**permalink**) March 9th, 2006, 09:34 PM

i guess I'll have to figure something else out I'm not looking for any big boost just about 6lbs its a small turbo I just want a little more power right now and it still be reliable I'm not even looking for 200whp maybe 160 or 70

Johnlude85 · #5 (**permalink**) March 9th, 2006, 09:41 PM

well what car and engine do you have. you asked if the vafc will operate vtec if the ecu doesent have it. do you have a vtec engine??? if not, you can opt for the safc which is basically just a piggy back air/fuel controller. they can be had for about 220 on ebay if you only wanna do like small tuning. http://search.ebay.com/safc_W0QQfkrZ1QQfromZR8

theCrimsonEK · #6 (**permalink**) March 9th, 2006, 10:06 PM

While on the topic of piggyback systems.. did anyone see the new emanage ultimate? It actually looks really good. Has alot of different tuning options. Ive been thinking about going this route since obd1 tuning will be hard once inspection rolls around each year.

ltlblkcvc · #7 (**permalink**) March 9th, 2006, 10:23 PM

well since I'm talking about p2e and p2p I would have either a d16y7 or y8 but since I said control vtec that would rule out y7 since its doesn't have vtec. so that leaves 1 option y8. so I have a d16y8 and since I'm in the civic forum I would also assume I have a civic. since the p2e and p2p are obd2 ecus then that would mean I have an obd2 car which would mean I have a 96-00 honda civic with a d16y8
ok anyways back to reality I have a 99 honda civic dx with a d16y8 and 92-95 si tranny. I'm not looking for much a small sidemount intercooler small turbo(I dont even thinks its a t25 it might be the same size or smaller)I might be able to get away with stock injectors. I just got the car running right since I did the swap. I don't feel like putting the other ecu in b/c I don't feel like taking the iacv off and replace with the manual tranny iacv. like i said I don't want much out of the engine I want it cheap and reliable.

Johnlude85 · #8 (**permalink**) March 9th, 2006, 10:34 PM

why dont you go with nitrous? itll be alot faster then it is, but you wont have to sacrifice reliability due to the fact that youll be boosting a stock internal engine (stock internals that i know of, you didnt mention anything about upgraded). thats the route i might be going with my 4th gen prelude. iono, just a thought.

Blake · #9 (**permalink**) March 9th, 2006, 10:43 PM

even if you are boosting small. A good tune will go a long way regardless of the setup.

njn63 · #10 (**permalink**) March 9th, 2006, 10:56 PM

Quote:

Originally Posted by Blake

even if you are boosting small. A good tune will go a long way regardless of the setup.

i'm with him. You're talking about a $1,000 turbo setup, why not spend the extra few dollars to have a decent ecu setup (it'll probably be close to the cost of a VAFC).

ltlblkcvc · #11 (**permalink**) March 9th, 2006, 11:34 PM

1000 ha what you smoking? no I have alot of stuff laying around and can get turbo stuff extremely cheap if not free from a few friends. and I'm a welder so any piping or manifolds I can make myself and with all the scrap aluminum and steel I'm sure that will be free as well. I even have access to the dyno at work to tune it. the main thing I'm trying to figure out is the tune. yea the engine is stock but they can handle around 225whp like I said all I want is about 160 170 maybe 180. nitrous would be costly in the end with bottle refills and all. and I don't want something I have to turn on and off. I want something that will be there all the time.

ltlblkcvc · #12 (**permalink**) March 10th, 2006, 08:35 PM

what do you guys think of greddy's e-manage?

98CivicEK · #13 (**permalink**) March 11th, 2006, 11:26 AM

Come i thought you knew what management you were gonna run. yeah i do remember seeing where a guy used a vtec controller to activate vtec ina non-vetc ecu. honestly i thought he was an idiot, but i didn't say anything.

just do the p2p as you were and if you use e-manage you can run a mild setup till you get the money for a better system, or are wanting to boost more.

this is also why i'm doing the obd1 conversion. more options, and cheaper at that too.

ltlblkcvc · #14 (**permalink**) March 11th, 2006, 02:47 PM

I found a guy selling a e-manage and he has an fzr so I might be able to get it and sell some of my stuff at the same time I'm hooking up th p2p either today or tommorow