ss2.4lvvt

i know everyones using Hptuners for their tunes but will apex'i's afc neo work on a car like ours for fuel management? i havent seen the application on their website but could it be wired to work on our cars? thanks..

ss2.4lvvt

maybe this should be switched to tuning?

bc3tech

it would work all you need is an ECM diagram to help you hook it up.

beyond that the only downside to piggyback tuning when you have HPT available to you is that the piggyback's only making changes at >85% throttle when the ECM switches to open loop. blow the 85% throttle, the ECM's doing its own thing and the piggyback can't change anything.

spring for HPT man.. it's like what, 75% more money and you can do anything you can imagine at any time you want to. much better deal

ss2.4lvvt

ok i get where your going.. but another question and forgive me cause im a newbie on tuning..
there are maybe 2 dyno tuning places around here and as far as i know most are experienced with imports, if i get this hptuners for myself and just take it with me to do dyno tuning will they be able to use it without much hassel if they are a experiencned tuning place? i dont wanna get it and then spend 3 years learning how to use it... then take it to a dyno and let them say i cant use it there..

ss2.4lvvt

another thing can you explain in layman terms what open loop is so i can know why the piggy back will only work after 85% throttle.. on the apexi website it says you have 16 points of fuel correction.. i cant see them being only after 85% throttle.. a guy i know on another local forum has a stand alone system for his ford escort zx2 with a done up NA motor and he said he wishes something like the neo would have been around when he done his motor cause he would have gotten that instead since you dont need a computer for anything and you can tune on the fly.. im sure the hptuners is great but seems like alot of money when i can get the afc neo on ebay for little to nothing and wireing things up is one of my strong points..

bc3tech

honestly my advice would be to use your online community here for what it's here for - knowledge sharing. Hit up somebody else on the boards (most likely it'd be a 2.0 guy) that has HPTuners, and head to his place for a crash course. then you can get your car tuned and learn a ton in the process Make a road trip outta it if you have to, that's what i'd do anyway. But yeah for the most part if a dyno shop is DSM's they're likely using the SAFC-series for piggyback, or full standalones for other tuning.
In layman's terms it's a "gate" taht says the ECM can be run by an "outside source" (SAFC) in "open loop" or in "closed loop" it's accepting no information from anybody else... think of it as a door, if the door's open (open loop) the SAFC can barge in and say "hey you do this and this and this" and it gets done. if the door's closed (close loop) the SAFC can sit out here and talk all it wants but the engine's not going to listen.
as far as there being 16 points of correction, yes you CAN use all 16 points at 85%+ throttle... think about it, you can go WOT at any point in your RPM range.. if your'e going slow (2krpm) and punch it, you're WOT @ 2krpm, and the adjustment point for that area will take effect... and so on.

LewiSS

Actually, I believe you have it backward. The ECU meters fuel and sets spark below the switch point based on inputs from all the sensors (TPS, MAF, etc.). After the switch point (in open loop) it reverts to a set table that's hard-coded into the ECU and ignores the sensors.

The way a piggy-back works is that the sensor input wires are cut and routed through the piggy-back, which then alters the signal the ECU sees, thus "tricking" the ECU into doing what you want it to without actually re-programming the ECU (with something like HPTune).