lews930

Is there a difference between these? Do they do the same thing(s)? which is better? least expensive?

Trying to fix the lean problem caused by adding the 3 inch RB exhaust system to my car. I don't want ot do stand alone ems, I just want to be able to drive the car!

thanks for the help in advance

lewis

xfeastonarsex

iTrader: (5)

I noticed that the s-afc is cheaper, I also wonder the difference... the hks f-con also has a fuel cut defensor to prevent fuel-cut during overboost

RylAssassin

The S-AFC is a piggy back fuel controller. It allows you to adjust how much fuel you want at certain rpm ranges.
The FCON is better. It plugs directly in line with the stock ECU, its does all that the S-AFC does but a lot more, and it comes with the FCD (fuel cut defensor) so taht you dont blow your engine.
From what ive read and heard if your going to go with a piggy back and you have a little extra the FCON is better.
S-AFC's cost around 200-300 bucks. FCONS go for twice that, but you should be able to find one used at a good price.
I have an S-AFC and the only complaint i have about it is that i had to hack up my main wiring harness to hook it up.

Scott 89t2

first thing you need is a boost gauge and a bigger fuel pump.

then find out how much boost you are running. if you are running over 11-12psi neither will help you.

lews930

I went to HKS.com. the f-con is listed at $1250. am I looking at the right product? Also, I found an f-con for sale on this site but it's for an S5. can it be altered for the S4? who's got the best price on the f-con?

thanks

reboot

^^

Scott 89t2

F-cons brand new are a rip off. used should be able to find them $300-400. can't swap between S4 and S5

personaly I would take the S-afc (cheaper and better) but you'll need to get it tuned which will cost another $100 or so. (still around same price)

xzyras

The F-con is used to tune a stock car."Refine the fuel curve" It's kinda like reflashing your rom. If you want to adjust the fuel curve,(only +/- 15%) u need the GCC. Thats another device.

I thought it was used when the car was mostly stock, and when you raised the boost just past cut off? (you know, just a bit) 10+psi is way over, and you will need bigger injectors to run that much, then you will need the GCC to lean out the fuel curve. Also a bigger fuel pump. Then a rewire.

Installing the S-afc isnt so bad. Just tap and spliced a wire. But they would both work. The GCC would also need to be dyno tuned.

Jaared

i had the fcon.. i loved it... but it can only be used with stock injectors.

i now have 680cc secondaries and it made it stutter at high rpms cuz it was soo rich.

stock turbo, ic, injectors... with upgraded fuel pump, DP, catback, and mbc set to 10lbs the fcon is great.
fuel maps adjusted by boost and rpm seems soo much than just by rpm and TPS.

lots of people run the safc and like it... so its up to you. you can upgrade your injectors and keep the safc.. thats a plus.

if you have bigger plans then 10psi.. then look into a EMS... and FMIC... and bigger injectors... and... and....ect

reboot

hes asking because i have the unit for sale. but its for a s5.. so i dont think he can use it now since he has a s4

skold

i have a f con for a s4 that i will sell for 400 shipped.

reboot

.. what is the condition of that and does it include FCD? hate to burst your bubble but I have one for the S5 with FCD for $250.....