Originally Posted by booja

the "tps" they are referring to is the map/pressure sensor... i dont know why they call it the tps. even in the wiring it is tapping into the pressure/map sensor.

both the US cars and jdm cars have boost cut set up the same way... they both read off the turbo pressure signal (map sensor... or according to them the "tps"). im not sure what they are talking about the tps signal, the throttle reading comes from pin 43 which is up and to the left of the wire that bcc guide tells you to wire to (pressure/map sensor). the US cars or MAF based cars can also eliminate boost cut by capping off the bottom (i think it was the bottom one)port of the pressure/map sensor. by doing this the ecu does not read any pressure what so ever so there is never a cut. you cant do this on the map cars... ill explain below.

on MAF based US cars, the MAF does the mapping and fueling, so capping the MAP/pressure sensor off or reducing the voltage to the ecu does not affect the way the car runs at all. the pressure/map sensor on US cars was basically just used for boost cut. the jdm ecu/map based cars run all the mapping off the map/pressure sensor.

the SAFC works on US cars along side with the BCC because the wiring of the AFC taps into the maf wires instead the map (i think they tap into the map too but just for logging) it adjusts the voltage coming from the maf to adjust the fuel and ignition maps i believe. with the jdm ecu and map cars both afc and bcc tap into the pressure signal, when doing this the problem i explained above arises.

ive tried many different ways with mine and ended up selling my afc. you can try capping off the pressure signal like the US cars and youll notice your car will idle like crap... but the US cars run fine. i have even left everything the same in my car (boost settings) and adjusted the voltage reading from the bcc box. when i lowered the voltage from inside the box my car ran more lean. 12-13 afr. as i raised the voltage closer to 4.3 (rich fuel maps with more voltage) my car dipped into the 10's.



yes the fcd taps into the same wire... from what i remember the bcc is better because the fcd eliminates the boost cut by scrambling the input signal and gives out a corrupt inconsistent value... if it does this your fuel and ignition maps will be all over the place ALL the time. but this will work fine on US cars.

the bcc keeps all voltage values the same until it reaches that threshold you set... once reached it just keeps it there so you do not reach the boost cut.

on mkiv.com they also explain the difference between the 2... they said after testing the bcc was better and more safe

Originally Posted by lemmiewink

So, what are you using instead of an safc, if you don't mind saying? Its obvious the boost cut NEEDS to be dealt with, so I will probably still use the bcc. But for a piggy back system, I will have to look around more.

I'm not savvy at all with which piggy back does what and how it hooks up and what not. Please. Enlighten us if you will or me at the very least.

Originally Posted by tampa mike

Yes that is some good info, although im very up on my MAP cars as I have barely owned ANY MAF cars, so this is an issue I have always dealt with, which is why I am still wondering why I cannot just cap the voltage via a resistor, and still use an AFC seing is it will still give fueling per RPM? Somehow someway it can work I just need to give it a shot, since I own my own shop and dyno it doesnt really cost ME anything ya know

Also this can be a PITA as I will be switching over to AEM and a 5BAR MAP shortly, so I want to get this resolved for the guys who want to stay stock ecu and still make a little more power