Piggybacks
 

I have heard you can run a BPT with piggybacks on the normal BP ECU??? If so, which ones are a good choice???

Thanx for any help!!!:D

Re: Piggybacks
 

SAFC with bp ecu wont compensate for fuel.u would need to run boost depended fuel preasure regulator and then use SAFC to corect idle and part throtle.bp or bpt ecu is not reding vaf when u are 100% throtle so it wond add any fuel at that point.

So.... To run a BPT with a N/A ECU I would need,

Auto BP TB
Apexi S-AFC
Rising Rate FPR



What exactly do you/does he mean by that???



Sorry for the dumb questions, but thanx for answering them!!

I meant the Auto BP TB, not the ECU; but I cant edit it for some reason?

SAFC modifies a signal from vaf to ECU. When ecu reads 100% throtle its not calculating fuel mixture from vaf reading.it is pre-programed.

So the AFC overrides the pre-programmed signal???

no it dont so its only good for part throtle and idle.

Re: Piggybacks
 

Check out Perfect Power's SMT-6. Best piggyback solution I have seen to date. 6 wires on most cars and your done! Can't get any easier than that and the results I have seen personally speak volumes.

Re: Re: Piggybacks
 

yes piggy back gizmos work good on most off the cars but dont woork that good on mazdas

What' so special about Proteges? I haven't seen anything that says that units like these can't be used. You'll gain something on a bone stock car if you have control over ignition timing and fuel.

at full throtle the fuel map and ignition map is taken from ecu and difrent reading from vaf(piggybacks units change vaf,maf or map signals to ecu)wont be taken to calculate fuel or timing.That how older mazdas are.

Couldn't you just modify the throttle position sensor so the ecu never "sees" full throttle? I'm just asking, so if I'm missing something obvious dont FLAME me :D

All of us have had various success stories in running FI with piggy backs and stand alones. I know for a fact that piggy backs will work, and are effective in use with OBD-I based proteges.

The bare minimum requirements that I see necessary for someone to run the Turbo on a 1G are:

Apex'i S-AFC (Blue Model) or equivalent
MSD Boost Timing Retard or equivalent
Cartech FMU or equivalent
330-460cc injectors
High Volume / High Pressure Fuel Pump

Otherwise count your blessings as the motor is very detonation prone without these.

Branden, I understand that things will need to be upgraded for boost, I just never understood the blanket statment that piggy back type units don't work cause they get overridden under full throttle. Seemed simple to never let it "see" full throttle.
Pseudo, glad to hear it was discussed and that I wasn't missing something painfully obvious........ :D

The ECU DOES read the VAF voltage under full throttle. The MECS-I (Mazda Engine Control Strategies) table shows TPS, VAF, ECT (engine coolant temp), ACT (air temp), and CKP as active sensors.

I've proved the AFC works well at WOT. I've got 35,000 boosted miles, the last 7,500 at 15 psi, on my 1995 EGT (OBD-I). My setup consists of:

460cc injectors
Cartech 20005 FMU
Walbro high flow fuel pump
Starion IC -front mounted
2.25" mandrel IC piping
2.5" crush bent exhaust
high flow cat. convertor
MSD ignition retard
S-AFC
2 bar MAP
VJ-20 hybrid (88 t-bird cold side)

The AFC works better when coupled with a MAP sensor. When I had a 4-wire TPS installed, the fuel didn't follow boost and the engine backfired easily when dropping throttle. With the MAP sensor wired in place of the TPS, the fuel curve follows the boost curve. I turned down the FMU fuel pressures to about 60-70 psi under boost. The AFC does the rest. 330-460cc injectors work well under boost. 330cc will get you 10-11 psi with the FMU maxed out. 460cc are pushing the limits. I would love a set around 380-400cc.

Jess