fuel upgrade question

[vinh766]

i've read about ppl installing either SAFC or MAFT or some other sort of fuel management and stating that they have 550 injectors or 255 walbro fuel pump even before they got their fuel management unit. what i don't understand is, what did they use to tell the ecu that they have upgraded to bigger injectors or a higher pressure fuel pump? or did they install them at the same time with their fuel management unit? or is it just fine to just pop in bigger injectors and or fuel pump whenever you please. i've search, and i couldn't find anything. any help, would help a lot. thanks

 

[dynatos]

the bigger injectors is the larger reason for the safc. Our ecu's can't be told whats under the hood if we change something. So if we have a 550 injector, the ECU still thinks it's a stock injector. The SAFC tricks the ECU into working correctly, so that you can take advantage of more fuel and less fuel cut effectively.

The fuel pump delivers more fuel at more psi. The car is only going to use as much fuel as it needs, but with larger injectors and maybe a larger turbo - more fuel is needed. hence the walbro.

So yes, normally they are installed at the same time.

 

[vinh766]

but is it possible to upgrade injectors or pump without any other supporting eletronics?

 

[v2ner]

yes, it is possible. w/ the pump and the injectors in place and not having the electronics, it will work fine. but it won't work to the injector's maximum. if u want it to work to the max, that's when u get the electronics. think of the injectors and the pump as a turbo, it will work fine but if u got the supporting mods to go w/ it, it will work up to it's potential.

 

[99blackgst]

The fuel pump is fine w/ out supporting elctronics, get an afpr if your running a 255 or larger pump. You can run injector w/ out a sfac or something to compensate for the larger injectors but i don't recommend it. Chances are your car will be running pig rich.

I recommenc installing the SAFC a few weeks prior to getting injectors to get a hang of the SAFC and how it work. If your tuning your cars SAFC your going to need to get a logger too.

 

[dynatos]

with larger injectors, the ecu is still sending the same pulse width - which equates to more gas. hence it running rich, and the need for a safc.

 

[vinh766]

Originally posted by 99blackgst
I recommenc installing the SAFC a few weeks prior to getting injectors to get a hang of the SAFC and how it work. If your tuning your cars SAFC your going to need to get a logger too.

i plan on getting a 3inch GM MAF and a MAFT about a week or 2 before installing my fuel pump and injectors, the maft should just be fine right?

i plan on running 255walbro with 550 injectors on stock t-25 until i upgrade to the big 16g. are the 255 and the 550 injectors an overkill for the stock t-2small for the time before i get the 16g on? and with the 16g on, will the 550 be good enough? and will the 255 still be an overkill for the 16g? or should i just get a 190 pump?

 

[99blackgst]

you can get a 255 but then you'll need a fpr to keep it from over running your injectors. if i could do it again i'd just get a 190. buy a fpr and plumbing lines and fittings is kind of a pain in the ass. you might want to change your fuel filter too while your changing your injectors.

the 550's and fuel pump won't be overkill aslong as your car is tuned fine w/ the safc.

 

[dynatos]

if you can get the new gm mas v2.08 ( check out this thread ) it should do fine if you don't have the money for an safc.

i would also look into the supra tt fp (click here) , which is more quite. i think 550s would do you fine on the setup mentioned, but if you are planning on going bigger.. i'd save for the safc, 650s, better fuel pump, fpr, and datalogger. (or dsmlink instead of safc/datalogger).