Fuel Management

[Frankenstien93]

if i am running 8 psi what will i need for fuel management system or can i just run the stock system?

[2fast2forty]

I would just run a safc. Or if its possible run a hacked ecu but i dont that anyone knows how to on a ka yet.

[Structure240sx]

thats fine for management, to have the fuel to keep up with 8psi depending on the turbo, you will need a walbro 255lph fuel pump 370cc injectors at least (sr20det injectors will work great if you are dohc).

you should also retard your base timing 2-4 degrees

[Frankenstien93]

im running a t3/t4 so i would just need the injectors, new pump, what about the o2 sensor can i just leave it stock and manually turn the timing back on the rotor or will i have to buy a widdeband o2 sensor and do the whole tuning thing like that?

[Craving4Boost]

im running a t3/t4 so i would just need the injectors, new pump, what about the o2 sensor can i just leave it stock and manually turn the timing back on the rotor or will i have to buy a widdeband o2 sensor and do the whole tuning thing like that?

im confused...what does the 02 sensor have to do with the timing? anyways if you tune with an SAFC you need a wideband which comes with an 02 sensor or a dyno

[Frankenstien93]

i just got into this stuff so im trying to fidgure out what i will need to get it to work right and not blow up and waste all the time and money so i can just get 370 injectors and a bigger fuel pump? or what im a nood at this stuff and ill admit it

[Craving4Boost]

you'll need a piggy back system like a SAFCII or e-manage...than you'll need a wideband 02 with a monitor to tune with because you need to keep track of the air fuel ratios..then you'll be boosting an easy 8psi...and you'll already have the right equipment for bigger injectors

[Frankenstien93]

so the injectors off a sr20 will plug into my ka wiring i wont need anything else other than those three things i just took out a loan to finish up and im seeing if im going to need more money cuz it just keeps mounting

[hysteria]

you can run 8 psi with a walbro pump and a rrfpr. you'll end up spending about $200 for these two items. if you have the money and a desire to have a better setup go for something else. bikirom, safc, etc. something in that price range. but it's gonna cost a bit more. temporarily i'd go with the rrfpr and walbro pump because if you decide to sell them and get the other setup people will pay you a lot for those parts even used. rrfpr's don't realy lose value unless they break. it's safe to expect a return on those items if you decide to upgrade to something else.

[Frankenstien93]

uhhh yea what is a rrfpr?

[hysteria]

rrfpr - rising rate fuel pressure regulator... aka fmu. it increases fuel pressure directly proportional to boost pressure... for example, a 8:1 rrfpr/fmu will increase the fuel pressure 8 psi for every 1 psi above atmospheric pressure it reads.

so if you were running 8 psi of boost, the fuel pressure would be the stock pressure (43 psi or something like that) plus 8*8/1 = 43+64 = 107 psi fuel pressure. similarly for a 12:1 rrfpr you would theoretically have 43+96 = 139 psi fuel pressure. but a walbro pump doesn't even have the ability to hold 139 psi of fuel pressure, so basically the capabilities of an rrfpr/fmu are often limited by the ability of the pump to supply adequate pressure. so (and i'm not certain of what the max pressure a walbro pump can supply is) at the max capacity of the fuel pump, no matter what rrfpr you have, you will have the same fuel supply.

this is just a cheap and relatively safe way to add boost, because you will always have more than enough fuel, and at the low levels of boost you're not in much danger of blowing up the engine. but of course it is a cheap thing to do so it is horribly inaccurate (always rich), and if you want anything above 8 psi you're going to need a better fuel system before you do anything else. like i said though it is safe to expect a return on those items if you want to upgrade... and they are cheap enough that even if you get no return on them you are not losing the much. but for some people 8 psi is just plenty. i definitely reccommend this as an entry level setup, and so do the people that make turbo kits for the ka apparently, because the majority of them come with an fmu as the initial stage 1 fuel setup.

[sunnys14]

12:1 fmu should only be use temporarily... long term WILL damage them due to overworking them.

[DammitBobby]

I have a used FMU that I will sell you. I was able to push mine up to 10psi.

[hysteria]

haha i was gonna say i'm going to sell mine soon in order to get my biki board and everything else up and running.

[Nismo_Freak]

Hackazztuningville, population - this thread.

Get SR injectors, get a fuel pump, and get a S-AFC.

If you can afford it, ditch the S-AFC for an Emanage Ultimate.

Running a RRFPR along with stock maxed out injectors, retarded base timing, and a stock ECU is a recipe for a craptastic running car. For those of you that have this setup and think it's great, you have yet to reap the benefits of a true engine management.

[DammitBobby]

Hard to beat the price of a FMU and a Walbro fuel pump. I dynoed 202 rwhp 8psi on a POS BD setup using a FMU. If memory serves me right a SR stock is 200HP at the crank. I was able to raise the boost level to 10psi on this setup but never dynoed to know the HP level. Nothing wrong starting with a FMU and upgrading latter. Its not like you got to throw everything away and start over.