I posted this before.....i don`t have a wideband yet, but it is on its way. My question is: at about 5000rpms it wants to lean according to the narrow band and loses power, this is at 12psi. i have a fmic 2.5" piping, majestic stage I turbo, ported wastegate, 550cc pri, 720 sec, rtek 1.7, s-afc, 255 walbro pump(rewired). 3"dp/exhaust. I can`t figure out why it does this, any solutions? I`m gonna try 890cc sec and put the 720s in pri. my fuel corections are: 3500rpm 18%, 4000rpm 20%, 5000rpm 26%, 6000rpm 28%, 7000rpm 30%. Any help would be appreciated!

 

Most likely your injectors are too small unless you fuel filter or something is reducing fuel flow. The FD runs 550-850 and these are only safe for about 330whp.

 

i just changed the fuel filter and no change....i put 3"rb dp and full exhaust....its fine at 8 psi...so i guess bigger injects.

 

the 550/720 combo will outflow your turbo.

could be a bunk warlboro or a plugged filter. could be a fuel pump voltage issue (is it stock or rewired?)

start by bumping up the fuel in those areas. 550/720 should give you enough gas for ~300whp @90-95% duty cycle. that's more than your turbo flows.

stock is limited to 58% duty cycle iirc. so 58% + 30% of 58%... just crank the fuel up, but definately get the wideband or get it on the dyno. it's not worth risking the engine just to find out.

 

pump has been rewired, and i changed the filter.....i`m running 8psi, and now its fine....i`m gonna try bigger injectors too