fuel cut after exhaust
 

finally got my car running, only thing thats wrong w/ it now is I can't go wot... is there a free way to stop fuel cut after installing 3" turboback?

not that I've heard of.... I guess it's possible to engineer something, but that's why somebody else did it. They aren't expensive.

in the 1/4 and dyno section I read I could disconect the vacuum line to the map sensor to stop fuel cut... is this true, safe?

I imagine if the map sensor isn't getting information you're probably going to run stupid rich.

best thing for improved exhaust is upgrading your fuel delivery (ie injectors, fuel pump) and fuel management (anywhere from SAFC stuff to standalone). also, if your car is turbocharged, port your wastegate so you don't overboost.

He's not gonna run rich with the map sensor disconnected. He's gonna POP.

either way, it's not the proper fix, but it's good to know if you'll run lean or not...

unplugging map = fail
FCD = fail

rtek or standalone = win

Mazda realized that loss of the MAP signal would be catastrophic, so the ECU goes to default mode if the MAP signal is bad.
However, pulling off the hose may not be detected - & BOOM!

Same thing if the FPR hose fails, only the ECU has no check circuit for it.

The fuel cut is a safety to keep you exceeding the limits of the stock fuel system & ECU maps.

how does default mode act?

I have not actually tested that one, but it's supposed to limit power like it does for a MOP fault: retard spark, rich fuel, rev limit/fuel cut.

Yeah, it runs in limp mode, literally.

Suck it up and get an FCD, man. Or sell that car because you obviously want to cheap out on it.

Am I reading this right? If you install a 3inch exhaust on a stock TII than in high RPMs / WOT it'll starve for fuel? And whats overboost?

buy my RB FCD. $45 shipped

only because the stock fuel system can't keep up with much higher than stock boost, which is what can easily happen when you remove most the restriction from the exhaust. porting your wastegate helps with the problem.

i foresee another dead 7 in the near future...

Thanks, just curious, cause my friend is swapping a TII engine into something, and is fabbing a straight through 3 inch exhaust, and is using the stock ECU, better feed him this info.

actually, I brought It back from the dead after buying it from previous owner after he blew the engine and let it sit for 4 years... :shocking:

thanks for the replies

If this is the Racingbeat exhaust it raises the boost to about 10psi. This is higher then the map sensor can handle for boost cut out. YOu need to get a FCD or you will kill your seals.

uhhh

if u get a FCD thats WHEN you kill your seals.

The cheepest way to make more power:
a mechanical boost gauge to verify actual boost levels
a wideband AFR gauge for tuning
720 secondary injectors
A fresh rewired 255LPH fuel pump
A rising rate FPR or an S-AFC
port the waste gate to prevent out of control boost
FCD
a header dump or a big exhaust
a high flow intake- smooth TID behind a CAI
a boost controller to push up boost- a manual BC with a bypass circuit works well, electronic is better
at rebuild time- port the engine

To go any higher you're looking at a FMIC, Stand alone ECU, and a bigger turbo.