fusion-turbo

I just installed my FCD on my 10thAE with a free flow exhaust (no cats) and upgraded intake/TB mod. At high RPM's im boost creeping to about 13 pounds of boost. I have a completely stock fuel system (four 550cc injectors and stock pump).

Can the stock system handle that much boost safely?

Also, i have installed an s5 turbo recently. Shouldnt that have stopped my boost creep problem?

Tyblat

excuse the rudeness.


Why would you disable a safety precaution thats meant to keep your engine from dying of to much boost?

The engine cuts fuel for a reason. It can't handle more than that amount of boost its programmed for safely. Upgrade the fuel system before you do anything else.


Do yourself a favor and save 2,000 on a rebuild by doing the following.

Disconnect the FCD

Revert to stock boost

UPGRADE FUEL SYSTEM

then you can do whatever you want.

Again, sorry if I appeared rude, but would you rather pay 350 for an upgraded system, or 2k on a rebuild and end up back at square one?

turbo80cid

13psi on the stock fuel system would be really pushing it. I wouldn't do it.
You should have ported the S5 wastegate.
I run 11 psi on a S5 turbo w/ported wastegate, mbc, 720 secondaries, bigger fuel pump and a Microtech.
Boost peeks at 11psi around 5k rpm and tapers down to 8psi at 7000rpm.
I have run as much as 13psi but now my turbo is making noises.

fusion-turbo

Agreed Tyblat, i ask this question because i just got the car running this week EXPECTING my new s5 turbo to stop boost at approx ~9psi which is more than capable for the stock fuel system. So before sinking more money into the car i figured id ask because lots of vehicles have stock parts capable for higher-than-factory power output.

As for being rude, no, maybe a little rough around the edges.

So my next question, isnt the s5 wastegate supposed to handle boost creep better than the s4 turbo? Because i was seeing LESS (almost none) boost creep when i had my s4 turbo on the car. I did notice that the wastegate linkage (the rod that goes the wastegate lever) is bent... could that be hindering my wastegate opening fully? Or is it supposed to have a bend in it?

adrock3217

The S5 turbo DOES have a more efficient wastegate system - but with an opened intake or exhaust, will also experience creep. It needs to be ported.

And..I wouldn't run anything higher than stock boost without any means to control fuel. Get yourself a cheap SAFC2..you'll love yourself later.

Oh and, I wouldn't recommend pulling the FCD out. This *minor* lean condition of his is NOTHING compared to a complete fuel-cut to the rear rotor under boost. I wouldn't have a fuel cut, even on a completely stock car...it's stupid!

fusion-turbo

Ive hit fuel cut before and its retarded! The FCD stays. Will i be ok running a walbro pump and keeping my boost at the same psi (approx 13 max)? Or will i need an injector upgrade?

In the ideal world i would redo the entire fuel system; better too much fuel than too little. Im not one to *skeet* by ONLY doing the minimal. But do you guys think just upgrading my fuel pump will be enough for 13psi? If not i will just mod the wastegate and play it safe.... but the extra boost is so fun

hurleysurf24

iTrader: (3)

you should be fine .. but at some poiunt the warlboro is going to out do the puny size injectores we have

Asterisk

iTrader: (3)

wait, so you're running 27psi of boost? DAMN.

fusion-turbo

No, im running 13Lbs boost.... where'd you get 27?

So a walbro upgrade and stock injectors should handle 13 pounds ok?

7dust

iTrader: (14)

wrong. Wrong. WRONG.

Do you really think Mazda would program the ECU to destroy the engine should it encounter higher than stock boost levels?

The fuel cut is designed to save the engine.

Dom_C

yea but the fuel cut is not good for the engine. If you have the fuel mods than it's not a problem. Obviously if you havn't ported your wastegat eand don't have supporting mods the fuel cut is better than the alternative. The s5 turbo is only superior in an unported state. The ported s4 turbo is just as good as a ported s5 turbo.

Dom

Funkspectrum

iTrader: (5)

answer to the original question....port the wastegate and you should be safe. I'd say max 10psi on the stock fuel system unless you have a way to control the fuel input at higher boost levels. The suggestion of an SAFC is a good one just to richen up the mixture a bit. I'd run it as a short term "band-aid" until I was able to pick up an EMS like a microtech or haltech...

But before anything, port that wastegate. Then save for an EMS.

Turblown

iTrader: (12)

Complete fuel cut is safe. Zero fuel = zero cylinder pressure

13psi on the stock fuel system is not safe, stock ecu doesn't push the OEM injectors to full duty cycle.

I maxxed out(100 duty cycle) cleaned 550cc and a walbro pump @ 11psi stock s4 turbo several years ago, that however was with a haltech e6K.

Bottom line is find someone with a wideband and find out.

fidelity101

iTrader: (11)

no

RotaryEvolution

iTrader: (30)

definitely not, you need to port the wastegate #1 and #2 get a wideband on it and a piggyback to richen up the mixtures.

if you keep pushing it to 13PSI the way it is we will be seeing a thread next week along the lines of "my car is running like *** and has no power, what could the problem be?".

i will even foretell the future and tell you the majority of the replies to that thread would be along the lines of "do a compression test"..

peachykeenwight

You're such a charmer, Karack.

Juiceh

iTrader: (4)

The only part of your fuel system that is up to par for 13pis boost is the lines.