FUEL PRESSURE @ 12psi

[micaguy]

Does anyone out there running 12psi+ know what there fuel pressure is @ full boost? Some one with a gauge? Hopefully someone can provide me with this info as I'll be needing it to base some mods on. Thanks, Ryan (uhm)

 

[micaguy]

Anyone?

 

[Mr. Win]

yea i think like 85-95 psi ubder boost. could be wrong

 

[KyRaceFan]

No way its near 85psi. Closer to 50 would be a good guess.

 

[Mr. Win]

75psi is what begi takes at 6-7psi at 12 id say thats a decent guess

 

[micaguy]

Hard to compare a BEGI kit (T-3 turbo) to a Mazdaspeed (T-25 turbo). A T-3 flows approx. 30% more air than a T-25. Should I then assume that I will require 30% more fuel? Please help. Any insight would be greatly appreciated.

 

[02p5]

Yo man, I'm running 10 and I'm close over 90 PSI I believe. I'm running a tad rich too. The Apex'i AVCR is telling me the stock injectors are not maxing out yet either.

 

[Dexter]

The begi kit has a fuel pump, no?

 

[02p5]

The Begi kit comes with a fuel pump, A Pierberg I believe.

 

[MSPDAVE125]

MSP fuel pressure should be around 55-58psi at WOT at 12 psi.

The MSP ECU will compensate injector pulse width when it sees more boost. Therefore less Fuel pressure is needed as the injector will stay open longer to add more fuel to the mixture.

The BEGI kit ramps up the Fuel pressure using an FPR which works on a ratio (8:1 / 12:1) Because this kit is designed for NA motors the ECU will not compensate the injector pulse width under boost. The Fuel pressure is increased dramatically to force the extra fuel (per lb of boost) through the injectors OE pulse width.

This is why the BEGI kits Fuel pressure is so high.

If you are concerned about Fuel Pressure on the MSP, Change the power wire on the Fuel pump to a larger gauge wire. The stock power wire only gets about 12.5 / 12.9 volts to the pump. A larger wire will increase voltage to the pump creating a greater output from the pump.

 

[JONBOY688]

what kind of liters per hour is a stock fuel punp worth? and also wouldnt a inline fuel pump help with a msp?? like a nos inline or bbk or vortech trex?

 

[igdrasil]

what kind of liters per hour is a stock fuel punp worth? and also wouldnt a inline fuel pump help with a msp?? like a nos inline or bbk or vortech trex?

Hey, just replace your stock FPR and use an adjustable one....

 

[Mr. Win]

Hey, just replace your stock FPR and use an adjustable one....

and also upgrade your intank fuel pump fpr build pressure quite a bit...

 

[CustomMSP]

MSP fuel pressure should be around 55-58psi at WOT at 12 psi.

The MSP ECU will compensate injector pulse width when it sees more boost. Therefore less Fuel pressure is needed as the injector will stay open longer to add more fuel to the mixture.

The BEGI kit ramps up the Fuel pressure using an FPR which works on a ratio (8:1 / 12:1) Because this kit is designed for NA motors the ECU will not compensate the injector pulse width under boost. The Fuel pressure is increased dramatically to force the extra fuel (per lb of boost) through the injectors OE pulse width.

This is why the BEGI kits Fuel pressure is so high.

If you are concerned about Fuel Pressure on the MSP, Change the power wire on the Fuel pump to a larger gauge wire. The stock power wire only gets about 12.5 / 12.9 volts to the pump. A larger wire will increase voltage to the pump creating a greater output from the pump.

Will changing the power wire be benefitial for daily driving on an already rich running MSP? Or is it only required for those that are running a little lean on stock fuel system with higher boost?

Thanks.

 

[MSPDAVE125]

OMG! NO! An FPR is totally not neccesary for the OE injector size and if you've seen any of the guys posting dyno results you'd see the that there A/F is 12:1 (around) at WOT. There is no reason to introduce mechanical parts to add or remove fuel unless your motor is ingesting sufficient air to require it. And the fact that a T25 pushes 250 CFM there is no need for it. Yes tuning is required for lower RPM fuel maps. But that is all ECU based.

 

[Matthew]

my AFR is less than 11 at WOT at 8psi.

 

[MSPDAVE125]

Ok but your ECU is for a N/A application to start. You NEED a mechanical fuel pressure regulator to compensate for boost. It's a different application all togather.

The MSP computer will increase injector pulse width under boost to add more fuel.

 

[Matthew]

i cant believe at 15psi or whatever the fuel pressure is like 60...blows my mind.

 

[MSPDAVE125]

For a P5 turbo or MSP?

 

[Matthew]

msp