What should The fuel pressure be set at?

[ShortThrow50]

When installing the trick flow top end street heat kit, what should i set the fuel pressure at for a starting point? I plan on getting a bbk fuel pressure regulator and fuel gauge. I want to be on the safe side and not run lean .Im not there yet but I soon will be because Im still painting and cleaning. Hey, im a neat freak. Went through the trouble to pull engine and trans and i dont want to put dirty crap back in the engine bay. Thanks fellas

 

[86bluecobra]

well set it to 40psi. No way you will be lean with that setting.

 

[cobradvm]

39-40 psi is fine as a starting point. But the reality is that it doesn't really matter what you set your fuel pressure at. Once your car goes into closed loop and reads the O2 sensors it will adjust the pulse width of your injectors to get the A/F to where it thinks it should be - will it be lean or rich? Who knows - you will need to get a wideband to tell you that. Once the computer adapts, when you go WOT, it goes to the tables it stored when in closed loop, so what ever it is doing in closed loop will have a similar effect at WOT. If you bump up the fuel pressure, the computer will shorten the injector pulses and vice versa if you drop it. So set it where ever you want to, it doesnt' really matter!

 

[jtfairlane]

The above ^ is kind of true, and kind of not true. The computer can only adjust the injector pulse if the fuel pressure is set within a certain range. If its really rich or really lean, the computer cant adjust the pulse enough to get it to idle/run correctly. Otherwise he's right.

 

[ShortThrow50]

eh. I was afraid of this. Id rather not take my car to get dyno tuned. What are my options? What is the wideband thing? Some sort of programmer. Please explain. I know car engines and such but not the computer part. Thanks

 

[vristang]

A wideband O2 is an oxygen sensor that is more accurate than the stocker.
Stock O2's are narrow band. An aftermarket wideband O2 will set you back at least $200, depending on options. Most will include some form of datalogging, and the ability to simulate the narrow band signal.

A narrow band O2 is only accurate in a 'narrow' range, which happens to be near stoich. Effectively the narrow band O2 is a switch type sensor. It can only tell the computer that the exhaust is either Rich or Lean; not how far rich or lean though.

A wide band O2 is accurate over a very large range. More than you are likely to use.

The Adaptive Strategy of the EEC-IV can adapt within a range of +/- 12.5%.
Once you peg out of that range, there is no further adaptation to the injector pulsewidths.

jason

 

[ls1beater4eva]

pro pruducts intake??

ok well a friend of mine baught the propruducts intake for his car and the screen that goes under the pcv grommet falls strait to the bottom of the baffel has anybody else had this prob with this intake ?

 

[ShortThrow50]

A wideband O2 is an oxygen sensor that is more accurate than the stocker.
Stock O2's are narrow band. An aftermarket wideband O2 will set you back at least $200, depending on options. Most will include some form of datalogging, and the ability to simulate the narrow band signal.

A narrow band O2 is only accurate in a 'narrow' range, which happens to be near stoich. Effectively the narrow band O2 is a switch type sensor. It can only tell the computer that the exhaust is either Rich or Lean; not how far rich or lean though.

A wide band O2 is accurate over a very large range. More than you are likely to use.

The Adaptive Strategy of the EEC-IV can adapt within a range of +/- 12.5%.
Once you peg out of that range, there is no further adaptation to the injector pulsewidths.

jason

So would one of these be beneficial for a top end job? Or should i hold off till the day i do something bigger such as a stroker?

 

[Flavadave4]

start at 40psi with the vac off.

 

[ShortThrow50]

start at 40psi with the vac off.

With the vac disconneted? Ok. Ill do that. Gotta love this site for all the fox owners. I would be up ****s creek without you guys. Thanks

 

[ronburgundy]

i have the aeromotive press. reg. it said to start at 48 psi static(no vaccuum). mine seems to run fine with the tf top end and 24 squirters.