about how much fuel pressure should i be running in a 305 tbi motor that i installed 58cc vortec heads and running a small cam and is running long tube headers true duel.
the fuel pump and regulator and injectors are stock.
one i dont know what FP im running now.
two i dont know how to check it.
three i dont know how to figure out how much i need.
and four i want to find out which one i should swap first. Or maybe all
I need is a throttle body from a 350 or 454? Would tht work?
please help.
thanks in advance.

 

Sufficient to fuel motor at 12.5.1 A/F at WOT at 80% injector duty cycle. You really need a WB to monitor. The size of TB unit can be checked with a datalog of your map sensor. A reading of 95-100 MAP shows minimal restriction. 100 MAP shows no restriction. You will need to change the fueling in the chip as well as increasing fuel pressure. Stock FP is 12 lbs.

 

can fuel pressure be increased just by changing to an adjustable fuel pressure regulator or do i need to change more than just that and how much pressure would u suggest i run?
i know i need to tune it. but i need to be able to drive the car for the time being. thanks for your reply.

 

Research. Fuel pressure can be turned up, but not all injectors react well to it. I hate to be the "use the search" guy, but I don't have this info off the top of my head.

 

I have searched it and have not found it. So far seems tht 20 to 30 psi is what
Many run. But I don't want to mess anything up.

 

I think Fast355 is the King of use of high pressure TBI injectors. I think he was successfull up to around 35 lbs. I read the 90 lbs did not like the high pressure. That was a recent post. In fact the 80's may be a better choice. Also nothing wrong with running smaller at higher pressures. Right now I am using 80's at 20 lbs at low VAC and am finding I am too fat for AE. I am at minimal values in AE tps and map.

 

My plan is to use the high pressure BBC injectors that at 74# @ 2.0 bar. If that isn't sufficient, a bump to 2.5-3.0 bar should get me where I want to go.

What does this mean?

 

I am cuurently at minimum values in my AE-TPS and MAP. 61 usec in tables. When AE is involked I see 9.9/1 on WB at lower rpms. Too rich too fat. I cannot reduce lower than 61 msec I believe due to xdf. I am at 20 lbs FP with 80's. Fortunately I do have an AE RPM modifier that can accept negative numbers. I can therefore pull out AE leaving the 61msec in tables. I was made aware of that this past summer by RBob. So I am working on that right now and retuning.

Too fat for AE simply means I am flowing too much fuel during AE. Not relatedd to my diet of fried fish.

 

Oh, too fat = too rich. That sounds like a software issue, what system are you using? Strictly speaking, it's probably better than being too skinny.

 

I proudly run EBL. EBL.xdf. My AE adjustments are done by TunerPro. Not all masks (TBI) allow AE(+ or-) % modifications based on RPM. Stock F Body .bin had positive %numbers in that . Now my .bin has 50/50 + as well as -. Fortunately I have IAT(intake air temp) control as well. These cool days my intake air is 50% cooler than coolant temps.

 

What you need is an Actron 7817 pressure testing gauge. Use it per the instructions and report back.