Hey guys my rebuilt 355 is making 400 FWHP. I currently have a BB TBI with 67# injectors fed by a TPI pump and ran by EBL. Wondering if I should run the 65# @ 32 psi or am I better off buying a set of 80# injectors and running them @ 22 psi? Any advice welcome, engine swap will be happening in the next month.

 

i am in the process of converting to 80# at 22 psi to feed my 355 w/vac ref. fuel pressure regulator. I want lower psi at lower rpms to help conserve fuel in my daily driver

 

Avoid the big injectors if you can, they offer no advantage.

I think guys use them trying to make up for other shortcomings.

The last run of BB TBI GM built ran 28-32psi. with smaller injectors. Ya think they knew what they were doing?

 

xch3no2, i seem to remember you are running injectors in the +30 psi range. What you are you using for injector offsets?

 

I'm putting a 350 in mine that is making a tad bit over 330 fwhp and I heavily relayed on everyone here for help for my decision. I have a GM Performance intake I'm having a 46mm TB built with 55# injectors running at around 20 psi. This is what I've decided on after a lengthy talk with Sean at SPR performance who is building it for me. If you come up with the perfect combination let us know. How do you like you EBL? I'm going that rout too. Again after taking the advice of pretty much everyone on here.
Good Luck

 

55 #/hr injectors at 20 psi will only support 258 HP (85% DC, and .45 BSFC).

Need 32 psi to support 326 HP, which may be enough. Otherwise can step up to a set of 61#/hr 5.7l injectors.

Definitely use a VRFPR (vacuum referenced FPR). Can use the injector compensation values from the included EBL_F_3001.BIN, and be sure to zero out the async transition PW table:

INJ - ASync Transition PW - TBI Only

RBob.

 

Yes, I'm 30+ psi. It takes 58 psi on 5235231 injectors to feed the Rat at a 1.1 hp/cube ratio. If I could get more fuel she will rev a a little higher...kinda pointless, it's a tow rig not a racecar, full throttle means wheelspin or 3 tons of steel traveling far too fast on a 4x4 platform.

My settings developed while bringing idle afr's to commanded values, after I was happy with the BPC. The numbers are 50-100% greater then original.
The F_3001 settings give a very good example of changes your likely to need.

Greg the 55#'s @ 32 is cool with me, do suggest VRFPR.

 

I wonder if that is the way I should go. I have 70 less hp then you. Anyhow let us know which way you go.

 

Right, going to run the 65# injectors at 32-34 psi. Putting my trans back together, need to bend up fuel lines so I can run my VAFPR and then I can do the swap. Will report back once it is running.