When is a adj fuel pressure regulator needed I have a new lo5 with intake headers 3 imch exhaust ultimate tbi mods and some more mods do I need more fuel preasure

 

Only way to know for sure is monitor the duty cycle of injectors. You may need a stronger fuel pump(TPI).

 

This site has some good info on TBI mods & fuel pressure: http://www.cfm-tech.com/gm_tbi_fuel_pressure.htm

On my K2500 with the L05 (tb spacer, ultimate tbi mods, salad bowl & k&n) I'm running right about 14.5 psi and it seems to be happy there. It does run a little rich until it reaches closed loop (I need to upgrade to a heated o2 sensor so it gets there quicker), but I can pull down 18.5 mpg running 75-80 so I know it's pretty close to where it needs to be.

 

I have tbi set up ronny.....
What regulator did you use 88monte and what is stock psi

 

I would not trust anything from that cfm site, what is not BS is just totally inaccurate.

This is a site where you can find good, accurate information on TBI fueling.

http://www.dynamicefi.com/TBI_Fueling.php

 

What Ronny was referring to is that the tbi pump is not capable of supplying more than 15-16 psi, maybe 18 if it's a good one, so what most people do is swap it out with a tpi pump since it's a direct fit replacement.

As for my regulator I have the cfm-tech unit, instead of buying their adapter & gauge setup I just picked up one of the actron units that comes with the tbi adapter and permanently installed the adapter:


And stock pressure is 11-13 psi.


Curious as to what you find to be BS/inaccurate on the cfm site, on most of the truck forums it's referred to as a decent set of info for someone with bolt-on mods only. The EBL site has nice info (and a lot more specific), but (at least in my impression) without having dyno'd the engine you're ultimately still guessing a bit, although it's likely you'd be much closer to the correct pressure.

And if I weren't planning to do a 6.0 swap on my truck I would definitely have EBL on it already, just don't want to spend the $ (and the time to install & get it tuned right, that's the big part) on something that's going to be replaced

 

Funny because most of the truck guys looking to get performance out of their TBIs come to TGO. CFM sure claims a lot but has no dyno comparisons for any of their products last I checked.