hello,

i got a evo 8 with :

fp red ss jb turbo
​​​​​​built block 9:1 wisco pistons
manley i beam rods
s2 cams, ti spring and retainers
stock valves
aem ems v2
fic 1650 injectors
fic fuel Rail
gm flex fuel sensor
aem FPR set at 45 psi vaccumed from mainfold
bpr duble pumper 450's walbros (hobbs activated)
8an feed 6 an return
DW 100 micron fuel filter with 8 an fittings
sparktech cdi system coils
custom 3 inch down pipe
custom 3.5 inch kakimoto exhaust
2 10an fittings from valve cover to vented catch can.

i am running out of fuel with the 1650 fic's with injector with duty cycle at 95% and only at 2 bar or 29psi of boost on pure ethnol mixed with pump gas too make E85.

​​​​no boost leaks all vaccume lines are good, battery voltage is at 13.60 on WOT @8200 rpms

AFR are in the 11's on WOT all the way too cut off.

​​​​​​my question is are the 1650 fic not big enough for this setup?? i want too boost more but im out of fuel with the injectors at 95% duty cycle.
all parts are new fuel pumps are new.

i can not find any restrictions in my system that could cause this as the twin 450's should
Should i go for bigger injectors?? as i want boost too till 33 psi or 35 psi if tuner finds all is good.

any suggestions or help would be appreciated.

thanks
​​​​

 

Surprised also that you are out of fuel. Why not go to a 2000cc or 2600cc injector. You can also bump up the fuel pressure if you want to keep the 1650’s. Are you sure your ethanol content is e85 and not higher?

 

hey,

​​​​​we get 100% ethnol here and we have to mix the blend our self with pump gas to get any wthnol content we want... its never the same as its hand mixed and not from a filling station.

but on this occasion my zetronix content reader and ecu showed i was at e86 so close enough.

 

can you log your fuel pressure during a pull?

 

yes ofcrose i have a aem pressure sensor attatched on my FPR ... fuel pressure remains constant till 7k rpms... and drops abt 40-50kpa from 7k till 8k... afr does not change, stays in this 11's

 

test with new set of pumps 450's made no difference in fuel pressure... fpr set to 45 psi

but i reduced the ethnol levels too E80 and duty of the 1650's drop to 93% from 100% with E87

i dont understand why my duty cycle is maxing out on only 2bara of boost... logs shows fuel pressure is fine with only 20kpa drop around 8200rpm my red line.

2 walbros 450's is a lor of fuel for a red and fix 1650's with 8 an feed and 6an return.
battery voltage is 13.60 at wot so voltage isn't the issue.

do i need bigger injectors?? say 2150 fic or id2000 which are more the less same.

any suggestions
​​​​​

 

If you are running out of fuel on your setup I would check your double pumper. There is no reason with 2x 450s your running out of fuel. I would look at the hobbs switch and make sure its wired correctly and is working properly. I had this happen with my car had 285s hp 255s in it. I would get real lean and it was cause the hobbs switch wasn't activating. I solved this issue with getting rid of the hobbs switch and went to the ecu to control the second pump.

 

Way overkill for the 500 whp he will make. I mean I will make north of 1000 wheel in my setup and I went from 2150s to 2600s being I would run out of fuel.

 

fuel pressure should not be constant during the pull..
it should ramp up with the boost.

im assuming you mean 40-50 psi ... and if this is the case at wot..., you dont have enough fuel pressure.

 

no its 50 to 60 kpa of drop at around 7800 rpms which is equal to 7-8 psi before that there is no drop in pressure. before 7800rpms there is no drop... my cut off is 8200 rpms. (red line)

how is it possible that two 450's are not providing enough fuel pressure when my batt are at 13.60 at wot.
afr does not go lean.

tested with new spare 450's
100 micron fuel filter
8an feed line
6an return.

im confused 🤦

 

white line is fuel pressure and yellow is rpms

as you can see there are small dips of 6-7 psi till red line from 4k rpms

 

Again check and make sure your second pump is coming on. Where is your boost source coming from for the second pump that controls your hobbs switch. I would stick with this or double check with the line off your afpr to make sure your fuel pressure is where it says it is. As hutch said fuel pressure should be constant throughout the rpm range.

 

my dublepump kit is from bpr and brand new with 450's... and yes I have checked the hobbs with external pressure and secondary pump turns on.

i even put in a set of brand new pumps again just to make sure pumps are not at fault... no change happened.

with line on the afpr its reading 45 psi and with vac line off it goes too 50 psi

is the it possible that my max'ed out 1650's are cauing the pressure drop of 10 to 15 KPA's at their. very end of the rpm range 7600jsh rpms.

does this drop at the end be caused by the maxed out injecctors?

 

First of all, that 100 micron fuel filter is insufficient, you need something <10 micron.


Second, FIC 1650's will max out around 610-620whp at standard fuel pressure (43.5psi base) when you have sufficient fuel flow (pump, lines, fuel rail, etc.. which you do seem to have covered here).

So if you're truly out of fuel, it would depend on how much power its making.

 

isn't 100 micron supposed to be less restricted then say 10 microns?

it was maxing out on E87 at 97% duty cycle but when i reduced the ethnol content to E80 the duty cycle camw down to 87-88% but i see 1-2 psi of fuel pressure drop at around 7600 rpm red line is 8200rpm

my problem is i cant rise my boost anymore of my fp red anymore with out rising the duty cycle as it will go up with boost.

currently im at 2 bar or 29 psi with the red and im sure the car would not be making more then 420iah whp with this much boost... my goel is 33- 35 psi too cross the 500whp mark.

i check all wiring anf both pumps are giving good voltages... pump 1 is around 14 v and 2 pump is 13.8 v on wot with batt voltage is 13.70 stable

all fuel lines are good and not restricted or pressed in any way.

fuel filter is good and not dirty at all.

​​​​​​afpr is at 45 base pressure with vac and 50 without vac

no leaks on vac or boost.

either fic 1650' are maxed out on ethnol or there is something not adding up 🤷