last 2 days im runing on 61mm pulley, also have d cai,82mm tb, updated cooling system,and ecu tune.... this is todays dyno, im run 20-21 psi-of boost and afr is 16!!! need advice

 

Hi,
1. check engine codes
2. check/change fuel filter - maybe a clogged fuel filter (happen to me).
i would recommend going from stock fuel filter/regulator to adjustable like Needswings adjustable regulator/filter.
then raise fuel pressure/adjust to the needed afr ratio @ wot (you need a innovate afr controller or similar).

Steven

Berlin Germany

 

thanks steven, i have stock mann filter with 4 bar inside regulator, i think about adjustable regulator and simple flow filter, but stock fuel pump and injectors can handle good afr to 20 21 psi?

 

Well IMHO the stock fuel pump can handle the fuel demmand @21 psi but not without raising the fuel pressure.
Do a research here on the crossfire forum.
Boost pressure is "fighting" against fuel pressure. The more boost, the more fuel pressure is needed in general, especially when the pump is not big enough.
Raising the pressure to about 4.5 bar would probabely solve your problem including not to change to bigger fuel injectors/fuel pump.
I would check the pump as well (free flow). As far as i know the pump flows 160l/hr, but please recheck.

 

i cant find info about pump,2.3 k and 3,2 k share same pump and i think its weak ,if someone have info pls help

 

once you break 18.9psi you lean out on the stock fuel system, the 61mm pulley you are running is far beyond that.


lower the boost or add more fuel

 

i am not running as much boost from a 178mm crank pulley but mine ran lean at the top before i changed the fuel pump out for the SL55 pump , then it was fine.

 

thanks, i can fix the problem with 5 bar regulator only and stright fuel filter?can oem pump and injectors handle 20 psi? only with more pressure on rail

 

updated!!!
i have installed sl55 pump the afr is better after 5200,before was 16 now its 14.5 but i think fuel pressure needed.

 

When you start to go past 20 psi boost, you are going to max out your fuel supply system. Some members get by with a fuel pressure regulator and pressure boost to about 66 psi. Some do not, probably due to location, atmospheric differences, etc. The problem is that at max boost with OE fuel system, the duty cycle of the stock injectors is extreme. Best answer is SL55 pump, adj. regulator and 550cc injectors, not all that much $ all in all. Good insurance to avoid catastrophic disasters.

 

Depends on your elevation, but I'm running a CL63 fuel pump, stock fuel filter (until I hook up the AFPR setup) and stock injectors with a 65 and hitting 19.3 psi @ WOT with 11.5 AFR. There were a bunch of Colorado members running the 62 pulley with no fuel upgrades.

 

this was my answer on 4-1 in answering a pm


16 afr is tring to explode your engine maybe get rob needswings adjustable furl system and set it around 75 psi
with the stock fuel and without a extreme tune you can't run the stacked pulleys what was the afr before when you had the higher hp,,, something
is wrong with tune,,,pulleys,, or fuel system,, if u still have cats on the car they could be going bad. jim
__________________

 

Im hitting 20 psi with 61 mm pulley,d cai and 82 mm tb lots of cfm 😉,ill try pressure regulator

 

55 fuel pump, 550 injectors, and retune from jerry at eurocharged... I'm at a 11.7afr on 22psi with a 185mm pulley

 

Wouldn`t afr 16 @ wot @ 20 psi @ 5700 @ IAT 60-70°C detonate like hell? Knock sensor didn`t shut you down to limp mode once?

Maybe check afr gauge first or O2 sensor or both before changing too much.

Steven

Berlin Germany

 

thanks to all, i already buy sl55 pump ,will try fuel regulator or will drop boost to 19 psi.

 

Before i started on the design of the adjustable fuel regulator i once hooked my boost to the regulator port on the refuel regulator, at 20 ++ boost I was hitting 9:1 with the stock system!! The rail pressure is everything and raising it a few PSI is all that is needed, see ROB for the kit, youll be fine. Bigger injectors do not do too much unless the fuel pressure is adjusted up.

REMEMBER the boost is pushing against the fuel back into the injector, like 20 psi off the rail pressure with a pulley kit. You can run the engine without the fuel pump on idle as the suction will draw fuel from the injector body. Been there done that. The adjustable regulator just adds boost signal to the regulator as you increase the boost - DYNAMICALLY as you drive.. High rail pressure would flood the motor if it were set up all the time, ie my 9:1. Its all about effective injector pressure:: Rail pressure minus the boost pressure= effective fuel pressure

Enjoy Woody

 

useful info thanks woody

 

Rising the fuel pressure a couple of psi`s seems to be ok.

But don`t forget: closed loop (lambda/02-controll) isn`t present only @ wot, it also isn`t acitived on cold start periods for about 3 - 5 minutes until the o2 sensors are heating up. (open loop)

That means the engine is running very rich on much higher fuel pressures for a certain peroid after starting a cold engine. Maybe your are not concerned about the fuel consumption. But spark plugs for example don`t like wet periods for a very long time. And of course we all love clean combustion chambers .

When the O2 sensors are heated up, the closed loop is starting and the the efi is trying to correct the rich conditions caused by the higher fuel pressure as much as possilbe but probabely not mucho macho fuel pressures

For better understanding one of my favourite videos


cheers

Steven

Berlin Germany

 

Agree, going too high on pressure also makes the ECU pull fuel out in closed loop during normal driving. These LTFT are applied to your open loop WOT maps also which is counter productive.