tuning advise

[awdmonster1904]

I am new at this but the first thing i noticed is that i get lots of knock after 5000rpms
Also sometimes my o2 0.67V on the logger on high rpms


my mods are 680cc,2GMAF SAFC, Loger, 255 walbro fuel pump bastard 20g chiped ecu for my set up
FMIC 3IN TBE

basicily i get no knock until 5000rpms and up boosting 15psi 10counts and up timing is 10°~20° on the high
IDC is btw 76%@5100rpm 86 ~91% to red line
my base fuel pressuse is at 38.5psi vac deattached
I dont understand why my injectors are almost maxed out

Also i might have phantom knock but not on low rpms
I added 10%fuel with the safc on the high throtle from 5k to 7k
the knock went from 20~23 to 9~10
the car still feels bad though I could do better
I know I need to get A wideband and I will I just need some input on this situation

thanks

 

[JayRolla]

You need to pull some timing out and since all you have is a safc you will have to pull 3* out with the CAS.

 

[awdmonster1904]

You need to pull some timing out and since all you have is a safc you will have to pull 3* out with the CAS.

OK I would do that with the timing light
I should also re wire my fuel pump

 

[awdmonster1904]

OK I would do that with the timing light
I should also re wire my fuel pump

*update*

Pulled timing to 2* ,Rewire my fuel pump

the car runs rich pig rich knock has gone from to 10counts to 1 or 2 here and there on the high rpms
the crapy thing about all this is that now it runs rich timing is still all *exmple* 5675rpm,IDC 78% knock 1 timing 45*
them the logger died no more battery is that normal for timing to be all that high ?
on the butt dyno it feels better on the high On the low it feels slugish rich
wideband is on the way I should have it by friday

 

[gsx7707]

i had almost exact setup and got 28lbs on race gas with no knock i was taking out 8-9 percent on my afc

 

[awdmonster1904]

i had almost exact setup and got 28lbs on race gas with no knock i was taking out 8-9 percent on my afc

how about on pump gas ?

 

[5150DSM]

Do you have a AFPR for that 255? If not, that could be the root of your problems. The stock FPR cannot handle the flow from a 255 and you end up with a non-linear fuel curve. From experience, it is nearly impossible to get an optimum tune from a non-linear curve. You'll be rich in some rpms, lean in others and never consistent from log to log.

 

[awdmonster1904]

Do you have a AFPR for that 255? If not, that could be the root of your problems. The stock FPR cannot handle the flow from a 255 and you end up with a non-linear fuel curve. From experience, it is nearly impossible to get an optimum tune from a non-linear curve. You'll be rich in some rpms, lean in others and never consistent from log to log.

yes I have a AFPR and its set up 37.5psi

 

[5150DSM]

yes I have a AFPR and its set up 37.5psi

Hose on or off?
Try 43.5 for base fuel pressure, that's what your injectors are rated for. Your duty cycle should drop and you will get better AFR's in the upper RPM's.

 

[awdmonster1904]

Hose on or off?
Try 43.5 for base fuel pressure, that's what your injectors are rated for. Your duty cycle should drop and you will get better AFR's in the upper RPM's.

I ill give that a try but woulud it make me run richer?

 

[TastyTalon]

I tuned a guy and was having similiar problems and turns out the fuel line had a slight kink in it and after replacing it with some goodyear fuel line at Smucks it was fine. Something to check out possibly. Just my 2 cents.

 

[awdmonster1904]

I checked the lines they are not kinked they are curbed
how's bumping the fuel going to help ?

 

[awdmonster1904]

Hose on or off?
Try 43.5 for base fuel pressure, that's what your injectors are rated for. Your duty cycle should drop and you will get better AFR's in the upper RPM's.

with the hose off 37.5

 

[5150DSM]

I checked the lines they are not kinked they are curbed
how's bumping the fuel going to help ?

I suggest a base pressure of 43.5 because that is what most aftermarket injectors are rated for running at 37.5 decreases the overall fuel volume coming to the injectors, which will make them work harder to achieve the desired fuel delivery parameters. (I/E higher duty cycle) At duty cycles over 80-85% the injectors can go static and provide erratic fuel delivery. You said your car is running "pig rich", how do you know? Based on the O2 voltage you stated, your car is running quite lean. At the higher fuel pressure I suggested you will get lower duty cycles, which will make your fuel delivery more linear and consistent and hopefully pull your AFR's closer to the acceptable range; with the narrowband you are shooting for .88-.95v
Also, have you checked the knock sensor itself for deterioration? If there is goo running out of the back of your KS, it is shot. It becomes much more sensitive to mechanical noise and has a tendency to read such as knock.

 

[steve]

I just got a AEM wideband where do I wire up the white wire
so I can log it on my MMCD ?

The typical place is to the EGRT input. That's pin 15 on the 1G ECU connector. Since yours is a California car that's going to be in use and you don't have an available analog input to the ECU unless you switch to running a Federal emissions setup. (Fed ECU, DSMLink, or a chip)