L3R + 720cc injector question

[DELTA_Rotary]

Ok heres the deal. Got everything put on the car finally. L3R, IRC Race Core, 720cc injectors, hacked 1g mas (yes I know i need a 2g). Well anyway I go out to make some pulls. start off down around 15 psi. AFC settings are -20% across the board. Knocks like mad when boost comes online. Drop it down to -10% same results. finally go all the way down to -2-3% and Im still getting a knock count of 30 or more at 5400+ rpms. Now I thought for sure these damn injectors would choke the car out like crazy running rich. Now why the hell am I still getting this terrible knock count with them? The duty cycle on the injectors never gets higher than 72% so I know im not getting close to maxing them out. Im confused as hell right now. Only thing I can think of is the fuel filter may be clogged.



PS these pulls were with 93 octane.

 

[RocketBoy]

Why don't you try going leaner. Being overly-rich can cause knock just the same as being too lean. What does your EGT read?

 

[DELTA_Rotary]

Originally posted by RocketBoy
Why don't you try going leaner. Being overly-rich can cause knock just the same as being too lean. What does your EGT read?

No EGT yet... yes I know Im supposed to have it but cash is tight.

 

[Kaane]

I have same problem. I just logged my car for a first time since major rebuild. I am getting knock at part throttle as soon as I see any boost (4000RPM +)

I got a L3r and 720's 40PSI base fuel pressure, and I am using the Ramchargers translator set globally for 700cc injectors which is neg 35% correction. I was looking at my 02 trim and when I saw knock it was pegged at 199%. My low mid and high trims don't wanna move yet, but I haven't driven the car more then half a mile so far.

Let me know what settings work for you. I got an AFC as well, but it's zeroed out at the moment.

 

[Mindslayer]

I had this problem and drive like that for 4 days and the day b4 I was going to the dyno to tune it. I blew my motor. You are too rich. I had 750cc(really 780) and I vented to the atmosphere. When I went into boost it knock bad and pulled timing. NOW I know. this is the fomal you need to use to find out what your overal stands need to be (450/your injectors=....-1= ().AFC setting.

Example 450cc/780=0.57692308-1=0.42

So my setting should had been -42 across the board and work it from there.


How this helps...

My car will be ready in a few weeks

 

[DELTA_Rotary]

Originally posted by Mindslayer
I had this problem and drive like that for 4 days and the day b4 I was going to the dyno to tune it. I blew my motor. You are too rich. I had 750cc(really 780) and I vented to the atmosphere. When I went into boost it knock bad and pulled timing. NOW I know. this is the fomal you need to use to find out what your overal stands need to be (450/your injectors=....-1= ().AFC setting.

Example 450cc/780=0.57692308-1=0.42

So my setting should had been -42 across the board and work it from there.


How this helps...

My car will be ready in a few weeks

I will go try that out. Looks like it should have been at -37.

 

[kingearl]

wow, if that the way to calculate it then -28 I will start off with on my new injectors.

Thanks for the tip!

 

[Turbo Guru]

Are you using a 2.0L with the L3R? How late is the spool?

Thanks,
Joe

 

[Kaane]

I get 15lbs of boost by 4100RPM

 

[DELTA_Rotary]

I get about the same spool time.

Mindslayer I havent gone out to test your theory but my 02 readings when Im knocking suggest that Im running lean which would lead me to believe I couldnt possibly still running rich. I will still test out the theory but im going to make sure I run low psi.

 

[Mindslayer]

keep us posted

 

[Unreal]

Taking a set percent out is stupid.

Start off with a basic tune up. You should have done that before even try tuning. Fresh bpre7es, fuel filter. Make sure the base timing is set right. If its too high you will knock very easily.

Start at 0 and see which way you need to go. When I had the l3r and even now, I'm mostly + with my 720ccs. I think +6% or so.

Also, don't even try tuning till you get rid of that 1g mas. With my 20g, I couldn't even go past 15psi without getting mas overrun, and the car knocking/bucking/missing.