Balance rates, whacha think?

[gamudslinger88]

My build is in process, power goals are 750 to 850 hp right now on my single then 1000 on twins. I'll be sending my injectors to someone to get worked to either 60 or 100% just for the sake of conversation and opinions what do yall think of these balance rates.

Cold at first start up in park


After a short drive and engine temp at 165 ish in park.


These are after 30 mins of driving, completely warm 178 and in drive.



I know balance rates are not "take it to the bank" information on injectors health but what's yalls thought. Seems like from one extreme to another.

 

[paint94979]

Sure they're in spec... +4 / -4

 

[gamudslinger88]

I guess the cold start up +6 throws me off.

 

[mike diesel]

Doesn't the cts tell you what spec is when you select balance rate pid??

 

[gamudslinger88]

It does. The prompt screen says +4/-4 in park +6/-6 in drive, also says to check at start up with engine cold, everyone else says to check with engine warm. What I'm getting at is the extreme swing in a few injectors, is this narmal to swing this much. I don't want to send some junk injectors in to be built although I don't believe these are junk.

 

[OregonDMAX]

Don't even check them cold, checking hot is a more valid test

 

[cstephens93]

Look good to me. But do a quick search for Fermanators injector balance rates

 

[gamudslinger88]

I read his write up a while back. I guess I forgot about it, I should reread it. I remeber something about using the frp at idle as a bar line and add or subtract
That from the rates. That bees the one?

 

[cstephens93]

Yeah you take what the main injection fuel rate is at idle i believe vs what it SHOULD be at idle then use that and compare it to you balance rates

Here is what I found when I did mine

I drove my truck for about 30 minutes up to operating temp around 185 degrees, and both desired and actual rail pressure was 4.3 Kpsi. According to my edge, my MIFR was 4mm3. So I take 9mm3 and subtract 4mm3 which leaves 5mm3. So Im supposed to use 5 when looking at my injector balance rates.

Parked, in idle, my rates were as follows

Injector 1=-0.5 +-5 = -5.5
Injector 2=0.2 +-5 = -4.8
Injector 3=0.0 +-5 = -5
Injector 4=-0.8 +-5 = -5.8
Injector 5=2.5 +-5 = -2.5
Injector 6=-0.1 +-5 = -5.1
Injector 7=0.5 +-5 = -4.5
Injector 8=-1.8 +-5= -6.8



I had my truck parked for about two hours. Drove home and when I got home,
at idle, parked, and operating temp my balance rates were as follows

Injector 1=-0.4 +-5 = -5.4
Injector 2=0.4 +-5 = -4.6
Injector 3=0.0 +-5 = -5
Injector 4=-0.8 +-5 = -5.8
Injector 5=2.6 +-5 = -2.4
Injector 6=-0.4 +-5 = -5.4
Injector 7=0.9 +-5 = -4.1
Injector 8=-2.0 +-5= -3

 

[gamudslinger88]

FRP 4.9Kpsi
CFR 8mm3 (fluctuated between 6 and 12 but stayed around 7 and 10)

+2.3 inj1
-1.0 inj2
+1.6 inj3
-2.5 inj4
+2.0 inj5
+0.0 inj6
-2.0 inj7
-0.3 inj8

This is running 4 hours of driving, at idle in park.

 

[gamudslinger88]

So would I add 1 to everything?