tweecer says injector duty cycle = 101% ???

[HotRodKid]

yea, the datalog says 101% on a highway pull at one point

is this a problem ? or is this a errorous side effect of something else we might have done ?

 

[SeanMc]

Bigger injectors ??

 

[Ishodu]

Running too much fuel rich, or running out of fuel injectors too small. How is the AF ratio?

 

[1slickRED89]

The ATX doesn't datalog somethings corretly, don't know why but it has never been corrected in the software. I would double check that with an automotive multimeter than does dutycycle.

BTW congrats to on the R/t upgrade.

 

[sho_sc]

yea, the datalog says 101% on a highway pull at one point

is this a problem ? or is this a errorous side effect of something else we might have done ?

Problem?!? Yes! With my 48# injectors I was seeing 102% and more. I would get a CEL when it was over 103%. If you have a "correct tune" and you are seeing anything more than 92%, then your injectors are going static. No way to adjust the AFR when that happens.

 

[LeddZepp8687]

Yea but over 100% DC on 48# Injectors???

My buddie is pushing over 550 RWHP on Accel 48# Injectors.....Thats a V8 too. Uhhhhhhh

 

[40BelowSummer]

Yea but over 100% DC on 48# Injectors???

My buddie is pushing over 550 RWHP on Accel 48# Injectors.....Thats a V8 too. Uhhhhhhh

You're buddy has two extra cylinders. You can increase the fuel pressure and injector size scalars for more flow too.

 

[Bringetto]

right, you cant compare carb or injector sizing from one motor to the next. like a guy i know has a 1300 cfm carb on his car and its making only about 250 hp.



btw its a ghia. a really fast one.

 

[somedude_001]

nick post the whole story and the data logs.

 

[yamahaSHO]

right, you cant compare carb or injector sizing from one motor to the next. like a guy i know has a 1300 cfm carb on his car and its making only about 250 hp.



btw its a ghia. a really fast one.

You don't compare them for motor's, you size them with the amount of power...

As said above, the turbo V8 has more cylinders, and it has two more injectors with the power is being spread across two more cylinders than it would with our V6. Therefore, the V8 will see less cylinder pressure per cylinder than a similar V6 setup.

 

[LeddZepp8687]

Seems to me that with 2 extra cylinders you would need more fuel. Expecially since hes making much more power. Am I ********?

 

[HotRodKid]

550 hp on a v8 is 412 hp on the same engine missing 2 cylinders, so a 550hp chevy 350 would need the same injectors a 412 hp 90* chevy 4.3L would need ... at the same fuel pressure (asuming the same driveline loss and such)

but anyways, we need to get some more datalogs b4 we can realy start to say theres a problem, and we need to get a different wideband in the car

currently, PW1 and PW2 dont line up ... AT ALL, 1 starts at 20ms @ idle and drops as speed increases, pw2 dispalys properly .... but i dont know if i added pw1 to the payload ... so it could just be a ghost reading ...

doesnt help that the wideband is on the fritz and wont last a full pull, so by the time we are supposedly @ 101% DC, theres no wideband reading

oddly, we have only SLIGHTLY down graded the injectors since that 17psi pull we made, no other mods that would realy change anything ... and the car held an 11.5:1 AFR on that 17psi run ..

so obviously i have my doubts about weather the injectors are realy going static ...

edit: and oh yea, the maf seams to be reading 5000kg/hour ... wtf ?????

 

[yamahaSHO]

Seems to me that with 2 extra cylinders you would need more fuel. Expecially since hes making much more power. Am I ********?

Theoretically, X amount of power requires Y amount of fuel. Meaning, in a perfect inviroment, it takes the same amount of fuel to make X amount of power, regardless of cylinders (not accounting for drag, weight, design, effeciency, etc).

So if a 3L V6 and a 4L V8 are making 500 hp, the V6 will see more stress and higher cylinder pressure in each indiviual cylinder. Considering that each cylinder in the V6 is seeing more of a load and you have less cylinders to put it in, you start maxing out the X injector when the V8 has 2 more of X injector size to spread the load. The more cylinders you have, the less need for a larger injector to make X amount of power.

This is over-simplified, but does it make sense?

 

[1slickRED89]

The ATX doesn't datalog somethings corretly, don't know why but it has never been corrected in the software. I would double check that with an automotive multimeter than does dutycycle.

currently, PW1 and PW2 dont line up ... AT ALL, 1 starts at 20ms @ idle and drops as speed increases, pw2 dispalys properly .... but i dont know if i added pw1 to the payload ... so it could just be a ghost reading ...

have fun finding all the little things that are not right in the ATX datalogs. you will find alot of the fuel related features (on one bank only) and the MAF voltage are completely wrong and misleading.

 

[sho_sc]

Yea but over 100% DC on 48# Injectors???

My buddie is pushing over 550 RWHP on Accel 48# Injectors.....Thats a V8 too. Uhhhhhhh

This is back in the winter. I was running Accel 48# set at 48 psi base pressure (TwEECer set at 48.5...Accels flow 46.0 at 43.5 fuel pressure). Notice the duty cycle?

 

[sho_sc]

550 hp on a v8 is 412 hp on the same engine missing 2 cylinders, so a 550hp chevy 350 would need the same injectors a 412 hp 90* chevy 4.3L would need ... at the same fuel pressure (asuming the same driveline loss and such)

but anyways, we need to get some more datalogs b4 we can realy start to say theres a problem, and we need to get a different wideband in the car

currently, PW1 and PW2 dont line up ... AT ALL, 1 starts at 20ms @ idle and drops as speed increases, pw2 dispalys properly .... but i dont know if i added pw1 to the payload ... so it could just be a ghost reading ...

doesnt help that the wideband is on the fritz and wont last a full pull, so by the time we are supposedly @ 101% DC, theres no wideband reading

oddly, we have only SLIGHTLY down graded the injectors since that 17psi pull we made, no other mods that would realy change anything ... and the car held an 11.5:1 AFR on that 17psi run ..

so obviously i have my doubts about weather the injectors are realy going static ...

edit: and oh yea, the maf seams to be reading 5000kg/hour ... wtf ?????

If you want I can post an Excel graph that I call the million dollar graph. It graphs injector duty cycle and AFR over MAF voltage. It shows exactly what some of the high dollar "professional" tuners have kept to themselves, that once injectors go 92% that just stay on.

 

[Axianator]

yea, the datalog says 101% on a highway pull at one point

is this a problem ? or is this a errorous side effect of something else we might have done ?

Unlike some of the other broken D4U1 datalogging registers (such as MAF voltage and flow, injector pulsewidth and KAMRF), CalCon has always calculated and displayed the correct injector duty cycle for both banks on the D4U1 calibration.

currently, PW1 and PW2 dont line up ... AT ALL, 1 starts at 20ms @ idle and drops as speed increases, pw2 dispalys properly .... but i dont know if i added pw1 to the payload ... so it could just be a ghost reading ...

edit: and oh yea, the maf seams to be reading 5000kg/hour ... wtf ?????

As I noted in a recent reply in your other thread, I am actively working to remedy these datalogging display problems.

Please stay tuned for some more information on this particular point.

so obviously i have my doubts about weather the injectors are realy going static ...

Given your modifications, the amount of boost you're seeing, and my own tuning experience with a similar setup that utilized Accel 48s, I have no doubt that you're running your injectors static at mid- to high-RPM WOT operation.

 

[somedude_001]

Given your modifications, the amount of boost you're seeing, and my own tuning experience with a similar setup that utilized Accel 48s, I have no doubt that you're running your injectors static at mid- to high-RPM WOT operation.

this my friends is why you don't just get the smaller ones when because "you wont need them"

my only question is if i'm maxing them in warm weather at 10psi how is my engine still alive after 17+PSI in the winter when my wastegate vac lines froze? luck?

 

[Axianator]

my only question is if i'm maxing them in warm weather at 10psi how is my engine still alive after 17+PSI in the winter when my wastegate vac lines froze? luck?

Although I think I may have accidentally misread some of the posts that you or Nick made earlier regarding your current boost readings (I thought you guys said you were now seeing upwards of 17psi at warm cruise), I still stand by my previous statement, assuming the remaining variables of engine load, injector duty cycle, and MAF voltage readings (which can be multiplied by 3.1415 to obtain the correct voltage) are within the ranges that I think they are.

Also, with the possible exception of this newest CalCon database file, I should note that all of the previous software releases have correctly calculated injector duty cycle on both banks for the D4U1 and X2J SHO calibrations. Thus, if CalCon is consistently reporting 100%+ duty cycle on your dashboard, then your injectors are nothing more than teeny fire hoses at WOT.

 

[HotRodKid]

17 psi didnt happen all tomuch realy, a pair of 17psi runs whenthe car was first out

a weeks worth of light driving during that winter week the car was out

at 17psi, its holds 12.5 afr all the way till the shift
at 10psi (or thre about) it holds the same afr, and reports 101% afr

if they are going static at 10psi,how do they supply enough fuel at 17psi?