IFR table
12-29-2006, 12:47 PM
#11
Originally Posted by 02sierraz71_5.3
Most of the trucks Ive seen fluctuate from 55psi at idle and part throttle to 58-60 at WOT. The thing about the IFR table is that it will never be perfect there are other factors that can influence what the actual injector flow rate like voltage fluctuations etc..
But, the good news is that any discrepancies can be made up by the VE table and/or maf so I set the IFR according to the max injector rating (60psi) and then go about tuning the rest any slack is taken up in the other air tables.
Thats my take on it.
But, the good news is that any discrepancies can be made up by the VE table and/or maf so I set the IFR according to the max injector rating (60psi) and then go about tuning the rest any slack is taken up in the other air tables.
Thats my take on it.
12-29-2006, 01:01 PM
#12
Originally Posted by Whippled 496
Okay, thanks Chris. So if i go messing with the IFR table, I am going to be messing with the VE and MAF tables as well. Hmmmm, maybe i shouldnt even fool with it yet and just wait till get the nerve to just go with the 2bar COS and do it all at one time.
12-29-2006, 01:34 PM
#13
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yea, that's not tuning, that's fudging...
you need your IFR table to reflect changing fuel pressure and the pressure in the manifold.
2barMAP is mandatory, as it will allow you to calculate the true airflow. MAF is not suited for FI in GM PCM's because it has a low airflow limit, that just about any LSx motor with even small boost can outflow, making MAF flatline and not report proper airflow (there's a current thread on this topic on tech if you want more reading).
COS will allow you to take the 2barMAP readings and provide you with proper airflow readings. once you have airflow and injectors both properly set up, tuning is easy. on top of that, COS makes it actually easier than stock to monitor and control fueling under boost. most importantly, the big reward for doing things properly, you end up with a tune that is ready and able to take on different pressures, temperatures, altitudes, load, etc safely and without adjustments.
as for dicking with IFR to achieve proper final fueling...well, i'm writing something up on this topic right now, should be ready in few hours, it should blow some minds
you need your IFR table to reflect changing fuel pressure and the pressure in the manifold.
2barMAP is mandatory, as it will allow you to calculate the true airflow. MAF is not suited for FI in GM PCM's because it has a low airflow limit, that just about any LSx motor with even small boost can outflow, making MAF flatline and not report proper airflow (there's a current thread on this topic on tech if you want more reading).
COS will allow you to take the 2barMAP readings and provide you with proper airflow readings. once you have airflow and injectors both properly set up, tuning is easy. on top of that, COS makes it actually easier than stock to monitor and control fueling under boost. most importantly, the big reward for doing things properly, you end up with a tune that is ready and able to take on different pressures, temperatures, altitudes, load, etc safely and without adjustments.
as for dicking with IFR to achieve proper final fueling...well, i'm writing something up on this topic right now, should be ready in few hours, it should blow some minds
12-29-2006, 06:26 PM
#14
Originally Posted by RedHardSupra
yea, that's not tuning, that's fudging...
you need your IFR table to reflect changing fuel pressure and the pressure in the manifold.
2barMAP is mandatory, as it will allow you to calculate the true airflow. MAF is not suited for FI in GM PCM's because it has a low airflow limit, that just about any LSx motor with even small boost can outflow, making MAF flatline and not report proper airflow (there's a current thread on this topic on tech if you want more reading).
COS will allow you to take the 2barMAP readings and provide you with proper airflow readings. once you have airflow and injectors both properly set up, tuning is easy. on top of that, COS makes it actually easier than stock to monitor and control fueling under boost. most importantly, the big reward for doing things properly, you end up with a tune that is ready and able to take on different pressures, temperatures, altitudes, load, etc safely and without adjustments.
as for dicking with IFR to achieve proper final fueling...well, i'm writing something up on this topic right now, should be ready in few hours, it should blow some minds
you need your IFR table to reflect changing fuel pressure and the pressure in the manifold.
2barMAP is mandatory, as it will allow you to calculate the true airflow. MAF is not suited for FI in GM PCM's because it has a low airflow limit, that just about any LSx motor with even small boost can outflow, making MAF flatline and not report proper airflow (there's a current thread on this topic on tech if you want more reading).
COS will allow you to take the 2barMAP readings and provide you with proper airflow readings. once you have airflow and injectors both properly set up, tuning is easy. on top of that, COS makes it actually easier than stock to monitor and control fueling under boost. most importantly, the big reward for doing things properly, you end up with a tune that is ready and able to take on different pressures, temperatures, altitudes, load, etc safely and without adjustments.
as for dicking with IFR to achieve proper final fueling...well, i'm writing something up on this topic right now, should be ready in few hours, it should blow some minds
If you leave now, you could be here by Sunday.....SEE THIS
12-29-2006, 06:40 PM
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if you're in MD, why not hit up Larry from GreenLightMotorsports? he's an efi guru with a lot of experience.
actually, i'm gonna be in DC 8-12th of january, dunno if that helps you any
actually, i'm gonna be in DC 8-12th of january, dunno if that helps you any
12-29-2006, 07:06 PM
#16
Originally Posted by RedHardSupra
if you're in MD, why not hit up Larry from GreenLightMotorsports? he's an efi guru with a lot of experience.
actually, i'm gonna be in DC 8-12th of january, dunno if that helps you any
actually, i'm gonna be in DC 8-12th of january, dunno if that helps you any
12-29-2006, 07:33 PM
#17
Originally Posted by Whippled 496
Cool stuff RHS, i may have to set that up so i can log FP with EFILive, very cool. However, lol...in the meantime, what is the general concensus on that B4001 table? I know I can tweak it once I have logged the data, but just for starters what should those columns be populated with? Should they inducate the full p/hr ability of the injector which would be 44.0, or should they be slightly lower like mine is now at 40.8?
What I'd do is disconnect vac line, test fuel pressure at idle using a mechanical gauge (or electric one that you can be certain of accuracy). Set it to 58psi if it's off to begin with. Then adjust up a few PSI to say, 62psi. Take the sqrt of the difference of the pressure change, and multiply that by the 44lb and set that up as your IFR.
And in this case, I agree with Marcin on the need for 2 bar. As you saw long, long ago, you're maxed at above 4k rpms with your 8.1l.
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