2014 c7 automatic twin turbo

[gotparts]

Hello to all! Having an issue here on a c7 automatic we had just finished the twin turbo kit on. Scaled the tune enough to have the throttle stay open on the pulls and Afr from the wide and reading 11.6 to 11.7 to make sure we have enough fuel before touching timing. Timing is at 11 degrees. All is well til about 5300 and up. Commanded Afr is 12.16 and stays in the commanded pe throughout the run. The maf hits 86.68lb of air at 5300 then the car just leans out. Making around 590 whp at that point. We had a pull where it ran the Afr we wanted to 5700 and made 625 whp but still having the issue. We would adjust for the fuel pressure drop but then the idc and the inj ms would drop and the fuel pressure would rise. We would the. Adjust to have the idc and inj ms stay above 48 percent and the inj ms above 10ms but it still leans out. Tried soi from 300 to 370. Tried scaling the maf also. Maf hz is right at 11500 to 11800 hz by that time. Maf is in a 3.5 inch diameter pipe. Twin air to water cores with a decent sized cooler. 117 to 118 iat at that point. Once I get to the shop I'll post up a fresh log and the map we made depicting both good fuel pressure but low idc and inj ms, and the other would be high idc and inj ms and low fuel pressure .anthiny lower then 600 on the dd table and it will shut the throttle down to 69 percent. Just seeing you guys have any ideas what it would be? More of a discussion to figure out the answer on how to tune these.
Video of it on the Dyno http://www.youtube.com/watch?v=N9mJtVSVVr0&sns=em

[Ben Charles]

IF IDC is around 48 percent, sounds like your just out of fuel. You can push the SOI earlier and will give you a little head room, but that's not the best way to fix it.
What fuel system mods? I'm assuming stock cam/HPFP.......

[gotparts]

Yes stock cam and hpfp. Would doing the z06 injectors and fuel pump be the fix? Lift pump upgrade too? I can adjust to have the idc drop and ipw drop and fuel pressure stay up but still same thing.

[gotparts]

attached is the map and the last log on dyno 3rd gear pull

[Redline MS]

Hello to all! Having an issue here on a c7 automatic we had just finished the twin turbo kit on. Scaled the tune enough to have the throttle stay open on the pulls and Afr from the wide and reading 11.6 to 11.7 to make sure we have enough fuel before touching timing. Timing is at 11 degrees. All is well til about 5300 and up. Commanded Afr is 12.16 and stays in the commanded pe throughout the run. The maf hits 86.68lb of air at 5300 then the car just leans out. Making around 590 whp at that point. We had a pull where it ran the Afr we wanted to 5700 and made 625 whp but still having the issue. We would adjust for the fuel pressure drop but then the idc and the inj ms would drop and the fuel pressure would rise. We would the. Adjust to have the idc and inj ms stay above 48 percent and the inj ms above 10ms but it still leans out. Tried soi from 300 to 370. Tried scaling the maf also. Maf hz is right at 11500 to 11800 hz by that time. Maf is in a 3.5 inch diameter pipe. Twin air to water cores with a decent sized cooler. 117 to 118 iat at that point. Once I get to the shop I'll post up a fresh log and the map we made depicting both good fuel pressure but low idc and inj ms, and the other would be high idc and inj ms and low fuel pressure .anthiny lower then 600 on the dd table and it will shut the throttle down to 69 percent. Just seeing you guys have any ideas what it would be? More of a discussion to figure out the answer on how to tune these.
Video of it on the Dyno http://www.youtube.com/watch?v=N9mJtVSVVr0&sns=em

Did we talk today via e mail?

[gotparts]

Yes we did! Did your test go well with the new fuel setup?

[Redline MS]

I got a late jump on that car today was getting pulled in a millions directions.... Have quite a bit to do with low speed stuff before we move some serious airflow. Our setup will work for sure just haven't got there yet with this build.

I think as we discussed and Ben also noted your outta fuel mass for sure. A couple of hair driers will suck yah dry quick!

I'll keep you posted!

[thewrx]

What was the fuel setup you went with?

[gotparts]

New pump installed yesterday. Strapped on Dyno now! Gonna see if we can pull it to redline finally!

[gotparts]

Made 700 whp and backed it up 697whp at 7 psi on 10 degrees of timing. New file pump obviously helped. Mpa stays around 20 to 22 then drops around 5500 to 15 to 16 then shoots back up to 20 by 6200 and rises to 22 Mpa by redline. Idc is at 35 percent peak and inj ms is at 7.1 peak. Thanks for everyone's help!

[nkautz]

Made 700 whp and backed it up 697whp at 7 psi on 10 degrees of timing. New file pump obviously helped. Mpa stays around 20 to 22 then drops around 5500 to 15 to 16 then shoots back up to 20 by 6200 and rises to 22 Mpa by redline. Idc is at 35 percent peak and inj ms is at 7.1 peak. Thanks for everyone's help!

This is the stock stingray motor? How on earth did you make 700whp at 7psi and 10* if I made 610 at 8psi and 18* (meth injection) ??!!

[Higgs Boson]

This is the stock stingray motor? How on earth did you make 700whp at 7psi and 10* if I made 610 at 8psi and 18* (meth injection) ??!!

turbo

[Redline MS]

turbo

Got to love efficiency.......

[gotparts]

Stock yes and yes 700whp at 7 psi and yes twin turbo! Twin 67mm turbos and tial housings. Twin air to water coolers and stock catback exhaust. 18 degrees?!?! That's a bit excessive on timing even on meth?! What I seen on the Dyno today was messing with the soi from earlier injection to later injection numbers and also adjusting the Afr to be the same between runs by scaling the maf it made a big difference on power for sure.

[Higgs Boson]

Stock yes and yes 700whp at 7 psi and yes twin turbo! Twin 67mm turbos and tial housings. Twin air to water coolers and stock catback exhaust. 18 degrees?!?! That's a bit excessive on timing even on meth?! What I seen on the Dyno today was messing with the soi from earlier injection to later injection numbers and also adjusting the Afr to be the same between runs by scaling the maf it made a big difference on power for sure.

what made more power for you, earlier or later injection?

[gotparts]

Went from 360 and slowly lowered the numbers from there. Ended up around 330ish where it made the most power with the same style of tuning. Adjust soi, adjust maf for Afr. Looked at result and also log and then repeat til power dropped. It dropped at 325 so crept it back up to confirm. Eoi is stock, 180.
The lower the pe number (i.e. 1.12-1.13) the better the Mpa. Regardless of the leaner commanded Afr, I had adjusted the maf to set the Afr to my liking. Final Afr was 12.0 on spool up and then 11.6 in mid range and 11.0 at redline. learned a lot from this new style ecu. Still learning. A lot different from what I'm usually tuning. Stayed away from reading too much of the vague information on the web!!! Would love to eventually help or aid in whatever needs to be done to have an officially thread on how to tune this ecu!

[Redline MS]

Trick question......why would it make more power by moving the SOI......where was fueling and spark relative to you making a power increase? We move the SOI to ensure that we can fill the cylinder with a proportionate amount of fuel mass relative to air mass (especially after a air mass increase) as long as we aren't blowing it back out the exhaust port. We need to be careful we don't mislead people in thinking that setting SOI at these values are going to make power. Good job of getting it under control!

Those are some big turbos for a stock motor....put some pistons in that bitch and turn it up!

[Higgs Boson]

Went from 360 and slowly lowered the numbers from there. Ended up around 330ish where it made the most power with the same style of tuning. Adjust soi, adjust maf for Afr. Looked at result and also log and then repeat til power dropped. It dropped at 325 so crept it back up to confirm. Eoi is stock, 180.
The lower the pe number (i.e. 1.12-1.13) the better the Mpa. Regardless of the leaner commanded Afr, I had adjusted the maf to set the Afr to my liking. Final Afr was 12.0 on spool up and then 11.6 in mid range and 11.0 at redline. learned a lot from this new style ecu. Still learning. A lot different from what I'm usually tuning. Stayed away from reading too much of the vague information on the web!!! Would love to eventually help or aid in whatever needs to be done to have an officially thread on how to tune this ecu!

What is your injector pulse width at WOT?

[gotparts]

changing soi to match the cylinder air mass, rather being more or less,means more or less fuel for the air mass correct? So that means running the ipw up or down also adjust the amount of fuel the soi is hitting the air mass with correct? So if we are to impact the mixture at whatever level of soi the car is happy with, then it should make more power correct?
Soi 330 eoi 180 ipw of 7.1 ms spread over the time of injection correct?
Soi 325 eoi 180 ipw of 7.1 ms spread over the time of injection correct?
So which would have more fuel impacting the cylinder on every degree of injection? would it effect it that much? I'm not sure, this is the first c7 I tuned and I took the time not to blow it up and try to understand what I am doing to gain more knowledge. Spreading what I learned to see if we can get more questions answered for understanding of how to tune them.
Inj ms at peak was 7.1 peak at wot and dropped by redline as the Mpa started to rise again.

[Higgs Boson]

changing soi to match the cylinder air mass, rather being more or less,means more or less fuel for the air mass correct? So that means running the ipw up or down also adjust the amount of fuel the soi is hitting the air mass with correct? So if we are to impact the mixture at whatever level of soi the car is happy with, then it should make more power correct?
Soi 330 eoi 180 ipw of 7.1 ms spread over the time of injection correct?
Soi 325 eoi 180 ipw of 7.1 ms spread over the time of injection correct?
So which would have more fuel impacting the cylinder on every degree of injection? would it effect it that much? I'm not sure, this is the first c7 I tuned and I took the time not to blow it up and try to understand what I am doing to gain more knowledge. Spreading what I learned to see if we can get more questions answered for understanding of how to tune them.
Inj ms at peak was 7.1 peak at wot and dropped by redline as the Mpa started to rise again.

I am of the opinion that SOI should be as early as possible without losing control of your IPW. If it is 7.1 at 330 and 325, then what is it at 300? or 310? Once PW starts to go up, really 7.1 is as much as I would want to see, then you start puddling fuel on the piston.