Are bigger injectors needed with heads and cam?
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From: St. Charles, IL
Are bigger injectors needed with heads and cam? I have a 00 M6 Z and should put down roughly 415+ to the wheels. Will I need bigger injectors? Any body running bigger ones and what kind? SVO 30#??
I have stock cubes.
Thanks
Brad
I have stock cubes.
Thanks
Brad
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Re: Are bigger injectors needed with heads and cam? Here is two LS1 based cars.
Both have about the same mods and 450 HP at the flywheel.
Both are headed to 130 MPH.
One has SVO 30, the other stock injectors.
Compare both from what was seen via the PCM and see what the injector duty cycle (injdc) was, relate that to RPM, MPH, LTFT, and how much Delivered torque was needed and ask which setup you would perfer ?
Both have about the same mods and 450 HP at the flywheel.
Both are headed to 130 MPH.
One has SVO 30, the other stock injectors.
Compare both from what was seen via the PCM and see what the injector duty cycle (injdc) was, relate that to RPM, MPH, LTFT, and how much Delivered torque was needed and ask which setup you would perfer ?
Re: Are bigger injectors needed with heads and cam? What's up with the fuel cell changing back and forth on the 1st chart?
I'm assuming the 2nd (lower) chart is of a the 30 lb svos since the injectors are at a lower duty cycle?
I'm assuming the 2nd (lower) chart is of a the 30 lb svos since the injectors are at a lower duty cycle?
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From: USA
Re: Are bigger injectors needed with heads and cam? This excel sheet was sorted as to Max RPM first, thus not in exact cycles as recorded.
Correct SVO 30's bottom car.
Notice in lower car that O2 report a bit rich and thus if adjusted a bit with MAFT the duty cycle would be even less.
Del Tq for bottom car shows it had to do less load to pull.
Correct SVO 30's bottom car.
Notice in lower car that O2 report a bit rich and thus if adjusted a bit with MAFT the duty cycle would be even less.
Del Tq for bottom car shows it had to do less load to pull.
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Re: Are bigger injectors needed with heads and cam? Both cars ( one a C5 and the other F-body) are using a MAFT.
Top car set to a base (LTFT) of +25% lean, bottom car set to a +15% lean.
Both have custom PCM code by two different vendors which neither in my view coded correct for best performance.
Clearly bottom car pulling to 130 MPH smoother.
[quote]Originally posted by Ragtop 99:
<strong>MAF readings really vary too. Was a translator used to correct for the larger injectors?</strong><hr></blockquote>
Top car set to a base (LTFT) of +25% lean, bottom car set to a +15% lean.
Both have custom PCM code by two different vendors which neither in my view coded correct for best performance.
Clearly bottom car pulling to 130 MPH smoother.
[quote]Originally posted by Ragtop 99:
<strong>MAF readings really vary too. Was a translator used to correct for the larger injectors?</strong><hr></blockquote>
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Re: Are bigger injectors needed with heads and cam? Wow, looks like someone cloned my car! <img src="gr_grin.gif" border="0">
What is cell 15 for, anyway? why would it be spending time there at WOT?
What is cell 15 for, anyway? why would it be spending time there at WOT?
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Verdad Gallardo TECH Resident
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From: USA
Re: Are bigger injectors needed with heads and cam? Hehehe,
Jim was starting a discusson I thoughtyou could make use of.
I assume car was headed into WOT, thus you can see why LTFT is not at zero.
Cell 15 is part of part throttle (0-19)
My real point though is top car is working much harder at 80 MPH then bottom car at 130 so again maybe a car does not need a larger injector, but by using them you have lots of tuning ability wirh less overall load but in this case 95% duty cycle is not where I would run my car.
Ohh and think about this,
duty cycle is high but have to use a MAFT and set it 25% lean, says something about state of PCM coding?
[quote]Originally posted by JimMueller:
<strong>Wow, looks like someone cloned my car! <img src="gr_grin.gif" border="0">
What is cell 15 for, anyway? why would it be spending time there at WOT?</strong><hr></blockquote>
[ February 04, 2002: Message edited by: Team ZR-1 ]</p>
Jim was starting a discusson I thoughtyou could make use of.
I assume car was headed into WOT, thus you can see why LTFT is not at zero.
Cell 15 is part of part throttle (0-19)
My real point though is top car is working much harder at 80 MPH then bottom car at 130 so again maybe a car does not need a larger injector, but by using them you have lots of tuning ability wirh less overall load but in this case 95% duty cycle is not where I would run my car.
Ohh and think about this,
duty cycle is high but have to use a MAFT and set it 25% lean, says something about state of PCM coding?
[quote]Originally posted by JimMueller:
<strong>Wow, looks like someone cloned my car! <img src="gr_grin.gif" border="0">
What is cell 15 for, anyway? why would it be spending time there at WOT?</strong><hr></blockquote>
[ February 04, 2002: Message edited by: Team ZR-1 ]</p>
Re: Are bigger injectors needed with heads and cam? I'm surprised you didn't chime in on https://ls1tech.com/ubb/cgi-bin/ulti...c&f=1&t=002685 yet. <img src="gr_stretch.gif" border="0">
Thread Starter
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From: St. Charles, IL
Re: Are bigger injectors needed with heads and cam? Could the one working harder have to do with the C5 being more aerodynamic than the f body? How about the weight of the cars.
I do still agree that I would rather have my injector duty cycle lower for easier tuning.
I do still agree that I would rather have my injector duty cycle lower for easier tuning.
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Re: Are bigger injectors needed with heads and cam? But the top car is only doing 80 MPH at that time and has a high duty cycle so a "don't care" as to C5 airodynamic differences. Either way the powertain setup should ot cause injectors to run over a max 85% duty cycle.
Injectors being driven to static is not how I'd want it.
[quote]Originally posted by MBC Racing:
<strong>Could the one working harder have to do with the C5 being more aerodynamic than the f body? How about the weight of the cars.
I do still agree that I would rather have my injector duty cycle lower for easier tuning.</strong><hr></blockquote>
Injectors being driven to static is not how I'd want it.
[quote]Originally posted by MBC Racing:
<strong>Could the one working harder have to do with the C5 being more aerodynamic than the f body? How about the weight of the cars.
I do still agree that I would rather have my injector duty cycle lower for easier tuning.</strong><hr></blockquote>
On The Tree
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Re: Are bigger injectors needed with heads and cam? John - Are you trying to use the Delivered Torque from the PCM as an exact for comparison? Delivered Torque by the PCM is based on the calculated load of the PCM. When you skew the MAF with a MAFT, it is in no way comparible to another vehicle.
D(irecto)r Pepper
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From: Houston Raceway Park...in TEXAS.
Re: Are bigger injectors needed with heads and cam? Do you NEED bigger injectors at those power levels? nah. Will they hurt you? nah.
But, if you have no custom tuning... they can allow you to run more timing ( the motor gives up a bit more timing becuase it sees less load).
Bottom line. You can get by with out them... but I recommend the bigger injectors. For the reasons of; a) more timing b) easily tuned with a MAFT.
If the car is a 98,99 or 2001,2002 then the need is not as great as a smaller injectored 99~2000 car.
p.s., i REALLY dont like those "zero" LTFT's.
But, if you have no custom tuning... they can allow you to run more timing ( the motor gives up a bit more timing becuase it sees less load).
Bottom line. You can get by with out them... but I recommend the bigger injectors. For the reasons of; a) more timing b) easily tuned with a MAFT.
If the car is a 98,99 or 2001,2002 then the need is not as great as a smaller injectored 99~2000 car.
p.s., i REALLY dont like those "zero" LTFT's.
Re: Are bigger injectors needed with heads and cam? LTFT's @ zero...yeah, not what I want, but hell, I'm at +25/+2 in that first chart. I'm almost out of range of the MAFT.
I'd like to see them between -1 & -2, but have not had much luck getting them there <img src="images/icons/confused.gif" border="0">
I've heard conflicting reports on how easy it is to tune the 30# SVO's with the MAFT. I've read some couldn't go lean enough to help. Seems like the tuners say it's not needed and the owners say it is, at least in these power ranges. WTF?
I'd like to see them between -1 & -2, but have not had much luck getting them there <img src="images/icons/confused.gif" border="0">
I've heard conflicting reports on how easy it is to tune the 30# SVO's with the MAFT. I've read some couldn't go lean enough to help. Seems like the tuners say it's not needed and the owners say it is, at least in these power ranges. WTF?
Re: Are bigger injectors needed with heads and cam? [quote]Originally posted by Team ZR-1:
<strong>Both cars ( one a C5 and the other F-body) are using a MAFT.
Top car set to a base (LTFT) of +25% lean, bottom car set to a +15% lean.
Both have custom PCM code by two different vendors which neither in my view coded correct for best performance.
Clearly bottom car pulling to 130 MPH smoother.
</strong><hr></blockquote>
Glad to see you on an LS1 forum again, John.
C5Noir here from the forum. Miss ya' over there at the CF <img src="gr_sad.gif" border="0">
<strong>Both cars ( one a C5 and the other F-body) are using a MAFT.
Top car set to a base (LTFT) of +25% lean, bottom car set to a +15% lean.
Both have custom PCM code by two different vendors which neither in my view coded correct for best performance.
Clearly bottom car pulling to 130 MPH smoother.
</strong><hr></blockquote>
Glad to see you on an LS1 forum again, John.
C5Noir here from the forum. Miss ya' over there at the CF <img src="gr_sad.gif" border="0">
Re: Are bigger injectors needed with heads and cam? [quote]Originally posted by JimMueller:
<strong>LTFT's @ zero...yeah, not what I want, but hell, I'm at +25/+2 in that first chart. I'm almost out of range of the MAFT.
I'd like to see them between -1 & -2, but have not had much luck getting them there <img src="images/icons/confused.gif" border="0">
I've heard conflicting reports on how easy it is to tune the 30# SVO's with the MAFT. I've read some couldn't go lean enough to help. Seems like the tuners say it's not needed and the owners say it is, at least in these power ranges. WTF?</strong><hr></blockquote>
I set my Base to 10% lean and WOT to 0 and I have LTRIMS at 0 and WOT O2's at .92 (good enough for me on spray <img src="gr_grin.gif" border="0"> )
<strong>LTFT's @ zero...yeah, not what I want, but hell, I'm at +25/+2 in that first chart. I'm almost out of range of the MAFT.
I'd like to see them between -1 & -2, but have not had much luck getting them there <img src="images/icons/confused.gif" border="0">
I've heard conflicting reports on how easy it is to tune the 30# SVO's with the MAFT. I've read some couldn't go lean enough to help. Seems like the tuners say it's not needed and the owners say it is, at least in these power ranges. WTF?</strong><hr></blockquote>
I set my Base to 10% lean and WOT to 0 and I have LTRIMS at 0 and WOT O2's at .92 (good enough for me on spray <img src="gr_grin.gif" border="0"> )
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Re: Are bigger injectors needed with heads and cam? If you look st the bottom car you see that the engine was in WOT (cell 22 and TPS > 80)
thus if the AFR tune is correct, the LTFT should read zero, for the PCM snapshots STFT, looks at LTFT, freezes trim to zero and goes power enrichment into WOT.
This tune assures at WOT it does not get too rich due to a lean LTFT right before going to WOT.
At part throttle I tune LTFT -2 to +2 depending on the weather and type of driving/racing.
[quote]Originally posted by Raughammer:
<strong>
p.s., i REALLY dont like those "zero" LTFT's.</strong><hr></blockquote>
thus if the AFR tune is correct, the LTFT should read zero, for the PCM snapshots STFT, looks at LTFT, freezes trim to zero and goes power enrichment into WOT.
This tune assures at WOT it does not get too rich due to a lean LTFT right before going to WOT.
At part throttle I tune LTFT -2 to +2 depending on the weather and type of driving/racing.
[quote]Originally posted by Raughammer:
<strong>
p.s., i REALLY dont like those "zero" LTFT's.</strong><hr></blockquote>
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Re: Are bigger injectors needed with heads and cam? Levi,
I will not support that CF, its crap and only interest is them making money.
You e-mailed me a month or so ago and I replied with my phone mumber but you did not call back to call about your questions.
[quote]Originally posted by NastyC5:
<strong>
Glad to see you on an LS1 forum again, John.
C5Noir here from the forum. Miss ya' over there at the CF <img src="gr_sad.gif" border="0"> </strong><hr></blockquote>
I will not support that CF, its crap and only interest is them making money.
You e-mailed me a month or so ago and I replied with my phone mumber but you did not call back to call about your questions.
[quote]Originally posted by NastyC5:
<strong>
Glad to see you on an LS1 forum again, John.
C5Noir here from the forum. Miss ya' over there at the CF <img src="gr_sad.gif" border="0"> </strong><hr></blockquote>