bigger injectors now lean
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From: Monroe,NY
bigger injectors now lean I put DeatschWerks 38lb truck injectors which are 50lbs on ls pressure. I had 8.1 truck injectors before these. I put them in since i will be putting a bigger motor in the near future so i wanted to get the kinks worked out. I have all the proper data. I was just surprised i had to richen it up so much. I just wanted to know if this is normal?
I have a 5.3 lm7 with texas speed 2.5 5.3 58cc heads and a 222/226 115+3 .600 lift.
I have a 5.3 lm7 with texas speed 2.5 5.3 58cc heads and a 222/226 115+3 .600 lift.
I know that 42 lb injectors typically run right at 48-50 on LS pressure. a 38 lb injector, I would have thought would be in the range of 44 at LS pressure. If they're rated at 43 psi, you typically multiply by 1.16 to get the 58psi flow rates.
Thread Starter
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Joined: Aug 2005
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From: Monroe,NY
Here is there data site I have the gas vortec 32d-00-0038-8 38lb/hr http://www.deatschwerks.com/gm-calibration-data
Last edited by gagliano7; Jul 31, 2017 at 05:31 PM.
Oh well. Would have been nice if it was simple. 46.9 seems right.
Fwiw, a while back I swapped out deatshwerks fir FIC and had to make some tweaks. Wasn't 15% though.
Fwiw, a while back I swapped out deatshwerks fir FIC and had to make some tweaks. Wasn't 15% though.
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Verdad Gallardo Injectors are reverse-backwards logic sometimes. You aren't "programming the flow rate" in the sense of telling the computer what to make them flow - You're "identifying" the flow rate so the computer can calculate pulse width.
You can do this in your tune and verify it for yourself. Leave the current injectors in and don't touch them. Now, set the flow rate in the tune higher than the data calls for. All your pulse width calculations will get shorter. But, since your actual flow rate doesn't change, the car runs lean, so your fuel trims go up. Then set your flow rates low in the tune. All your pulse widths will get longer, and since the actual flow rate doesn't change, the fuel trims go down.
You can do this in your tune and verify it for yourself. Leave the current injectors in and don't touch them. Now, set the flow rate in the tune higher than the data calls for. All your pulse width calculations will get shorter. But, since your actual flow rate doesn't change, the car runs lean, so your fuel trims go up. Then set your flow rates low in the tune. All your pulse widths will get longer, and since the actual flow rate doesn't change, the fuel trims go down.
Thread Starter
TECH Addict
Joined: Aug 2005
Posts: 2,305
Likes: 126
From: Monroe,NY
Injectors are reverse-backwards logic sometimes. You aren't "programming the flow rate" in the sense of telling the computer what to make them flow - You're "identifying" the flow rate so the computer can calculate pulse width.
You can do this in your tune and verify it for yourself. Leave the current injectors in and don't touch them. Now, set the flow rate in the tune higher than the data calls for. All your pulse width calculations will get shorter. But, since your actual flow rate doesn't change, the car runs lean, so your fuel trims go up. Then set your flow rates low in the tune. All your pulse widths will get longer, and since the actual flow rate doesn't change, the fuel trims go down.
You can do this in your tune and verify it for yourself. Leave the current injectors in and don't touch them. Now, set the flow rate in the tune higher than the data calls for. All your pulse width calculations will get shorter. But, since your actual flow rate doesn't change, the car runs lean, so your fuel trims go up. Then set your flow rates low in the tune. All your pulse widths will get longer, and since the actual flow rate doesn't change, the fuel trims go down.
Thread Starter
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Joined: Aug 2005
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From: Monroe,NY
If you get the Nbs/tbss intake the silverado stock injectors are 30lbs not sure what the flex are but they will be bigger than the 30lb. The old truck intake at best are 24lbs. The 8.1 injectors which will fit either intake are 30lbs.
Thread Starter
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Joined: Aug 2005
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From: Monroe,NY
I tuned my ve and wot with my wideband and that was also near 20% lean. Some of my ve wot #'s are now in the 125% range. But at WOT at 6500 rpms i am only at 60% injector duty cycle so i am in good shape for my future 6.0 motor. The truck runs a lot smoother with the Deatschwerks injectors. If anyone switches to Deatschwerks injectors be prepared for them to be lean when you start tuning.