Adjusting Injector Flow Rate vs Vacuum Table
Thread Starter
Teching In
Joined: May 2021
Posts: 19
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Adjusting Injector Flow Rate vs Vacuum Table Hi there,
I have a 5.3 with an LS6 intake manifold and injectors, everything else is stock for now. The stock injectors on my L33 were 25.2 lb/hr, LS6 are 28.8. I am sure this is a common question but I have not yet found a clear answer on the forum.
With my tuning software (Jet DST - I know, I know) to compensate for the larger injectors do I just multiply the flow rate at all vacuum levels by 0.875? (25.2 / 28.8 = 0.875) My logic is that the the PCM still thinks the injectors are 25.2 lb/hr but since they are not, the reduced flow rate is made up by the larger injectors.
It can't be that simple right? I have been reading about MAF and volumetric efficiency tables but again, no clear answers.
Keep in mind I am very new to tuning so please don't use a lot of acronyms! I just want to get this thing running reasonably well so I can get it built and drive it to an actual tuner. Any advice or handy links would be great. Thanks!
I have a 5.3 with an LS6 intake manifold and injectors, everything else is stock for now. The stock injectors on my L33 were 25.2 lb/hr, LS6 are 28.8. I am sure this is a common question but I have not yet found a clear answer on the forum.
With my tuning software (Jet DST - I know, I know) to compensate for the larger injectors do I just multiply the flow rate at all vacuum levels by 0.875? (25.2 / 28.8 = 0.875) My logic is that the the PCM still thinks the injectors are 25.2 lb/hr but since they are not, the reduced flow rate is made up by the larger injectors.
It can't be that simple right? I have been reading about MAF and volumetric efficiency tables but again, no clear answers.
Keep in mind I am very new to tuning so please don't use a lot of acronyms! I just want to get this thing running reasonably well so I can get it built and drive it to an actual tuner. Any advice or handy links would be great. Thanks!
TECH Addict
Joined: Aug 2005
Posts: 2,305
Likes: 126
From: Monroe,NY
Go to the tune repository and look up an LS6 car. Look at the injector data and compare to see if your numbers work. But just copy all injector data from LS6 and put it into your tune. Easiest way and the correct way.
Not trying to steal the thread, but I have a similar question.
I have a 2014 Camaro (E38 ECU) I am installing a set of FIC 850cc injectors in, and have pretty much the same question about the flow rate vs. vacuum table?
FIC provides the offset vs volts table for HP Tuners, but I'm very green on adjusting this table, and a few others that go with changing out injectors to this size.
I have a 2014 Camaro (E38 ECU) I am installing a set of FIC 850cc injectors in, and have pretty much the same question about the flow rate vs. vacuum table?
FIC provides the offset vs volts table for HP Tuners, but I'm very green on adjusting this table, and a few others that go with changing out injectors to this size.
When changing to slightly different factory injectors, it really is as simple as changing flow rate. when making a large change, things get into multiple tables that could be almost infinitely complex. This is complicated by the fact that the quality of injectors varies wildly. Your best bet is sometimes to get injector data from a manufacturer, and sometimes from internet forums. Just creep up on your full throttle tuning, and you should be ok.
