injector upgrade when adding 1.6:1 RR'S
Thread Starter
Intermediate
Joined: Oct 2004
Posts: 43
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From: Pittsburgh Pa
injector upgrade when adding 1.6:1 RR'S
I've been told that when changing RR'S from 1.5's to 1.6's , that it allows your engine to operate at a higher RPM, Lets say from stock 5700 to about 6400 on a LT1. I know that if you raise your rev limiter that u want to stay about 200 RPM'S on the safe side of that rev limit.
But i know that the stock injectors really cant keep up at those higher rpm's (my 95 having 24lb injectors).
is it a good idea or should i say "is it nessasary to move up to the LT4 28lb injectors if i want to benefit from the higher rpm's? and will i need to reprogram my PCM if i do that?
some one take me too SCHOOL!!
i'm all ears
But i know that the stock injectors really cant keep up at those higher rpm's (my 95 having 24lb injectors).
is it a good idea or should i say "is it nessasary to move up to the LT4 28lb injectors if i want to benefit from the higher rpm's? and will i need to reprogram my PCM if i do that?
some one take me too SCHOOL!!
i'm all ears
Large Impressive Member
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From: Good health is merely the slowest possible rate at which one can die
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You're many mods away from needing an injector upgrade. I still run stock ones and have no reason to think I need larger, at this point.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Originally Posted by 1c44ya
I've been told that when changing RR'S from 1.5's to 1.6's , that it allows your engine to operate at a higher RPM, Lets say from stock 5700 to about 6400 on a LT1. I know that if you raise your rev limiter that u want to stay about 200 RPM'S on the safe side of that rev limit.
But i know that the stock injectors really cant keep up at those higher rpm's (my 95 having 24lb injectors).
is it a good idea or should i say "is it nessasary to move up to the LT4 28lb injectors if i want to benefit from the higher rpm's? and will i need to reprogram my PCM if i do that?
some one take me too SCHOOL!!
i'm all ears
But i know that the stock injectors really cant keep up at those higher rpm's (my 95 having 24lb injectors).
is it a good idea or should i say "is it nessasary to move up to the LT4 28lb injectors if i want to benefit from the higher rpm's? and will i need to reprogram my PCM if i do that?
some one take me too SCHOOL!!
i'm all earsThe stock injectors will work fine if you're simply adding roller rockers.
The factory programming tends to be a tad rich. The extra lift from the 1.6s will lean things out a little. This may or may not help as every car is different. The only way to know for sure is to get on a dyno with a wideband o2 sensor and experiment with the programming. Regardless, you'll still be well within range of what the PCM can compensate for as far as idle and part throttle fueling, so that'll be fine.
Put 'em on (a new set of valve springs should be considered too) and enjoy the extra 10 or 15 rwhp they provide.
Thread Starter
Intermediate
Joined: Oct 2004
Posts: 43
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From: Pittsburgh Pa
where do u have your car shifting at 1to2 and 2to 3 ? what rpm? if u are shifting at the stock shift points then i can see that u wouldnt need the extra fuel, but operating above the stock shift point like 6100 on the 1to2 shift, ccan the stock injectors handle that?
Last edited by 1c44ya; Nov 2, 2004 at 06:12 PM.
Le Mans Master
Joined: Feb 2002
Posts: 5,970
Likes: 20
From: San Marcos Texas
Those 24lb injectors should be good for upwards of 500HP. Ski_dwn_it and Corkvette are both running 24lb injectors and their engines make around 550-600HP....I am also using 24lb injectors on my 380ci motor. 
Its all in the tuning and fuel pressure...
Its all in the tuning and fuel pressure...
Race Director
Joined: Apr 2000
Posts: 15,344
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From: Texas
Originally Posted by chriswtx
Those 24lb injectors should be good for upwards of 500HP. Ski_dwn_it and Corkvette are both running 24lb injectors and their engines make around 550-600HP....I am also using 24lb injectors on my 380ci motor. Its all in the tuning and fuel pressure...
Its all in the tuning and fuel pressure...As mentioned above, "24lbs/hr" is simply the injector rating at a given fuel pressure. Increasing the fuel pressure makes it "larger" and with proper tuning allows it to be used with higher hp engines while retaining a reasonable duty cycle.
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Thread Starter
Intermediate
Joined: Oct 2004
Posts: 43
Likes: 0
From: Pittsburgh Pa
Originally Posted by 96BLKTN
You have 26lb injectors not 24. In 94 the Corvette got Sequintial (sp) fuel injection and bigger 26lbers in place the the earlier LT1 24lbs. Just a FYI.