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Discussion Starter #1
hey guys, quick question.

i have a 99 camaro SS g2 handling package, with long tube headers, hollow cat, 3.5" cat back borla,
LS6 intake, some sort of aftermarket larger mass airflow sensor, and throttle body (larger than stock) and a bad ass tune on it. thing runs like crazy...

previous owned claims 389 horse... i believe him. or.. believe he's not TOO far off anyway... i've owned a few LS1 F-bodies, and this one smokes the dog crap out of all of them.

anyway........

a buddy of mine just pulled his stock injectors out of his 44,000 mile factory stock Z06, I'm wondering if buying these injectors would help me gain a little more power???

biggest question is,

1. would i have to re-tune?
2. need a bigger fuel pump?

yes....... granted, i could get a set of larger injectors to whatever lb i want, there is no shortage of injectors in the world, but.....

buying isn't free...... we yanked his motor out, he's about to do a bunch of crap to it and use considerably larger injectors, so he's giving these to me, and another LS6 intake for helping him.

But,.......... honestly, i have no idea if the injectors in my car are stock. i am 90% sure they are. if not, they would be Z06, they are factory grey either way.

so... thoughts?
 

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If your car is running that well, why would you want to change the injectors?

Unless you change to the same rating injectors, you have to tune pcm for them. Since I don't have a clue as to what your old injectors or new injectors flow, don't know how much different they are.

Can't say on fuel pump either, without knowing specs on injectors.

Again, if car is good, why mess with it?
 

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Discussion Starter #3
If your car is running that well, why would you want to change the injectors?

Unless you change to the same rating injectors, you have to tune pcm for them. Since I don't have a clue as to what your old injectors or new injectors flow, don't know how much different they are.

Can't say on fuel pump either, without knowing specs on injectors.

Again, if car is good, why mess with it?
well the car isn't with me today, it's in the garage at home, but, i took a picture of the number on the injectors, though it is fuzzy, and i can't quite make out the numbers (go figure)

i think it says something along the lines of 12956894 on them, which should give someone an idea if they are stock or not...

i know the fuel pump is stock just by the sound (or lack thereof.) walboro's are loud, this one is not, and i doubt the last owner would have paid them to drop the tank and install a bigger pump...

as for your question to me,

it's necessity vs want. meaning, i don't neeeeed it, but would like to have it. lol

and yeah, it does run great but, my question is, with the z06 injectors, will i be able to get closer to 400hp?

in 98 and prior, the LS1 cars all had slightly larger injectors than 99+. they downsized the injectors in 99, but the performance wasn't hindered. it just makes it slightly more difficult to tune for higher HP applications when you start modding.

the 2000 Z06 (LS6) injectors spray 10% more fuel than the stock 99+ C5 vette injectors, which, may or may not be the same injectors as are in the 99+ F-bodies.

what i don't know though, is how the 2000 C5 Z06 injectors compare to the 97-98 injectors. I don't know what size the 97-98 injectors were, so they may be 10% more too!

but yeah, typing this stuff out, it seems blatantly apparent that i would have to re-tune the motor for the extra 10% fuel, because that is significant!

so with that said, we're looking at a few hundred bucks worth of dyno time to put these new injectors in, but........



---- at what gain?

the z06 vette was rated at 385 horse, the base vette was like 347, SS was 347 as well, and the z28 was like 327 or something. (not positive about those numbers) i'm already at 389, how hard could it possibly be to get another 11 by shoving more fuel down it's throat? it already breaths like an Olympic sprinter. i really can't get much better regarding exhaust and maintain street status. and the intake is pretty much where it needs to be too.

It IS however a stock cam, and i know that a Z06 cam, or even a 2000 vette cam would wake it up quite a bit, but that's an expensive alteration.


the 99+ c5's acquired a more aggressive cam than the 97-98 because of the pup cats, and various new emmissions crap they had to put on them, in order to maintain horsepower. i think the Fbodies kept the same cams from 98-02. so, a 99-2000 stock vette, or LS6 vette cam would do a world of good, but i have no idea what the power gain would be. not significant enough to justify a few thousand bucks haha, so if i was going to do that, i'd put a fairly aggressive cam in it, and try to push 425 horse(ish) but then i may or may not need head work too to achieve that goal. i think a 30 hp gain with a cam may be possible? probably more... i don't know, i'm not a camshaft guy.. but either way, that's tuning again, AND a fuel pump AND injectors. i dunno.

it's a street car, but i plan to put logos on it and take it down the drag strip.

the transmission is bad in the car, i'm about to yank it this weekend and have it rebuilt with all the goodies. carbon fiber, viper parts, blah blah (not a transmission guy either). i have a guy who will do it for free if i buy the parts, i just gotta yank it and take it next door to my buddie's tranny shop. we trade out work all the time.

the suspension is where it needs to be already... G2!! the rear end may need some work to handle more power, i don't know. but this car is ALMOST there... it has the beginnings of something insanely [email protected]@$$ just depends how much money i feel like dumping into it before i decide to sell it and buy something else.
 

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If it were my car, i'd put it on a scanner that does real time sensor data and see what the fuel trims, injector pulse width are looking like. If pulse widths are real long, or pcm is having trouble keeping trims even at 0, with pcm constantly having to add more fuel, then I would think about bigger injectors.
 

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98, and 01-02 fbodies had 28lb injectors, and so does a Z06. 99-00 had 26lb. Not that much of a difference is there? I swapped to 28lb when I cammed my car. If you are bolt on only, then you don't need larger injectors. All that will happen is you'll pay for a retune, and they adjust the larger injectors to a slightly lower duty cycle to provide the same fuel that your 26lb injectors are providing resulting in the same whp.
Fuel pump.... I ran a stock fuel pump with my 408. Unless it is bad, your bolt on car doesn't need one.

Cam, 99-00 had the "more agressive" cam. It didn't amount to much of a difference when you actually look at the specs and it didn't make any difference on the dyno or the track when compared to 98 with the smaller grind. 01-02 was faster and made more whp on a dyno with the smaller cam. The difference was the LS6 intake.

Now lets talk about your 389 hp. That isn't whp if it is the real output. The best I have ever seen from a bolt on fbody was 350ish whp. Most are 330-340ish whp This is based off of being in the scene since 2002. Maybe the guy was full of crap or he was going by adding 20% to get bhp from 330ish whp to make a sale. But don't go around claiming that is whp being bolt on or people in the know will start rolling their eyes. Any LS guy I ever spoke to will talk in whp. Also, drop the factory rating comparisons. They were all BS for marketing. An LS1 is an LS1 regardless of what car it came in. The real world difference happened as I stated, with the LS6 intake.
Borla also only made 3" cat backs for 4th gens. I had one. Is yours a custom 3.5" with a Borla muffler or did the guy tell you that too? Why would you have hollow cats and LT's in TX? I passed many inspections without cats, EGR, or the AIR pump.

G2= Granatelli. They are in the DFW area. Just an FYI if you didn'tt know.
 
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