Mods & injectors

[t&t moyer]

I'm on the learning curve with the ZL1. At what point in mod progression is it required to upgrade the injectors? Headers and CAI with a tune are on the short list but at what point when changing pulley(s) and porting the TB & snout are injectors needed, what is a "safe" happy medium?

[ZL1Kid_AL]

Anything over 10% overdrive I believe, if you're doing blower porting then just swap injectors while the blower is off. Piece of mind and easy to do with blower off

[STUNNAH]

Check out some of the vendors on this site...They usually have several upgrade packages to choose from and each package tells you what parts make it up based on your desired HP gain...They go from Stage 1 to damn near unlimited...

[Fishinfirefighter]

I had only cat deletes, cai and a 2.4 upper with 85lb injectors and my stock pump couldn't keep up without a BAP. I know lots of guys say you can run a decent size pulley without Injectors or any fuel upgrades....but keep in mind all cars are different. My tuner and I were both shocked when my fuel pressure dropped to 37psi with what id consider "minimal" mods.

[t&t moyer]

It all seems fair enough, LT headers and CAI are a safe place but when I jump to TB & snout work & a pulley then injectors and BAP are required.

[ZO6 Bryan]

Originally Posted by t&t moyer

I'm on the learning curve with the ZL1. At what point in mod progression is it required to upgrade the injectors? Headers and CAI with a tune are on the short list but at what point when changing pulley(s) and porting the TB & snout are injectors needed, what is a "safe" happy medium?

Stock tune, stock car, the injectors hit 93% duty cycle already. So any significant jump in engine airflow (increasing the boost) will likely put it over 100% injector duty cycle.
CAI and headers would probably be OK. But when you start swapping pulleys you're going to need injectors.

For instance, a 9.55" lower pulley and nothing else pushed my stock injectors to 130% duty cycle.

For reference, most tuners would like max duty cycle to be 85%. So even the stock ZL1 is pushing past that.

[Josephg55]

no BAP is required only injectors

[hawk02]

ZO6 Bryan is spot on. I maxed out the stock injectors with just a Roto-Fab CAI, Big Gulp and 10% lower pulley.

Anytime you up the boost, the fuel system is likely going to need an upgrade as well.

[Can'tHave2MuchHP]

Originally Posted by ZO6 Bryan

Stock tune, stock car, the injectors hit 93% duty cycle already. So any significant jump in engine airflow (increasing the boost) will likely put it over 100% injector duty cycle.
CAI and headers would probably be OK. But when you start swapping pulleys you're going to need injectors.

For instance, a 9.55" lower pulley and nothing else pushed my stock injectors to 130% duty cycle.

For reference, most tuners would like max duty cycle to be 85%. So even the stock ZL1 is pushing past that.

Knowing that, would it be a good idea to change injectors even if just doing 8.6 lower?

Can't tell you how much these injectors are a damn bottleneck on this car.

[ZO6 Bryan]

Originally Posted by Josephg55

no BAP is required only injectors

If you get up around 12-13 lbs of boost you will need a BAP also.

[Crash76]

Doing E85, Flex Fuel Sensor, 1300 IDs, and Fore or Squash system soon ... Problems solved

[Can'tHave2MuchHP]

1300s? Dayum.

[t&t moyer]

Some good info to chew on guys, thank you!! I'm mowing over the options and how far I want to take things.

[Fishinfirefighter]

Originally Posted by ZO6 Bryan

If you get up around 12-13 lbs of boost you will need a BAP also.

Yep. At 13psi is when my pump fell flat on its face at 37psi and the AFR slowly leaned out all the way to mid 12s on the dyno.