When do you upgrade injectors?

[RSTURBO]

Ive heard alot of people say the stock injectors are maxed out with just a tune. But i see alot of Sonics with lots of mods running stock injectors at 100% duty cycle. Why not have this be one of the first upgrades? Its a cheap upgrade and easy to install. I have a ZZP intake, ported manifold, Trifecta performance tune and ZZP catless DP. Would injectors and a re- tune increase my hp or would i not even notice the power til after full exhaust?

 

[Eric Smit]

it's not really a big performance gain, just a couple of HP max, but it's better for your injectors.

 

[cndctrdj]

It's a safety issue. For lots of components. I would love to see how hard people are pushing the injectors.

 

[Tommyboy4725]

I daily my sonic, and I noticed a nice little increase in torque running 93 tunes. It's small but it's there

 

[Swordsmith]

I thought there would be a downside to upgrading injectors, that they would have trouble making very small volume available, but that doesn't seem to be the case, the low end is all still there, there's just a bigger top end. I don't know how much modding has to be done before they actually help, but if you're planning on doing them in the long run then there wouldn't be any real reason not to do them early on.

 

[neary]

I wouldn't reccommend running the injectors at 100% duty cycle its a reliability issue and you can lean out and you will need to do it at some point anyway when you mod further. I beleive in over building rather than running it on the edge. I'm not even going to tune before i do clutch/flywheel its just running it on the edge of a fail point. And I'm sirr mpost of us dd our cars so why not have some extra insurance?

 

[Swordsmith]

I don't think I came anywhere close to running at 100% duty cycle on the old injectors, because most of the time I am not pushing WOT... despite the fact that I do it a LOT, as I am addicted to onramp madness. Think about it, onramps are less than 1% of my total drive time, even if I was lucky enough to never have anyone in front of me impeding my desire for a mad rush from 0-80mph on every onramp I still wouldn't be running pedal to the metal very often at all.

Am I wrong about how this works, that somehow the other mods mean I'm using the injectors (or would be) at 100% even when my (torque demand pedal) is only at 20%?

Don't get me wrong, I still think upgrading the injectors is a good idea and that it has no downside other than cost and (minimal) install time, but I think calling them a nearly necessary mod is overstating the case. It's the tune that's nearly necessary, without that you're running a, well.... no no, it's fine, I'm sure you can be happy in a stock sonic with stock power. Still better than every other car in the segment. Just don't borrow someone's tuned car and you won't realize what you're missing.

 

[Maddmatts]

Increased fuel pressure is another way to reduce injector duty cycles. The caveat being increased stress on the fuel pump.

 

[kevindaniels63]

How does changing your injectors affect fuel mileage with just a tune?

 

[Eric Smit]

How does changing your injectors affect fuel mileage with just a tune?

seems to be negligible.

to clarify, it seems to be negligible on this car when switch from 28# injectors to 42# injectors. Generally, swapping larger injectors will net you worse economy.

 

[cndctrdj]

if your car is using 7 pounds of fuel an hour it will still use the same amount but just do it the correct way

 

[american_tuner]

I've been wondering If I do need to upgrade on my injectors as well?!.....

 

[NewZJ]

If I have the full tune already and I buy the larger injectors, can I just throw them on or do I need the tune altered to accommodate the change?

 

[ungawd]

If I have the full tune already and I buy the larger injectors, can I just throw them on or do I need the tune altered to accommodate the change?

You need a custom tune to compensate for having different injectors. Without the tuning the computer will send a certain voltage to the injectors for a certain amount of fuel. The larger injectors won't flow an equivalent amount of fuel per voltage and you'll run extremely rich, if at all.

 

[NewZJ]

You need a custom tune to compensate for having different injectors. Without the tuning the computer will send a certain voltage to the injectors for a certain amount of fuel. The larger injectors won't flow an equivalent amount of fuel per voltage and you'll run extremely rich, if at all.

That's what I was afraid of, thanks

 

[rdss]

If you have the full tune already I would submit a ticket now and get a tune that will at least run with the 42# injectors and then log and fine tune it once they are in.

 

[american_tuner]

Are these the same injectors that e85 use?

 

[NewZJ]

If you have the full tune already I would submit a ticket now and get a tune that will at least run with the 42# injectors and then log and fine tune it once they are in.

IIRC the injectors swap doesn't take very long. I'm planning on having it tuned on a dyno by Trifecta directly as they aren't very far from me.

I can install the sensor and lines/harness in preparation, then I can throw the injectors in while it is being tuned.

I should have a dyno sheet showing custom tune, custom short ram intake, ported manifold, and injectors after I'm done.

 

[rdss]

IIRC the injectors swap doesn't take very long. I'm planning on having it tuned on a dyno by Trifecta directly as they aren't very far from me.

I can install the sensor and lines/harness in preparation, then I can throw the injectors in while it is being tuned.

I should have a dyno sheet showing custom tune, custom short ram intake, ported manifold, and injectors after I'm done.

Gotcha. That makes sense. I look forward to your post and pics on the dyno session.

 

[NewZJ]

Gotcha. That makes sense. I look forward to your post and pics on the dyno session.

Me too, I'm excited to finally have something to contribute to the community. And having trifecta themselves dyno and custom tune it is certainly worth the price.