at what hp are we pushing stock injectors too hard?

[Patrick Javert]

what is the limit of the stock injectors? i've looked and seen 270, 280, 300, 320, ect. if I were to put a larger fuel pump in my car as well as an adj. fpr, what would the max hp limit be? batman's ati kit runs on stock injectors, doesn't it? Thanks for the imput.

[Magnus]

@50PSI I'd say maybe 240rwhp with a 6K limiter.

My injectors are maxed I know that.. Sometimes I see 24ms pulse widths. Mike Huff is also in need of more injector.

We're good until we get to 5800 RPM's or so.

Stock setups are fine.

I wonder what the pulse widths are on a dry nitrous shot.. I bet 5600+ it gets risky.

[Nachius]

So when your injectors are maxed you shouldn't replace them with a bigger one without a reprogram correct? and with your setup Magnus how high would you go (lb. wise) to comfortably not worry about maxing them?

[Patrick Javert]

The only thing you'd have to worry about w/ getting bigger injectors is the computer learning how much fuel too add w/ x rpm and y throttle position and z air/fuel ratio. if you were to jump from 22(stock) to say 24 or 26, the computer wouldn't get too weird about it, I think. I think Hypertech can customize their HPP3's w/ specs you give them over the phone. One of my friends has a 97 vette, hypertech'd it, then put intake, filter, and low-restriction maf sensor on, and sent the programmer back to be recalibrated for the increase of air into the engine. he saw a supposed 5-7 hp increase and 10-15 torque increase at the rear wheels after he installed the new parameters(I cannot vouch for this bc I was not there to see it.) Our computers tend to learn on their own all the time since air intake temp isn't always the same, humidity can change rapidly, ect. Small changes won't hurt the car if done in intervals of 75-100 miles or so, or the computer is reset.

[Ironman24]

Yeah, I need more injector for sure. With the blower I'm seeing pulse widths in the 30ms range, and that's at only 4500rpms. I haven't logged up to 6K yet. I'm having a hard enough time getting the car to run at the desired .890 O2 range so I don't want to put larger injectors in there with no programming in fear it may make the car run worse. I'm sure my injector spray pattern looks like a garden hose. lol

[Pro Stock John]

Well, you could use what us LS1 guys use.

If you go with bigger injectors, you will run richer at idle and cruise / part throttle. I'd use a MAF T to lean out the car.

After I did a fuel pump swap my car had a tuff time idling with my pcm programming. So I had the MAF T base setting set to be more lean.

A ported MAF works to help lean an LS1 at idle too but I'm not sure about the 3.8 the MAF/TB looks very complicated.

I would also go to bigger injectors Ironman because your stock injectors maybe not all work equally efficient at max pulsewidths. I don't know much boost you can see but if it's a lot you might need more than 24 lb injectors.

Mag, I wonder how your car would idle with 99 LS1 injectors and the MAF T to fix the AF.