DanielRicany

Just wondering for everyone with 24 lb injectors, what HP are you making? Trying to see who has the most on 24 lbs.

STL94LT1

24# injectors at 50psi pressure I made ~375rwhp. 350ci LT1.

TA

325/450 at the wheels

85vet

600 +
An 85 is a batch setup. This has a lot to do with the fuel available.

VikingTrad3r

would Upgrading to higher pressure pump help the "batch" style fuel injection system?

85vet

That is one of the first items I upgraded - to a Racetronix fuel pump.

Tapio@FTTRacing

Would you care to elaborate on that? I dont see why would batch setup has anything to do with fuel injector sizing

85vet

There have been many discussions on this subject (just do a search). The batch fire fires the injectors once every revolution, this is quite a bit more fuel than the precise control of the injector that is expected of todays computers.

bjankuski

342 RWHP and 410 RWTQ on a 355 superram auto car.

Tapio@FTTRacing

With patch you fire each injector twice per cam rotation

With sequential you fire each injector once per cam rotation.

Because on batch mode you have to fire your injectors more often, they have less time to be open. With sequential you have more than twice the time to keep your injectors open (remember dead time).

Total volume of injected fuel is about the same. with sequential you may even get slightly more fuel since you can run them with higher duty cycle and less dead time per cam revolution.

85vet

However, GM went with batch fire for the purpose of using smaller injectors. I will not argue with you over the fact that I am not running lean and use only 42lbs of pressure with Ford 24lb injectors.

Tapio@FTTRacing

That's something I find awesome and odd, shouldnt be possible. And you are making 600hp with those?

85vet

Yes, at least - I am running a 427 solid roller utilizing the original 85 computer - I fill up with super (93 octane) and go racing.

bjankuski

I agree with your conclusion that batch fire has nothing to do with being able to run more power. On the GM system batch fire means that they fire all four injectors on one side of the engine at one time. The length of time the injectors are open is the same between batch and sequential. So both systems should be able to support the same amount of power.

I also agree that 24 lb injectors should not support 600 HP but is possible if the engine is very efficient. Ford 24 lb injectors are rated at 39.5 PSI since he is running at 42 PSI the injectors are actually running at 25 lbs per hour. An engine making 600 HP with a very good BSFC number of .33 lbs/hp (very rare) could run on injectors of 25 lbs/hr with 100% duty cycle. Since the duty cycle max is only achieved for brief periods of time at or near max power, it is possible.

383vett

Is the 10.67@126 your time for the 600+ hp?

85vet

Yes

93 ragtop

When I had a stock bottom end, hotcam, ported factory heads, and headers, I made 362hp 376 tq. on factory 22lb injectors. Pressure was stock. But Alvin (pcm4less) said I was maxed out and was starting to go lean. Best times were 11.71 at 117.3 with that combo.
BTW I now have 60lb injectors. Ed Hutchings tuned the motor for both e85 or pump gas. It runs great!! Ed said that the newer, big injectors are no problem to tune if you get someone who knows what they are doing. Again, he did great with mine.
One other point,4WIW, the 2006 ZO6 uses 42lb injectors.