Fuel injection help

[95V64ME]

95 3.4l Would it help performance to go to larger fuel injectors than stock?
(Like the old days) 2bbl off-4bbl on.
I would think it will deliver more fuel at WOT and cut down on the duty cycle.
Wouldn't the PCM still correct for proper A/F at different RPM levels from the o2 signal.
But get some overhead on fuel delivery.
If so, what manufacture, type and size should I look for.
Have K&N Intake system, installing Headers and 3'' Magnaflow Exhaust / Wide Band o2 in a week or two.
Heads and Intake Manifold / Cam, High Output Fuel Pump and Fuel Reg. (Upgrades later). I know this engine can do more that the 160HP Chevy set it up to do:)

[Smoke Panther]

Re: Fuel injection help

95 3.4l Would it help performance to go to larger fuel injectors than stock?

If your car is pulling so much air in that you're starting to lean out, yes.

(Like the old days) 2bbl off-4bbl on.

what

I would think it will deliver more fuel at WOT and cut down on the duty cycle.

It will deliver more fuel, all the time without tuning

Wouldn't the PCM still correct for proper A/F at different RPM levels from the o2 signal.

Not if it doesn't know that you changed the fuel injectors...and since you've made no mention of tuning in this thread, I can only assume that you were just planning on swapping your old ones out for larger ones without telling your PCM of the changes....and, if you do that, you'll be running rich all the time

If so, what manufacture, type and size should I look for.
Have K&N Intake system, installing Headers and 3'' Magnaflow Exhaust / Wide Band o2 in a week or two.

For a bolt-on car, your stock injectors are fine.

Heads and Intake Manifold / Cam, High Output Fuel Pump and Fuel Reg. (Upgrades later).

19# injectors would probably be more than sufficient to allow for further growth/development than what your 17#'s would

[ssms5411]

Re: Fuel injection help

I don't know too much on the 3.4's but I'll try to help ya. Once you have the wideband on and working you should be able to see if your running lean or not, I think for the 3.4's you can use the 3.8 injectors which are 22lb vs. the 3.4 which are 19lb injectors. I think the 3.4 you can get a adjustable fuel pressure regulator to adjust for the bigger injectors, but you would need the wideband. I would look into the advance section, I think their are some guys doing alot of stuff for the 3.4. You could PM them or email them. They could offer you alot more advice than I would. I know they are putting together some good #'s out of the 3.4. Good luck to ya.

[Smoke Panther]

Re: Fuel injection help

I think for the 3.4's you can use the 3.8 injectors which are 22lb vs. the 3.4 which are 19lb injectors.

3.4 injectors are 17#, 3.8 are 19#

[ssms5411]

Re: Fuel injection help

3.4 injectors are 17#, 3.8 are 19#

On my hptuners it shows mine as 22lb injectors. 96' Camaro

[Mr. Logger]

Re: Fuel injection help

Mine too. Even the Engine Tech lists them as 22#...

http://engine.firebirdv6.com/

[Smoke Panther]

Re: Fuel injection help

^the same source that cites 4.10s as being too much for NA V6 in terms of performance and fuel efficiency, despite the fact that all the record holding NA cars have 4.10s or higher and A4 cars with 4.10s have averaged 30mpg on the highway...yea ok

[Mr. Logger]

Re: Fuel injection help

I guess Chevy put in the wrong numbers when they programmed the PCM. I'll have to change that... :tdown:

[ssms5411]

Re: Fuel injection help

I think I'm going to trust what I see on Hptuners since their the ones programing most of everyones car. Also I have flash/tuned about 4-5 cars now and it shows 22.77 in the injector flow rate table.

[Mr. Logger]

Re: Fuel injection help

I know. Sarcasm is hard to show over the web.

[zpwn06]

Re: Fuel injection help

I know. Sarcasm is hard to show over the web.

yeh. there should be some kinda of punctuation for it.

could use # signs.

#I'm being sarcastic#

[ssms5411]

Re: Fuel injection help

Yeah, I know. I just don't want anyone to get the wrong info. and end up blowing up their engine due to the wrong info.

[95V64ME]

Re: Fuel injection help

I have not did any tuning to the PCM. My other project car (I'll probably get ribbed for this) 1990 Talon 2.0l. Turbo. Had stock 450cc injectors. I changed them out to 550cc and the car ran much faster. Only had A/F meter to monitor, but no sign's of a lean or in this case, rich mix on A/F meter or exhaust manifold temperature.The 17# just don't sound like they could keep up or would top out to soon. I know someone out there has a lot of data on fuel output or differant size injectors
and air intake mix to make HP. I know at some point a larger injector would just be to much, just don't know what size that would be???
As was said, I would think It could handle 22# with the PCM controlling the fuel from it's signal sources, but I'll keep checking the board for more information before making any changes. And Oh (Chevy Rules)!!!
I won't get into how many V8's the little 2.0l has put down:naughty:
I love my V6 CAMARO !!!!!!!!!

[95V64ME]

Re: Fuel injection help

Wow! Just checked out the sticky buy black34V6 on Advanced Engines.
He hit the nail right on the head, now thats what I'm talking about!
Good right up on the 3.4L.

[The_Beast]

Re: Fuel injection help

I've heard that the stock 3.4 injectors limit the engine to 160 HP. I don't know if this is true, but in that same thread they were saying that even with mods, the 3.4 can't get past 160 HP without upgrading the injectors. Any info on that?