Fire&ashborn

my car is fuel injected..is it worth it n wise to get larger injectors?? or is it just not neccessary?

travishenry

Throw some 3.1 injectors in. i have a blown 3.1 that has the rod blown out the block. I have the complete engine here. the injectors i put in it were brand new. Like 5k before the engine blew. ill sell the whole intake for like 100 bucks.

Fire&ashborn

i have a hundred bucks in my pocket rite now..wat kind of intake is it?? and if everything is good...ill buy it all we need to do is figure out shippin n handlein..just lemme kno wats going on n everything

ibmtech

iTrader: (1)

Just putting larger injectors in a car is just wasting time if you don't plan on tuning the ECM also. Then when you change your injectors and adjust your VE tables it is going to change the pulse width down and it appear to run just like before. Don't waste your money putting larger injectors in unless you are planning on doing some major mods on your engine too.
Just to give you an example. I was stock running stock 305 TPI with 19lb injectors. Put a 350 TPI in and had to change to 24lb.. Finally changed to a LSX 454 SBC with S/C @ 18lbs boost on a TPIS Mini-ram and new AFR 210 heads and put 80lb injectors in. Had to modify the VE Tables and Injector BPW each time because of major engine modifications.

ttypecamaro

iTrader: (2)

from my experience on my brother's 88 2.8 Firebird, the 3.1 injectors are better suited for the 2.8 than the stock injectors. The stock chip causes the car to run very lean untill the BLM finally rises to about 151-153 across the board, then it runs correctly. With the 3.1 injectors the BLM stays right around 127-130 everywhere. Now that the tune is where it "should" be... future modificaions are easier to account for in the ecm. I've read about quite a few people running 3.1 injectors in a 2.8 with no bad effects and no other modifications.

ibmtech

iTrader: (1)

That is a good thing. I wonder why people at GM haven't noticed that the car is running into somewhat of a lean condition before. I was thinking if you run 3.1 injectors your BLM's would be around 100ish.. I have a couple of 2.8 cars at our shop, I will get the MODUS scan-tool and go get them running and see what the INT & BLM's are on those.

bl85c

iTrader: (2)

IMO, the 3.1 intake manifold is basically the same as the 2.8. Injectors are the same size too, just a different design.

Fire&ashborn

yea i just wanna throw a larger intake on my car for more hp for now to i save up enough money to pull my swap..n plus i hate fuel injection im rdy to go back carbed

ibmtech

iTrader: (1)

IMO if you are just planning on throwing on a larger intake to get more HP, I think you are mistaken. That would be like saying I need more horsepower so I am going to put larger tires on. If you are planning on going carb, there is nothing wrong with that. Some people don't like fuel injection either because they don't understand how it works or because they don't know to effectively tune modifications. No matter what engine you run, You can throw on bigger and better parts, but without ECM tuning or manually adjusting carbed applications, You are just wasting your time.

Excellegions

How About if you're planning on putting 8 to 10 psi boost in a custom turbo fab like I am? How big do the injectors have to be then? And what can I do to the computer to run with boost? I installed the jet chip in it already, Is that all I have to do to the computer?

KyleP

IMO I would run some 42s. I have a s/c ls1 and that is what I used and it worked great.