are they worth the money?? will they add any noticable hp?? i plan on putting on ported n polished lb9 heads so i was figuring i needed the extra fuel flow for them.

anyone have the 65 lb injectors?? did they help anything at all?

 

After you swap those heads you are definetely going to want to use the 65pph injectors. Just keep in mind you will need another custom prom to compensate for both the heads and the injectors.

 

I've changed my thinking about big injectors. Since the 65 and the 80 and 90 pound injectors are expensive and hard to find. I think its better just to run the stock 350 injectors at higher pressure. After my 90# injectors crapped out a little while ago, I just cranked my fuel pressure up to 35psi with the 55# stock injectors (roughly 105 lb/hr). No problems yet, and if they fail, the 55# can be found at junkyards and "pick a parts" for cheap.

And as far as a new pump, walboro makes a unit that supports 600hp, for $95. Thats cheaper than new injectors.

 

Injectors do not add horsepower if you do not need them.

 

well, i have them in my hands, funny thing is, they werent hard to find at all, i got em at napa lol....had to search a good bit though

so to make sure, the part # for these is 17112400

they dont look any different than the 55lb ones.. in any event mine were spraying un even so i figured, same price for the 65 lb. might as well get em.

so there will be NO difference when i stick these in??

i wasnt aware they made 80 and 90 lb. tthey do anything different? any mods needed to run them??

 

To run the bigger injectors, you need to tell the computer what size they are, so it doesn't think that the stock ones are still in there. Its just one value in the prom. The old rule about injectors is a good one to follow. 1 pound of injector supports 2hp, so 65# will support 260 hp +/- a little.

 

so what happens if i run the injectors with the custom prom i have?

i got it from Brian @ tbichips.com, real good guy, in fact he will prolly re burn the prom for a few bucks if any charge at all.

i drove the car after i installed them 10 mins ago, drove perfect, in face it gained back a lil lost sluggishness.

im going to have the 55 lb injectors cleaned real well and sell them if anyone wants them.

they didnt run bad , i just wanted the 65 lb ones because im putting better heads on and wanted it to deliver enough fuel for the lb9's i have sitting in my garage.

figured id run the 65 regardless, not change the fuel pressure, and id be safe til i put the new heads on and get a afpr. run it at 18-20 and be good to go.


correct me if any of my judgement is incorrect.

EDIT:

so basicly, the 65 lb injectors will support the hp i have currently due to all the mods?

do i need higher lb injectors for the Lb9's? 80, 90?

 

The reason the car runs fine is because the computer has an "auto learn capability" so its compensating for the larger injectors @ part throttle.

The 65# should be good enough whatever you do, look at me, I'm running 55# cranked up, and hoping for 13.5s - 14.0s (4200lb truck) track times real soon (as soon as I get my dumps welded into my exhaust)

 

eithr way im gonna get brian to write a new chip for the lb9's, so ill just get him to add on the 65 lb injectors and take off the smog crap --nods--

this is going to be the badest L03 ever!! well, at least ...itll be a good L03 lmao

considering only the block will be L03, the rest, uhm....half napa parts half random parts comanies i.e. msd, edel. etc etc etc etc etc

this car is no longer gm lolol

 

Generally, the reason people swap to larger injectors instead of turning up the fuel pressure to compensate is because too much fuel pressure can cause idle problems with certain engine combos. Some people can run high pressure at idle and get away with it. Low C1500s sounds like it runs pretty good at 35psi, JPrevost runs his @ 28psi, and I'm running at 22psi without an idle issue. However, that isn't to say that your combo would run as good at idle w/ high fuel pressure, so going to 65pph injectors wasn't a bad decision.
Like Low C1500 said, the Walbro 255 is a great pump which you may consider installing, you are going to be getting to the point where your stock pump isn't going to be able to keep up.
Also, a custom prom is never a bad idea when doing mods such as heads. They are going to change the fuel and spark values needed for optimum performance.

 

yeah, i got em *just in case* besides i had the choice of getting either the 55 or 65 for the same price.

it turns out i didnt need new injectors though, wonder if i can send these back lol

oh well, im going to go check my oil pan, i bottomed out my car on a damn dip in the road i didnt see.

lets pray it hit the cross member and not the pan heh.

 

I have a vac ref regulator which (@ idle) knocks the pressure below 30 psi. I think the reason I don't have pulse width problems @ idle, is because I idle @ 850 rpm. If I had a stock cam and tried to idle my setup @ 550 rpm, I think problems would occur.

 

whats a good AFPR to get, and does it have a guage on it or do i have to go buy a 80 dollar fuel pressure guage.

part #?

i wanna set mine at 22 or so, i think stock is like 10-12.....

im just trying to get everything figured out to give the new heads the fuel flow it needs

 

I'm not sure of part numbers, but mine is a gm model which was originally off a BBC boat motor.

 

you can find the gm part number for the afpr by doing a search, I know it has been posted a few times. Limit your search to the tbi and aftermarket product review boards to narrow your search.
Also, don't pay $80 for a fuel pressure gauge. I bought mine from Auto Zone for $40, advertised for tbi, and works great. It comes with a hose long enough to tape to your windshield as well, so you know if your pressure is dropping when under full load.