What size injectors?

[vmss10]

I'm upgrading to a marine intake. At this point I have a 260AHR magnum cam, ported and polished vortec heads, Powerdyne, & Edelbrock header system. I think that's it. I may upgrade to 2.02/1.60 valves also. I'm trying to decide on what size injectors to go with. Or at least a good size to start with. I've seen that the ones that come on the marine intake are slightly larger, but I'm sure thy're not large enough. Any input would be greatly appreciated.

[King_Ice_flash]

I think the ones that come with the manifold are still 19LB. Do you have a part number off of them?
You can probably find a set of LS1 injectors (which were around 28LB if I remember correctly) for pretty cheap. These should be OK for just about anything you can throw at them with a supercharger.

I would suggest a hotter cam (Like the 270).

I am using 48LB injectors, and will probably max them out. ~30LB is the MINIMUM usable for e85.

[vmss10]

I know on the cam. I've been thinking about the 270 magnum cam. Just trying to prioritise accordingly. Without hearing about it too loudly from the wife.

No I didn't look for a p/n on them. I'll have to that tonight when I get home. All I know is that they are the new EV6 style injectors(skinny ones with the new style connecter).

[King_Ice_flash]

What are you using for tuning?

[vmss10]

What are you using for tuning?

I'm using the Jet DST, an A-tap & Fast wide band. Had it for about 2 years.

[vmss10]

Just looked at the injectors on the marine intake. There are numbers on both sides. One side is 12567905and on the other is 0280156081. Guess I'll try to find a sight that can run the #'s on.

[King_Ice_flash]

The second number looks like the Bosch part number, and they appear to be 24LB. I'm trying to find more info.

[King_Ice_flash]

You sure that first number is right?

http://users.erols.com/srweiss/tableifc.htm
24.75@43.5

[vmss10]

On Stan Weiss' fuel injector site they are 24.57lb @ 43.5 psi. What do you think about the 27lb injectors on ebay for the Jeep 4.0 stroker engines? Or the LS2 34lb @ 58 psi, they figure to 29.45lb @ 34.5psi with his calculator? Just some thoughts.

[vmss10]

You sure that first number is right?

http://users.erols.com/srweiss/tableifc.htm
24.75@43.5

Yes, I double checked them.

[rabidbandit]

On Stan Weiss' fuel injector site they are 24.57lb @ 43.5 psi. What do you think about the 27lb injectors on ebay for the Jeep 4.0 stroker engines? Or the LS2 34lb @ 58 psi, they figure to 29.45lb @ 34.5psi with his calculator? Just some thoughts.

For your setup and that cam...no reason to have more than 24lb/hr. Hell....at 58 to 60psi on your fuel rail stock....they work out to north of 28lb/hr giving that they operated normally on a 43.5;) Which is basically a stock LS1 injector. They fed my friends car to about 435hp at the crank according to the engine dyno, that's all cam and heads;) After we raised the rev limiter up to 7200+....we up'd to 36#'s:D

If you plan is to go F/I....then like DOJ said...shoot for the 42's. Up to you...also...I have an injector calculator for setting the voltage offset in your tunning software from a good friend that's a frequenter of LS1Tech.com:D He's opened up the doors on tunning for many, including me;)

[vmss10]

For your setup and that cam...no reason to have more than 24lb/hr. Hell....at 58 to 60psi on your fuel rail stock....they work out to north of 28lb/hr giving that they operated normally on a 43.5;) Which is basically a stock LS1 injector. They fed my friends car to about 435hp at the crank according to the engine dyno, that's all cam and heads;) After we raised the rev limiter up to 7200+....we up'd to 36#'s:D

If you plan is to go F/I....then like DOJ said...shoot for the 42's. Up to you...also...I have an injector calculator for setting the voltage offset in your tunning software from a good friend that's a frequenter of LS1Tech.com:D He's opened up the doors on tunning for many, including me;)

I'm interested in the injector calculaor for setting the voltage offset you have. I believe I'm going to leave the 24.75lb@43.5 injectors on it to start and go from there depending on what the wide band shows me.

[12sws27]

I have an injector calculator for setting the voltage offset in your tunning software from a good friend that's a frequenter of LS1Tech.com:D He's opened up the doors on tunning for many, including me;)
I'll be needing that kind sir! :D

[12sws27]

I'm interested in the injector calculaor for setting the voltage offset you have. I believe I'm going to leave the 24.75lb@43.5 injectors on it to start and go from there depending on what the wide band shows me.

What did you change in your injector control setting for the Bosch 24s? I got as far as setting the flow rate at 27.95 which is at 59psi. 28.18 worked good to but my fuel pressure isn't quite 60psi with 0 vacuum. I just want to set my tune up right.

[Dogsofjune]

Some light reading.

http://www.monodax.com/forums/tunercat-jet-obdii-hardware-software/1199-fuel-injector-calculations.html

[12sws27]

Some light reading.

http://www.monodax.com/forums/tunercat-jet-obdii-hardware-software/1199-fuel-injector-calculations.html

Thanks. Now if I could just find the info I need for these injectors. Seems to be the hardest part. Then with the Ford Racing 39s I have theres the split spray pattern thing. This is why I've thought about different injectors.

Right now I can get the truck to run ok. Hell right now it's perfectly drivable. It's just my LTFT and STFT are all over the place. Putting in the right size flow rate helped but for a proper tune more injector info is needed. I figured if I can find the correct info on these injectors it could help many others as well. If they chose to keep the 24lb Bosch's that is.

[Dogsofjune]

Not much help there. I went originally with 32#'s out of an LS motor, then to 42# greentops. Tweaked the tune, cut down the inj pulse timing and been happy ever since. Well, till I needed more hp and went with a more efficient form of boost.

You do need to get those long term fuel trims in order to stay consistent. Your LTFT should be around 0.

STFT will move a bit.

[12sws27]

I guess I'm just going to be stuck play with flow rate. I keep reading that the right way to do it is one way but can't find the info on the inj to do it that way. I also keep reading how playing with the flow rate isn't the proper way be there sure is a sh!t load of guys that do it that way. I'll be damned if I'm going to buy that Greg's cd.

[vmss10]

That's why I went to Ed Wright and had him tune mine this spring. Was tired of f**n with it.