BashamWS6

iTrader: (8)

I have a Bolt on LS1 with the 26lbs injectors with 89K miles on them
would it help anything if i were to put the 28lbs injectors with 42K miles on them?

Mods
LTS, ORY, LMII, LID, Ported TB, free mods

deatschwerks

iTrader: (2)

You'd need to get it retuned.

How much is the set of 28#'s going to cost you? How much would a new tune cost?

If your AFRs are still good, I'd recommend just getting the injectors you have cleaned. ...unless you will be looking for more power soon.

BashamWS6

iTrader: (8)

well i didnt know if there would be any benefits. i got them off of a friend who totalled his car and figured that he wouldnt be able to sell them.
i will be around 350rwhp and i will need a tune reguardless for other mods.
so.. your suggesting i sell theM?

deatschwerks

iTrader: (2)

With the 24# injectors, you are going to be close to using all of them (~90% IDC). I think the 28# would be a good move, just so you have some extra room later on.

98transbum

im getting confused the poster asked about 26 vs 28lbs you say 24's.. Dont forget our cars run at 58psi fuel pressure so a 26 is really a 22 and a 28 is really a 24. so do your calcs based on that.

deatschwerks

iTrader: (2)

My bad. Shows how good my attention is this morning.

We rate all of our injectors at 43.5 psi, which is industry standard.

I knew the LSx's run at 58psi, so I was making the assumption the 24# (should have been 26#s) was the 3 bar flow rating.

For ~350whp, you are going to need about 28# of fuel per injector @ 90% IDC (my estimates are conservative, I'd rather be on the safe side).

98transbum

not to be a wise ***, but he should get the right info. if he has 350whp he has 425 chp ... a 28lb injector rated at 58psi would run at 95ids, so how is this conservative? unless im wrong on the hp.... how did you calculate your conservative number?

deatschwerks

iTrader: (2)

I use our fueling calculator here: http://www.deatschwerks.com/fuel-calculators/

400 horsepower
8 injectors
.5 BSFC
90% IDC

= 27.8 lb/hr or 291.7 cc/min

98transbum

you are right if the OP had a 28 injector rated at 43.5.. he has a 24 at 3 bar.. i think he is talking about a oem 28 injector which is not rated at 43.5.... i hope he responds so he can get the right info and not go do this to find out he is still in need of injectors.

98transbum

thats fine but my point being if he has 28 oem injectors they will not work at your numbers

deatschwerks

iTrader: (2)

If he has 28# OEM injectors, they should be enough to get him to power he's wanting to make. ...but it is going to be on the edge of what that injector can do.

I was mistaken about the 26# injectors, as I made an incorrect assumption about the flow rating fuel pressure.

The 28# (@4 bar) should be just enough. If he'd like some extra head room to get the IDCs down, the next size up would be recommended.

I'm not even trying to sell the guy my injectors. Just trying to be helpful. The smallest injector I current have available is a 42# (@3bar) which would be way overkill.

BashamWS6

iTrader: (8)

well the way i look at it is... GM replaced the 26s of the 98-99 models with 28s on the 00-02 models.
i wont be doing any internals and only bolt ons with the ls1
and many people run OEM 28s with bolt ons... some even with the 26s.
i have the 28s because i was going to go with an LS6 (however they were discontinued) so i have them just laying around.
when i send my pcm to frost i will just specify that i will have the 28s installed and install them while the pcm is out.

ZL1Killa

iTrader: (17)

To answer this statement, injectors do not make power. If you were losing fueling up top (going lean), then going to a higher flowing injector would "make more power"

26 vs 28 Injector duty cycle would be ~5% reduction with all other things the same.

would it help, well it would give you more breathing room & possibly prevent any fueling problems from the smaller injectors getting "stuck". I have known people with 26# injectors with mods you have maxing them out, and also running a high duty cycle with the 28LB injectors. What do you expect? The setup that GM sells is the bare minimum that will work with what the car has...and everyone is about saving money.

If you have 28LB setting around and can swap them for the 26# while you are getting a tune, go for it.

BashamWS6

iTrader: (8)

yup thats what i figured. well see when me and charles can get it on the dyno

ZL1Killa

iTrader: (17)

just holler or PM me if you need more info. Been around this injector stuff for a while, and there are some good fuel sponsors on here too that know their stuff.