lt1mc

iTrader: (1)

first let me introduce myself and say hey to everybody. this seems like a great board and im happy to be a part of it. im attempting my first lt1 swap into my 86 monte (also my very first experience with fuel injection), so be prepared for lots of questions and thanks in advance. so, first question- what fuel injectors should i go with? somebody has stripped the fuel rails and injectors off of this engine and from what i understand stock injectors are 24lb injectors. is this a good size or should i go bigger? also the injectors are VERY pricey, but egay has some great deals on remanufactured sets of 8. does this sound like a good idea to you guys? $90 a peice from autozone ($720 for all 8 ) is waaay to much

koolaid_kid

iTrader: (21)

Welcome to the board.
We cannot predict what size injectors to use until you outline what you will do/have done to the engine. Is it completely stock?
If not, what mods does it have? Injector size is the last thing that you calculate, after all the mods have been made or at least decided.
I paid less than 300 for my 42 pound injectors, but most pay around 350-400 (for varying brands).
LT1s cost money to feed and maintain, but the rush is worth it.

lt1mc

iTrader: (1)

thanks man i appreciate it. how can i calculate the injector size? is there a formula or is it more or less a good estimation? not sure what all i wil be doing, just pulled the engine so havent done much yet. thanks man

ZFan88

iTrader: (4)

https://ls1tech.com/forums/fueling-injection/293742-fuel-injector-size-calculator-fuel-pump-chart.html

onephatZ28

iTrader: (8)

You can get a good set of fuel injection for about $220 I would not pay more thean $300, if you plan on dueing any mods then go with the SVO's

onephatZ28

iTrader: (8)

HP * .07 = #/HR

In other words, if I want to run 500 FWHP, then I'd need at least a 35# injector to be safe.

GIZMO

iTrader: (8)

24 lb injectors work just fine at 500 FWHP.

onephatZ28

iTrader: (8)

I got that from someone on the forum, but I think if you are making more than 360rwh you should go with a bigger injector. So 500 hp at the fly multiply by .20=400 at rear wheels you will need a bigger injector

onephatZ28

iTrader: (8)

so what are the new ZO6's running if they are 500hp at the fly

Hot94Z28

I use SVO's.

koolaid_kid

iTrader: (21)

You also have to factor in fuel pressure. If you read the LS1 posts, the 42 pound injectors that we use they are getting about 46 or so pounds due to their increased pressure.
I find the statement that 24 pound injectors can support 500 hp to be quite interesting. In the Fueling and Injection section, they are recommending 42 pound injectors.
You might also let lt1mc know where he can get a new set of quality injectors for 220. Of course, we all know that the price increases as the capacity increases, so he will also want to know what size you were quoting.

koolaid_kid

iTrader: (21)

Of course, in order to make the calculation, you would have to know whether it is N/A or FI, and if FI, whether it is SC or TC. These factor into the calculation of injector size. Plus, you would not want to maxed out at 80% duty right at the start. You will want to leave room to grow, say 60-65% duty cycle.
Just some things to think about.

LT1MAN

iTrader: (6)

$220 for 42# here. they say 42's tune better

GIZMO

iTrader: (8)

I think that the 24 lb SVO injectors are around $220.00 from Jegs, etc. I had them in my Camaro which ran 10.5's @ 3200 lbs N/A (50 psi fuel pressure). I tried 30 lb injectors and once the tune was right performance was down by a bunch, especially in the sixty.

Daren

GIZMO

iTrader: (8)

If you want to foul plugs, that is the way to go.

koolaid_kid

iTrader: (21)

LT1mc, go to the fuel injector calculator at http://www.rceng.com/technical.htm and use that to calculate what size injector you need. Always do the work yourself when the tools are available. As to injector prices, do the same. Good sources to start with are Jegs and Summit, but don't stop there. Ebay is also a starting place, but you can usually beat their prices if you shop around. If you don't mind used injectors, members here sometimes sell them in the For Sale section.

lt1mc

iTrader: (1)

thanks to everybody for all the replies. and thanks for the calculator koolaid kid. didnt mean to start an arguement or anything. i appreciate all the help

koolaid_kid

iTrader: (21)

Not a problem. My fault for reacting.
If you choose to change things, such as heads, cam, rockers, exhaust, etc., go to the appropriate section in the LS1-LS2-LS6-LS7 PERFORMANCE section. Even though it is titled with the other engines, they are also experts in the LT1 and will be happy to answer your questions.
And best of luck, you will be very pleased with the results.

Frost

iTrader: (45)

Then why are everyone's 28lbers static in the 400-430RWHP range at 58psi?




If you swapped out to 30s and there was ANY difference in performance (except that the 30s won't be STATIC UP TOP) then the tune was NOT "right".

60lbers are rated at 43.5psi and they can be made to work on a stock engine with no loss of performance at 59psi. It's in the tune.

GIZMO

iTrader: (8)

How much FWHP does it take to make 400-430RWHP?

Sorry, but I probably spend way much more time in my lap top than you do. I have run the same basic combination for a bunch of years and I know what works on my cars.

Is this "seat of the pants" or hard data. Dyno or race track?


Daren