30# injectors too much?
TECH Fanatic
Joined: Jan 2005
Posts: 1,162
Likes: 0
From: St. Augustine, FL
Hijacking this but, on a similar angle... Is it bad to oversize your injectors? I'm not very well informed how the injector sizes make such a difference. I understand that if you increase your airflow enough that the injectors cant keep up you have to up the size so to richen the mixture and not go boom. But, if you have say the 30# injector on a stock car or even bigger on a stock or lightly modded car (assuming the tuning was changed to reflect the bigger injector)... would it be a catastrophe? Why?
Staging Lane
Joined: Jan 2007
Posts: 71
Likes: 2
From: st-jean baptiste, quebec ,canada
Hey Gizmo ,
you really run those 24lbs on a 10sec car !
ive bought some 36lbs for my modified LT1 ....I was told to do so ...
first ever time i hear someone run 24lbs and run in the 10's
they must run at 100 % cycle!
hope some other guys will comment on this ? i dont understand
Dan
you really run those 24lbs on a 10sec car !
ive bought some 36lbs for my modified LT1 ....I was told to do so ...
first ever time i hear someone run 24lbs and run in the 10's
they must run at 100 % cycle!
hope some other guys will comment on this ? i dont understand
Dan
The max. duty cycle gets thrown around a lot on here to justify bigger injectors. I have tried a couple of sets of 30 lb injectors in my cars and they just don't run as good in the sixty as the 24's (at higher fuel pressure). I have never had a 24 lb injector fail. I think that it is because I am only at WOT for a short time. If I were road racing a similar motor I would run bigger injectors to keep the duty cycle down.
Hey Gizmo ,
you really run those 24lbs on a 10sec car !
ive bought some 36lbs for my modified LT1 ....I was told to do so ...
first ever time i hear someone run 24lbs and run in the 10's
they must run at 100 % cycle!
hope some other guys will comment on this ? i dont understand
Dan
you really run those 24lbs on a 10sec car !
ive bought some 36lbs for my modified LT1 ....I was told to do so ...
first ever time i hear someone run 24lbs and run in the 10's
they must run at 100 % cycle!
hope some other guys will comment on this ? i dont understand
Dan
Trending Topics
TECH Senior Member
iTrader: (3)
Joined: Oct 2006
Posts: 7,564
Likes: 4
From: Decatur, TN (N-W of Athens)
The max. duty cycle gets thrown around a lot on here to justify bigger injectors. I have tried a couple of sets of 30 lb injectors in my cars and they just don't run as good in the sixty as the 24's (at higher fuel pressure). I have never had a 24 lb injector fail. I think that it is because I am only at WOT for a short time. If I were road racing a similar motor I would run bigger injectors to keep the duty cycle down.
You run the stock 24s or like SVOs? I noticed a change w/o a tune when I went to the 24# SVO. Then again I had 22# stock in the 93. LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo In my first Firebird I ran the stock injectors at 45 PSI. It ran a best of 10.89. In my Camaro I installed 24 lb SVO's at 50 PSI. They are still in it and it is now low tens capable (ran 10.45 at 1200 ft with 200+ lbs of ballast recently!). I have tried both Accell and SVO 30 lb injectors. The SVO injectors are of really good quality. I ran the same set on four of five different motors.
Injectors are like jets in a carb. You need to optimize them for your combination. If you are expecting to make more power later, you should change them then. I have yet to find a need for bigger injectors in my race only application. My sixty foot times are generally in the low 1.3's. Just because a car will still run when it is "tuned down" doesn't mean that it is right. I would say that the proof shows up in the time slips.
One advantage of aftermarket fuel injectors is that unlike the stock units if you're using nitrous (typically dry) and cause the injectors to lock, they will lock open, not closed like the stock units a 30lb injector will be just fine as long as they're tuned for it.
a 30lb injector will be just fine as long as they're tuned for it. 
(I can't believe that you actually caused me to use a one of these!) Now Gizmo he asked if they'd work on a nearly stock car. To that, the answer would be yes just fine as long as it's tuned for it. Some of us don't have an adjustable FPR or even want one. Your 24lbers at 50psi are fairly close to 30lbs (27 by calculation).
Now for the cost he could spend his $$$ better somewhere else. IF he has plans for the future, and or he has worthless fuel injectors (beyond clogged/leaking/etc) then there is nothing wrong with the injectors as long as they're tuned.
What would you say if I told you that some people are running 24 lb injectors at 60+ lbs? How about a N/A LT4 running 9.8's with 24 lb injectors? Could you maybe concieve that I am trying to pass on a little bit of real world experience? Save the injector money and buy a good fuel system.
Good Luck,
Daren
Good Luck,
Daren
The 24's have great drivability. They spend almost no time at max. duty if you are drag racing and you have your fuel pressure and tune right. The 30's show a noticable loss of performance, I would guess that 38's would really cause problems when you get up on the converter.
