LT1-LT4 Modifications 1993-97 Gen II Small Block V8

30# injectors too much?

Thread Tools
 
Search this Thread
 
Old 11-01-2007, 07:15 PM
  #1  
Teching In
Thread Starter
 
B4C_LT1's Avatar
 
Join Date: Sep 2007
Location: Wamego, Ks
Posts: 21
Likes: 0
Received 0 Likes on 0 Posts
Default 30# injectors too much?

will 30# injectors work on a nearly stock car....just have free mods, cai, ud pulley.....just wondering if its too much..??
Old 11-01-2007, 09:15 PM
  #2  
TECH Addict
iTrader: (8)
 
GIZMO's Avatar
 
Join Date: Jan 2004
Location: Shelby, NC
Posts: 2,780
Received 3 Likes on 3 Posts

Default

Originally Posted by B4C_LT1
will 30# injectors work on a nearly stock car....just have free mods, cai, ud pulley.....just wondering if its too much..??
They will be way too much. I still run 24 lb injectors in my mid ten second race cars (N/A).
Old 11-01-2007, 09:54 PM
  #3  
TECH Fanatic
 
hyperzone's Avatar
 
Join Date: Jan 2005
Location: St. Augustine, FL
Posts: 1,162
Received 0 Likes on 0 Posts

Default

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?
Old 11-01-2007, 09:57 PM
  #4  
TECH Senior Member
iTrader: (3)
 
Formula350's Avatar
 
Join Date: Oct 2006
Location: Decatur, TN (N-W of Athens)
Posts: 7,564
Likes: 0
Received 4 Likes on 4 Posts
Default

24# are good up to around 350hp. But then you're looking at them running high duty cycle.
Old 11-01-2007, 10:27 PM
  #5  
Staging Lane
 
bigdan1's Avatar
 
Join Date: Jan 2007
Location: st-jean baptiste, quebec ,canada
Posts: 71
Likes: 0
Received 2 Likes on 2 Posts
Default

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
Old 11-01-2007, 10:33 PM
  #6  
TECH Addict
iTrader: (8)
 
GIZMO's Avatar
 
Join Date: Jan 2004
Location: Shelby, NC
Posts: 2,780
Received 3 Likes on 3 Posts

Default

Originally Posted by Formula350
24# are good up to around 350hp. But then you're looking at them running high duty cycle.
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.
Old 11-01-2007, 10:36 PM
  #7  
TECH Addict
iTrader: (8)
 
GIZMO's Avatar
 
Join Date: Jan 2004
Location: Shelby, NC
Posts: 2,780
Received 3 Likes on 3 Posts

Default

Originally Posted by bigdan1
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
They work just fine. 10.5's in a 3200+ lb car.
Old 11-02-2007, 03:56 AM
  #8  
TECH Senior Member
iTrader: (3)
 
Formula350's Avatar
 
Join Date: Oct 2006
Location: Decatur, TN (N-W of Athens)
Posts: 7,564
Likes: 0
Received 4 Likes on 4 Posts
Default

Originally Posted by GIZMO
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.
Good infor to have, thanks 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.
Old 11-02-2007, 06:39 AM
  #9  
TECH Addict
iTrader: (8)
 
GIZMO's Avatar
 
Join Date: Jan 2004
Location: Shelby, NC
Posts: 2,780
Received 3 Likes on 3 Posts

Default

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.
Old 11-02-2007, 06:41 AM
  #10  
TECH Addict
iTrader: (8)
 
GIZMO's Avatar
 
Join Date: Jan 2004
Location: Shelby, NC
Posts: 2,780
Received 3 Likes on 3 Posts

Default

To get the best out of anything you have to adjust the tune for every change, including the weather.
Old 11-02-2007, 07:16 AM
  #11  
TECH Addict
iTrader: (1)
 
myltwon's Avatar
 
Join Date: Jul 2004
Location: Palm Harbor, FL
Posts: 2,965
Received 6 Likes on 6 Posts

Default

aftermarket injectors on a stock tune = no

accell injectors = no again
Old 11-02-2007, 08:27 AM
  #12  
Internet Mechanic
iTrader: (17)
 
BlackScreaminMachine's Avatar
 
Join Date: May 2005
Location: Wallingford CT
Posts: 9,830
Likes: 0
Received 2 Likes on 2 Posts

Default

Yes, they are, but can be tuned down and run fine. If you can find a deal hold on to them if you expect to be making more power down the line.
Old 11-02-2007, 08:39 AM
  #13  
TECH Addict
iTrader: (8)
 
GIZMO's Avatar
 
Join Date: Jan 2004
Location: Shelby, NC
Posts: 2,780
Received 3 Likes on 3 Posts

Default

Originally Posted by BlackScreaminMachine
Yes, they are, but can be tuned down and run fine. If you can find a deal hold on to them if you expect to be making more power down the line.
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.
Old 11-02-2007, 04:22 PM
  #14  
TECH Addict
iTrader: (9)
 
buffman's Avatar
 
Join Date: Nov 2004
Location: Kzoo, MI
Posts: 2,289
Likes: 0
Received 0 Likes on 0 Posts

Default

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.
Old 11-02-2007, 06:02 PM
  #15  
TECH Addict
iTrader: (8)
 
GIZMO's Avatar
 
Join Date: Jan 2004
Location: Shelby, NC
Posts: 2,780
Received 3 Likes on 3 Posts

Default

Originally Posted by buffman
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!)
Old 11-02-2007, 07:07 PM
  #16  
TECH Addict
iTrader: (9)
 
buffman's Avatar
 
Join Date: Nov 2004
Location: Kzoo, MI
Posts: 2,289
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by GIZMO
(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.
Old 11-02-2007, 09:11 PM
  #17  
TECH Addict
iTrader: (8)
 
GIZMO's Avatar
 
Join Date: Jan 2004
Location: Shelby, NC
Posts: 2,780
Received 3 Likes on 3 Posts

Default

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
Old 11-02-2007, 09:50 PM
  #18  
TECH Senior Member
iTrader: (3)
 
Formula350's Avatar
 
Join Date: Oct 2006
Location: Decatur, TN (N-W of Athens)
Posts: 7,564
Likes: 0
Received 4 Likes on 4 Posts
Default

The injectors don't just crap out from the excess duty? What's the benefit of running the 24s so high, rather than say even 38s @ 60ish?
Old 11-02-2007, 11:10 PM
  #19  
TECH Addict
iTrader: (8)
 
GIZMO's Avatar
 
Join Date: Jan 2004
Location: Shelby, NC
Posts: 2,780
Received 3 Likes on 3 Posts

Default

Originally Posted by Formula350
The injectors don't just crap out from the excess duty? What's the benefit of running the 24s so high, rather than say even 38s @ 60ish?
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.
Old 11-02-2007, 11:25 PM
  #20  
TECH Addict
 
engineermike's Avatar
 
Join Date: Jul 2005
Posts: 2,153
Likes: 0
Received 3 Likes on 3 Posts

Default

You could run 96'ers on a stocker if you change the injector constant (and add an impedence converter).


Quick Reply: 30# injectors too much?



All times are GMT -5. The time now is 06:45 PM.