LS4 Performance Grand Prix GXP | Monte Carlo SS | Impala SS | LaCrosse Super

fuel injector question

Thread Tools
 
Search this Thread
 
Old Jul 25, 2011 | 05:21 PM
  #1  
tek9's Avatar
Thread Starter
Teching In
 
Joined: Mar 2011
Posts: 3
Likes: 0
Smile fuel injector question

Will ls3 injectors fit the stock ls4 manifold and fuel rail? Are the the same length as the ls4 injectors?
Reply
Old Jul 25, 2011 | 05:37 PM
  #2  
AlabamaGuy's Avatar
TECH Addict
iTrader: (5)
 
Joined: Jun 2009
Posts: 2,802
Likes: 0
Default

No they will not, and no they are not. We do share the same style plug with them IIRC.

Can I ask why?
Reply
Old Jul 25, 2011 | 07:50 PM
  #3  
tek9's Avatar
Thread Starter
Teching In
 
Joined: Mar 2011
Posts: 3
Likes: 0
Default

I was wondering cause I know were to pick up a set really cheap and I was gonna use them in addition with a turbo on my gxp.
Reply
Old Aug 1, 2011 | 11:04 AM
  #4  
deatschwerks's Avatar
FormerVendor
iTrader: (2)
 
Joined: Feb 2008
Posts: 230
Likes: 1
From: Oklahoma City
Default

Looks like they use similar injectors.

The LS3 injectors should be a direct replacement (regarding fitment) for your LS4 injectors.

Last edited by deatschwerks; Aug 1, 2011 at 01:44 PM.
Reply
Old Aug 1, 2011 | 01:37 PM
  #5  
AlabamaGuy's Avatar
TECH Addict
iTrader: (5)
 
Joined: Jun 2009
Posts: 2,802
Likes: 0
Default

Originally Posted by deatschwerks
Looks like they use similar injectors.

The LS3 injectors should be a direct replacement for your LS4 injectors.
I doubt they have the same flow rates. I'd like to see some numbers before bolting them on.
Reply
Old Aug 1, 2011 | 01:44 PM
  #6  
deatschwerks's Avatar
FormerVendor
iTrader: (2)
 
Joined: Feb 2008
Posts: 230
Likes: 1
From: Oklahoma City
Default

I agree with you there, since the guy is needing them for a turbo project I was assuming he was wanting them because they were bigger.

The LS3/LS7 injectors are ~34# @ 43.5 psi fuel pressure.

...and fixed my post to reflect I was referring to fitment.
Reply
Old Aug 1, 2011 | 02:08 PM
  #7  
AlabamaGuy's Avatar
TECH Addict
iTrader: (5)
 
Joined: Jun 2009
Posts: 2,802
Likes: 0
Default

Originally Posted by deatschwerks
I agree with you there, since the guy is needing them for a turbo project I was assuming he was wanting them because they were bigger.

The LS3/LS7 injectors are ~34# @ 43.5 psi fuel pressure.

...and fixed my post to reflect I was referring to fitment.
We are about a 27.8# if I remember correctly so those would probably do well for a turbo car.
Reply
Old Aug 1, 2011 | 04:20 PM
  #8  
nmp0098's Avatar
TECH Regular
 
Joined: Nov 2009
Posts: 446
Likes: 0
From: Farmington Hills, MI
Default

They drop right in and use the same connector. We have a 4 bar (58 psi) returnless fuel system. They flow 41.7 lb/hr @ 4 bar. However, I have noticed some irregularities which I partially attribute to fuel pressure not being measured directly by the ECM. Since the system is only regulated at the self-contained pump, the ECM assumes 58 psi at the fuel rail and uses the MAP sensor to find the actual pressure drop seen by the injector (engine vacuum increases flow). I have some work planned that will systematically get me to the bottom of the irregularity over the next 2 months. What year GXP? What tuning software will you be using?
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

 Brett Foote
story-1

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-2

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-3

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-4

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-5

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-6

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-7

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-8

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-9

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
Old Aug 1, 2011 | 05:49 PM
  #9  
LS1 Racing's Avatar
TECH Addict
20 Year Member
Photogenic
iTrader: (15)
 
Joined: Aug 2002
Posts: 2,419
Likes: 6
From: 78°14′46″N 15°27′56″E
Default

Tune is key here. I've seen what happens when people don't get tuned for newer injectors, and if left long enough, it ain't pretty!
Reply
Old Aug 1, 2011 | 11:38 PM
  #10  
nmp0098's Avatar
TECH Regular
 
Joined: Nov 2009
Posts: 446
Likes: 0
From: Farmington Hills, MI
Default

Originally Posted by LS1 Racing
Tune is key here. I've seen what happens when people don't get tuned for newer injectors, and if left long enough, it ain't pretty!
Agreed, although I would assume tuning with the addition of a turbo. I recommend using 08 Vette tables until I work on the issue further.

Here is my thread on the irregularity I was referring to:

https://ls1tech.com/forums/pcm-diagn...frequency.html

The original injectors are going back in the car temporarily for a more careful analysis of the issue, but that won't be for a while yet.
Reply




All times are GMT -5. The time now is 04:02 AM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-4
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-5
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-6
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-7
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-8
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-9
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE