Fueling & Injection Fuel Pumps | Injectors | Rails | Regulators | Tanks

injector size?

Thread Tools
 
Search this Thread
 
Old Dec 17, 2006 | 06:10 PM
  #1  
caviness's Avatar
Thread Starter
TECH Enthusiast
iTrader: (14)
 
Joined: Apr 2006
Posts: 698
Likes: 4
From: Liberty,NC
Default injector size?

what size injector for 450 to 550 rwhp? will my stock 2000 model injectors be big enough for 400 to 475?
Reply
Old Dec 17, 2006 | 08:04 PM
  #2  
caviness's Avatar
Thread Starter
TECH Enthusiast
iTrader: (14)
 
Joined: Apr 2006
Posts: 698
Likes: 4
From: Liberty,NC
Default

maybe i posted in the wrong place?
Reply
Old Dec 17, 2006 | 08:15 PM
  #3  
98LS1auto's Avatar
TECH Regular
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (3)
 
Joined: Aug 2006
Posts: 405
Likes: 47
From: North Carolina
Default

Originally Posted by caviness
what size injector for 450 to 550 rwhp? will my stock 2000 model injectors be big enough for 400 to 475?
From what I've just been told 42's will handle that rwhp just fine and then some. I'm going to get 42's because I'm gonna spray and I'm not going to take any chances when it comes to making sure that my motor has enough fuel. Better safe than sorry. Fuel upgrades are cheaper than a new motor.
Reply
Old Dec 17, 2006 | 09:08 PM
  #4  
caviness's Avatar
Thread Starter
TECH Enthusiast
iTrader: (14)
 
Joined: Apr 2006
Posts: 698
Likes: 4
From: Liberty,NC
Default

thanks for the info.
Reply
Old Dec 17, 2006 | 10:30 PM
  #5  
Boodyrider's Avatar
12 Second Club
iTrader: (2)
 
Joined: Jun 2006
Posts: 580
Likes: 1
From: Baltimore, Maryland
Default

42s are more than enough, even on juice or FI at those power levels... towards 475 rwhp you'd want to look closely at duty cycle if your getting there FI, but should still be fine.

Stock, despite some folks claims, are really beyond their ability to supply enough fuel SAFELY around 400.

Also... the 2000 injectors flow a bit less than the 98 or 01/02, so you'd be even further beyond the limits.

You could go 36, but the price of 42s is often lower than for 36s. And be aware that the Accel injectors have been known to fall short of advertised flow, sometimes dangerously so. Do a search for 42s you'll find some good deals out there.

Seriously consider pump upgrades as well, the Racetronics kit is well thought of.
Reply
Old Dec 18, 2006 | 12:09 AM
  #6  
2 fast 2000's Avatar
TECH Apprentice
iTrader: (4)
 
Joined: Nov 2006
Posts: 329
Likes: 0
From: Lawrenceville, GA
Default

Originally Posted by Boodyrider
42s are more than enough, even on juice or FI at those power levels... towards 475 rwhp you'd want to look closely at duty cycle if your getting there FI, but should still be fine.

Stock, despite some folks claims, are really beyond their ability to supply enough fuel SAFELY around 400.

Also... the 2000 injectors flow a bit less than the 98 or 01/02, so you'd be even further beyond the limits.

You could go 36, but the price of 42s is often lower than for 36s. And be aware that the Accel injectors have been known to fall short of advertised flow, sometimes dangerously so. Do a search for 42s you'll find some good deals out there.

Seriously consider pump upgrades as well, the Racetronics kit is well thought of.
The reason they flow less is because there smaller. 98,01,02's have bigger injectors (28lbs) from the factory. I have a 2000ss h/c, bolt-ons, and a 150 shot. At 560rwhp+ my injectors are fine, and they are factory 26lbs. Ran the car for over 100 passes and never had a problem. However I agree with you on the fuel pump upgrade though!
Reply
Old Dec 18, 2006 | 12:25 AM
  #7  
caviness's Avatar
Thread Starter
TECH Enthusiast
iTrader: (14)
 
Joined: Apr 2006
Posts: 698
Likes: 4
From: Liberty,NC
Default

looks like 42 to be safe. then i want need to upgrade no time soon.
Reply
Old Dec 18, 2006 | 08:03 AM
  #8  
john563's Avatar
TECH Fanatic
iTrader: (17)
 
Joined: Sep 2006
Posts: 1,638
Likes: 0
From: dayton ohio
Default

Originally Posted by 2 fast 2000
The reason they flow less is because there smaller. 98,01,02's have bigger injectors (28lbs) from the factory. I have a 2000ss h/c, bolt-ons, and a 150 shot. At 560rwhp+ my injectors are fine, and they are factory 26lbs. Ran the car for over 100 passes and never had a problem. However I agree with you on the fuel pump upgrade though!
Im cammed and heads are going in about a wk and wife just ordered a harris kit and im probly gonna do 100 shot.I was just wondering what rear do you have and are you an A4? dont know what these 10 bolts can hold on an a4
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 Dec 18, 2006 | 10:14 AM
  #9  
caviness's Avatar
Thread Starter
TECH Enthusiast
iTrader: (14)
 
Joined: Apr 2006
Posts: 698
Likes: 4
From: Liberty,NC
Default

any more info. i need it.
Reply
Old Dec 18, 2006 | 10:38 AM
  #10  
MeentSS02's Avatar
Kleeborp the Moderator™
20 Year Member
iTrader: (11)
 
Joined: Mar 2004
Posts: 10,316
Likes: 6
From: Dayton, OH
Default

Yes, this sorta is the wrong place to post this, as it belongs in the fuel system section, but either way, here are my thoughts:

If you monitor your fuel pressure like I do, you'll quickly see that the stock fuel systems in these cars drop pressure with increased load. This requires the injectors to stay open longer to compensate for the pressure drop to keep the fueling where it needs to be, driving your injector duty cycle up. So really, there are a couple options here:

1. You get larger injectors that can compensate for any fuel pressure deviations without getting over 80% duty cycle
2. You upgrade the fuel pump
3. You find a way to regulate the fuel pressure so that it stays steady at the rails

In reality, it will probably take a combination of all three to get where you need to be with your fuel system. If you want to take the easier/cheaper way out, get some 42 lb/hr injectors and a Racetronix plug and play system. That should get you where you need to be. You wouldn't need as large of an injector if you could keep the rail pressure constant though, and I'm not sure how to fix that...yet.
Reply
Old Dec 18, 2006 | 05:01 PM
  #11  
caviness's Avatar
Thread Starter
TECH Enthusiast
iTrader: (14)
 
Joined: Apr 2006
Posts: 698
Likes: 4
From: Liberty,NC
Default

thanks for the info guys.
Reply
Old Dec 18, 2006 | 06:51 PM
  #12  
caviness's Avatar
Thread Starter
TECH Enthusiast
iTrader: (14)
 
Joined: Apr 2006
Posts: 698
Likes: 4
From: Liberty,NC
Default

thanks for moving my thread.
Reply




All times are GMT -5. The time now is 11:06 PM.

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