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

need injector advice

Thread Tools
 
Search this Thread
 
Old 05-30-2008, 01:39 AM
  #1  
On The Tree
Thread Starter
iTrader: (8)
 
chucks ss's Avatar
 
Join Date: Jan 2008
Location: ankeny ,iowa
Posts: 195
Likes: 0
Received 1 Like on 1 Post

Default need injector advice

im running stock injectors on my 2001 ls1 camaro and a 150 shot of gas , what size are the stock injectors ? should i up grade? if so to what size / and what mileage should i look at replacing them ? im at 44,000 miles
Old 05-30-2008, 07:34 AM
  #2  
TECH Resident
iTrader: (17)
 
ZL1Killa's Avatar
 
Join Date: Sep 2004
Location: NC - Charlotte area
Posts: 3,747
Likes: 0
Received 0 Likes on 0 Posts

Default

on a 2001 they are 28.8lb/hr injectors

how much more power are you planning on going?

you can get away with 32#/hr or 37b/hr, 38#, or even 42#/hr and be fine idling and WOT

IF you bought the above injectors I named off at a rating of 43.5psi, they would actually be : at our fuel rail pressure:


If you don't plan on making more than 500 rear wheel HP I would just recommend getting 36.5lb injectors

http://www.racetronix.com/

If you planned on being above 500HP then I would get the 42#, if not stick with the #37 or 38#
Old 05-31-2008, 01:29 PM
  #3  
Staging Lane
 
odd boy's Avatar
 
Join Date: Apr 2008
Posts: 55
Likes: 0
Received 0 Likes on 0 Posts

Default

Let us assume that your car is around 350 hp (+/-) 10 hp, and 150 hp will be shot of gas. So, your engine will run 500 hp. Calculate it this way, hp= lb/hr x no of injectors x 2 x 0.9 , therefore lb/hr = hp/(no of injectors x 2 x 0.9)

lb/hr= 500/(8 x 2 x 0.9) = 34.8 lb/hr, so you should be fine with 36, but watch out for the rail pressure, if the 36 lb/hr injectors are rated at 45 psi and the rail pressure is 60 psi, each will deliver flow of 42 lb/hr and the tuning part will be difficult especially the idle.
Old 05-31-2008, 05:57 PM
  #4  
Teching In
 
pmj341's Avatar
 
Join Date: May 2008
Location: Sebring, Fl
Posts: 23
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by odd boy
Let us assume that your car is around 350 hp (+/-) 10 hp, and 150 hp will be shot of gas. So, your engine will run 500 hp. Calculate it this way, hp= lb/hr x no of injectors x 2 x 0.9 , therefore lb/hr = hp/(no of injectors x 2 x 0.9)

lb/hr= 500/(8 x 2 x 0.9) = 34.8 lb/hr, so you should be fine with 36, but watch out for the rail pressure, if the 36 lb/hr injectors are rated at 45 psi and the rail pressure is 60 psi, each will deliver flow of 42 lb/hr and the tuning part will be difficult especially the idle.
Question
If the injectors are 33lbs @ 60 psi and you install 42lbs the car will run rich thru the whole power range, and would have to be tuned.
would that a good assumtion??
Old 05-31-2008, 09:34 PM
  #5  
Staging Lane
 
odd boy's Avatar
 
Join Date: Apr 2008
Posts: 55
Likes: 0
Received 0 Likes on 0 Posts

Default

yes, it is
Old 06-01-2008, 07:22 AM
  #6  
TECH Resident
iTrader: (17)
 
ZL1Killa's Avatar
 
Join Date: Sep 2004
Location: NC - Charlotte area
Posts: 3,747
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by pmj341
Question
If the injectors are 33lbs @ 60 psi and you install 42lbs the car will run rich thru the whole power range, and would have to be tuned.
would that a good assumtion??

if you install ANY injectors LARGER than your current ones and DON'T TUNE IT it will run rich regardless


Injectors are rated usually at 43.5psi... apparently 45psi is the new thing??? wheres all this 45psi coming from??

and then injectors are rated at 5x psi?
Old 06-01-2008, 10:41 AM
  #7  
TECH Apprentice
iTrader: (24)
 
Goldfinger911's Avatar
 
Join Date: Jul 2007
Location: Sumner, WA
Posts: 319
Likes: 0
Received 0 Likes on 0 Posts

Default

Good info here on sizing and ratings:
http://www.rceng.com/technical.aspx?...qUIfHgT1sDASLp
Old 06-01-2008, 01:35 PM
  #8  
Staging Lane
 
odd boy's Avatar
 
Join Date: Apr 2008
Posts: 55
Likes: 0
Received 0 Likes on 0 Posts

Default

ZL1Killa,

Please read the gray color down of the table in the below link

http://www.fuelairspark.com/Products...ection_468.asp
Old 06-01-2008, 02:08 PM
  #9  
TECH Addict
iTrader: (11)
 
405HP_Z06's Avatar
 
Join Date: Jun 2003
Location: Arlington, Tx
Posts: 2,215
Received 18 Likes on 14 Posts

Default

Originally Posted by ZL1Killa
if you install ANY injectors LARGER than your current ones and DON'T TUNE IT it will run rich regardless


Injectors are rated usually at 43.5psi... apparently 45psi is the new thing??? wheres all this 45psi coming from??

and then injectors are rated at 5x psi?
Don't sweat it, the 45 psi test rating is WRONG.

I had an issue tuning FAST 36 lb/hr injectors in an LS1 and went back and forth with FAST on the flow rating. Turns out the 45 psi should be 43.5. You would think they would fix their website.
Old 06-01-2008, 02:35 PM
  #10  
TECH Addict
iTrader: (11)
 
405HP_Z06's Avatar
 
Join Date: Jun 2003
Location: Arlington, Tx
Posts: 2,215
Received 18 Likes on 14 Posts

Default

More data to show the 45 psi rating on the FAST website is incorrect:

Old 06-01-2008, 03:06 PM
  #11  
TECH Resident
iTrader: (17)
 
ZL1Killa's Avatar
 
Join Date: Sep 2004
Location: NC - Charlotte area
Posts: 3,747
Likes: 0
Received 0 Likes on 0 Posts

Default

Lmao!!!!!!



Quick Reply: need injector advice



All times are GMT -5. The time now is 07:17 AM.