30 lb injectors enough?
Thread Starter
Registered User
Joined: Mar 2004
Posts: 123
From: Bronx,NY
30 lb injectors enough?
Hey all I just sent out my heads to be ported/polished bla bla bla. And I am ordering the bbk 58mm throttle body tonight i was thinking about upping the injectors. Can ya please check out my sig and let me know what size of injectors to buy or even if its worth it thanks
Registered User
Joined: Sep 2002
Posts: 333
From: Palm Bay, Florida
Re: 30 lb injectors enough?
Not worth it with what you have. Stock ones are good to ~450hp NA.
You listed your header bolts and gaskets as a mod? Come on, man!
-Dave C. '97 Z28
-Permatex Blue RTV, floor mats, Armor all, locking gas cap.
You listed your header bolts and gaskets as a mod? Come on, man!
-Dave C. '97 Z28
-Permatex Blue RTV, floor mats, Armor all, locking gas cap.
Last edited by Dave C. '97 Z28; Sep 13, 2004 at 03:34 PM.
Thread Starter
Registered User
Joined: Mar 2004
Posts: 123
From: Bronx,NY
Re: 30 lb injectors enough?
so the stock injectors are good until what 450 rwhp or at the engines. and as for mods in the sig Permatex Blue RTV, floor mats, Armor all, locking gas cap.what the hell is that?
Registered User
Joined: Apr 2001
Posts: 2,195
From: Springfield, IL
Re: 30 lb injectors enough?
not rear wheel and i think that even 450 flywheel HP is starting to push the limits with stock 24# injectors
some say yes, some say no
if you have the mods that need more fuel (P+P heads and aftermarket cam etc.) 30's atleast IMO would be needed
Dave is saying shorten your sig up a bit, that kind of detail is a bit much c?
some say yes, some say no
if you have the mods that need more fuel (P+P heads and aftermarket cam etc.) 30's atleast IMO would be needed
Dave is saying shorten your sig up a bit, that kind of detail is a bit much c?
Registered User
Joined: Feb 2002
Posts: 1,534
From: Lousiana
Re: 30 lb injectors enough?
I was hitting 103% duty cycle at WOT according to Datamaster on my stock 24lbers. After installing Ford SVO 30lbers it reads about 80% duty cycle at WOT. I am only running about 380 rwhp btw which I think is about 450 at the flywheel with an auto. We pretty much have the same setup. I would get bigger injectors imo.
Last edited by PoorMan; Sep 13, 2004 at 08:22 PM.
Registered User
Joined: Dec 1999
Posts: 1,697
From: Petersham, MA
Re: 30 lb injectors enough?
Even at stock fuel pressure levels, a stock 24# injector will support 425+ for short blasts. Realistically, you shouldn't exceed 400-410 fwhp with stockers, as it will command too large of a duty cycle for any kind of continous use. Of course, you could just turn up the fuel pressure. At 45 psi, a 24# will support 458 fwhp...buts its going static at that point.
http://www.smokemup.com/auto_math/fuel_injector2.php
http://www.smokemup.com/auto_math/fuel_injector2.php
Registered User
Joined: Jun 2002
Posts: 2,456
From: sarasota, fl
Re: 30 lb injectors enough?
some smart engine builders have said that you should buy big enough injectors so that you will not exceed 85% duty cycle at max power. that way you always have a good safety margin.
30lbs would probably be cutting it close..........id try and grab some ford 36lbs....you can get them used on the mustang boards really cheap.
30lbs would probably be cutting it close..........id try and grab some ford 36lbs....you can get them used on the mustang boards really cheap.
Thread Starter
Registered User
Joined: Mar 2004
Posts: 123
From: Bronx,NY
Re: 30 lb injectors enough?
Man really 36lb injectors? with my setup well i am going to make up my sumitt order today hopefully they have the svo injectors if not should i just get the accell? is there an in between injector at about 32lb?
Registered User
Joined: Sep 2002
Posts: 333
From: Palm Bay, Florida
Re: 30 lb injectors enough?
I think that for a street car the 24lber's are good for ~450 flywheel horsepower on a NA motor.
If the motor will see extended high power running (like in road racing) then you will need to get bigger ones. If you're running nitrous or a blower then normally you'd want bigger ones at 450HP because usually people bandaid a poorly matched engine by trying to richen up the mixture to prevent detonation, and when you do that the stock ones can't handle it.
But on the street, when normally you only see short blasts at WOT, then stock ones are fine. Are they the BEST choice? No.... but they will work.
-Dave C. '97 Z28
If the motor will see extended high power running (like in road racing) then you will need to get bigger ones. If you're running nitrous or a blower then normally you'd want bigger ones at 450HP because usually people bandaid a poorly matched engine by trying to richen up the mixture to prevent detonation, and when you do that the stock ones can't handle it.
But on the street, when normally you only see short blasts at WOT, then stock ones are fine. Are they the BEST choice? No.... but they will work.
-Dave C. '97 Z28
Last edited by Dave C. '97 Z28; Sep 14, 2004 at 12:29 PM.
Registered User
Joined: Jul 2001
Posts: 1,887
From: Kingsport, TN
Re: 30 lb injectors enough?
Originally Posted by Dave C. '97 Z28
I think that for a street car the 24lber's are good for ~450 flywheel horsepower on a NA motor.
If the motor will see extended high power running (like in road racing) then you will need to get bigger ones. If you're running nitrous or a blower then normally you'd want bigger ones at 450HP because usually people bandaid a poorly matched engine by trying to richen up the mixture to prevent detonation, and when you do that the stock ones can't handle it.
But on the street, when normally you only see short blasts at WOT, then stock ones are fine. Are they the BEST choice? No.... but they will work.
-Dave C. '97 Z28
If the motor will see extended high power running (like in road racing) then you will need to get bigger ones. If you're running nitrous or a blower then normally you'd want bigger ones at 450HP because usually people bandaid a poorly matched engine by trying to richen up the mixture to prevent detonation, and when you do that the stock ones can't handle it.
But on the street, when normally you only see short blasts at WOT, then stock ones are fine. Are they the BEST choice? No.... but they will work.
-Dave C. '97 Z28
...until they lock up from having their duty cycle maxed the hell out. Best case scenario you have to buy new injectors, which you should have done in the first place. Worst case, you'd better have some duct tape to patch up that hole in your oilpan.
An average track run for a car with 24 lb injectors will last about 13 seconds. That's 13 seconds of your duty cycle being maxed out.
I'm not trying to argue, but I know that I'd be pissed if I toasted a motor because some guy on a messageboard told me wrong.
To the original poster. Just go ahead and get some FMS 36#ers. They're not THAT much more than 30#s. Don't worry about a FPR either.
http://www.corral.net/forums/forumdi...s=&forumid=323
Registered User
Joined: Apr 2004
Posts: 55
From: jax, fl
Re: 30 lb injectors enough?
i ran the times in the sig and ive got 30# Accel injectors right now. going to use them with a 175 shot with an NX kit soon, compared to my dry NOS 100 shot.
2 years ago, car was a lil lighter, solid roller cam setup, and a NX 150 shot and went 10.98@127.9 with stock 22# injectors from a 94.
dont know how much that helps, but thats what this car has gotten away with.
that wasn't even with forged pistons..
2 years ago, car was a lil lighter, solid roller cam setup, and a NX 150 shot and went 10.98@127.9 with stock 22# injectors from a 94.
dont know how much that helps, but thats what this car has gotten away with.
that wasn't even with forged pistons..