When Do I Go To 24lbs Injectors?

[mrbeer99]

My Stang is a NA. Mildly Moded with a good Exhaust, 70mm TB, Accufab Plenum, DiabloSport Pedator Tuned, Pullies and other little add-ons. I must be getting close to the limit of the Air/Fuel range of the Fuel Injectors. I read in SHM 4.6L Motor Guide that the stock 19lbs were good to 304HP @ 90% Duty Cycle. I must be close to that limit.

When do I start down that path for adding the 24lbs injectors with a recalibrated MAF?

Thanks

 

[billfisher]

when you make more power.


i wouldn't read a lot of SHM stuff. in my opinion you will get screwed i have heard.

 

[BlackenedSVT]

I have the same mods as you (minus the tune) and i dont really think we need to upgrade injectors. Although i forget what kind of injectors my car has stock. I want to say my car has 24lb already. Didn't the 99 GTs have 19lbs and then they upgraded them for the later models?

Not to hyjack the thread here...but what lb injectors came in what model year GTs? Can someone include colors of the injectors too?

I think i have pinks

 

[01Steeda]

My Stang is a NA. Mildly Moded with a good Exhaust, 70mm TB, Accufab Plenum, DiabloSport Pedator Tuned, Pullies and other little add-ons. I must be getting close to the limit of the Air/Fuel range of the Fuel Injectors. I read in SHM 4.6L Motor Guide that the stock 19lbs were good to 304HP @ 90% Duty Cycle. I must be close to that limit.

When do I start down that path for adding the 24lbs injectors with a recalibrated MAF?

Thanks

unless your talking crank HP your not even close without cams at the least.

 

[Gearbanger 101]

A 90% duty cycle is not where you want to be with any injector. 80% is where they run happiest. I say if you're going to bother upgrading them and making any major power in N/A form, go right for a set of 30lb'ers. They can be tuned for just as easily as 24's, will provide extra insurance and are probably cheaper to buy than the 24's.

 

[BLKsteeda]

my car makes 310/325 N/A and I'm still running 19's...When Steeda installed my heads and headers and retuned the car they said the 19's are flowing plenty for the power my car makes.

 

[billfisher]

i'm running 19lb for now. 326hp 5.4 3v. @ 5800. i can use bigger ones... so i have them ready. tune it first then spend the money if you need it. let a datalogger or dyno with wideband tell you, not an article. or you can do what i do... use your experience and feel for motors and just kinda wing it. i will tell you this i can up the pressure to blow blue flames out of the pipes. the limit is duty and cylinder washout. push them hard enough and they forget to atomize and just dump wads of fuel and you get to buy another motor. i'm going to swap them before i go much farther to avoid scuffing piston skirts.

24# or 30# won't hurt, but why? that HP rating crap depends strictly on pressure @ wot open loop. well there you have it.

 

[BlackenedSVT]

my car makes 310/325 N/A and I'm still running 19's...When Steeda installed my heads and headers and retuned the car they said the 19's are flowing plenty for the power my car makes.

really? I kninda always went by the the fact that the 99/01 Cobras have 320hp and 24lb injectors. So i always figured when i reach 275rwhp/320hp to the crank, i would upgrade to 24lb injectors. BLKSteeda im thinking you really should do the same, im surprised STEEDA said that.... i guess they would know better than i would. But im just sayin the Cobras run 24lb injectors at 275rwhp, so i always use that for a gauge.

 

[tomustang]

im surprised STEEDA said that....

Why would you be? It's not like steeda knows everything

 

[mrshl13]

My tuner recommended 24lb injectors. Numbers in sig. and a nice A/F ratio.

You don't need to upgrade yet.

 

[BLKsteeda]

really? I kninda always went by the the fact that the 99/01 Cobras have 320hp and 24lb injectors. So i always figured when i reach 275rwhp/320hp to the crank, i would upgrade to 24lb injectors. BLKSteeda im thinking you really should do the same, im surprised STEEDA said that.... i guess they would know better than i would. But im just sayin the Cobras run 24lb injectors at 275rwhp, so i always use that for a gauge.

The injectors were one of the things I was concerned about when I did my heads and I told them if they need to upgrade go ahead and do it...they said they were flowing more than enough for my power...I live 5 minutes from them and have been a customer for 8 years...I'm great friends with the guys there and trust what they say.

 

[Gearbanger 101]

Enough with the theory....let's do the math!!!

http://www.rceng.com/technical.htm