injector sizes recommendation 500+ hp

[h_friesen]

Hey guys hope you can help, i have a 6.0 LQ4 project going and i'm planning to use 6.2L HO heads, L76 intake manifold and stock injectors. Cam choice i'm considering a Texas Speed & Performance 225/230 with .614/.612 lift. I really dont think the stock injectors are going to do it they are GM P/N #12580681. What size should i go with? 42's? 60's? The cam dyno shows 560 peak hp and 515 peak torque.
Thanks!!

[pl4yboy]

I doubt you hit 500 with that setup, but you might. 42s will work for you, 60 if you plan on some FI later.

[motorholmes]

My buddy that took my 6.0 off my hands punched it out to 6.2, used the L92 heads and L76 intake, and a TSP 232/234 598-608 112 cam, and I think he's shooting for about 550 hp. This is all info from some old chicken-scratch on an old notepad, but the injectors I have written down are p/n 12576341? IIRC he scrapped the L76 injectors and got some that were 3 or 4 lb bigger or so. Maybe 46lb?

There's a few fuel injector calculators floating around here somewhere.. And you might as well get ones that are just a little larger than needed so you don't have to re-tune later when you realize you're nearing 100% duty cycle (that from personal experience)

[Sleaper]

I would say go with 60's just to be sure. Better safe than sorry and better to only have to do it once!

[skeet]

i run #50s on my setup, 42's will work fine also, either way your duty cycle is less than 50%.. that 500 mark isnt as easy as most think, i am right at it before i did some changes at 460 i'll hit the dyno this friday to see my final results

[h_friesen]

hey motorholmes, what you do think of that cam from TSP? I'm considering the LS3 225/230 as i mentioned just thought a second opinion would be great
Sleaper, yeah i agree 60lbs so no more worries, Go Big or Go Home I always say

[motorholmes]

hey motorholmes, what you do think of that cam from TSP? I'm considering the LS3 225/230 as i mentioned just thought a second opinion would be great
Sleaper, yeah i agree 60lbs so no more worries, Go Big or Go Home I always say

He hasn't run the engine yet, so who knows. I happen to like torque and driveability over top end, so his speed parts and mine are vastly different. His is going in a '72 Corvette. I just have a 212/218 560 cam in mine and I love it (so far ). the TSP 220 is also quite popular with the truck crowd.

If you're doing your own tune, and you already have those 42# l76 injectors, why not run 'em and see what your duty cycle turns out to be? Otherwise look around the forums. You just have to figure out which injectors will fit your manifold and rails

[h_friesen]

question now is where to get these injectors, I know GM doesnt make a 60lb 42 is the biggest i think. Who is recommended for this... FAST?

[Sleaper]

question now is where to get these injectors, I know GM doesnt make a 60lb 42 is the biggest i think. Who is recommended for this... FAST?

There is someone on here and pt.net that sells 60# injectors that are a direct swap. I'll have to find his info....

Edit:

Send a pm to SRT10KLLR. He can get you some plug and play 60's.

[truckinL33]

http://www.fordracingparts.com/downl...d_Adaptors.pdf

A very good article on injector selection, and fuel pump selection.