I have a 347 with AFR 185s , holly intake,70mm tb ,and a custom cam , 1 5/8 long tubes .The cam is good to about 6000 to 6400 rpms. I'm thinking the car should make 380 to 400 rwh.
30 or 36 pound injectors
- Thread starter jromeo
- Start date
-
Sponsors (?)
I got to go find that link for the injector table. 400rwhp should not max out a 30lb/hr injector.
Kurt
Here's one. If you are putting down 400hp, you'll be ok with a 30lb/hr injector.
http://z31.com/software/injector.pl
Kurt
http://z31.com/software/injector.pl
Kurt
I would like to mention 
All of those inj size programs I've seen relate to fwhp
Most of us gearheads of today think in terms of rwhp
Another thing is if you are runnin a centri charger .......
those programs don't take into account the drain of the sc as well
If you are gonna tune it
I just can't see a reason not to have a bit of breathin room
Just somethin to think about
Grady
All of those inj size programs I've seen relate to fwhp
Most of us gearheads of today think in terms of rwhp
Another thing is if you are runnin a centri charger .......
those programs don't take into account the drain of the sc as well
If you are gonna tune it
I just can't see a reason not to have a bit of breathin room
Just somethin to think about
Grady
I don't go by internet calculators, I go by real world tuning devices. I was seeing 96% duty cycle before the shift light came on with my PMS. Car NEEDED 42's but I decided to sell it before doing more changes.
All of those inj size programs I've seen relate to fwhp
Grady
The one I posted was crank hp. Wheel hp is really immaterial when you are calculating injector size.
Kurt
Right..now the new owner of my car dynoed it on a MUSTANG dyno like I mentioned. So your 370 dynojet hp would be appx 400ish for my old car on a dynojet. What rpm were you turning? My old car would go to about 6,800-7,000.
Well, that would explain it I guess. I was doing that pull on a dynojet, and I make peak power at about 5500rpm. I let out on the dyno at about 6300rpm.
Kurt
nmcgrawj
Advanced Member
I'd rather have too much injector that i can tune down then have not enough injector that i have to up the fuel pressure for to squeek by.
I've seen some h/c/i 302s run 30s....
I've seen some h/c/i 302s run 30s....
How do you see it that way when the op said he was lookin for 400rwhp
I mean ... That equates to about 475 fwhp
You gotta tie one to the other
If I am missing something here
I guess I need someone to enlighten me
Grady
Black95GTS
Active Member
How do you see it that way when the op said he was lookin for 400rwhp
I mean ... That equates to about 475 fwhp
You gotta tie one to the other
If I am missing something here
I guess I need someone to enlighten me
Grady
36s, if you can find them. I understand they are hard to come by these days. The standard 42 pound injectors and 90mm LMAF would work fine in this situation, especially if you don't want to crank up the fuel pressure past the stock setting. If your cam can make power to 6400 you will be shifting around 7000. Another advantage of the LMAF is that a lot of people have experience with it so you'll find good support if you self-tune. You'll also want the 255 in tank pump.
Your 70mm TB is likely too small. If you have it already keep it, but if you have the chance, step up to at least a 75mm unit. Not sure if you have to modify the Holley intake to accept that size, but you'll likely be using the trickflow adapter elbow and thats setup for 75mm anyway. Don't worry, it won't "hurt your low-end grunt" WTF that means. [hides from keyboard dragracers]
Adam
Similar threads
