TDMKR496

iTrader: (3)

My 5.3 LS Mustang swap has 80 lb EV1 injectors and I found out last night that my duty cycle is 120% I'm only at 17 lbs of boost and I thought that 80's were good for about 1200 hp. I'm wondering if it has anything to do with how I have the fuel system plumbed. I have 2 Bosch 044 pumps Y'd to a -6 line which feeds the first injector rail, loops to the second and then goes into the regulator and back to the tank. Should each rail be fed independently? I also need to make sure the regulator is rising under boost, going to check that after work. Any thoughts or suggestions are greatly appreciated!!

3.8redbird

iTrader: (3)

E85 or gasoline? any meth?

TDMKR496

iTrader: (3)

Gas, no meth

soundengineer

iTrader: (16)

whoever said they were good to 1200 hp is a dumbass...

simple math will tell you exactly how much you can make on them

at 43 base pressure they are good to around 1066 at the Crank(not the tire)
at 58 base pressure they are good to around 1200 at the Crank(not the tire)

and that is assuming your setup is ideal and pretty dam efficient...which is not typical

realistically... your transmission eats up 20-30% of the power you make at the crank.


so...120% duty cycle means you need AT LEAST an injector that is 20% bigger

I would suggest you step up to something in the 120 lb/hr range

TDMKR496

iTrader: (3)

Thank you sir, I appreciate you taking the time to educate me. I was thinking 120's but you just confirmed it lol. I don't think I'm anywhere near this power level so I'm trying to figure out if something is wrong somewhere in the car before I pull the trigger on injectors....

soundengineer

iTrader: (16)

check fuel pressure,....
if pressure drops at WOT under your normal Full tilt Boogie...then your pump is the issue

Pressure should rise along with boost

no regulator is perfect...but..
at 17 psi, and a 43 base, you should see 60 PSI fuel pressure (or somewhat close to it)
at 17 psi and a 58 base you should see 75 psi fuel pressure (or somewhat close to it)



you also, may need to change up your fuel system
I personally would prefer to see an 8an or a 10an feed to a Y block then an 8an to each rail, with an 8 or a 6 from each rail to the regulator, then return to the tank with one size smaller than your main feed


what EFI system are you using...
if you use one that corrects at WOT, the other possibility is that you are blowing out spark and the EFI system is compensating by throwing a bunch of fuel at it...
we see it all the time here with systems like the Holley that will correct to desired AFR at WOT.

TDMKR496

iTrader: (3)

I checked FP already and it is steady (car has twin 044's), the only thing I can think of is to up the feed line from the pumps to the rails from -6 to -8 and put a Y block before the rails (current setup feeds one rail and loops into the second). I'm using a 411 PCM tuned with EFI live.

TDMKR496

iTrader: (3)

Any 120lb injector suggestions?

iliveonnitro

You'll want larger line than -6 AN if you're maxing out 80lb injectors. When I talked to Magnafuel, they recommended -10 from pumps to y-block (split to 2 rails) and -8 back to the tank. This was at ~1000 crank hp.

PM me if you're going to sell the 80s.