At what psi do 50's lockup?

[Tom87GN]

I have heard that 50 lb injectors will lockup at a certain high fuel pressure. I'm sure that it varies just like anything else, but what do I have to look forward to with respect to my new 50's?

I plan to run no more than 24 psi of boost with the mods listed in my signature below.

Thanks in advance for any help. I love this board!

 

[TurboDave]

I've heard this too, but don't know of anyone that has actually experienced it.

Problem is, they bandy the number around of somewhere on the high side of 60psi.

HOWEVER, it must be remembered that that number is NOT the differential pressure number.

Since we run fuel pressure regulators that are vacuum/boost controlled, our differential fuel pressre across the injectors should never exceed your static fuel pressure adjustment.

In other words, suppose your static (zero vacuum/boost) fuel pressure is set to 45psi.

Then, even though you might run boost up as high as 30psi, which would increase your fuel pressure to 75psi (ideally), the differential pressure is still 45psi. 75psi on the inlet side, 30psi (because of manifold pressure) on the outlet side.

I wouldn't worry about the lockup problem until somebody can convince me they've actually experienced it.

 

[bruce]

Some years ago the Syclone guys had Kinsler flow some injectors trying to get them to lock up. At the limits of the machine, ie 120 PSI they were still linear. I forget the exact sizes they ran, but none suffered *lock-up*.

I'd be more worried about the operating DC, being wrong, and having a problem.

 

[gnjones231]

Hey Tom, If you give me an email, I've got some interesting data for you.

Dave

 

[TurboDave]

Originally posted by gnjones231
Hey Tom, If you give me an email, I've got some interesting data for you.

Dave

Why not share????

 

[smokinttype]

Everyone says they wont support 600hp but they will if you use a 3" or 3.5" MAF and an EXTENDER CHIP so you can double the mass air tables which is very important so that you dont have to cheat it with fuel pressure. If you go cranking fuel pressure to it your only shutting the injector down premature b4 you reach its limit of 600hp. People can say what ever they want but there is ONE guy on here that has MSD 50's that runs 3.5" maf and an extender chip and he has run a best of 10.59 I dont know the MPH but the ET is all that matters so if you do the math if your around 3600 or so thats about 600hp give or take a few one way or another depending on weight. I ran these injectors on my dads car with a stock maf no extender chip and I had 48psi of fuel pressure and was ran a best of 7.26 popping b/c it was soo lean b/c of the pressure that I was using. I ran as high as 23#'s but still ran like crap. If you look back on information MSD said they would be good to 600hp at 43psi of fuel pressure!!! which is true!! People like Red says their junk but here again his car isnt stock either, the thing has stage one heads on it and if you know anything about those particular heads as cast (unported)they flow way better than a set of ported GN1's do. IF you have any other questions about how far you can go on 50's gimme a holla back I'll help you as best I can. SO basically what I'm sayin is if you want the full benefit from 50's you need a bigger MAF to read the air coming across and get an extender chip to double the mass air tables..