I found a set of 280150945 svo 30lbs injectors new for 200$. I have the current mods:
Lloyd elliot cam
aeromotive FP and FPR
kooks LTs with 3" magnaflow catback
Armstrong racing engines built 50 over with stock heads
moroso CAI
ed Wright tune
3200 vigilante
Unsure horsepower, was last dynoed at 311rwhp with stock exhaust, stock cam

the car is mostly used 1/4 mile at a time.

 

What pressure are the injectors flow rated at? Some Ford injectors are flow rated at 39.15 PSI (2.7 bar), and flow 5.4% more than rated when operated at the LT1’s 43.5 PSI (3 bar).

Have you data logged it or checked the fuel pressure at WOT/max RPM in the current configuration to see if there are any signs of running short of fuel?

 

The ad says 43.5psi and I'm not really sure because i have yet to run down the track with new cam and exhaust. FP gauge is in the engine bay so I cant tell FP at WOT, although with vacuum connected the FP seemed to drop off 5psi when given half throttle while parked, not sure if that's normal.

if 30 is too much will it washout the cylinder walls with fuel and dump fuel in my oil?

 

Hook up a test pressure gauge to the Schrader valve, tape the gauge to the windshield, take it out on the road and run it up to max RPM at WOT. Alternatively, get data logging software, and log it under the same conditions, so we can see if it’s already running out of fuel. Revving the engine at idle is pointless.

What year is the car/PCM? That affects the scan software options.

As long as you program the correct injector flow rate and offsets in the PCM, doesn’t matter if the injectors are a bit larger than needed. The PCM will calculate the correct injector pulse width to supply the correct amount of fuel to match the mass air flow.

 

do you have a few 1/4mi timeslips?

 

I got a foot of snow where I am right now , so I cant drive it for awhile. Its a 94 obd1 Pcm. Will scan9495 datalog it? What do you use? I will probably buy them and get a new tune if it wont hurt my new motor, thank you for the answers!

 

had limp mode issues last year and didnt get fixed until race season was over. Was 13.70s in limp mode. Air was around 2000ft

 

Scan9495 will work great.

 

“Limp mode” is basically a mode used when the PCM has very limited input. Engine will barely run, just enough to get you off the street, or get home. Don’t see how you could run a 13.7 with that condition. How did you know it was in “limp mode”? Or, was it only your trans that was in limp mode? That's something completely different.

To avoid the possibility of running out of fuel, I would recommend true 30 #/HR for up to 425 flywheel HP. Beyond that, you may get into duty cycle problems. There is no absolute answer to injector size requirement. The key element in the sizing equation is brake specific fuel consumption (BSFC). Most injector sizing guides recommend using 0.5 #/HR/HP. But a well designed combustion chamber, quench, etc. can significantly reduce BSFC, allowing use of a smaller injector. Engine dyno testing showed the BSFC on my 381ci stroker to be in the low 0.4x range. The sizing formulas also generally use 80% max duty cycle. Modern injector design seems to have improved the ability of the injectors to run at higher duty cycle.

The big issue with very large injectors is the ability of the injector to provide the very tiny pulse widths required for the engine to idle. The stock PCM seems to be able to control high impedance injectors as large as 42 #/HR. Again, modern injectors seem to provide these shorter pulse widths.

If you plan to eventually get a set of ported heads, now is the time to choose an injector larger than 30 #/HR. A 36 #/HR injector can take you to 500+ flywheel HP. Or buy the 30’s and bump the pressure from 43.5 PSI (3 bar) to 58 PSI (4 bar) in the future.

 

The Ford 30# on GM’s fuel pressure is more than plenty for this combo. The old style Ford/SVO/Bosch wont wash down the cylinders. Its when the GM guys drop in Ford injectors designed for modular engines is where they have that issue.

 

OP

If Ed Wright did the tune for your "existing" cam than what ever injectors you told him you had, even stock 24 lb, is what he would have set the tune up for or raised his hand and advised going a larger injector.

The 30 Ford SVO aka "red top" will work great with your build but you will need tune adjusted if it is not for those injectors

As Injuneer notes get a FP gauge with a hose on it, Hyertech makes one, and tape it to the windshield and go for a SUSTAINED WOT pull somewhere and see if the FP holds at 43.5. If it does than you are good with the caveat that if you have 24 lb injectors sustained WOT use may take the 24 lb injectors to 100% duty cycle. Not horrible but long term WOT the injectors get tired.

 

I have a high voltage code issue and was able to restart car after the burnout and manual shifting would allow to avoid a 1-3 shift. And motor is built by Armstrong's, the best stock/superstock builders in canada. And knew of the top in north amarrica , aruguabley the best. I plan to not port the heads, and will get the 30#/hr injectors. Thank you for response. Also bad at math here, let's say I will now make 375 flywheel horsepower what injectors should I have?

 

I will definetly tall to ed about this then too. I mostly run at the track, so probably might get tired pretty quick you're saying then? I am getting an autometer isolator too so I can run the analog fp gauge inside. The hose is long enough I can run outside too. Thanks for response.

 

here is the Photos from ad too, he says they're new but I'm sceptical of the scratches if they are.

 

Be VERY careful with the AutoMeter isolator. Many years ago I ran one with a mechanical gauge. The gauge was mounted in the center vent of my Formula dash. The isolator failed and allowed gasoline to enter the line to the gauge. I complained to AutoMeter, they agreed it was defective, indicating it was a material of construction problem. They gave me full credit for the isolator and the mechanical gauge, and I applied it to the purchase of their electronic fuel pressure sensor and analog (electrical) gauge. Maybe they solved the issue by now, but I would NEVER install a mechanical fuel pressure gauge inside my passenger compartment after that experience.

When we modified my fuel rails to run in parallel instead of in series, we welded to bung to the passenger side rail, and mounted the pressure sensor there.