FactoryFreak

iTrader: (2)

Alright I'm planning on runing a 383 stroker with the Holley Stealth Ram and will be running a 150-250 hp TNT nitrous kit. I was wondering if SVO 30lb fuel injectors would be a good pick for this application?
Thanks

Floor guy

I have a 383 combo with super ram that uses 24 lbs. I shift at 5400 rpm. My car is pig rich . I wish I would have left the 22 lb'er in there.

Vader

I can't answer definitively, but here are a few things I know that may help you decide:

SVO injectors are reportedly flow rated at a higher pressure, so operation at stock TPI pressure of 37 PSIG would result in a lower flow than the stated 30 lb/hr.

The 383 should tolerate more flow at low RPM, and will require more flow at higher RPM and loads. However, if you have any difficulty tuning the injectors correctly, it is going to be at the low RPM end, since the propagation delay of the injectors is going to be closer to the necessary "ON" time you will want at idle and low RPM. Restated, there might be a very fine line between adequate cycle time to actually operate the injector and deliver any fuel, and the cycle time that makes the operation at low RPMs too rich. Again, the lower flow at 37 PSIG and larger displacement are going to be in your favor.

The SVO injectors should be compatible with the output drivers of your ECM, and should directly plug into the harness. The only thing you would have to do is change the supplied Ford 'O' rings to GM 'O' rings, since the GM rings have a larger cross section.

I'm sure others have more experience in this area, so feel free to correct me where I may be in error.

NEEDforSPEED

200hp Injector Size 15.63
300hp Injector Size 23.44
325hp Injector Size 25.39
350hp Injector Size 27.34
375hp Injector Size 29.3
400hp Injector Size 31.25

FactoryFreak

iTrader: (2)

Well on the motor alone, I'm shooting for 400+hp and around 450 torque. Then throw on a 150 nitrous kit, I was hoping that the 30lbs would be enough

Floor guy

In my opinion 30 is too much. This is assuming the nos kit is wet. Remember, if it is a wet kit it gets its fuel from the fuel rail. My post assumes stock programming.

406TPI

iTrader: (1)

I would say 30's might be a bit much but it all depends on what pressure you are running them at. 24's will keep up with a big motor just fine if you raise the pressure on them. The biggest factor is what method you use to tune with? Do you tune by adjusting fuel pressure or by burning chips?

FactoryFreak

iTrader: (2)

I'm going to be installing megasquirt before the motor goes in

ChevelleFan

iTrader: (4)

I'm putting together a somewhat similar combo -- HSR on a 406 controlled by a MegaSquirt. I picked up a set of the 30 lb (red top) SVO injectors on eBay for my project.

I don't know anything about adjusting GM computers, but with MS, you shouldn't have any trouble using those. Just make sure you know what the fuel pressure is actually at on your fuel rail, and make sure you adjust the Req_Fuel settings accordingly.

Vader was right when he said the Ford injectors are flow-rated at a different pressure than GM. Unfortunately, I don't remember off hand the pressure they are rated at, so I'll make up some numbers for the sake of an example.

If the Ford injectors are rated 30 lbs/hr at 40 psi, and the actual pressure on your fuel rail is 35 psi, your injectors will be flowing less than 30 lbs/hr. If your fuel rail is at 45 psi, they will flow more than 30 lbs/hr. You need to know the fuel rail's pressure so you can accurately compute the flow rate. Or, make sure you adjust the pressure on the rail to whatever PSI Ford rates them at and use 30 lbs/hr in your Req_Fuel settings. There's a formula in the MegaManual for computing the flow rate at different pressures.

I'm probably making this sound more difficult than it is. It's not complicated. If you can't find the formula, let me know here or in a PM and I'll try to help you out.

-Dave