1992rs/ss

so I am finally getting back to my car. I am adding a procharger P600B to the car. Already a well built 383 with an HSR in the car. I am only planning to run about 5-6 psi as this will be street car. Best estimate this should put me in the mid 500hp range. I talked with Fiveo Motorsports and their suggestion for a set of injectors is this:

http://www.fiveomotorsport.com/denso...470-45lb-uscar

Now I will be running the Holley HP fuel management system as well and I have the adj regulator with a Walbro 225 pump in the tank. How do others feel about this suggestion? 47lb/hour seems ok if I use .55 as the BFSC coefficient. If I use .6 though its a little low as the formula would say I should be about 50lb/hour. I can always turn up the fuel pressure to get a bit more out of them, I just want to be as close as I can @ 43.5psi. I hear of bad things under fueling under boost and over fueling makes for a crappy idle

quadgoat

iTrader: (1)

Those might be enough, but if it was me I'd probably go with 60 lb/hr injectors. That's what I have in my car right now. I'm running the Holley Commander 950 and I'm not having any trouble with idle quality. Now that I've got a brand new 400+LPH pump in the tank the 60's are giving me plenty of fuel! I'd rather have extra up top, going lean under boost is BAD NEWS!! Just my $.02

1992rs/ss

http://www.fiveomotorsport.com/107961-siemens-60lbs

would these seem more appropriate? Ok for a street car application running pump gas?

83 Crossfire TA

iTrader: (2)

It used to be that you didn't want to go with too big an injector because if idle quality issues. Modern injector designs are fast. I don't see a big reason not to go with 60s of 80s unless u get a smoking deal on something smaller and older

quadgoat

iTrader: (1)

I think those would do the job just fine 1992rs/ss They look pretty comparable to what I'm running now.

Like 83 Crossfire TA said, injector technology has come a long way over the years!

-Paul

Orr89RocZ

iTrader: (20)

Whats done to the motor currently? 5-6 psi isnt alot and 47's should handle 550-560 whp which i dont see you making on 6 psi unless its big cammed and has good heads.

As said tho, injectors design has come a long way. I run 127 lbs just fine. Siemens 80's were awesome too. But overkill for what you are doing. If you ever plan on more boost 60's will be best for you but you will need better fuel pump. Single walbro is only good to 550 whp or so, not on a boost a pump kit

1992rs/ss

Its a 383 4 bolt main. Trick flow heads, cam similar to LT4 hot cam, HSR, will be running Holley HP management system, msd ignition system, and as noted a Procharger p600b with intercooler system 5-6psi. I would go higher on boost pressure, but its not a motor specifically built for boost. Almost 10:1 compression and I don't want to run race gas or methanol injection just to make it live. The LSx kits they offer run in that pressure range and those motors are a similar compression. I want to make sure I have enough fuel and coolest intake charge to avoid detonating (major fear).....if a 60lbs injector like the one I posted will idle just as well as a 47lbs injector I am ok with going bigger

Orr89RocZ

iTrader: (20)

60's will idle fine. I have 115's that idle as good as 80's which idled as well as 42's which idled as well as stockers lol.

47's should handle what you plan tho. Small blower, milder cam, 5-6 psi is all you need on 10:1 comp at this time, so figure 450-500whp