Hello, I have been wondering how I am supposed to upgrade the fuel system. I did a conversion on my 92 corvette turning the LT1 into a 383 Stroker. Completely rebuilt, forged pistons, aluminum crank, Comp, lifters, rockers, rods, Cams etc.. I don’t know how to go about upgrading the fuel system, so any insight on that And anything you guys might think I should probably do would be great Insight. Thank you

 

Do you have a carb now or original set up? Plenty of guys here have upgraded their fuel systems with better pumps and upgraded wiring kits. If you carbed your 92 then you will need a fuel pressure regulator to lower the fuel pressure!

 

Am using a fuel injection setup

 

Im surprised no one had chimed in on this one yet !

Is your fuel system still stock ?
If so you will need to look at a Walbro 255 lph or Aeromotive 340 lph type pump. I have run both on my previous 383 and current LS1.
I would highly recommend at least an under hood fuel pressure gauge and have an adjustable regulator.
You will need a shroud around the sock or Hydromat type sock to avoid surge issues with the stock C4 tank.
Next will be the stock fuel pump wiring loom - it will need a 20 amp fuse to cope with the extra amperage. The proper fix is an upgraded loom such as Racetronix offer.
I have just bought a Racetronix fuel pump loom and will probably do a short install thread.

 

In my 1992, I have the following:

Stock hard + rubber lines from the sending unit to the fuel filter. They are both 3/8 stainless and plenty large.
Stock (clean replacement) fuel filter
Metric O-ring to -6AN conversions fittings at the filter and return feeding an Aeromotive FPR, mounted near the coolant surge tank
Aeromotive Stealth 340 Pump in tank, deleted the pulse dampener
Racetronix high current bulkhead connector and pigtails both inside and outside the tank
10 Gauge from Alternator stud, thru a high power relay & 20amp fuse, that feeds the bulkhead pigtail
Additional ground wires and strapping for fuel pump ground

 

Well if you upgraded everything else, then the tuner who does the programming should be the one to suggest the injector size you need for the power you plan to make. They generally use a formula that takes into account the size and duty cycle/pulse width required to safely support the changes and obtain the power, so you have done the ECM yet or not?

My 398 required 42lb/hr, I could've gotten by with smaller but I went with what FIC recommended here, and the tuner said it was good for him. So thats the first step.

The stock pump can support quite a bit unless you're sticking with really high RPM all the time, such as road racing. The first dyno tune run will likely end up showing if its not enough. But I upgraded to a Walbro 255 to be safe, and then that change led to a wiring harness upgrade necessary to support the max effort of that pump.

I added an adjustable FP Regulator to complete things, but I've never needed to tweak it.

 

92 uses batch fire and speed density and a "chip" . You will need data logs to get your tune right. Get a adjustable fuel pressure regulator and bump pressure to 50 psi, that will help make up for the extra cubic inches.

 

Aem 50-1000 is rated at 340 lph @ 43 psi, I just installed on the stock pickup, did not change wiring or fuse size on my 91, for an na 383-400 producing 450-475 hp it is more than adequate, there is no increased amperage as long as you keep the pressure around 43-48, at least not enough of an increase to warrant updated wiring, fuses etc. It's worth noting the modern 250-340 lph pumps are much more efficient than the OEM pumps that came in the 84-96 cars, unless you have a power adder, the stock wiring, stock fuse and relay is fine for most hot street mild strip stuff. If doing extreme cornering or acceleration a Holley hydramat is a good idea though, I have observed pressure fluctuations when the tank is below 1/4-1/3, if full or above half a tank I've had zero issues. And I have Holley HP with a fuel pressure sensor on the regulator. Even sustained wot pulls with a healthy 383 it's been just fine. Stock lines all the way to the filter on the passenger side, from there I ran -6 lines up to a eBay aeromotive knockoff and to the miniram rails. 36pph injectors even at over 80% duty cycle the pressure is fine. Engine is a solid 465-480 hp. Just my experience with my 91 c4. Stock filter, stock sock on the pump. Left the stock fuse and relay in place. If it was drawing enough amps to blow a fuse or relay I'd have had issues by now. Look at the literature for the 50-1000 as long as pressure is kept around 43-45 psi and your alternator can keep voltage stable at 13.5-14.0 volts the stock fuse size is fine.

 

The data they provide is consistent with my results, I used an amp clamp to verify. Unless you plan to run it at insanely high pressure the stock wiring is fine. 95% of na and boosted street small blocks making 300-600 hp this is all the pump you'll ever need, it can easily support 1000 hp. Aaron Schoech has been using this pump (50-1000) for years on boosted c4 making in excess of 550 rwhp and can confirm what I am saying. These pumps are cheap, a direct plug and play swap, less than $100 us dollars, and are always in stock at summit, jegs, midstates distributing, speedway, etc. Don't buy the eBay knockoff, purchase it from a reputable source 50-1000,50-1200 is enough for most built c4, you don't need to rewire the car or go to extremes just because someone offers a part number. Not knocking raceteonix, they sell some great stuff. It just isn't necessary for what the op is trying to do.




Updating the ground strap, and sock is a good idea, and if you have corrosion replacing the power feed is just common sense, but if the car is in good shape a plug and play 340 lph intank pump is more than enough for a street c4 making 450-500 hp on pump gas.

 

I should point out that my car has had the ac, and heater blower motor deleted. If it was sharing voltage with those two items my results could be different, but so far it's been fine. But even if it was not, a 40 amp relay and fuse with new wiring to the tank is pretty straightforward, and would bypass the stock wiring, at substantial savings compared to raceteonix kit. If using any aftermarket efi like Holley their manual usually gives a good set of instructions for installation of a larger pump, relay, and wiring.

 

. Your knowledge is much appreciated, thank you for taking the time to offer your insight, will definitely look into it

 

Thank you for insight, plan to get this build right the first time

 

I actually planned on doing the same thing because I don’t use either, so thank you

 

Much appreciated I will definitely see what they suggest when I get to the tuner

 

thank you will definitely be getting a fuel pressure, wasnt even on my Radar