Drowning Your Thirsty Silverado: Fuel Delivery Upgrades

The Silverado is supplied fuel by the following parts:

• Fuel pump
• Fuel lines
• Fuel rails
• Fuel injectors

The fuel pump pushes the gas from the fuel tank through the lines. That gas that gets fed into the fuel rails and then dispersed into the injectors. The injectors spray the fuel into each cylinder where it then goes through the standard combustion process and mixes with air and a spark to ignite. 

All of the components outlined above can be modified and upgraded to help supply your Silverado with more fuel. However, upgrading your injectors will make the biggest difference and provide the largest increase in power.

Below is a chart for all of the different flow rates of the stock Silverado engine fuel injectors. Worth noting is how the newer direct injection engines flow at a much higher rate than older port injection engines; the more advanced/higher flowing direct injection engines measure flow by PSI, while port injection engines measure flow by pounds per hour.

The fuel pump is like the heart of the fuel system as it pumps the fuel to where it needs to go. You would want to upgrade the fuel pump either when the stock one breaks or if your Silverado is modified to have a large amount of horsepower (talking when you hit 600 HP). 

The stock fuel pump on Silverados is fairly reliable and not very likely to leave you high and dry on the road (pending normal driving conditions and maintenance habits). However, if your Silverado has high mileage on it (over 150,000 miles) then you may need to replace it. Should that be the case, then going with one that is capable of pumping more fuel is never a bad option. 

On the flip side, if your Silverado is heavily modified and making big power with the help of some forced induction, that not being able to supply your engine with enough fuel will limit the power and performance of your Silverado. It doesn’t matter if you modify all the other parts of your fuel system, if you don’t have a fuel pump that can adequately get the fuel out of the tank and into the lines/injectors, then your engine will starve and be limited in reaching its full potential.

The fuel lines on your Silverado are the carrier for the fuel as they transport it from the tank to the rails and injectors. The fuel lines are a part that is not typically modified or upgraded. They are viewed as more of a maintenance item and are replaced when there is an issue with the stock ones. 

With that said, the stock fuel lines can be ditched and replaced with metal ones (either aluminum or the higher quality stainless steel option), in either the same size or larger diameter. This type of modification is not typically needed unless you have a Silverado that is built for racing. If you have a Silverado that is making 600 HP, then going to a braided, wider fuel line will help to make sure your engine is supplied with enough fuel so that it won’t starve in the higher RPM range.

Upgrading the fuel rails on your Silverado is a modification that is only done when you’ve upgraded all the other parts of your Silverado’s fuel system and are trying to squeeze out that last little bit of power that is left on the table. The fuel rails help to feed more fuel to the injectors. 

Without the rest of the fuel system upgraded to help supply more fuel to the engine, then upgrading the fuel rails is kind of pointless. However, if you are in pursuit of those high triple digit dyno numbers, then the fuel rails are one more piece of the puzzle that you will need to address.

Upgrading your Silverado’s fuel injectors should be one of the first modifications in the upgrade process. Swapping out the stock fuel injectors for a set of aftermarket ones will make the biggest difference in the performance and power of your Silverado. 

Bigger fuel injectors that can supply a larger volume of fuel to your engine will help your Silverado to produce more power easier. You will need some aftermarket tuning to help things run smoothly, however, it will be a noticeable upgrade that will throw you back in your seat.

If you go through and upgrade your entire fuel system or even just the injectors, then you will absolutely want to upgrade the intake system as well because without more air flow, all that extra fuel won’t be worth a damn. Your engine makes power by taking air and fuel, making a small explosion, and doing that repeatedly; with extra fuel and no extra air, you run the risk of damaging your engine, while not really increasing the power. 

Honestly, before you upgrade the fuel system, you should upgrade the intake system with either forced induction (if you want to go all out) or a new intake and intake manifold. The stock fuel system is more than capable of providing enough fuel to minor mods to be efficient.

If you do upgrade your fuel system on your Silverado, then you may run into issues with emissions testing (if your state has them). Increasing the amount of fuel going into your engine will ultimately create more exhaust gases and could have your Silverado running rich, which would lead to not passing on emissions. 

This is where the importance of a proper tune comes into play. With an aftermarket tune helping to manage and regulate how much fuel is going into the engine, you can have a well-balanced air-fuel mixture that will pass emissions without an issue.

When you increase the amount of fuel and air in your engine, you are increasing the tiny explosions in the cylinders. These tiny explosions, in turn, generate heat, which increases the engine bay temperature and can lead to higher cylinder head temperatures. 

In order to address this, you may need to modify your radiator and cooling system to help dissipate some of this heat, and keep temperatures closer to a stock level. Keeping your engine and engine bay cool (relatively speaking) is incredibly important to keep your performance and powertrain consistent and reliable.