Duramax LLY FASS Lift Pump Upgrade Kit

The LLY doesn't come from the factory with a lift pump. This puts a lot of stress and pressure on the factory CP3 injection pump and the injectors. It forces the pump to pull fuel under vacuum which can allow air into the system, ultimately reducing the lifespan and longevity of the injection pump and your injectors - both of which are very expensive parts to replace.

Not having a lift pump becomes more of an issue once you add tuning to the LLY. Tuning and higher power levels require more fueling which puts additional stress on the factory CP3 injection system. We recommend adding a lift pump to your LLY before you do any sort of tuning or performance upgrades. This will ensure longevity of the pump and injectors while helping support higher power levels and higher boost.

FASS is our top recommendation for lift pumps. We offer four options for the LLY which can support power levels from 600hp up to 1,500hp+. Here is our recommendation on which pump to get for your build:

100gph: Up to 600hp

100gph is the entry level lift pump. It's great for lightly modified builds that aren't running very aggressive tuning. It can support up to 600hp, but this is in reality probably closer to the 550whp range. It's only an extra $50 to get a 165gph pump that can handle 800whp so we pretty much always recommend spending the extra dollars to get a stronger system. But if you are just running a light tune and aren't pushing very serious power levels, or if you are completely stock and looking to save your CP3 and injectors then this is a great option.

165gph: Up to 900hp

A 165gph pump can handle up to about 900hp at the crank or 800whp. This is going to be the best lift pump for 99% of LLY owners and our top recommendation. Unless you're dropping $30k+ into a build then this is going to be able to handle everything you throw at it. If you plan on running a pretty consistent 450whp+ then we recommend this lift pump, too. While the 100gph can handle those power levels it's always better to run a performance part at 50% capacity vs 80%+ so the extra $50 is worth the reduced load.

250gph: Up to 1,200hp

This is where things really kick up a notch, capable of supporting 1,200 crank hp. This pump is overkill on the majority of LLY builds, unless we're talking competition level pullers. You might be thinking "for an extra $50, why not?" and that is certainly valid. If you want the added flow to run the pump at a way lower load then great. It certainly doesn't hurt, it just also isn't really necessary. Until you start pushing the upper 600's at the wheels, 165gph is plenty of flow.

290gph: Up to 1,500hp

Now we are pretty much exclusively talking about competition builds. If you need (or want) maximum flow and performance, then this is it. 

FASS Titanium Series Benefits

• FASS Whisper Technology (FWT) was engineered to meet the stringent demands of  today’s quiet diesel engines. FASS Whisper Technology was in development and testing for over two and a half years to meet FASS Fuel System’s high quality and durability standards. FASS Whisper Technology effectively and drastically reduces the sound levels of the Signature Series FASS Diesel Fuel System to a “whisper”while at the same time increasing fuel flow rates. Our competition reduces noise levels by reducing flow rates.
• Performance Radius Cuts (PRC) are an advanced machining technique used to improve the flow of fuel through the FASS System by creating smooth flowing cuts within the aluminum housing. This prevents the reintroduction of air and vapor back into the fuel and to prevent eddy currents from forming within the corner of a 90-degree sharp angle. FASS Titanium Signature Fuel Systems are the only Fuel Air Separation System that incorporates these exclusive Performance Radius Cuts, lesser competitors commonly use T-Bone and square 90-degree fittings that can limit fuel flow, cause restrictions and reintroduce air back into your fuel.
• Mass Flow Return (MFR) technology is used to continually polish your fuel by keeping a positive pressure on the fuel being delivered to the engine to prevent cavitation along with galling and scoring. Then returning the fuel, that’s not yet needed, back to the tank after it has been passed through the filtration process, removing dirt, air, vapor and water. This means your fuel is being constantly “Polished” (cleaned), guaranteeing that your diesel truck always has the cleanest fuel possible. The MFR in combination with the optional FASS Fuel Heater options will help insure “EXTREME” cold weather operations!
• Bolt On Bracket Mounts old mounting styles required drilling or welding when mounting your new System. This has now been simplified with our new bolt on brackets that utilize your Ford Super Duty factory bed bolt, the bolt that secures your truck bed to your frame. Mounting your Titanium Signature Series System takes only minutes and all brackets are made from machined steel for superior support and strength.