CAMARO6 - View Single Post - Guide to fueling for higher horsepower LT4 ZL1s

WEAPON-X · 01-13-2018, 08:08 PM

Alternative LTX DI Fuel Supply Options:
1. Meth Injection
2. Camshaft Kit with 38% Fuel Lobe
3. Low Side Line Pump Fuel Kit
4. LPE Big Bore DI High Pressure Fuel Pump
5. Larger DI Injectors
6. Port Injection Systems

1. Meth Injection Kit:
https://weaponxmotorsports.com/produ...th-kit-lsa-lt4

WEAPON-X recommended use - as slight cooling and octane boost with proper fuel system supply from the tank.

Pros - Methanol kits are inexpensive starting at $600 and adds octane, cooling, cleans the valves which was an issue with DI motors mentioned earlier
Cons - Uneven distribution, Kit ends up being around $1,200 installed, additional cost to add a meth tank or losing washer tank, refilling and storage of meth, flammable liquid in the trunk or engine bay, potential pump/solenoid failures which can cause engine failure if the car is too dependent on methanol

Notes - Sure a meth kit is cheap, but you'll have 6-8 hours of installation, the hassle of refilling the methanol, and the worst part, keeping an eye on the entire thing and hope the pump doesn't go out when you're heavy into the throttle. When tuning a car that is dependent on methanol for fuel supply, the engine is relying on the added methanol to maintain the proper air fuel ratio, which really is never what alky meth kits were intended for. The second inherent problem with these is fuel delivery. Engines always have what are called "hot cylinders" where the natural airflow path is stronger so you have more uneven cylinder distribution. So, if you're spraying heavy amounts you need to run what is called direct port meth which means there is one nozzle per cylinder to control the flow. This gets really pricey starting around $2,000 plus install because you need check valves and extra solenoids to make sure the pressurized air isn't pushing against the tip of the nozzle, and even in this instance, you always have rich and lean spikes because the methanol nozzles are just not as refined and controllable as a fuel injector tip.

2. Camshaft Kit with 38% Fuel Lobe:
https://weaponxmotorsports.com/searc...6+camshaft+kit

WEAPON-X recommended use - obvious performance gains depending on the cam, but for fuel supply on 93/91 octane pump gas builds up to about 750 wheel HP

Pros - Adds desired sound, increased performance, and reliable necessary fuel delivery over 700 HP
Cons - Labor intensive installation taking most cam kits to more than $4,000 installed, added stress on high pressure fuel pump, great for sound and engine optimized performance, but not a great bang for the buck for fuel delivery

Notes - Cam kits are almost always on the list for pushrod V8 guys. The thump of a properly designed cam makes mouths drop and power gains are plentiful. On the gen 5 platform, the "need" for a camshaft is more prevelant because the high pressure fuel pump (HPFP) rides on it's own specific camshaft lobe. So, we quickly figure out you can redesign that lobe on a custom camshaft to overdrive the OEM HPFP for more rail pressure output. The only drawback is this supply is limited and the installation to get a camshaft in properly on an LT engine requires pulling the motor.

3. Low Side Line Pump Kit:
https://weaponxmotorsports.com/produ...en-6-lt1-lt4-1

WEAPON-X recommended use - for additional fuel supply to the high pressure fuel pump HPFP for flex fuel/E85

Pros - Inexpensive easy fuel supply increase, added octane from flex, kit keeps HPFP primed for max output
Cons - Only help with lower HP increases but high side will still starve on big builds, no ability to upgrade later, no going back once tank is tapped

Notes - The low side line pump kit is a good option for stock supercharger builds up to a certain point, but big boost over 800 HP will need more fuel than the high side pump, injectors, and rail can deliver... even with an upgraded high side DI system too. These line pump kits aren't upgradeable, so once you've done all of that work to get it in and desire to go larger, your tank is already tapped and you have to undo that and redo a larger pump kit.

4. LPE Big Bore DI High Pressure Fuel Pump:
https://weaponxmotorsports.com/produ...-cts-v-lt1-lt4

WEAPON-X recommended use - this pump supplies 10% more fuel and when used with larger injectors and a line pump kit, can prevent the need to upgrade the camshaft for some 750 HP builds.

Pros - Simple bolt on option once the supercharger is removed, 10% more flow
Cons - 10% flow isn't a lot in the DI world, expensive at $1,500 for gains.

Notes - The larger DI pump helps some, but it's not a huge increase as 10% more fuel is not 10% more power. This pump is $1,500 and has it's benefits when used with the larger FIC or Nostrum injectors which add another $3-5,000 to the cost as well as the need for a low side kit still to supply more fuel to maximize the effort. All of this can benefit someone who does not want to do a camshaft, but you're at a minimum cost of about $5,000 plus installation going this route. The DI pump cannot be overdriven by a camshaft lobe greater than 6.5mm either, so anyone doing a cam later would have to go back to the LT4 pump and the LT4 pump with an overdriven +7.8mm camshaft can outflow the +10% pump with a 6.5mm lift by about 15-20% if I recall. This is a great option for someone willing to spend the money on the ancillary times that wants bolt on, reversible parts and doesn't want to open up the motor. It's just limited on max power.

5. Larger DI Injectors:
https://weaponxmotorsports.com/produ...-cts-v-lt1-lt4

WEAPON-X recommended use - The FIC injectors supply 30% and are able to support 1,000, while Nostrum is advertising 50% more fuel and 1,200 crank HP; however, still need the high pressure pump supply. These can be good for sub 1,000 HP builds when combined with other mods like the HPFP or camshaft and low side line pump fuel kits.

Pros - Simple bolt on option once the supercharger is removed, 30% more flow
Cons - Expensive upgrade at $3,000 - $5,000, limited by HPFP and line pump, requires other mods for potential

Notes - The larger injectors help for those looking to do bolt on power, but they require ancillary mods to reach their potential. The injectors are $3-5,000 and need a cam and a low side kit still to supply more fuel to bet worthwhile too, which puts you into a minimum of $9,000 installed. This is a great option for someone willing to spend the money on the ancillary times that wants bolt on, reversible parts and doesn't want to open up the motor; however, while the injectors aren't the ceiling, the max power limitation is restricted by the high pressure fuel pump pressurizing the rail to keep the pressure on the near 3,000 PSI target.

6. Port Injection Fuel System:
https://weaponxmotorsports.com/produ...-cts-v-lt1-lt4

WEAPON-X recommended use - This kit is really for anyone who is looking for proven reliable power with the intentions to get more than 800whp, especially on E85.

Pros - Cost is about the same as doing a low side kit, HPFP, and larger DI injectors or a cam kit installed
Cons - Requires low side, harness, injectors, rails, and modifying your existing supercharger/manifold

Notes - We now have a reasonable solution a true port injection kits specific to Camaros, Corvettes, and CTS Vs! It is a complete kit with plug and play wiring harness, pump, lines, injectors, rails, and we have successfully installed these on the LT4 Whipples, Procharger manifolds, and even the OEM Eaton LT4 supercharger! We offer in-house modifications to those for the port kit too and pricing will be released later this month for all!

Let us know if you have any questions!

01-13-2018, 08:08 PM	#2
WEAPON-X Drives: ZL1 ATS-V CTS-V C7Z Range Sport SC Join Date: Mar 2016 Location: Cincinnati, OH Posts: 580	WEAPON-X Solutions Alternative LTX DI Fuel Supply Options: 1. Meth Injection 2. Camshaft Kit with 38% Fuel Lobe 3. Low Side Line Pump Fuel Kit 4. LPE Big Bore DI High Pressure Fuel Pump 5. Larger DI Injectors 6. Port Injection Systems 1. Meth Injection Kit: https://weaponxmotorsports.com/produ...th-kit-lsa-lt4 WEAPON-X recommended use - as slight cooling and octane boost with proper fuel system supply from the tank. Pros - Methanol kits are inexpensive starting at $600 and adds octane, cooling, cleans the valves which was an issue with DI motors mentioned earlier Cons - Uneven distribution, Kit ends up being around $1,200 installed, additional cost to add a meth tank or losing washer tank, refilling and storage of meth, flammable liquid in the trunk or engine bay, potential pump/solenoid failures which can cause engine failure if the car is too dependent on methanol Notes - Sure a meth kit is cheap, but you'll have 6-8 hours of installation, the hassle of refilling the methanol, and the worst part, keeping an eye on the entire thing and hope the pump doesn't go out when you're heavy into the throttle. When tuning a car that is dependent on methanol for fuel supply, the engine is relying on the added methanol to maintain the proper air fuel ratio, which really is never what alky meth kits were intended for. The second inherent problem with these is fuel delivery. Engines always have what are called "hot cylinders" where the natural airflow path is stronger so you have more uneven cylinder distribution. So, if you're spraying heavy amounts you need to run what is called direct port meth which means there is one nozzle per cylinder to control the flow. This gets really pricey starting around $2,000 plus install because you need check valves and extra solenoids to make sure the pressurized air isn't pushing against the tip of the nozzle, and even in this instance, you always have rich and lean spikes because the methanol nozzles are just not as refined and controllable as a fuel injector tip. 2. Camshaft Kit with 38% Fuel Lobe: https://weaponxmotorsports.com/searc...6+camshaft+kit WEAPON-X recommended use - obvious performance gains depending on the cam, but for fuel supply on 93/91 octane pump gas builds up to about 750 wheel HP Pros - Adds desired sound, increased performance, and reliable necessary fuel delivery over 700 HP Cons - Labor intensive installation taking most cam kits to more than $4,000 installed, added stress on high pressure fuel pump, great for sound and engine optimized performance, but not a great bang for the buck for fuel delivery Notes - Cam kits are almost always on the list for pushrod V8 guys. The thump of a properly designed cam makes mouths drop and power gains are plentiful. On the gen 5 platform, the "need" for a camshaft is more prevelant because the high pressure fuel pump (HPFP) rides on it's own specific camshaft lobe. So, we quickly figure out you can redesign that lobe on a custom camshaft to overdrive the OEM HPFP for more rail pressure output. The only drawback is this supply is limited and the installation to get a camshaft in properly on an LT engine requires pulling the motor. 3. Low Side Line Pump Kit: https://weaponxmotorsports.com/produ...en-6-lt1-lt4-1 WEAPON-X recommended use - for additional fuel supply to the high pressure fuel pump HPFP for flex fuel/E85 Pros - Inexpensive easy fuel supply increase, added octane from flex, kit keeps HPFP primed for max output Cons - Only help with lower HP increases but high side will still starve on big builds, no ability to upgrade later, no going back once tank is tapped Notes - The low side line pump kit is a good option for stock supercharger builds up to a certain point, but big boost over 800 HP will need more fuel than the high side pump, injectors, and rail can deliver... even with an upgraded high side DI system too. These line pump kits aren't upgradeable, so once you've done all of that work to get it in and desire to go larger, your tank is already tapped and you have to undo that and redo a larger pump kit. 4. LPE Big Bore DI High Pressure Fuel Pump: https://weaponxmotorsports.com/produ...-cts-v-lt1-lt4 WEAPON-X recommended use - this pump supplies 10% more fuel and when used with larger injectors and a line pump kit, can prevent the need to upgrade the camshaft for some 750 HP builds. Pros - Simple bolt on option once the supercharger is removed, 10% more flow Cons - 10% flow isn't a lot in the DI world, expensive at $1,500 for gains. Notes - The larger DI pump helps some, but it's not a huge increase as 10% more fuel is not 10% more power. This pump is $1,500 and has it's benefits when used with the larger FIC or Nostrum injectors which add another $3-5,000 to the cost as well as the need for a low side kit still to supply more fuel to maximize the effort. All of this can benefit someone who does not want to do a camshaft, but you're at a minimum cost of about $5,000 plus installation going this route. The DI pump cannot be overdriven by a camshaft lobe greater than 6.5mm either, so anyone doing a cam later would have to go back to the LT4 pump and the LT4 pump with an overdriven +7.8mm camshaft can outflow the +10% pump with a 6.5mm lift by about 15-20% if I recall. This is a great option for someone willing to spend the money on the ancillary times that wants bolt on, reversible parts and doesn't want to open up the motor. It's just limited on max power. 5. Larger DI Injectors: https://weaponxmotorsports.com/produ...-cts-v-lt1-lt4 WEAPON-X recommended use - The FIC injectors supply 30% and are able to support 1,000, while Nostrum is advertising 50% more fuel and 1,200 crank HP; however, still need the high pressure pump supply. These can be good for sub 1,000 HP builds when combined with other mods like the HPFP or camshaft and low side line pump fuel kits. Pros - Simple bolt on option once the supercharger is removed, 30% more flow Cons - Expensive upgrade at $3,000 - $5,000, limited by HPFP and line pump, requires other mods for potential Notes - The larger injectors help for those looking to do bolt on power, but they require ancillary mods to reach their potential. The injectors are $3-5,000 and need a cam and a low side kit still to supply more fuel to bet worthwhile too, which puts you into a minimum of $9,000 installed. This is a great option for someone willing to spend the money on the ancillary times that wants bolt on, reversible parts and doesn't want to open up the motor; however, while the injectors aren't the ceiling, the max power limitation is restricted by the high pressure fuel pump pressurizing the rail to keep the pressure on the near 3,000 PSI target. 6. Port Injection Fuel System: https://weaponxmotorsports.com/produ...-cts-v-lt1-lt4 WEAPON-X recommended use - This kit is really for anyone who is looking for proven reliable power with the intentions to get more than 800whp, especially on E85. Pros - Cost is about the same as doing a low side kit, HPFP, and larger DI injectors or a cam kit installed Cons - Requires low side, harness, injectors, rails, and modifying your existing supercharger/manifold Notes - We now have a reasonable solution a true port injection kits specific to Camaros, Corvettes, and CTS Vs! It is a complete kit with plug and play wiring harness, pump, lines, injectors, rails, and we have successfully installed these on the LT4 Whipples, Procharger manifolds, and even the OEM Eaton LT4 supercharger! We offer in-house modifications to those for the port kit too and pricing will be released later this month for all! Let us know if you have any questions! Last edited by WEAPON-X; 11-27-2018 at 12:38 PM.