Our project car Blank Slate, the first generation 1969 Camaro that we plan to take road racing, had a high-end engine built that was suitable for the task. Our friends at Late Model Engines (LME) from Houston, Texas, helped us by building a Texas-sized LS engine that promised big horsepower for the track. We covered that engine build in a two-part series of articles, LME’s 502ci 700+ hp LS Build Part 1: The Short-Block and Engine Build Part 2: Wrapping Up The RHS-Backed, 720 hp LSX 502.
At the time, we noted that LME used Fuel Air Spark Technology‘s (FAST) XFI 2.0 engine control system for tuning because it allows users to process, analyze, and adjust parameters more quickly. The results were about what we expected as the mill came off the dyno making a very potent 720.3 horsepower at 6,400 rpm and 669.6 lb-ft of torque at 5,300 rpm.
It is the simplest EFI system to install and get up and running quickly. – David Page
Previous models of self learning EFI systems were thought to be limited to engines delivering around 600 horses. We liked the challenge of proving that a self-learning EFI system could support an engine with over 700 horsepower so we called our friends at FAST.
The really big deal that makes the LS EZ-EFI 2.0 system unique, is the ability to support multi-port and a factory throttle body, not just the EZ EFI throttle body with the integrated injectors. In short, the LS EZ-EFI 2.0 can be used with factory-style intakes with eight individual injectors.
The FAST EZ-EFI 2.0 System
The engineers at FAST worked hard to find an answer to the self-learning EFI for higher horsepower engine question. What they came up with is a simple self learning EFI system that utilizes an easy-to-use interface, and doesn’t require a laptop or tuning experience. While our crew has plenty of EFI tuning experience, we wanted to prove that you don’t need years of experience if you have a self-learning and self-tuning system that can support a high-end engine build.
“The FAST EZ-EFI 2.0 is the simplest system to install and get up and running quickly,” said David Page of FAST. “When mated with the EZ LS ignition controller, this is a great system for running any one of the LS platform engines.”
Truly, the EZ-EFI 2.0 multi-port EFI (Part #30411T-10T) system that the FAST engineers have put together is a simple plug and play unit. The self tuning engine control specially designed for LS series engines, makes the transition trouble-free. Stock LS units can be complex and require PCM flashing and electrical harness reworking in order to function properly. The FAST EZ-EFI 2.0 kit takes care of those problems with the award-winning ECU included in the kit. The EZ-LS ignition controller further simplifies the swap by allowing the use of stock or aftermarket LS injectors, sensors, and coil packs.
“The system is self learning, so no tuning experience is required. The system includes a clean, simple touch-screen handheld unit for easy initial setup, so no laptop is needed,” added Page. In addition to the easy-to-use interface included with the touch screen handheld device, the handheld unit can replace the tach and most other gauges for engine monitoring. After initial setup, the handheld can be used as a digital dash with the included suction cup window mount.
The beauty of self-tuning/self-learning EFI systems is that they continue to tune as the operator drives. Because the system is continuously tuning, any engine upgrades that are made in the future are simplified as well. There are no special trips to the garage for tuning changes. Everything is handled with the onboard system. The multi-port installation kit that we installed on our project car is compatible with all LS-based car and truck engines. A purpose-built, OEM-quality wiring harness that features a clean, mesh wrapping is included in the kit as well. This harness dramatically improves engine aesthetics over the factory harness, plus the clearly labeled connections makes wiring up a monster LS build quick and easy.
Features of the FAST EZ-EFI 2.0 Systems:
- Made in the USA
- Self tuning LS-EFI gets you up and running quick and easy: No laptop or tuning knowledge necessary
- EZ-LS Ignition Controller offers “no tuning” quick setup option as well as custom tuning via hand-held controller
- Hand-held displays up to 20 live-data readings/sensors; various dash display options
- Limited lifetime warranty and backed by industry’s most extensive tech support team
- Modern, mesh-wrapped wiring harness replaces stock harness
- 100-percent designed and engineered in house by FAST staff
- Uses OE/stock-style, LS sensors, ignition, and injectors
- Hand-held start-up gauge screen is user selectable
The Rest Of The System
Aditional System Components
- Air temp sensor (PN 307004)
- Coolant temp sensor (PN 307003)
- ECU/Tuning FAST XFI (PN 301000)
- EFI harness (PN 301108)
- FAST 65-lb. fuel injectors (PN 30657-8)
- FAST billet fuel rails for LS7 LSXR intake (PN 146027-kit)
- FAST coils (PN 30256-8)
- FAST 102mm LSXR intake for LS7 heads (Pn 146202)
- FAST throttle body 102mm (PN 54103)
- FAST XIM ignition box (PN 301312)
- Fuel injector harness (PN 301209)
- IAC (PN 307059)
- MAP sensor (PN 307029)
- RHS LS7 intake spacers for tall deck block (PN 549109)
Finally, we were ready for the FAST EFI 102 mm throttle body. This throttle body maximizes air flow while also creating a well-mannered, street-driven engine.
We matched all of this up with a FAST 102 mm LSXR manifold to maximize low- and mid-range torque. The FAST manifold has proven itself to carry the horsepower through the upper power band making it ideal for our needs.
According to Page, “When used with a Big Mouth 102 mm throttle body, the LSXR intake manifold produced gains of 16-plus horsepower on a near stock LS7 engine, and 26-plus rear wheel horsepower on a 500ci RHS LS aluminum-block based engine.”
Beefing Up The Fuel System
As with all modern fuel injection systems, the EZ-EFI 2.0 kit requires a much higher pressure fuel system than carbureted applications. For this reason, you will need to install a new fuel-injection-rated fuel system, especially when switching from carburetor to EFI. We need to make some major changes in the fuel system, or we face a fuel supply problem that would be on the scale of trying to suck a basketball through a straw. To cure the issue, we decided to use an electric fuel pump and plumbing from Holley and Earl’s Performance Plumbing, along with a tank and pickup from Rick’s Stainless Tanks. To get all the details on our fuel system upgrade, check out our tech article on building a street performance fuel system.
The engineers at FAST recommend an in-tank fuel pump when possible, because of the advantages over an inline fuel pump. In-tank pumps are always primed, so they run cooler and quieter than in-line fuel pumps. Inline pumps are easier to install because you don’t have to remove the fuel tank. We mounted our Holley Dominator fuel pump inline and just below the chassis on the frame rail.
In order for the EZ-EFI 2.0 to control ignition timing on a coil-per-cylinder engine, a FAST EZ-LS or FAST XIM ignition system is required. It will supply the EZ-EFI with an RPM signal, and also drive the coils. We opted to install the FAST XIM ignition box (PN 301312), which is designed to work with GM/Chevrolet Gen IV small-block LS based engines that use a 58-tooth crankshaft signal. This kit is engine specific, and comes with a clearly labeled harness that allows for a simplified plug and play installation. The unit is encased in a water and heat resistant billet aluminum enclosure, which is perfect for under-hood placement.
We also opted to use the FAST coil packs (PN 30256-8) instead of a distributor ignition system. Coil-per-cylinder ignition systems are engineered to have one less link in the system. They eliminate the mechanical connection of the distributor by taking the signal directly from the ECU to the spark plugs. This helps resolve or eliminate the possibility of any misfire or rough idle issues.
Increased airflow is a key ingredient when improving engine performance, which is why we were interested in the FAST Big Mouth throttle body. FAST has two Big Mouth choices for LS engines. The company offers a 92 mm throttle body with the FAST LSX intake manifold, or a monster 102mm throttle body with the LSXR intake for even more airflow capabilities. Page explained that FAST “invested significant testing and engineering resources into optimizing cross-sectional flow, and eliminating airflow turbulence, especially at part throttle operation” in these throttle bodies.
We are not sure what future upgrades we might try, so the increased blade thickness in these throttle bodies help eliminate deflection, which is particularly important in boosted applications. Ideally the FAST Big Mouth 92 mm throttle body is designed as bolt-on horsepower to LS1, LS2, and LS6 engines, while the LSXR setup with the 102 mm throttle body is designed to maximize potential performance upgrades on L92, LS3, and LS7 engines. Needless to say, we selected the LSXR intake (PN 146202) with 102 mm throttle body (PN 54103).
LSXR Intake for LS7 Heads
The engineers at FAST actually worked with the engineers and airflow specialists at RHS to develop a line of polymer intake manifolds for LS based engines. From a stock-like LS7 engine, the crew’s intake with 102 mm throttle body produced gains of over 26 horsepower at the wheels on a 500ci engine. The LSXR intake (PN 146202) features a new modular design that the engineers call “revolutionary,” allowing fast and easy disassembly with the ability to remove individual runners for porting.
Constructed with an advanced polymer material, it is lighter than aluminum intakes, and has better heat dissipating characteristics. Other features include integrated nitrous bungs, and perfect bolt-on fitment that allows the use of factory accessories without modification or clearance concerns.
The nitrous bung may come in handy down the road as the EZ-EFI 2.0 system will work with the classic nitrous wet-plate type systems. There is even a Nitrous category in the setup that will allow the user to select a target A/F ratio and target total timing number. This only works if the ignition is integrated into the EFI system like we have done.
Setting Up The System
Another unique feature with the LS EZ-EFI 2.0 system is the user interface. A hand-held display is used to set-up and monitor the system. Not only is a laptop computer not needed, you could not hook one up to the display even if you wanted to! This system is built and designed for simplicity and ease of use with maximum control over a very complicated engine system.
The menu-driven displays allow users to make changes to any portion of the electronic fuel system that were previously only available on systems using laptop computers, and users with years of training. Setting up engine parameters has never been easier, and features like timing control and fuel curves are completely accessible from the display.
The hand-held display can be set up as a dashboard for engine performance with several different display options, allowing the user to pick what features, or all of the engine parameters, to monitor on the display.
Overview On Self Tuning
The self-tuning nature of this system is the biggest selling point. A large group of variables can be defined in the setup, like engine idle and the target A/F ratio that is desired. Parameters like engine size, injector size, and other variables are dialed in, which allows the ECU to estimate the amount of fuel required for those operating conditions. Now here is the good part: The ECU gets feedback from sensors like the wide band oxygen sensor. The ECU takes these readings and compares them to the initial settings. It then determines a new injector pulse-width to refine the tune. Then the process begins again and continues until the engine is shut off.
The ECU hones down the parameters quickly, learning the sweet-spot of the parameters, making the engine run extremely well. The sensors used in the feedback loop have gotten so dependable and have improved to the point where this automatic performance is possible, even with frequent engine upgrades.
The only way to clearly prove our point that the FAST EZ-EFI self-learning EFI system will work effectively with a higher horsepower engine is to take our project car back to the dyno after the installation. Our RHS-based LS engine made an impressive 720.3 horsepower at 6,400 rpm and 669.6 lb-ft. of torque at 5,300 rpm back at LME on the engine dyno with the FAST XFI system, so we were eagerly anticipating our chassis dyno run in our garage.
Based on our real world testing, we are satisfied that the FAST EZ-EFI 2.0 system breaks through the 600 engine horsepower barrier for self-learning EFI systems. We measured 587.0 horses on our Dynojet chassis dyno after only a few miles of self-tuning. Confident that our horsepower numbers would be well above the 600 mark on an engine dyno, we were satisfied with the results.
The engine’s performance on the dyno, as well as our trips around town, have shown us that the system works well, keeping the engine running smoothly and efficiently. It’s mild mannered enough that grandma could drive it to Bingo night at church, or for your brother-in-law to take to the track.