The Top 7 LS1 Improvements. The General Motors/Chevrolet LS1 engine already has some outstanding performance right out of the box. It was installed in the C5 Corvette and the fourth generation Camaro SS and Z28, as well as the fourth generation Pontiac Trans-Am and Formula, as well as the 2004 GTO. The LS1 engine in these vehicles developed 305-350 horsepower and 335-365 lb-ft of torque. However, while the LS1 is already quite competent, some LS1 modifications can truly open it up for greater power.
This article will discuss the finest LS1 mods and upgrades for your setup. The 5.7 L V8 is capable of handling significant power, and it performs admirably with minor ventilation and fueling improvements. However, we won’t stop there; we’ll teach you how to create everything from a 375 horsepower build to a 1,000 horsepower monster.
Basic LS1 Engine Information for Modding
Before we get into true LS1 enhancements, let’s start with the fundamentals. From 1997 until 2004, GM/Chevy built the LS1, a 5.7L naturally aspirated V8 engine. The LS1 was the first of GM’s third generation of small block V8 engines to be released, and it was responsible for the engine series’ more popular appellation, the LS-series. The LS1 was advertised with a compression ratio of 10.1:1, but most sources put it at 10.2:1.
The compression ratio is ideal for boosted applications, and the LS engine family enjoys forced induction. The head and block are both constructed of aluminum, which helps to reduce weight while maintaining strength. While this does not make the LS1 indestructible, it does make it robust and capable of withstanding significant abuse.
The LS1 employs cathedral-port cylinder heads from the LS series. It used one set of heads from 1997 to 2000, then from 2001 to 2004, GM/Chevy gave the LS1 the LS6 heads. Although GM/Chevy only announced a 5 horsepower boost, the LS6 heads are believed to be far better flowing than the LS1 heads. However, for insurance purposes, this is believed to be a conservative estimate.
Power Limits of a Modded LS1 Engine
The LS1 engine, as well as the entire LS-series, is recognized for having rather high power limits. The LS1 block is usually regarded to be capable of withstanding 800 wheel-horsepower before failing. That isn’t usually the true, as some people have run hundreds of horsepower more, but for the most part, 800 horsepower is regarded a relatively dependable maximum. It won’t last 50,000 miles, but it also won’t fall apart after a few runs.
Internally, the LS1 pistons and rods, like the rest of the early LS-series, are good until roughly 500 horsepower. Although the rods are stronger than the pistons, it’s a good idea to update them to stronger forged ones if you want to consistently exceed 500 horsepower. You should also add head studs at this point. If your LS1 upgrades include valve train upgrades, you should at the very least strengthen it with new pushrods and lifters.
Top 7 LS1 Improvements
Our top seven LS1 upgrades are as follows:
- Improved Intake
- Headers for Long-Tube Vehicles
- Manifold for Intake
- Head of a Cylinder
- Camshaft
- ECU Programming
- Supercharger
Modifications for the LS1 naturally aspirated engine
For most people, basic bolt-on mods like as an improved intake and long-tube headers are excellent first LS1 upgrades. They aid with the improvement of airflow into and out of the engine, both in terms of volume and velocity, which is critical for improving power.
The intake manifold is the next LS1 improvement. The factory LS1 intake manifold is far from ideal, and is likely the worst in the LS-series. The LS1 intake manifold from 1997 to 2000 was so terrible that GM/Chevy replaced it with the LS6 intake manifold in 2001. While the LS6 manifold is an improvement, it may be worth upgrading depending on your power level.
Let’s go on to LS1 improved cylinder heads. As previously stated, the LS1 employs the LS cathedral-port cylinder head. While these are good for low-end torque, they struggle with top-end flow. The early LS1 cylinder heads, like the intake manifolds, performed so poorly that GM/Chevy modified them to the LS6 versions in 2001. While the LS6 heads outperform the LS1 heads in terms of performance, there is still opportunity for improvement, as we’ll see below.
Another popular modification is to replace the LS1 camshaft. Camshaft selection is critical since there will be a trade-off between low-end torque and top-end performance. The correct cam will provide you a decent tradeoff by providing torque where you need it and power when you want it.
ECU Tuning for the LS1 and Blowers
Another significant LS2 modification is ECU tuning. While tuning may not appear to be important at first, it might mean the difference between a successful engine build and a blown engine. Tuning allows you to tweak ignition timing, air-to-fuel ratios, and other factors to make the most of your modifications. If you’re going to spend hundreds of dollars on bolt-ons, you’ll want to make the most of them.
Finally, forced induction is essential if you want to take your LS1 build to the next level. For most builds, a naturally aspirated LS1 produces 500-550 horsepower. A supercharger or a turbocharger is the most cost-effective approach to increase power.
1) LS1 Intake Improvements
An improved intake is one of the best enhancements that can be applied to practically any naturally aspirated engine, including the LS1. With just an intake, the LS1 can generate 10-15 horsepower. When it comes to starting to increase power, the factory intakes on most LS1 vehicles are somewhat restrictive, especially up top.
An improved intake will boost air flow while also, ideally, adding cooler air. The intake options for the LS1 are rather restricted. The majority of Corvette intakes will be ram air, as these work well with the engine bay arrangement. However, for other LS1 vehicles, a real cold air inlet is available, which is often preferable.
A cold air intake is designed to help collect cooler air from outside the engine bay for improved performance by moving the filter placement and reducing the restrictiveness of the OEM intake. In contrast, a ram air intake works by providing the quickest and least resistance path for incoming air. It normally does not bring in colder air, but it does remove constriction and boost flow.
While the standard intakes are normally adequate, adding bolt-ons such as long-tube headers can cause a limitation. A more free-flowing intake will improve throttle response, top-end power, and engine noise. It also improves and enhances the appearance of your engine bay.
Top LS1 Intakes
The ideal intake for an LS1 upgrade depends on your unique car model. One of the first modifications we recommend is a cold air intake. The choice between a closed and open airbox is critical. Open airboxes are more prone to heat soak, but they provide better ventilation. Closed airboxes reduce flow, but they also keep engine heat soak at bay for longer, resulting in cooler air.
The intake on the C5 Corvette is already near the front of the bay, making it difficult to relocate the filter while boosting flow. As a result, we recommend the Callaway Honker Ram Air intake on Corvettes. It’s a ram-style intake rather than a real cold air intake, but it works nicely on the C5 Corvette. They claim improvements of up to 16 horsepower, and the Callaway Honker is widely regarded as the industry standard for C5 Corvette intakes.
We recommend the Cold Air Inductions GTO cold air intake for the 2004 GTO with the LS1. This intake comes with a closed and insulated aluminum airbox as well as a 4″ intake tube. The airbox includes a clear top, allowing you to inspect the state of your filter without having to remove anything.
2) Upgraded LS1 Long-tube Header and Exhaust
Next, we’ll discuss replacing the factory LS1 headers with long-tube LS1 headers. The OEM headers are thick cast iron and extremely restricting. They are also prone to cracking over time; updating the long-tube headers is a necessary for any serious construction. The LS1 employs two headers, one for each cylinder bank.
Long-tube headers take the place of the OEM exhaust manifold and direct the exhaust back to the mufflers. Headers are essentially aftermarket exhaust manifolds. Aftermarket headers are often broader than OEM, constructed of lighter 304 stainless steel, and engineered for best exhaust flow. Everything works together to reduce back pressure and reversion while enhancing exhaust scavenging.
The reduced back pressure provides for improved exhaust flow. Exhaust gasses are eliminated faster and more clean air can enter the combustion chamber due to increased exhaust scavenging and less reversion. This results in greater and longer-lasting power.
Long-tube headers will surely increase exhaust volume significantly. As you can anticipate, the increased pipework and optional cats boost the LS1’s sound significantly.
Long-Tube Header Upgrades for LS1
Long-tube headers for the LS1 are classified as either catted or catless. While catless systems create somewhat greater power, they are also non-compliant with emissions regulations and will fail inspection.
We choose catted headers because the power differential is modest and they are more suitable for daily driving. Catted exhausts are slightly quieter and smell significantly nicer. Even with a high-flow catalytic converter, you should be able to meet your power objectives.
American Racing Headers (ARH) will be our first choice for LS1 long-tubes. ARH is a well-known brand in the LS-series exhaust business, and they’ve been making strong headers for a long time. Their LS1 exhaust systems are available in a variety of primary sizes and are all comprised of 304 stainless steel.
The following is from Kooks Headers for the C5 Corvette. The Kooks long-tubes are also catted, but instead of a y-pipe like the ARHs, they have an x-pipe. The x-pipe setup has been proved to flow better than the y-pipe setup, making the Kooks more appealing. Regardless of the long-tubes, headers on the LS1 alone can produce gains of up to 10-30 whp, and even more with tweaking.
3) Upgraded LS1 Intake Manifold and Throttle Body
Let’s have a look at the LS1 intake manifold now. An improved intake manifold is designed to increase the volume and velocity of air entering the engine. Larger capacity plenums and runners on aftermarket LS1 intake manifolds allow more air into the engine.
The throttle body is linked to the intake manifold. The stock throttle body on the LS1 is 78 mm. A larger throttle body, which is commonly improved together with the intake manifold, increases the amount of air that can enter the intake manifold.
The enhanced flow and reduced restriction of an improved LS1 intake manifold will allow for higher peak power and a wider power band. Some manifolds are more focused on top-end power, while others are more focused on the mid-range. Shorter runners have more top-end power, while longer runners have more low-end torque.
Upgrades for the LS1 Intake Manifold
If you have a 1997-2000 LS1, you should absolutely upgrade your manifold. As previously stated, GM/Chevy equipped stock 2001-2004 LS1 engines with the LS6 intake manifold, which is an excellent upgrade for early LS1s as well. It is a direct bolt-on replacement that will undoubtedly increase performance.
The FAST LSXR LS1 intake manifold is the most popular option for those wanting for even more power or if you already have the LS6 type intake manifold. The FAST intake is constructed of a polymer that is both tougher and lighter than aluminum.
The FAST LS1 intake manifold has a 102mm throttle body, which is a huge 24mm larger than standard. However, with an adapter, it may also be utilized with 92 mm and 90 mm throttle bodies, as well as the conventional 78 mm throttle body. The Fast LSXR LS1 intake manifold is best suited for high-performance LS1 designs that may use forced induction.
4) LS1 Cylinder Head Improvements
The cylinder heads are the next item on our list of LS1 upgrades. As previously stated, the LS1 employs cathedral-port design cylinder heads, which aren’t ideal for higher RPM flow. It has excellent low-end torque, but if you want more top-end horsepower, you’ll need to go elsewhere.
One method is to port the stock LS1 heads, which does assist a little. Porting effectively smoothes and rounds out the flaws in the stock manifold, increasing flow and decreasing air turbulence. Air turbulence is the polar opposite of flow, and it will stifle horsepower if it is severe enough.
The following option is to use a bigger cylinder head. You have two options: remain with a higher flowing version of the cathedral-port heads or upgrade to rectangular-port heads. Cathedral-style windows are less expensive because they bolt right on. However, for the most power, the rectangular-style reigns supreme.
Top LS1 Cylinder Head Improvements
We propose Livernois Motorsports Pro Series LS Cylinder Heads for LS1 cylinder head upgrades. These cathedral-port heads exceed the standard and LS6 heads significantly. Livernois Motorsports is a household name in the LS engine manufacturing market, with a solid reputation built over decades of exceptional labor.
Another suggestion is to upgrade to the LS6 cylinder heads if you have an LS1 from 1997 to 2000. While they will not deliver the same performance as the Livernois Motorsports heads, they are far superior to the stock LS1 heads. GM/Chevy changed the LS1 cylinder heads from 2001, which is a pretty clear indication that the LS6 heads are considerably better.
5) LS1 Camshaft Improvements
Our next recommendation for LS1 modifications will be an improved camshaft. The factory LS1 cam is adequate for stock power levels, but if you’re considering further bolt-ons, upgrading to a longer duration and higher lift cam is also recommended.
When it comes to camshaft upgrades, the most important factors to consider are duration and lift. A higher lift implies the valve opens wider, allowing more air into the engine for increased power. A greater duration indicates the valve will be open for a longer period of time, allowing more air into the engine. Duration is the number of degrees the crankshaft revolves while the valve is open, and lift is the distance from the valve to the head in inches.
Longer duration and higher lift cams provide more top-end power at the sacrifice of low-end torque. You’ll want a decent combination of low-end torque and top-end horsepower, especially if you’re creating a daily driver. This will keep your car drivable in traffic at low engine loads while allowing you to roast some rubber when you really need it.
Camshaft Upgrades for the LS1
We have two recommendations for LS1 camshaft modifications, both from Livernois Motorsports. Depending on the car, the stock LS1 cam has varied specs. The hottest cam was found in the 2000 Corvette and early Camaro/Firebird, although it was rapidly decreased the following year.
The lift on the Livernois Motorsports Stage 2 is 0.595″ and the lift on the Stage 3 is 0.612″. The duration of Stage 2 is 232° @ 0.050″, and the lift of Stage 3 is 224° @ 0.050″. Both of them have the potential to significantly increase top-end power.
None of the stock LS1 cams from any car have more left than.500, and they also have intake and exhaust durations of less than 200° and 209°, respectively. A camshaft is not an improvement to be handled lightly, but if you need some extra power, they can perform well.
6) Tuning the LS1 ECU
The LS1’s next step will be ECU tuning. LS1 tuning will offer you a nice 10-20% power gain over your current setup. Furthermore, while many of the above LS1 improvements, such as headers and manifolds, will enhance power on their own, tuning will be required to fully benefit from them. Tuners can tune characteristics like as ignition timing, air-to-fuel ratios, and fuel pressure to make the most of your bolt-on modifications.
While tuning can assist optimize the possibilities of your mod, it can also help it run as safely as possible. When you modify an engine’s intake and exhaust flow, such as by installing an intake and headers, the air-to-fuel ratios normally change as well. While most upgrades keep the ratios in a safe range, tuning is required to validate this. To ensure that your engine is functioning properly with your modifications, you should have a tuner inspect the vehicle.
The Best LS1 Tuners
There are two types of LS1 tuning available: bespoke tuning and canned tuning. Custom tuning outperforms canned tuning because it allows your tuner to tailor his work to your individual engine and atmospheric circumstances.
Canned music is one-size-fits-all music that is designed to operate in any environment. Custom tunes, on the other hand, offer precise modifications for factors such as elevation, humidity, and air quality. Obviously, someone living in Florida and someone living in Seattle will have very different weather conditions. So, in order to fully optimize your vehicle for your mods and environment, you must go bespoke.
A handheld programmer or a stand-alone tuning equipment will be required when using a bespoke tuner. Stand-alone systems, such as an AEM EMS or Haltech ECU, offer the most customization, but they are also the most expensive and advanced. Handheld programmers, such as the Diablo, are significantly more user pleasant, although their capabilities are restricted.
Your best bet is to consult an LS1 tuner and then use whichever tuning product they prefer.
Upgrades to the LS1 Supercharger
Superchargers will be included in our final LS1 upgrade. We understand that most builders aren’t going for the extreme commitment of a supercharger, but it’s certainly worth considering. The most typical supercharger kits for the LS1 use centrifugal superchargers. That’s not to say you can’t use others, but centrifugal kits are usually the best for fitting in the engine bay.
This is due to the LS1’s already limited hood clearance, making it difficult to install a large blower on top. Furthermore, most LS1 intake manifolds are forward facing and are not meant to accept a roots or twin-screw blower.
Centrifugal blowers work similarly to turbochargers, except instead of exhaust gases, they employ a belt to drive the compressor. The belt powers a compressor, which compresses fresh air from the intake and delivers it into the throttle body and intake manifold via an intercooler. Centrifugal superchargers can be positioned on the manifold’s side where there is more room.
A supercharger kit is your best option if you want to easily boost your automobile to 450-500 horsepower without making intake manifold, cylinder head, or camshaft adjustments. It is a much simpler upgrade than those combined, and it produces more power. If you want to get the most power out of the LS1, the supercharger is the frosting on the cake. If you want moderate street power, a supercharger with some long tubes can be very useful.
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Supercharger Kits for the LS1
The East Coast Supercharger C5 Corvette Supercharger Kit and the ProCharger Kit for the Camaro, Firebird/Trans-AM, and GTO are our top LS1 supercharger kits. Both kits contain intercoolers and tuning solutions as well as centrifugal superchargers.
ECS is a household name in the Corvette supercharger market, and their C5 kits are the best in the business. They have numerous alternatives that can produce 500-1,000+ horsepower depending on the blower size.
The ProCharger kits have also received positive feedback and give exceptional power and drivability. You can utilize any size ProCharger you choose, but the P-1SC supercharger is the most popular. It is capable of producing just about 550 horsepower, which is ideal for adding power while being drivable. The ProCharger kit may completely change your LS1 with just 5-7 PSI of boost.
Conclusion for the Top 7 LS1 Engine Mods
The LS1 engine is a superb small block V8 that thrives on power. It responds really well to most modifications, such as intakes and headers, and creates a lot of power with forced induction. The LS1 is also a very dependable engine capable of producing significant horsepower and torque.
This post covered a lot of ground, from LS1 fundamentals through selecting superchargers to produce more than 1,000 horsepower. For most folks, a simple intake, headers, and ECU tune will provide the best bang for their buck, resulting in a powerful LS1 powered car with dependable reliability.
