The Guide to the 5.7L Chevy LS1 Turbo Kit. With 305 to 350 horsepower in American spec, calling the Chevy 5.7L LS1 V8 a slouch is a stretch. Having said that, as a Gen III Chevy small-block, the LS1 isn’t the most powerful or contemporary engine in the Chevy LS lineup. Despite the fact that it was released 25 years ago, the Chevy LS1 maintains a cult following. It’s an understatement to say it’s cult-like. While some believe the LS1 engine to be basic, with a pushrod valvetrain and a shared rod bearing design with the 1954 Gen 1 and Gen 2 small-block engines, the LS1 engine offers a vast amount of untapped potential.
With the correct modifications to an LS1, there is no limit to the power that can be extracted from a turbocharged Chevy 5.7L, and even without major supporting changes, there is a very broad margin of power potential that can be extracted from a turbocharged LS1. This post will go through the fundamentals of turbocharging a Chevy 5.7L LS1 engine.
History of the Chevy 5.7L LS1 Engine
When it comes to setting the way for a new generation of strong American V8s, the LS1 stands at the top of the list. By the late 1990s, the Chevy Gen I and Gen II small blocks were approaching 45 years of age. It was evident that Chevy needed to invest more money in R&D to create a more modern platform. Unsurprisingly, Chevy dubbed this new generation “Gen III.” The Chevy Gen III small block was designed from the ground up. That is, it only borrowed a few components from the previous two versions. Finally, the Chevy Gen III engine was completely distinct while preserving the 4.400-inch bore spacing that has been a fixture in Chevy small block designs since the Gen I.
The first engine in the Gen III small block family, the 5.7L Chevy LS1 V8, was released in 1997. The LS1 was first discovered in the C5 Corvette before being used in a variety of other Chevy vehicles such as the Pontiac Firebird Formula Trans Am, Camaro Z28, Camaro SS, and Pontiac GTO. One of the most noticeable aspects of the LS1 is its aluminum block. Other Gen III Vortec engines had a cast iron block, but solely in Chevy truck applications. The LS1 also includes a deep skirt, built-in crank and cam sensor mounts, and a cross-bolted 6-bolt main engine. The LS1 block also includes a structural oil pan, which improves chassis rigidity.
The rotating assembly of the LS1 is particularly sturdy thanks to a solid iron crankshaft and powdered metal connecting rods. They also use flat-top alluminum alloy pistons that are both exceptionally strong and lightweight. The use of lightweight pistons enhances overall throttle response and efficiency.
Basics of Chevy 5.7L V8 Turbocharging
Let’s start with the fundamentals before diving into the world of Chevy LS1 turbochargers. If you know what you’re doing with an LS1, it’s a nearly unbreakable engine. When compared to other similar engines, a turbocharger may produce close to 650 horsepower with less effort. That being said, before cranking up the boost, it is critical to understand the limits of the factory LS1 internals.
5.7L LS1 Engine Capacity
As previously stated, the Chevy LS1 engine can sustain power levels well exceeding its factory performance. The 5.7L Chevy V8 is rated between 305 and 350 horsepower in factory trim, depending on the application. In terms of horsepower, LS1-powered C5 Corvettes edge out Camaro Z27 and Camaro SS applications. Regardless, turbocharged LS1s may produce nearly quadruple the factory figure in horsepower. That isn’t to suggest that a turbocharged LS1 hitting 4-digit horsepower figures doesn’t necessitate a significant lot of attention and other upgrades ahead of time, since they most emphatically do.
Finally, with correct feeding and a quality tune, a turbocharged Chevy LS1 can consistently produce around 550 horsepower. Beyond that point, you should start thinking about stronger internal components. Despite being exceptionally sturdy, the stock rods and pistons are cast aluminum at the end of the day. Although original LS1 pistons and rods have been reported to sustain up to 700 horsepower, forged pistons and steel rods are recommended for high-boost LS1s for reliability. In the next sections, we’ll go through LS1 supporting mods in greater depth.
Your tune and fueling are two of the most important aspects of developing a long-lasting enhanced LS1. These two parameters become considerably more critical as you approach the LS1’s internal limits. In terms of engine preservation, a safe tune is self-explanatory. Internal damage is reduced when the tune restricts detonation and keeps internal temperatures low. Using E85 instead of pump gas or installing a meth injection kit are both examples of this.
LS1 Turbo vs. Supercharger
If you’ve read this far, you’ve probably done some research on the differences between LS1 turbo kits and LS1 supercharger kits. However, if you haven’t considered it or are still undecided, we’ll explain the differences briefly. In reality, both approaches of LS1 forced induction have substantial advantages and disadvantages.
Turbochargers for the LS1
While it is practically hard to match the performance of an LS1 turbocharger, there are several significant drawbacks when compared to an LS1 supercharger. To begin, it is crucial to understand that severely modified turbocharged LS1s have been known to produce 2,000+ horsepower, well above what is achievable with a standard PD supercharger. However, getting there takes a lot more time and money.
Finally, LS1 turbochargers and superchargers compress air and deliver it through the engine in very similar ways. The fundamental distinction is that turbochargers spin the impeller with exhaust gas. Because LS1 turbos rely on exhaust gas to spin, there may be a large wait for a turbo to engage at lower RPMs. This is sometimes referred to as “turbo lag,” and it can be quite common with large single turbos. This can be reduced by installing a smaller turbo or even two small turbos.
Overall, the benefits of an LS1 turbocharger include the ability to produce more horsepower than a supercharger (at their limitations), more efficient power generation, no parasitic power loss, and the fact that you do not need to modify your hood to install an LS1 turbo. Who could ever forget the blow-off sound?
The main disadvantages of an LS1 turbocharger kit are that they are generally more expensive and time-consuming to install, have a lot of additional components to install, are difficult to install in a compact engine bay, and have turbo lag.
Superchargers for the LS1
The way the extra power is supplied is maybe the most significant distinction between the two. Because there is no lag in power delivery from a PD supercharger, an LS1 positive displacement blower will give more power low in the rev range. Positive displacement superchargers, regardless of how quickly they spin, pump a constant volume of air into the intake manifold. That means there is always power available, no matter where you are in the rev range.
Some people prefer this type of supercharger since it provides a practically naturally-aspirated sensation. Having said that, because LS1 positive displacement blowers are belt driven by the engine, there is some parasitic power loss when installing one.
Aside from LS1 positive displacement superchargers, another form of LS1 supercharger is a centrifugal supercharger, sometimes known as a ProCharger. ProChargers are more akin to turbochargers than superchargers. An LS1 ProCharger, like an LS1 turbo, draws in air via a rotating impeller. The compressed air is then passed through the engine. However, unlike a supercharger, the compressed air delivered by a ProCharger retains a constant force due to the fact that they are also belt driven. ProChargers are typically substantially more expensive than LS1 PD superchargers. They are also significantly louder.
Modifications and Tuning for the 5.7L Chevy LS1 Turbocharger
While it is possible to operate an LS1 turbocharger kit at a low boost level with only a tune, pushing a turbocharged LS1 to high horsepower figures may necessitate some extra modifications. Headers and fuelling adjustments are optional but recommended in the first 500-650 horsepower phases. Beyond that, LS1 power levels necessitate these and other reliability and performance-enhancing tweaks.
There are certain turbocharged LS1 horsepower benchmarks that don’t require any additional modifications. The Chevy LS’s construction quality and materials provide you some wriggle room before any supporting modifications are required. This is normally limited to 500-600 horsepower. That being said, changes to support a turbocharged LS1 are never a bad thing. They can only serve to improve the robustness of the already powerful LS1 engine and add some horsepower.
The supporting upgrades required for a turbocharged Chevy 5.7L LS1 engine are obviously largely dependant on your power goals. In the next sections, we’ll go over the additional modifications required to handle a turbocharged LS1. We’ll go over several escalating horsepower figures.
LS1 with 500 horsepower
Turbocharger Kit costs between $3,000 and $7,500.
Long-tube headers (optional): $700-1,500
If dependability is a top requirement, 500 horsepower is a good starting point for a turbocharged LS1 build. Indeed, based on how the LS1 was built from the factory, it appears like GM intended owners to break the 500-horsepower barrier, especially with forced induction.
Aftermarket supporting mods are truly optional at this horsepower level. You won’t need to run much boost with a 500-horsepower objective. Depending on the LS1 turbocharger/turbochargers you use, you will only need 9-12 psi of boost to achieve this basic level. The factory LS1 internals are more than capable of withstanding the forces supplied by a turbocharger to get there. Of course, regardless of horsepower, a proper LS1 tune is always required.
That being said, once you hit the 500-wheel-horsepower mark, long-tube headers may be worth considering. While the original exhaust manifolds flow well, they lack adequate merging collectors and so limit flow. Long-tube headers will boost high-rpm performance and increase flow overall, which will play to the strengths of an LS1 turbocharger in particular.
LS1 with 600 horsepower
(Recommended) Forged Rods/Pistons
ARP Head Studs: $300 (Advised)
ARP Main Studs: $227 (Suggested)
Optional water/methanol kit: $650-1,000
Most LS fans believe that once you exceed 550 horsepower on a turbo LS1 build, the bottom end is on borrowed time. The cast aluminum pistons and rods are the weak spot of the LS1 crank, which is rated for roughly 800 horsepower. There aren’t many stumbling blocks in this horsepower range, either. As a result, forged rods and pistons are suggested to future-proof your turbo configuration. Having said that, there are plenty of turbo LS1 owners that are pushing 600 horsepower on factory internals. There is just no guarantee of dependability. Installing an LS1 meth injection kit, which can dramatically reduce your LS1’s internal temperatures and prevent detonation, is one approach to mitigate this.
While the rotating assembly can bear the pressure, a quality set of head studs and main stud bolts are a worthwhile investment to guarantee the rotating assembly moves as little as possible.
You’ll also need to worry about fueling. When you reach 600 horsepower, you need replace both your fuel pump and injectors. Most LS enthusiasts advocate at least a Walbro 255 fuel pump, which is near the end of its useful life. They also propose 36 pound injectors, the most frequent of which is the FAST 36lb (Part # 303608). Racetronix 42lb injectors can also be utilized if you need more room to grow.
LS1 with 800-850+ Horsepower
$100 for Performance Valve Springs
$700 for 1050cc injectors
Fuel Pump Upgrade: $500-800
E85 Flex Fuel Kit costs $300.
$1,500-3,000 for forged pistons and rods
Heads with high CFM performance (recommended): $1,000-$1,500
The 800-horsepower mark is where some more intensive adjustments come into play. This is true from both a strength and performance aspect. Most LS1 internals will falter as they approach 800hp due to the stress. While I’m sure some folks have done it, running an 800-horsepower turbo system on stock internals is a horrible idea.
Forged rods and pistons are required at this point. That is, if you want to see any longevity out of your turbo LS1. While some individuals will pay top dollar for a set of off-the-shelf Weisco or Diamond-made forged pistons and rods, finding them for your specific build might be tough. To work with your build, custom pistons may be necessary, which can be pricey.
Many turbocharged LS1 owners choose to install a more aggressive camshaft engineered to work well with a turbocharger in order to genuinely push enormous horsepower figures. It is critical to consider the accompanying mods when switching in a larger LS1 cam. To prevent valve float caused by high RPMs, valve springs, for example, will need to be replaced with high-performance ones. Furthermore, the factory LS1 exhaust valves should be replaced with ones that can survive a wider temperature range.
When it comes to high-horsepower LS1 engines, fueling is another important factor to consider. To keep up with the demands of the turbocharger, your LS1 fuel system will require larger injectors and either a larger in-tank fuel pump or pump booster. For 850+ horsepower LS1s, 42 lb+ LS1 injectors combined with higher octane E85 gasoline is a solid combination.
5.7L Chevy LS1 Turbo Kits That Work
Due to the fact that the Chevy LS1 is approaching 25 years old at this point, new LS1 turbo kits are hard to come by. As a result, many users prefer to assemble their own bespoke turbo kit. With that being stated, there are several great choices on the used market that can be found on LS1, C5 Corvette, and general Chevy LS forums.
New LS1 twin-turbo kits are much more common than LS1 single-turbo kits. There are also some new twin-turbo LS1 kits on the market. In the following section, we will highlight certain kits. The majority of the new LS1 turbo kits do not include a turbo. You’ll have to find your own. There are also some common turbo flange and turbo compressor wheel diameters, which we shall discuss when we go over the specific LS1 turbo kits.
Turbocharger kits for the LS1 can cost anything from $4,000 to $10,000. It all comes down to the manufacturer, build quality, included parts, power capability, and chosen turbo/turbos.
1) Huron Speed Twin Turbo C5 Corvette Kit
550-1000+ horsepower rating
In no uncertain terms, we’ll begin this list with the greatest LS1 turbo kit available. That is also not always a single person’s subjective opinion. When it comes to user reviews, no other LS1 turbo kit has the street cred that the Huron Speed LS1 Twin-Turbo kit does. When it comes to LS1 turbo kits, whether to go with a single or twin-turbo layout is primarily a matter of personal opinion. While massive single turbos are frequently more efficient, twin turbos save a bit more engine bay area while spooling somewhat faster or at the same speed as a single LS1 turbo. The kit’s high-quality build materials, as well as its upgradability, have received the majority of the praise.
While the base Huron LS1 turbo kit does not include all of the necessary components out of the box, you will need to make some critical options on their website before acquiring the kit. The Huron LS1 kit is available with 19 different turbo choices. They range from VS Racing 6766 T4 0.81 a/r turbos to Precision PT6870cea Gen 2 turbos. These turbos cost an additional $1,295 to $4,000 on top of the $4,249 original price of the package.
Huron offers an intercooler, wastegates, BOV, a boost/vacuum reference kit, a boost controller, and even a meth injection kit in addition to turbo options. Hands down, the Huron has the best customisation for new LS1 turbo kits. Finally, the Huron LS1 twin-turbo kit has been reported to be trouble-free to install and run on the street/track.
2) GM LS1 PTK Turbo System
Price: $4,199 – $5,999
HP rating: 550-1,200 hp
If you’ve ever visited the “Forced Induction” section of any C5 Corvette forum, you’ve probably heard of the PTK GM LS1 Turbo kit. It also makes logic. For a while following its release, the PTK LS1 turbo kit was the benchmark for LS1 kits. In its higher trim levels, the PTK kit includes everything you need to get started with an LS1 turbo system. At least when it comes to turbo hardware. Because the kit does not include a handheld LS1 tuner or other tuning solution, you will need to look into those separately.
The PTK LS1 turbo kit includes a Tial wastegate and BOV, all necessary hardware, and silicon hoses in addition to the 304 stainless steel and coated hot side piping. They also allow you to choose the turbo size and intercooler separately, as well as the turbo options. That being said, the base turbo kit is only available with an MPT-70 Turbo with.96A/R, which will suffice for the majority of LS1 owners.
PTK LS1 turbo kits have exceeded 550 horsepower on a completely stock LS1 at moderate boost levels. With no fueling or exhaust adjustments, that is normally the low end of the PTK LS1 kit’s performance. As previously stated, finding a brand-new PTK kit for the LS1 can be tough. As a result, you’re more likely to find one listed on any number of GM forums.
3) Twin-Turbo LS1 Turbonetics T4 Kit
500-1,000+ horsepower rating
To round up our selection, we’ll suggest a popular low-cost choice. This kit may be suitable for individuals who already have some LS1 turbo parts lying around. While Turbonetics is best known as a “Ebay” turbo kit business, their LS1 turbo kit has received surprisingly positive feedback. Turbonetics turbos have a solid reputation among LS enthusiasts.
The Turbonetics T4 Twin-Turbo system includes two Turbonetics 68AR turbos, each of which produces 600-700 horsepower. While this is not proven, this kit has the potential to produce a lot of power. One of the most common complaints about Turbonetics turbos is that they blow oil seals. It is stated to be a “when” problem rather than a “if” problem.
The Turbonetics LS1 Turbo Kit’s pricing may surprise you, especially when compared to the other kits on our list. There is a major reason why the Turbonetics LS1 kit is so inexpensive. This is due to the fact that the kit does not include an intercooler, turbo manifold, manifold flange, downpipe, or intercooler pipework. Doesn’t that make a lot more sense now? Overall, this kit is perfect for someone who already has a collection of LS1 turbo kit parts. Alternatively, most of the missing parts from the kit can be obtained from other sellers.
Summary of the Chevy LS1 Turbocharger Kit Guide
A Chevy LS1 is a decent choice for turbocharging out of all the engines available. The LS1’s unrivaled strength, wide range of turbocharger options, and supportive aftermarket community make it an ideal candidate for a turbo kit. It’s no secret that the LS1 can handle a lot of horsepower right away. In truth, there are several 500-600 horsepower turbocharged C5 Corvettes on the road with minimal modifications. Many people are drawn to stock high-horsepower LS1 builds. However, it is safer to play it safe and match an LS1 turbo kit with quality supporting mods that will increase reliability and extend the life of your engine.
New LS1 turbo kits can be difficult to find. This is due to the LS1’s age, which is approaching 25 years. Having said that, there are a few go-to solutions in the LS1 community. These kits have been tried and tested with positive results. The Huron Speed C5 Twin-Turbo kit and the PTK GM LS1 Single Turbo Kit are both excellent choices that are well-liked by the LS1 community. If you can’t locate anything new, keep an eye on the forums. One is bound to appear at some point.