Lexus had been sticking it to the German luxury boys for nearly a decade by the time the first generation Lexus IS300 debuted in US showrooms. The Lexus IS300 (produced between 2000 and 2003) continued the brand’s commitment to dependable luxury. The original LS400 may be described as a land yacht, but the IS300 brought a more athletic vibe to the lineup.
Although the IS300 boasts other notable performance attributes, the 2JZ-GE engine’s 217 hp and 218 lb-ft of torque were the main draw when it first hit the market. In the N/A MK4 Toyota Supra, the motor became recognized for its outstanding strength and power potential, thus it should be instantly recognizable. Even then, 218 PS isn’t exactly awe-inspiring when it’s generated by a normally aspirated engine. The capability is present in some minivan models. However, when upgraded for speed, the Lexus IS300 becomes a completely other animal.
We have already established that the 2JZ-GE found in Lexus IS300s manufactured between 2001 and 2003 is one of the most powerful engines available. Forcing something into existence is where forced induction comes in. One of the best ways to add about 150–200 horsepower is to install a turbocharger on your IS300. Adding a turbocharger to a 2JZ-GE IS300, on the other hand, is an expensive and time-consuming endeavor. Read on to learn about available IS300 turbo kits and what it takes to turbocharge your vehicle.
How Much Power Can A Turbo IS300 Handle?
The first question that comes to mind when contemplating a turbocharger upgrade for your Lexus IS300 is how much extra power the 2JZ-GE will produce. As every knowledgeable Toyota fan knows, the 2JZ’s cast-iron block and aluminum head can take a lot of punishment before showing signs of wear. However, the 2JZ-GE in the IS300 differs slightly from the turbocharged 2JZ-GTE in the Supra, and these variances do affect the maximum horsepower statistics of an otherwise stock engine. The internal components of a 2JZ-GTE are better suited for forced induction due to minor differences in the compression pistons, head gasket, and forged piston rods.
Even if the 2JZ-power GTE’s numbers are through the roof, you can count on a stable 350–400 hp with the standard internals. Adding more pressure to already highly pressurized cylinders is a recipe for disaster, therefore the IS300’s greater compression ratio is the key limitation on creating extreme power. Without GTE rods and a GTE head gasket, together with other supporting changes, the conventional wisdom holds that 7-8 PSI of boost is the upper limit of the ceiling.
With a good turbo kit and some simple supporting mods, an IS300 can reliably run 350-400 horsepower without putting in a ton of work or spending a ton of money. When the mileage reaches 450 or higher, extra, and expensive, measures must be made to ensure the engine and transmission remain in working order.
Turbo Lexus IS300 Upgrade Considerations
It’s crucial to know what parts are included in an IS300 turbo kit and how they’ll work together before deciding on the first one that catches your eye. Size and construction quality are important considerations when shopping for a turbo, as not all models are identical. In addition to the turbocharger itself, you’ll need to give some thought to necessary supporting adjustments and a good tune. Your IS300’s condition is also important to think about, as the first generation IS300 is getting on in years. The 2JZ-GE may be a sturdy motor, but it doesn’t make it bulletproof.
2JZ-GE IS300 Turbo Sizing
When assembling an IS300 turbo setup, it’s crucial to pay attention to turbo sizing. The amount of horsepower that can be produced through forced induction and the means by which that power is transmitted are both affected by the turbo’s size. There is a big gap between, say, the power output of a T3 and a T70 size turbo. There are other factors to think about besides whether or not the power output and boost levels can be increased with a larger turbo.
The most frequent turbocharger sizes for the IS300 are the T3 and T4 varieties. On the whole, T4 flange turbos are used in the aftermarket IS300 turbo kits. The sweet spot for T4 turbos is between 300 and 350 horsepower. T4 turbos are bigger than T3s, but they have a shorter spool time, making them suitable for a daily-driven turbo IS300.
Though more power may be extracted from a large T70 turbocharger, the boost characteristics aren’t optimal for a street-legal turbo IS300. When using a turbocharger with a turbine diameter of T70 or greater, boost latency is magnified at low engine speeds. Some folks can’t bear the lack of low-end response that comes with slower spooling turbines. A larger turbo is the best option if you choose top-end power over low-end drivability, but this comes at the expense of acceleration. The horsepower of an IS300 equipped with a T70 turbocharger can be increased to far over 450. Of course, you’ll need to improve the internals of your 2JZ-GE, as well as the fuel system and any other changes that support it.
Turbo Lexus IS300 Fuel System
When it comes to turbocharging a 2JZ-GE, the fuel system is an essential supporting system. Adding a turbo to the mix increases airflow, therefore your fuel system must adjust accordingly. The basic IS300 fuel system can handle a turbo application up to a certain limit, however turbo IS300s with more beyond 300 horsepower will require fuelling changes.
You should give a more powerful fuel pump serious consideration as the most crucial modification. Walbro 225 fuel pumps are the most popular modification since they can handle up to 500 horsepower at the crank. Depending on how wild you want to get with your turbo IS300, you may also need to upgrade the fuel pressure regulator in tandem with the gasoline pump.
When considering forced induction, it is generally agreed that factory IS300 injectors are subpar. Only about that much power can be extracted from the stock injectors (260-290cc). Rule of thumb: 1cc is roughly equivalent to 1rwhp. Accordingly, bigger injectors are required for power in the 350-400 hp range. The turbo IS300 community favors 440cc injectors since they are affordable and widely available.
Turbo IS300 Engine Management System and Tuning
One of the most critical steps in successfully turbocharging an IS300 is achieving the optimal tune. The IS300 has a poor reputation for being easy to tune. The stock ECU is picky about what it can tolerate when a piggyback tune is installed. Even though turbo IS300 applications can utilise piggyback components like an S-AFC, the majority of the turbo IS300 community does not believe it is worth the hassle.
The other feasible choice is to replace the IS300’s original ECU with a modified or aftermarket version. A PNP wire harness adaptor is also required when using a replacement ECU. That will open the lines of communication between the new ECU and the IS300’s auxiliary systems. The new ECU can coexist with the original IS300 ECU thanks to several PNP adapters. This is required for IS300s equipped with automatic transmissions because the factory ECU is unable to control such a transmission.
If you’re looking for a replacement IS300 ECU, go no further than the AEM Infinity IS300 506. It includes built-in engine protection techniques and allows you to fine-tune the air/fuel ratio. Drive-by-wire, cam timing, boost control, traction control, and just much anything else you can think of can be adjusted as well. Because of this, you should talk to an expert who can fine-tune your turbo configuration for you. A good dyno tune is usually not cheap. It is, however, essential if you want to maximize the potential of your IS300 installation.
Best Lexus IS300 Turbo Kits
Alright. At last we reach the juicy bit. Selecting a turbo kit after establishing a financial plan and desired outcomes. This is not an all-inclusive list, and “best” is a relative term. Since the IS300 has been around for over 20 years, turbo kits are becoming increasingly difficult to come by. The majority of the widely used IS300 kits over the past decade or more have been removed from the market. There are, however, a few strong competitors that stand out in their own ways. Accordingly, below are a selection of kits that we think offer an excellent trade-off between those three factors.
1) CXRacing Lexus IS300 2JZ-GE Turbo Kit
No doubt you have already come across the CXRacing IS300 turbo kit in your hunt for information about IS300 turbo kits before reading this post. When it comes to IS300 turbo kits, the CXRacing offering is among the best available. The CX kit for the 2JZ-GE-powered IS300 includes a manifold, downpipe, turbo, and intercooler, which is more than can be said of many other kits. It has everything you could ever want.
The original hardware on some IS300 turbo kits needs to be modified for a proper fit. The CXRacing package does not replace the factory ABS unit. Because of this need for space, the turbo is installed in an aft orientation. The GT35 turbocharger supplied is of the T4 variety and produces between 300 and 500 horsepower. The GT35 has a 0.86 AR housing and a 4″ inlet, making it a fast-spooling turbo for low-end torque.
The direct-fit front-mount intercooler is included with the CXRacing IS300 turbo kit. The intercooler that comes with it is optimized to perform at its best under extreme conditions. Additionally, the front bumper doesn’t have to be altered for the installation to go well.
If you want to add more power to your 2JZ-GE with no effort, the CXRacing IS300 turbo kit is your best bet. This kit has everything you need to get your turbo system up and running without having to go out and hunt down individual components. If you’re looking for a complete kit, you won’t find one of better quality than the CXRacing kit, which costs $2,332.81.
2) DriftMotion 2JZ-GE Billet T04 IS300 Turbo Kit
If you already have a downpipe and intercooler setup, the DriftMotion IS300 turbo kit is a solid choice. The included turbo in the DriftMotion package is among the best available. The exhaust housing and compressor housing of the T04 turbo are both ceramic coated for enhanced durability. Either a regular aluminum cast compressor wheel or a billet 11-blade wheel made from billet aluminum can be purchased separately for the turbo. Because of its durability and resistance to stress, the billet wheel is a fantastic choice for individuals seeking to maximize the performance of their 2JZ engine.
The DriftMotion turbo can be adjusted not only in terms of the compressor wheel, but also the area over radius. The power and torque curves will shift downward in the rpm range with a smaller AR and upward in the rev range with a bigger AR. Adjusting the turbo’s AR also changes how quickly it spools, with lower AR turbos spooling more quickly. Any changes you make to the 2JZ-GE in your IS300 will rely on how and where you set the boost to activate.
Neither the IS300 turbo downpipe nor the intercooler are included in the DriftMotion package. To put it simply, you’ll need to look elsewhere for those parts. In all honesty, that’s not a bad thing, seeing as how most individuals have their own personal tastes when it comes to downpipes and intercoolers. The stock ABS unit must be moved in order to install the package.
3) XS-Power 2001-2005 Lexus IS300 Turbo Kit
In terms of cost, there is no upper limit on turbo kits for any vehicle. However, as evidenced by the XS-Power IS300 turbo kit, this is not necessarily the case. There are indications that the XS-Power kit will perform the job reliably, despite the fact that it is not the most high-end option available. Particularly when operated at moderate to low boost levels.
Trying to find a whole IS300 turbo kit for under $1,400 is a challenge. The XS-Power kit, however, is precisely that. Everything you need in terms of hardware is included. Everything from the turbo to the manifold to the wastegate to the FMIC to the pipes and gaskets to the chargepipe and downpipe. Although the kit comes with many of the components needed to make the IS300 work, some tweaking is still necessary. For IS300 applications, intercooler pipework, for instance, must be trimmed to size. In order to accommodate the huge front-mounted intercooler, the front radiator support will need to be adjusted somewhat.
A safe estimate of 350 hp may be made with the stock 2JZ-GE head gasket. That is, without making major alterations to the underlying infrastructure. For optimal performance and dependability, most IS300 owners who have installed the kit have found that the turbo pressure should be set at roughly 8 psi. Finally, it’s worth noting that some kit owners have complained about downpipe clearance concerns with their vehicle’s firewall. Possible solutions include replacing the firewall or acquiring a new IS300 turbo downpipe.
Lexus IS300 Turbo Upgrade Guide Summary
A turbo is a crucial missing piece that prevents the Lexus IS300 from reaching its full potential. The original 2JZ-GE engine is already quite powerful, but it has plenty of room to grow. Putting forced induction on a 2JZ-GE is a great idea because it is a very powerful engine. The fastest and most reliable way to increase your IS300’s performance significantly is to turbocharge it. Depending on your motivation for increasing your IS300’s output, turbo modifications might be quite pricey. Modest” increases in horsepower in the range of 75-100 can be made without breaking the pocketbook. To the extent that the 2JZ-inherent GE’s constraints are approached, only then do costs begin to escalate.
There are a lot of factors to think about while turbocharging an IS300. Turbo sizing, fueling needs, engine management, and tuning are some of the primary ones. Depending on how well you take care of all of these details, your turbo IS300’s power output and dependability will be set.
There are now three main choices for IS300 turbo kits. IS300 turbo kits are becoming increasingly difficult to find as time goes on. Many of the choices that were once readily available in the United States are now unavailable. The CXRacing IS300 turbo kit, the DriftMotion IS300 turbo kit, and the XS-Power IS300 turbo kit are all excellent choices. CXRacing’s setup is the best option if you’re seeking for a complete package. The DriftMotion package is second to none if you are willing to find your own downpipe and intercooler. For a low-cost IS300 turbo build with adequate performance, the XS-Power kit is a great choice.
