Bolt-on gains on the IS300 have a low ceiling. If you want to get a substantial amount of power out of it, forced induction is the only way to do it.
After all, it comes with the 2JZ, so it seems only fitting that the “baby Supra” should put down some serious power. Of course, like with any car, going from naturally aspirated to turbocharged is going to present its own set of challenges.
Deciding on which kit you want, along with the supporting mods you need to reliably and safely run your build, is a lengthy process. This guide covers the most important supporting upgrades and the best turbo kits on the market.
Supporting Mods
You can’t just install a turbo, do nothing else to the car, and expect it to work seamlessly. Supporting modifications are a must have, and the IS300 is no exception to this rule.
Some of these mods are universal and others are specific to the IS300. Let’s go over them now so you know what to expect when planning a turbo build.
ECU
The engine expects a certain amount of air and fuel in the combustion chamber, and a turbo kit significantly changes those ratios. You need to tune the ECU to adjust to the new ratios.
Be sure to read through the installation guide that comes with your kit. Read through it all, and when you’re installing it, don’t skip a single step.
If you don’t feel like you’re up for the task, there’s nothing wrong with seeking out an ASE-certified mechanic to install it for you.
A popular option is to swap your IS300’s ECU out for an aftermarket unit. Doing this will require a wiring harness adapter.
If you have an automatic transmission IS300, you need an adapter that will allow you to run both your stock ECU and the new ECU at the same time.
Fuel System
If you plan on a build at or above 300 hp, fuel system upgrades are a must. While the stock injectors might do fine until around 350 hp, the fuel pump ought to be upgraded at the 300 hp mark.
As for injectors, many IS300 owners upgrade to 440cc from the stock 260-290cc set. This will be more than sufficient for a 300-400hp turbo setup, but if you push the numbers higher, then larger fuel injectors will be needed.
Valve Body Upgrade
IS300s with automatic transmissions should also receive a valve body upgrade. The stock valve bodies are not designed to handle the higher power from forced induction, so it’s a matter of maximizing both performance and safety.
Additionally, the automatic transmissions are known for having 1st-2nd and 2nd-3rd redline hang, and the upgraded valve body will fix this. Redline hang will reduce performance and make the driving experience much less enjoyable overall.
Transmission Swap
Although we have already pointed out the necessary modifications for automatic IS300s, there is also the option of doing a manual swap.
However, this is a fairly involved process and can cost a couple thousand dollars, so this is really an option for someone who is dead set on having a manual but already has an automatic IS300.
Whether it makes sense to do is up to the individual, and some might even prefer selling their auto IS300 for a manual one. To each their own, as this is not a make or break modification for a turbo build.
Additional Mods
Handling upgrades, such as high-performance tires or upgraded suspension, are also worth considering when adding forced induction.
Coilovers, air suspension, or even simply replacing worn bushings can make a world of difference in your driving experience.
These are not mandatory for a turbo build, of course, but they can only serve to improve your IS300’s handling.
Best IS300 Turbo Kits
Below we’ve compiled a list of the best IS300 turbochargers. They are single turbo builds that can be purchased as a kit.
Unfortunately, some of these kits are no longer sold directly from their respective manufacturers and will have to be bought used or new from an aftermarket seller. However, they are worth including in the list as they are among the best you can get.
XS-Power
Manufacturer: XS-Power
Type: Single turbo
Turbine: T4 67mm
XS-Power Brand’s turbo kit is capable of up to 650 whp. It comes with most of the installation hardware that you’ll need, barring any additional parts such as fuel management systems, boost gauges, etc.
In other words, purchasing the kit gets you the basics, but you will end up needing more parts to get up and running.
Luckily, those extra items can be purchased from the XS-Power, keeping you with the same brand. The turbo can be used safely and effectively for 330 whp at 9 psi on stock internals and fuel injectors.
However, XS-Power recommends that a fuel tuning system is used, and you should always use 93 octane when refueling.
On the other hand, those looking for a higher power build can opt to push the turbo up to that 650 whp level. This will require greater prep work and forged internals to handle the higher output.
Overall, the XS-Power turbo kit for the IS300 is one with a long history and plenty of successful installs. It is a good choice for those who are more budget focused as well.
Turbonetics
Manufacturer: Turbonetics
Type: Single turbo
Turbine: Turbonetics 60-1/Stage V BB, .58 A/R
The IS300 turbo kit from Turbonetics is a true complete kit. It literally comes with everything you need to install and run your new turbo with ease.
In fact, it comes with pre-programmed fuel and ignition management systems, so there is no tuning required to get the perfect balance dialed in.
For the IS300, the kit even includes 380cc injectors, so no need to prep the car with new injectors prior to getting your kit.
While having everything included in one package is without a doubt a nice perk, and pre-tuned systems can reduce costs for hiring a tuner or having to buy other modules, some users have reported these systems to be unreliable.
If you plan on pushing high power (think 600 whp or higher) you are also going to run into the problem of needing bigger injectors and other upgraded internals, making this less of a plug and play kit than it initially seemed.
CXRacing
Manufacturer: CXRacing
Type: Single turbo
Turbine: T4 GT35
CXRacing offers a turbo capable of pushing up to 500hp, with 300hp being its low end. You can also buy the kit without the turbine, in case you prefer a different one or maybe you already have one but need the other components.
This kit is another fairly popular one, with plenty of satisfied IS300 owners having installed it. So you can rest assured that the quality of the included parts is top-notch. Fitment is guaranteed provided your IS300 is left-hand drive.
If you happen to have a right-hand drive IS300, be aware that the kit is likely to pose fitment problems on install. You might be able to modify your IS300, or CXRacing’s parts, but another setup might be preferable in that case.
The included intercooler is specially designed to fit within the stock front bumper assembly without cutting or other modification required.
This is a plus for those who want to maintain as much of the OEM chassis as possible and do not want to go fabricating/cutting away at their IS300.
DriftMotion
Manufacturer: DriftMotion
Type: Single turbo
Turbine: Billet 5962
DriftMotion boasts a turbo capable of producing power in excess of 550hp. Like the others on this list, it more or less comes with everything you need to install.
However, some users have reported fitment problems and had to substitute other aftermarket parts to install it properly. Specifically, DriftMotion claims their downpipe will fit either a 4th generation Supra or an SC300.
No mention is made of the IS300. Their description does state the kit should now fit most right hand drive models, but once again the specific models are not mentioned.
With this in mind, those thinking about going with the DriftMotion turbo setup should be mindful they might have to buy a couple other pieces from separate companies to ensure fitment.
This should not be a deal breaker though, as the kit comes with high-quality components, making it a good setup overall.
Turbo Specialties
Manufacturer: Turbo Specialties
Type: Single turbo
Turbine: T28R
Turbo Specialities provides a kit that includes an injection control unit and fuel injectors.
Their injection control system can add as much as a 20% increase in power in comparison to competitor turbo systems on the market. They claim this is possible with better air-fuel ratios and greater fuel delivery.
Be warned, however, that like some of the other options on this list, you might run into some fitment troubles. It will probably not be a bolt-on and forget about it type of install.
Of course, as enthusiasts, we are often presented with fitment issues and the need for modifications in order to install the original modification.
This has not prevented others from completing their builds, so it goes without saying that easy install out of the box is not the deciding factor when choosing a turbo kit for most people.
Concluding Thoughts
Turbocharging your IS300 is not a simple decision. You have to think about how much power you want to put down and how to make that power reliably.
Installation will probably take a good deal of time and maybe even some finesse when it comes to getting everything to fit right.
For some of the above kits, you can expect that they will not work as is and other parts (from other manufacturers) will have to be substituted.
Of course, paying a specialist to install your turbo for you can expedite the process, but be sure to let them know any possible issues you have learned might come up.
Ultimately, enthusiasts should pick the kit that best fits their goals for the car. If you want a 1000hp build, don’t settle for a turbo that can only handle 600hp, for example.
Do you prefer superchargers or turbos? Let us know by leaving a comment below!