Ultimate Toyota 3SGTE Upgrades Guide

Toyota’s 3S-GTE engine has long been one of the most popular JDM power plants for upgrading and modding. A turbocharged, 2.0 liter inline-four engine, the 3SGTE powered the 1986–1999 Toyota Celica and 1990–1999 Toyota MR2 sports cars. Its stock output isn’t too crazy at 182-260 horsepower and 184-239 lb-ft of torque. However, modified 3SGTEs have been seen to make north of 700 wheel-horsepower after extensive upgrades. While most people’s goals are that gargantuan, the 3S-GTE has shown itself to be a very capable and easy motor to mod. Let’s take a look at what’s required to make anywhere from 200-300+ wheel-horsepower on the Celica, MR2, and Caldina with our Toyota 3SGTE upgrades guide. 

Make sure to check out our other Toyota content, including our 1GZ-FE engine guide, ultimate 1JZ-GTE mods guide, ultimate 2JZ-GTE upgrade guide, and our Toyota 2JZ vs Nissan RB26 engine comparison guide. 

Toyota 3SGTE Upgrades Basics

Before we jump into our upgrade guide, let’s talk a few basics about the Toyota 3S-GTE engine. The 3S-GTE engine code breaks down as follows:

• 3 – 3rd Generation Engine
• S – Toyota S-series Engine Family
• G – DOHC, Twin-Cam Cylinder Head With Externally Driven Camshafts
• T – Turbocharged
• E – Electronic Fuel Injection

It is a 2.0 liter, four-cylinder inline engine that uses a cast iron engine block and aluminum cylinder head. The 3SGTE is a perfectly square engine with a bore and stroke of 86 mm x 86 mm. The valve train is a twin-cam, dual overhead camshaft (DOHC) design with four-valves per cylinder for 16-valves total. All versions of the 3S-GTE are turbocharged, which sets it apart from the naturally aspirated 3S-GE.

Toyota kept the 3SGTE in production for a very long time from the 1986–2007 model years. It mainly powered the 1st-3rd generation Toyota Celica, 2nd-3rd generation Toyota MR2, and 4th-5th generation Toyota Caldina. Depending on the year and model, the engine produced 182-260 horsepower and 184-239 lb-ft of torque. While that is pretty subpar by 2020s standards, at the time the smooth power delivery combined with exceptional handling and light curb weight, made the 3S-GTE powered Celica and MR2 very formidable at the track — especially when the boost was turned up. 

Overall, the engine went through five different generations during its 21 year production span. You can read about all of the different changes in our 3S-GTE engine guide. Mainly, Toyota increased the compression ratio, turned up the boost, installed larger turbochargers and bigger fuel injectors, which upped the horsepower and torque. 

How to Build the Toyota 3S-GTE Engine

There are many different paths you can take when building and choosing the right 3SGTE upgrades. Generally, there are a few areas that you need to concentrate your focus on. Upgrading the exhaust and intake to flow better, allowing the engine to run more boost than stock, and eventually, upgrading the turbocharger, fueling, and engine management systems. By making these basic adjustments, you can transform a pedestrian 160 wheel-horsepower MR2 into a 300+ wheel-horsepower beast. 

Importantly, these power figures are based on the MR2 and Celica with the Gen 2 3S-GTE engines (200-230 horsepower). The newer versions found in the Caldina already make a lot more power than the earlier engines, so expect to make even more with those motors on the stock turbo. 

Maintenance Prior to Modding

Before you begin down your path of 3SGTE upgrades, it’s important to be realistic about the condition of your engine and overall car. Toyota rolled the last 3S-GTE off the line all the way back in 2007. So, it’s been nearly two-decades since the engine was even in production. While it’s not always the case, typically that means most examples will have some wear and tear and possibly high-mileage accumulation. 

At a minimum, if you plan on building out your Celica or MR2, you’ll definitely want to make sure that everything is in good working condition first. That means all fluids on the engine and car should probably be flushed and replaced and their systems checked for leaks. You’ll also want to make sure the engine’s ignition system is refreshed with a new cap, rotor, and spark plugs. Make sure not to overlook any other basic maintenance, like the timing belt and making sure the valves are properly adjusted. 

After you know the car and engine are in good working condition, then you can start setting your sights on potential 3SGTE upgrades. First, let’s see what it takes to make up to 250 wheel-horsepower with the 3S-GTE. 

How to Make up to 250 Wheel-horsepower With 3SGTE Upgrades

Depending on the year, model, and version of the engine, a stock 3S-GTE will generally make 160-200 wheel-horsepower. The earlier models make less than the later ones due to having less powerful turbochargers and smaller fuel injectors. 

Regardless of which version you have, your first step is going to be opening up the exhaust and the intake. Intakes are not nearly as important as the exhaust, but are still worth upgrading. The most popular units are probably the Apexi or K&N intakes. At this power level, you won’t see a ton of benefit from an intake. Earlier Gen 1 and Gen 2 (through 1993) engines can also benefit from an upgraded throttle body turbo inlet. 

For the exhaust, that means a downpipe and full exhaust through the cat-back and mufflers. The downpipe connects directly to the turbocharger and is the most restrictive part of the exhaust. If you plan on staying below 300 wheel-horsepower, you’ll want a downpipe in the 2.5”-2.75” diameter range. For 300+ wheel-horsepower, 3” will be ideal. Anything smaller and your engine will struggle with too much back pressure, and anything larger is unnecessary. For the cat-back and mufflers, 3”-3.5” will be sufficient — and pretty loud.

After upgrading the exhaust and intake, you’ll need to work on running more boost to make more power.

How to Run More Boost

To run more boost, the first thing you’ll need to do is override the stock ECU’s fuel cut. The stock ECU will cut fuel at 12 PSI on ‘86–’92 cars and at 16 PSI on ‘93+ cars to avoid detonation. There are two main options for getting around this limitation. 

You can either install a fuel cut defenser system, or you can just unplug the vacuum hose that causes the fuel cut to happen. The stock manifold absolute pressure (MAP) sensor is what tells the ECU to cut fuel, but the ECU doesn’t use it for any other purpose. So, if you just unplug the vacuum hose leading from the turbo to the MAP sensor (and plug the opening to avoid a leak) it will never activate the boost cut. 

To actually run more boost you will need either a manual or electronic boost controller. MBCs are much cheaper but do not work as well and will struggle in the higher rpm. An EBC is the better option. They still allow for manual boost level control, but are much more efficient. However, they are about 5-15x more expensive. 

Finally, after upgrading everything and getting past the boost fuel cut, you’ll need a boost gauge. The stock gauge is basically useless past stock boost levels, so you’ll need an aftermarket gauge to verify your M/EBC is working correctly. Additionally, a wideband O2 sensor to make sure your air-to-fuel ratio is between 10.0:1 and 11.5:1 under full boost is a good idea. Anything leaner and your engine might detonate and suffer damage.

With these mods and the Gen 1/2 stock turbo running 15-17 PSI, you should be right around 200-250 wheel-horsepower depending on which version of the engine you are starting from. 

Getting to 275 Wheel-horsepower With 3SGTE Upgrades

For those with a Gen 1 or Gen 2 engine looking to get even more performance out of their 3S-GTE, you’ll need to look at a bigger turbo and better intercooler. If you have a Gen 3 or 4 engine, your stock turbo is capable of 275 wheel-horsepower (see next section “Picking Out A Turbo” for more info). 

For an intercooler, you will want something with a larger core and better fan. Since the stock location intercooler has poor airflow due its rear-mount location, many people relocate to a side-mounted intercooler that allows for better natural airflow. Either way, you’ll want something that can flow more air without dropping pressure. Additionally, you’ll also want a good fan to make sure the intercooler is getting the best air circulation possible. 

There are many intercooler options, and KO Racing and ATS are probably the most popular versions. These are all air-to-air intercoolers, which are sufficient at this power level. For those really looking at extreme builds above 400 wheel-horsepower, thinking about an air-to-water intercooler is the next step up. 

Fueling Limitations

The most power you will be able to safely make while still on the stock ECU and fuel system is about 275 wheel-horsepower. Running 15-18 PSI of boost will make your air-to-fuel ratios in the high 11s, bordering on 12:1. That’s extremely lean and is at the point where detonation will occur. At these power levels, detonation can be catastrophic if it is bad enough. 

To be safe, if you are upgrading your turbo you will definitely need a wideband O2 sensor to make sure your AFRs are in the safe range (10.0:1 – 11.5:1) under full boost. If your engine is not able to maintain a safe AFR, you will need to get engine management (see next section) or there is a problem with your fuel system that you will need to solve. The stock ECU can only compensate so much before the engine will begin to run unsafely. 

Picking Out a Turbo

Depending on your engine version, getting to 275 wheel-horsepower on the 3S-GTE may require an upgraded turbo. Importantly, you should figure which stock turbo you’re using before looking into an upgrade. The Gen 1 and Gen 2 engines used the CT26 turbo, the Gen 3 used the CT20B, and the Gen 4 used the CT15B. 

The CT26 will max out around 250 wheel-horsepower, while the CT20B and CT15B are good through 275 wheel-horsepower. If you have a Gen 1 or 2 engine and those are your power goals, a simple swap to the larger turbo will be perfect. You can also get an upgraded stock turbo with a larger compressor wheel and exhaust wheel. There are also aftermarket turbo kits with a T3/T4 flange that will bring you to 250-300 wheel-horsepower on any generation engine, too. 

300 Wheel-horsepower and Above With 3SGTE Upgrades

If you want to crack the 275-300 wheel-horsepower mark, you’ll need three more things: A larger turbo, stand alone engine management system, and a bigger fuel pump combined with bigger injectors. Your downpipe and exhaust will need to be full 3” at this stage, and an upgraded clutch is also a good idea to handle the power. 

For the fuel system, you’ll need a bigger fuel pump (Walbro 255 or bigger), 550+cc injectors (these are stock on the Gen 3 and 4, so those don’t need upgrading until past 300+ wheel-horsepower), and a bored fuel rail if you have a Gen 2 engine. If you plan on running different fuel than pump gas (like E85) or making more than 300 wheel-horsepower, you’ll need larger injectors. Colder spark plugs are also a good idea to keep cylinder pressure down. 

You’ll also need a stand alone engine management system, too. You’ll need this so you can dial in the boost control, air-to-fuel ratios, knock control, and other settings to make the engine run well. There are a lot of different options, including Link and ECUMaster, Hydra, AEM, etc.. 

For your turbocharger upgrades you have a lot of different options. For 300 wheel-horsepower, using an upgraded ATS-built CT16, CT21, or CT27 are very popular options. These can make as much as 350-400 wheel-horsepower on E85. Other options are the KO Racing Street Brawler T3/T4 kit, Mitsubishi TD05 or TD06, and the Garrett GT28RS and GT3071R. These will offer a wide range of power from 250-500 wheel-horsepower with a fantastic power band.

If you plan on going past 350 wheel-horsepower, you’ll need to start thinking about a built engine with forged internals. This means better rods, pistons, and a stronger block. 

Toyota 3SGTE Upgrades Guide Summary

Building the Toyota 3S-GTE 2.0 liter inline-four motor can be a very rewarding experience that nets a powerful motor. Depending on how far you want to go, many enthusiasts have made more than 1,000 wheel-horsepower with the right 3SGTE upgrades. While this might be a bit above the average driver’s purview, these engines are very easy to make 300+ wheel-horsepower with to dominate on the streets. 

When modifying the Toyota 3S-GTE, the main things you’ll need to focus on are upgrading the intake and exhaust, turning up the boost or running a larger turbocharger, increasing the fueling capacity, and eventually, getting a stand alone engine management system. The basic bolt-on mods include a bigger intake, 2.75”-3” downpipe and exhaust, a larger intercooler, and a bigger fuel pump and fuel injectors. 

For the turbos, there are a ton of different options for the 3SGTE. The stock Gen 1 and 2 CT26 turbo is capable of about 250 wheel-horsepower, and the Gen 3 and 4 CT20B/15B turbos are capable of about 275 wheel-horsepower. 

For 300+ wheel-horsepower, using an upgraded ATS-built CT16, CT21, or CT27 are very popular options. These can make as much as 350-400 wheel-horsepower on E85. Other options are the KO Racing Street Brawler T3/T4 kit, Mitsubishi TD05 or TD06, and the Garrett GT28RS and GT3071R. These will offer a wide range of power from 250-500 wheel-horsepower (depending on fuel) with a fantastic power band.

One great example is from the guys at ATS Racing with their CT16 or “Sweet 16” turbo as they call it. With just a stock engine, it made up to 280 wheel-horsepower, and made a monstrous 404 wheel-horsepower with E85 and a billet actuator. Very impressive to say the least and shows how powerful this platform can be. 

FAQ