Let me start of by first explaining my background. I am a degreed Mechanical Engineer having graduated from Oregon State University in 2002 with a Bachelor of Science. I have been building and selling parts for the 3SGTE powered MR2 from the time I was a Senior in college in 2000. In that time, I've innovated some of the items that are mainstays in the aftermarket community for the 3SGTE engine and the MR2 in particular. I've built and dyno tested many different configurations of the MR2 and feel I can help guide the new MR2 owner toward their ultimate power goals in as much as my experiences have achieved. I often get asked what is required for making XXX whp and what it will cost. I will attempt to create a guide here that explains the different stages of modification with respect to what parts will be required to achieve the power range that stage is known for. Dyno numbers would be as recorded in uncorrected format on a Dynojet Chassis dynamometer.

Note 1: It is always recommended to ensure that the vehicle is safe and reliable before starting on the path of modifications. Check your brakes, suspension components for wear, check for leaks that may be excessive, and ensure your cooling system is operating properly by performaing a system pressure test and pressure testing your coolant fill cap. Typically trying to fix a car that has a known issue by upgrading a part to an aftermarket part does not solve the problem unless the issue clearly is with the offending original part. Only use Premium 91 or better octane fuel with the 3SGTE engine. JDM engines actually were designed to run on slightly higher octane fuel (94) and may not perform as well with US fuels.

Note 2: The use of these recommendations is solely the responsibility of the reader. It is not recommended to violate any local city, state, or federal regulations regarding your vehicle for any reason. This guide contains no guarantees of the results one may achieve with their engine and car. By reading or referencing this guide, the reader accepts responsibility for any of their own actions, any subsequent issues they may have, and releases Kris Osheim and KO Racing, Inc. from any and all liability associated with the use of this guide.

Note 3: The whp values and times are based on a Dynojet and a 2nd Generation 3SGTE installed in an SW20 MR2.

Stage 0: 160-165whp; 0-60: ~5.9-6.1; 1/4 mile: ~14.5-14.9

Required:

• Stock engine
• Stock turbo
• Stock exhaust
• Stock intake
• Stock intercooler
• Stock fuel system
• Stock ecu
• Stock ignition
• Stock boost control
• Stock clutch
• Stock axles

• Boost gauge -- the stock unit is approximately useless. Fine for stock boost levels of 9-11psi, but if you plan to raise the boost, or simply want an accurate gauge, the aftermarket mechanical units works great.
• Synthetic Oil -- this is a high performance engine. Regular oil changes with high quality synthetic fluids will help to keep your engine running at its best.
• Ensure the ignition components are in proper working order and there are no engine codes present in the factory ECU

Stage 1: 200-230whp; 0-60: ~5.2-5.5; 1/4 mile: ~13.5-14.1

Required:

• Stock engine
• Stock turbo
• Upgraded Exhaust
  Both
  • TKO 2.5, TKO 3", or Single exit R1 exhaust
  • KO Racing Downpipe
• Free Flowing Air intake (Apex'i intake, K&N FIPK, or Cone filter with Vibrant adapter)
• Stock intercooler (Unplug the engine lid temp sensor to have the IC fan run always with the 'key on')
• Stock fuel system
• Stock ecu
• Stock ignition
• 15-16psi with boost controller (Either a manual boost controller, or electronic boost control, bypass the factory boost control)
• Aftermarket boost gauge
• Fuel cut defenser (factory ecus will typically cut fuel at boost levels above 11psi)
• Stock clutch
• Stock axles

• Upgraded ignition wires and plugs should not make a significant difference in the power output, though reliability and longevity of the parts can sometimes vary from one manufactuer to another. If using OEM Toyota plug wires, they should be changed every 6000 miles or when missing occurs (along with cap and rotor). The NGK spark plugs listed in the ignition components section of our website are one heat range cooler than the OEM specification meaning they can handle hotter engine combustion chamber temperatures better than the OEM heat range units. OEM cap and rotor are recommended as being the best units available for the 3SGTE.
• Synthetic Oil -- this is a high performance engine. Regular oil changes with high quality synthetic fluids will help to keep your enigne running at its best.

Stage 2: 250-280whp; 0-60: ~4.5-5; 1/4 mile: ~12.8-13.2

NOTE: This is the stage where the factory fuel system limits will be achieved. It will be necessary to monitor your air/fuel ratio with a wideband O2 sensor to safely approach these limits when raising boost. You do not want to run leaner than 12.0:1.

Required:

• Stock engine
• Upgraded Turbo
  Options:
  • Upgraded stock turbo (46trim compressor wheel, 10 degree exhaust wheel clip)
  • Stock Gen 3 3SGTE turbo (aka CT20b)
  • Street Brawler T3/T4 Turbo kit
• Upgraded Exhaust
  Both
  • TKO 2.5, TKO 3", or Single exit R1 exhaust
  • KO Racing Downpipe (this is not necessary if you purchase a KO Racing turbo kit as the turbo kits come with their own downpipes specific to the particular turbo
• Free Flowing Air intake (Apex'i intake, K&N FIPK, or Cone filter with Vibrant adapter)
• Upgraded intercooler (KO Racing High Performance Intercooler Kit)
• Stock fuel system
• Stock ecu
• NGK 4644 plugs or 2667 Iridium plugs gapped at .028", New OEM plug wires or NGK plug wires
• Either a manual boost controller, or electronic boost controller, bypass the factory boost control
  Boost Level:
  • 18psi with boost controller on the upgraded stock or CT20b turbos (Either a manual boost controller, or electronic boost controller, bypass the factory boost control)
  • 15-16psi with KO Racing Turbo kits
• Aftermarket boost gauge
• Fuel cut defencer (factory ecus will typically cut fuel at boost levels above 11psi)

• 270-280whp is the limitation of what the factory fuel system can produce. If you are unable to achieve this power level safely (as tested on a dyno monitoring the Air/Fuel ratio to be no leaner than 11.8:1) there is likely something underperforming in your factory fuel system, ignition system, or ECU. To go beyond this level you will need more fuel which introduces further issues. The factory ECU can control the factory fuel system quite well, but does not do well controlling larger injectors. Piggyback devices such as the S-AFC are strongly recommended to be avoided on the 3SGTE as the potentially engine killing issues associated with the way these devices "tune" the stock computer are too great to risk.

Stage 3: 300-350whp; 0-60: ~4.0-4.5; 1/4 mile: ~12.2-12.5 on pump gas; 350-375whp; 0-60: ~3.5-4.0 seconds; 1/4 mile: 11.9-12.1 on 110 octane race fuel or E85

NOTE: This is the first stage where the factory fuel system and ecu will be upgraded. It is critical that any engine management system that is fully capable of controlling all engine functions be properly and safely tuned by a competent tuner. Not all professional tuners will match this criteria, nor will all amateur tuners not match this criteria. The purpose of engine management is to get you something you weren't able to achieve with the factory computer. That said, there is little to no reason you should have to sacrifice driveability, idle quality, startup quality (cold or hot), throttle tip in response, or any other feature that is not related to simply making more power. Engine management in it's most basic form gives the ability to control much larger than stock sized injectors and thereby facilitate the capability of making a lot more horsepower (as all horsepower is derived by adding commensurate amounts of air and fuel). Tuning at wide open throttle to make XXX hp is probably one of the easiest parts of tuning, though there is the risk of blowing up or otherwise permanently damaging the engine, relatively speaking this is one of the shortest duration parts of tuning. This component of tuning comprises typically 20% or less of the time required to do a full tune in my experience.

Selecting the fuel system and turbo size at this stage should be done in such a way as to allow you to make the power you desire with some room to spare. In the case of the turbo, selecting the smallest turbo option that will support your horsepower goal will allow for the best transient response and quickest spool relative to your goal in most cases. On the fuel injector side: tuning a set of 680cc injectors or tuning a set of 880cc injectors will not change the effort involved, but the larger injectors will tend to run lower duty cycle and therefore possibly have some benefit in life. Smaller injectors typically will have a better spray pattern than large injectors, but as long as the idle quality is good, there can be negligible difference in the actual injector size from 880-1200 for example. If you, howeever, go to a very large injector, the resolution at idle will suffer and the injector may have so little time to open and close that it will not reliably be able to do so (typically seen with 2000+ cc injectors on 2.0 or 2.2L engines) and will require a higher idle speed (1200-1300 rpm in many cases).

This is also the first stage at which it is recommended to upgrade the clutch vs. OEM. The OEM clutch can handle this power level, but will not have the life or resilience of heavier duty aftermarket options. It is not uncommon to get a couple of drag strip launches at this power level on the stock clutch and then have it haze and go up in dust on the third try. Your mileage may vary. The clutch most commonly selected at this point is the ACT HD pressure plate with either the 6 puck or the organic full face disk. The 6 puck is rated at 499ftlbs, and the full friction disk is rated at 383ftlbs. These are flywheel measurements and given the common disparity between HP production and torque production, it becomes a happy coincidence that typically those torque ratings can be used as a rough guide for the equivalent wheel horsepower maximum the clutch is capable of also. For example: the full face friction ACT clutch rated at 383ftlbs of torque at the flywheel is often good to about 380 hp as measured at the wheels on a chassis dyno.

Required:

• Stock engine
• Upgraded Turbo
  Options:
  • Street Brawler T3/T4 Turbo kit
  • Street Brawler T3/T4 Turbo kit
  • Street Brawler T3/T4 Turbo kit
  • Street Brawler T3/T4 Turbo kit
• Upgraded Exhaust
  Both
  • TKO 2.5, TKO 3", or Single exit R1 exhaust
  • KO Racing Downpipe (this is not necessary if you purchase a KO Racing turbo kit as the turbo kits come with their own downpipes specific to the particular turbo
• Free Flowing Air intake (Apex'i intake, K&N FIPK, or Cone filter with Vibrant adapter)
• Upgraded intercooler (KO Racing High Performance Intercooler Kit)
• Upgraded Fuel system
  • Walbro 255 Fuel pump
  • Wolfkatz Top Feed Fuel Rail
  • Precision 880cc/min Top Feed injectors
  • Top feed injector connectors
• Hydra EMS engine managment system with wideband option minimum
• NGK 4644 plugs or 2667 Iridium plugs gapped at .022", New OEM plug wires or NGK wires or Magnecor wires.
• MSD Blaster SS coil
• Either a manual boost controller, electronic boost controller, or the Hydra EMS boost control option and you will bypass the factory boost control
  
  Boost Level:
  • 18-20psi with KO Racing Turbo kits on pump gas
  • 20-22psi with KO Racing Turbo kits on race gas

• Aftermarket boost gauge
• ACT TM1-HDR66 puck clutch or ACT TM1-HDSS full face clutch

• 22psi is the typical limit of the factory Gen 2 3sgte head gasket. 18-20 psi tends to be the limit on supreme pump gasoline between 91 and 93 octane. If you are unable to achieve this power level safely (as tested and tuned on a dyno monitoring the Air/Fuel ratio to be no leaner than 11.5:1, and knock levels in a safe range) there is likely something underperforming in the engine mechanically, or in the ignition system. It is best to seek out a reputable and experienced tuner to extract the most safe power as your engine combination can achieve. Pushing this kind of power level can be safe and reliable but will likely live a shorter time than 100% stock setups. You will find out the limitations of your stock system when pushing up to this power level more than likely. The factory fuel lines will still be ok at this level with the upgraded pump and injectors. Tuning with the EMS will also allow the ability to do a race fuel tune without changing anything else which should yield 350-380whp at 22psi on 110 octane fuel.