The CT20b is ceramic twin entry turbocharger that is one of the most sought after upgrades for the 3S-GTE engines in MR2’s and Celica’s, it came standard on all GEN III 3S-GTE motors and can usually be found from wreckers for around $800 used. The CT20b is designed by Toyota and manufactured by Hitachi which limits the amount of people who are able to work on them, If you are looking to rebuild a CT20b there is not much point unless you are doing a high flow as the re-builder will generally replace the ceramic wheel and shaft with steel ones, and by removing the lighter components you taking away what makes it spool faster.

The CT20b has a working pressure of 11.9 – 16.7psi which is very similar to the CT26 but still higher, the main advantage of using a CT20b over the CT26 is that the CT26 has a steel shaft and wheel where are the CT20b uses ceramic. Due to a revised and more efficient compressor wheel the CT20B will spool slightly slower but has more top end gains and although the ceramic is lighter and spools faster it is severely weaker than steel. The CT20b will hold boost right through to red line where as the CT26 starts to drop off at about 5500rpm, Max boost on a CT20b is 18-19psi but that is well outside of the efficiency range of the turbo and being over its limits it increases the chance of breaking the wheel and snapping the shaft. The Fensport website actually publish that the series one of the CT20b all have the common problem that the turbine shaft is prone to cracking.

The CT20b is rated at 400hp which is close to 280-300 rwhp so all in all it’s a excellent bolt on upgrade as 15-16 psi is approximately a 37 percent power increase over stock which is perfect for those who prefer a mildly worked street-able car. But if you are planning on doing some extensive upgrades like ECU and cams then I would not recommend it due to the fact that the CT20b technology is 15 – 20 years old now and if your going to pay near $800 you might as well get something a bit bigger.

RRP $800

Tech Specs

I have to say that the CT26 is one of the most misunderstood turbochargers in the history of turbos, it is brain teaser to figure out but is not as complicated as a rubix cube.

Most people steer clear of them because they run out of puff and just become a hair dryer after 15 psi and pump out nothing but hot air, But for Toyota’s complete in house design it’s not such a bad Turbocharger seeming how it will shit 300hp up the wall easy, even compared to the Disco Potato. As far as reliability goes it will out last and engine it looked after and common failure is popping a oil seal which is a quick fix anyway.   There are three different types of the CT26, there is CT26 from the Toyota Supra, Cressida and Soarer which has a steel wheel, is single entry, has different mounts for the wastegate, Then there is the CT26-a from the MR2 and Celica GT4 3SGTE engines know as the twin entry. First of all twin entry does not mean that the Compressor wheel has two sets of blades because thats normal, it mean the tubing inlet flange is split down the middle, why? so the gas flows across the rear of the Turbine wheel evenly.

While not being the most effective means of spooling, it does however keep the wheel temp a bit lower, which will help if you own a Import 2nd GEN 3SGTE as some had ceramic wheels. Factory wastegate for 89-93 is 8.5psi to 10psi, these are water and oil cooled and the shaft float in a coat of oil in the sleeve bearings.

Spooling is slightly better on the Supra’s CT26 as the single entry housing has a better design, but if you own the CT26a with a ceramic wheel spooling is also good with a decrease of lag, only issue how ever is how do you feel about a shattering wheel at 140,000rpm, not friendly, all variations of the CT26 have and internal wastegate , dump pipes are also different patterns and watch out for the ct26′s being sold cheap on E-bay as they list MR2 and Celica but turns out the only fit supra’s and land cruiser.

As far as upgrade goes for more top end boost clip the exhaust wheel but you will sacrifice a bit down low, and if you wish for that extra puff above 15psi a common mod is to fit Garrett T04e compressor wheel and re-bore the comp cover to end that struggle after 6000rpm (who seriously goes that hard all day long anyway), it’s not as good as a T4 but you will see a nice gain up to 16-18psi max, some people go a higher trim but this has had bad experience with shaft snapping and is also dyno proven to be more lag yetmore efficant by 3% for the 60trim. For anyone who thinks the ct26 isn’t that great, think of any other 2.0 twin cam engine like the 3SGTE that was produced in early 1990s erra that runs just as good, only other car being a SR20 which was garrets turbo anyway, So at the end of the day if you want to run up to 15psi keep your CT26, if you want 15-18psi High flow it with a Garrett T4 wheel, or for up to 15psi with a quicker spool get a CT20B, And when you are ready to upgrade to a larger turbo you would want to get some internal work done and a programmable ECU, cus there’s been plenty of engine’s blow to a CT26 and high boost.

CT26a RRP: $350 – $800

Tech Specs