The SR20DET Guide

The Nissan SR20DET 2-litre turbo engine is one of the mightiest four-cylinder engines ever produced. But what makes a 'redtop' version different from a 'blacktop' and what’s the deal with versions having variable inlet cam timing?

In this article we examine the different versions of the SR20DET as used in a range of vehicles...

Bluebird SSS ATTESA Limited

The first production car application of the SR20DET was in this – the humble U12-series Nissan Bluebird (aka Pintara).

Released in October 1989 (for the 1990 model year), the U12 Bluebird SSS ATTESA Limited debuted Nissan’s new all-alloy, twin-cam 16-valve in-line four with a turbocharger hung off the side. In the U12 SSS, the SR20DET runs an 8.5:1 static compression ratio and its ECCS management system (which uses a hot-wire airflow meter and knock sensor) fires a set of four ignition coils and 370cc injectors. The standard turbocharger is a Garrett-based T25G working with a small top-mount air-to-air intercooler and boost pressure is set to around 7 psi.

The power output of the U12-spec SR20DET is 150kW at 6000 rpm and there’s 275Nm of torque at 4000 rpm – pretty comparable with the output of twin-cam 2-litre turbos from other manufacturers. The SR engine is transversely mounted in the U12 and a 5-speed manual or 4-speed auto was offered. All SR20DET-powered U12 Bluebirds are also fitted with a constant AWD system.

In late 1991, the U12-series Bluebird was replaced by the curvy U13-series. For the U13 model, the SR20DET was enhanced to deliver 154kW. There are no obvious mechanical changes and it appears that the U13’s additional 4kW comes from very subtle exhaust, ECU and intercooler changes. Again, the SR20DET-powered U13 Bluebird was sold with the choice of a 5-speed manual or 4-speed auto and all are AWD.

These U12 and U13 engines are readily available at Japanese import wreckers and they are quite popular for conversions into front-wheel-drive Pulsars and NX Coupes.

Pulsar GTi-R

The Nissan Pulsar (aka Sunny) GTi-R employs the most sophisticated version of the SR20DET. The GTi-R engine is also built more strongly so that it can withstand the abuse of Group A rallying.

The standout feature of the GTi-R engine is its quad-throttle induction system. This improves throttle response compared to lesser models which survive with just a single 60mm throttle. Larger 444cc injectors are also aimed into the GTi-R combustion chambers.

Inside, the GTi-R engine has numerous improvements over conventional SR20DETs. The bottom-end boasts piston oil jets, a larger capacity oil pump with a water-to-oil cooler as well as stronger main cap bolts and conrods. The top-end features beefier head bolts, sodium filled exhaust valves, a revised exhaust cam profile, solid lifters, an improved head design and different piston crowns providing a static compression ratio of 8.3:1 (down from 8.5:1). A large T28 turbocharger delivers a claimed boost pressure of 10.5 psi – but we’ve seen a stock example peak at around 13.5 psi... A large top-mount air-to-air intercooler is also employed.

But despite it’s big ‘cooler, upsize turbo, quad throttles and other good bits, the GTi-R engine is not the most powerful SR20DET to roll out of the factory. That is, if you can believe Nissan’s claims...

On Japanese high octane fuel, the GTi-R engine is rated at 169kW at a relatively high 6400 rpm. This runs second to the Japanese S15 Silvia 6-speed manual. But, interestingly, the GTi-R’s peak torque is the highest of any mass produced SR – there’s a very healthy 284Nm at 4800 rpm.

Released in August 1990, the GTi-R SR20DET engine is transversely mounted and comes mated to a 5-speed manual gearbox – there was never an auto trans version.

These are relatively rare engines that fetch a high price at the Japanese import wreckers. But they are bullet-proof little buggers that are well suited for any motorsport application.

S13 Silvia Ks/180SX

One of the most widely available SR20DETs is fitted to the 1991 S13-series Silvia/180SX. The S13 engine has the same mechanical specs as the contemporary U12 Bluebird and so it generates the same 150kW/275Nm. Again, manual and auto versions are available - the biggest difference is the S13 engine is configured to suit rear-wheel-drive.

Interestingly, the 180SX continued production well after the S13 Silvia was axed. In late-model 180SXs (manufactured after 1994), the existing red rocker cover (aka redtop) version of the SR20DET was swapped for the black rocker cover (aka blacktop) version. Curiously, it seems there were no significant changes between the redtop and blacktop 180SX engine and power and torque figures remain unchanged.

S14 Silvia (200SX)

From late 1993, the Japanese market received the S14-series Silvia (aka 200SX) with an updated version of the SR20DET under the bonnet. Again, this late-model engine uses a black rocker cover.

In S14 spec, the blacktop SR20DET uses a completely different intake manifold (with the inlet plenum now mounted above the runners), a variable inlet cam timing system (VCT), new ECU and, as far as we can tell, a T28 turbo similar to the GTi-R. Peak power is increased to 162kW for both 5-speed manual and 4-speed auto versions. Torque stays pegged at 275Nm at 4000 rpm despite the power increase.

The S14 was the first vehicle to bring the SR20DET into Australia. The Australian-spec S14 (badged a 200SX) uses a smaller turbocharger and a more conservative ECU tune. Peak power is slashed to 147kW and peak torque is 265Nm.

Japanese S14 SRs are becoming quite common in the Japanese wreckers and Australian versions (which produce significantly less power) can be found in crashed 200SXs. Go for the Japanese version if you have the chance.

S15 Silvia (200SX)

The SR20DET’s final blaze of glory was in the snout of the S15-series Silvia (200SX) which was released in 1999.

The Japanese S15 with the newly introduced 6-speed manual gearbox offers the highest power of the range. This latest blacktop VCT engine receives a high-flow exhaust, larger 480cc injectors and a revised ECU to crank out 184kW. Curiously, this increased peak output is achieved at the same revs as previously (6000 rpm) but peak torque still remains the same. It’s almost like Nissan was keeping a lid on peak torque to help protect the driveline.

Interestingly, the auto version of the Japanese S15 has considerably less power than the 6-speed. The auto S15 uses essentially the same mechanicals as the superseded S14 and generates 165kW/275Nm.

Meanwhile, the Australian version of the S15 used the same engine configuration as in the S14 – it remains at 147kW and 265Nm.

Production of the SR20DET ceased in 2002.

Avenir/Liberty

One of the least recognised SR20DET-powered vehicles is the Nissan Avenir wagon, which was produced between 1995 and 2001.

Early Avenirs Salut GT Turbos (chassis code PNW10) use the same engine tune as the U13 Bluebird – an 8.5:1 static compression ratio, 370cc injectors, T25G turbo and front-mount intercooler to make 154kW and 275Nm. However, the Avenir version is distinguished by its silver rocker cover and AWD automatic transmission.

From 1998, the PNW11-series Avenir GT4-S and GT4-Z was released with a T28 turbo version of the SR20DET. Power increased to 169kW and peak torque (275Nm) arrives at a low 3600 rpm. Again, an AWD automatic transmission is fitted. The same 169kW/275Nm version of SR20DET was also fitted to the 1999/2000 Nissan Liberty Highway Star GT4 van. Once again, these silver rocker cover engines come attached to an AWD auto trans.

R’nessa

The final oddball vehicle to carry the SR20DET is the Japanese market Nissan R’nessa GT Turbo people mover.

Produced from late 1997, the R’nessa-spec SR20DET delivers just 147kW and 265Nm. Interestingly, this is exactly the same output as the Australian-spec S14/S15 200SX - so it seems logical that both engines use an identical tune. The R’nessa engine comes tied to an AWD automatic trans.

As far as we’re aware, the R’nessa SR20DET is transversely mounted and is suitable for Pulsar and NX Coupe conversions. They are relatively late-model, but these are very rare engines.

So now you know what’s what in the world of Nissan SR20DETs. Stick around – we’ll soon be examining the Nissan RB-series twin-cam range.