Friday, March 31, 2017

Nismo Works Special - S2 & R2 Engines Explained

Lately I have been receiving quite a few messages on the Facebook page inquiring about Nismo works engines, especially the S2 and R2 power-units as well as their predecessors, S1 and R1. There are a lot of myths and incorrect information floating around, so I thought it would be worth shedding some light. Both available for the BNR32, BCNR33 and BNR34, these engines represent Nismo latest offer for RB26 powered Skyline GT-Rs and are engineered following different philosophies.

S2



Developed with road use in mind, the S2 concept is Nismo answer to owners looking for fine street balance and enough performance to enjoy the occasional track day. Based on the older S1 Concept, Nismo went on and refined certain areas, especially in the torque department. Let's go with order: the S1 package is a hand-assembled unit usually based on a overhauled version of the owners current engine; while it is no longer for sale (replaced by the S2), its engineering concept is still used as a base for the newer version. The block is the RB26 OEM standard model: based on conditions and mileage, technicians would decide whether it needs replacing or not. Further my conversations with Nismo staff, unless your motor has less than 20,000km, given the age these cars have reached, they will likely advise to replace the block regardless of its state, mostly for warranty reasons (the engine comes with 1 year or 10,000km coverage). First step in the overhauling process is replacing the following parts with new OEM standard ones:

- Engine block: OEM - Standard (optional)
- Main bearings: OEM - Standard
- Conrod bearing: OEM - Standard
- Water pump: OEM - Standard
- Crank pulley & bolts: OEM - Standard
- Turbochargers: OEM - Standard
- Turbo outlet: OEM - Standard
- Engine gasket: OEM - Standard (overhauled)

The second step consists in upgrading the following part list to a higher spec:

- Pistons: N1 Version
- Piston rings: N1 Version
- Oil pump: N1 Version
- Timing belt: Nismo reinforced
- Oil pan baffle plate: Nismo
- Air filter: Nismo
- Spark plugs: Nismo racing type #7
- Heat-shield tape: Nismo 50mm

The end result of the workflow so far is the older S1 engine concept. The S2 represents the natural evolution of its predecessor and Nismo focused on modernizing certain areas by adding the following parts:

- Fuel injectors: R35 GT-R - Nissan OEM 570cc
- Fuel delivery pipe: Nismo R35 conversion 
- Camshaft: Nismo S2
- Head gasket: Nismo 0.9mm
- ECM: Nismo S2
- Engine cover: Nismo S2 exclusive

A point worth noticing is that, in case the engine is developed for a BNR32 or BCNR33, the turbos would be upgraded to BNR34 OEM Standard with ceramic internals, aiming to improve torque response from low/mid speed ranges.

The camshaft is also specifically designed to balance street-driving smoothness and torque delivery.

The dedicated ECM is tuned to implement the changes brought by the R35 fuel injectors, the new camshaft and bring all together by sharpening the acceleration response. Additionally, Nismo fine-tuned the unit to improve fuel efficiency, expecting S2 owners to spend more time on the road than on track.

Thanks to this upgrades and parts specifically developed for the S2 concept, the engine develops a characteristic linear torque band that makes it easier to use on the street. Below a comparative power/torque graph between S2, S1 and RB26 DETT Standard engines. 



Nismo focused on improving pick-up and response compared to the S1 model, aiming to improve track performance. Final power figures are 450ps and 45kg-m of torque.

R2



Like the S2, the R2 engine is the natural evolution of its older brother, the R1 Concept. As the name suggest, this power-unit is Nismo response to owners who enjoy tracking their car on a more regular basis. Nismo philosophy is based on a fine tuned balance between power, responsiveness and durability/reliability; while the R2 may pale in front of 700ps + set-ups from other tuners, the engineers wanted to create an engine that would allow owners to put their ride through their pace on the track and then drive back home with peace of mind. 

The list of differences between S2 and R2 is noticeable and quite long. Let's start with the R1 Concept base:

- Engine block: N1 Version
- Pistons: N1 Version
- Piston rings: N1 Version
- Exhaust manifold: N1 Version
- Main bearings: Nismo
- Conrod bearing: Nismo
- Head gasket: Nismo 0.9mm
- Engine gasket kit: OEM - Standard
- Spark plugs: Nismo racing type #8
- Turbochargers: Nismo R1 turbo kit
- Turbo outlet: Nismo large capacity type
- Heath-shield tape: Nismo 50mm
- Air flow meter: Nismo large capacity type 
- Oil pump: Nismo reinforced
- Oil pan baffle plate: Nismo
- Air filter: Nismo
- Timing belt: Nismo reinforced
- Exhaust manifold spacer: Nismo

As you can see almost everything is replaced with brand new Nismo parts. Amongst the most noticeable difference is worth noticing the presence of the N1 engine block, the same model originally mounted on the BNR34 Nür spec.

The N1 block is significantly stronger than the Standard one and has been extensively tested during racing in both the Super Taikyu series and the Nürburgring 24h.

The second component that stands out is the R1 turbo kit.

This kit is based on the N1 model with metal internals (instead of ceramic). Made by Garrett, they develop slightly more turbo-lag in favor of higher durability. However, Nismo took things a step further in developing the R1 kit and fitted the N1 base model with higher capacity ball bearings and reinforced actuator attachments to create an even more durable set-up.

The final step to finish the conversion to R2 is the same as the one for S2, but just with a different, dedicated camshaft and ECM unit. 

- Fuel injectors: R35 GT-R - Nissan OEM 570cc
- Fuel delivery pipe: Nismo R35 conversion 
- Camshaft: Nismo R2
- ECM: Nismo R2
- Engine cover: Nismo R2 exclusive

Completely hand-built, Nismo takes pride in assembling the R2 units with a very high degree of precision, aiming to optimal internal crank and pulley balance to deliver aggressive acceleration and peak torque response at lower revs.

Final power figures are 500ps and 48kg-m of torque. 



Nismo engines are not necessarily the most powerful and definitely come with high price tags, but when it comes to total package, balance and pedigree deeply rooted into racing, they are probably the best choice. What they lack in terms of neck-bending power figures, they compensate with OEM quality components, factory pedigree and reliability. With Nismo being an expensive option, it's quite rare to see models with these engines fitted to customer cars. The only tuner that, in my eyes, can compete in terms of allure is Mine's. 

Back in the days Nismo raced a Z-tune prototype at Nismo Festival in a Tuners Battle against all the major names (including MCR and Top Secret) and scored a win in 2000 and a third place in 2001, demonstrating that they can be well at the top both on the road and track.

Until next time.

(Photos Copyright: Nismo)

5 comments:

  1. Awesome article! Can you do a comparison between R2, F-Sport R and Z2?

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  2. Replies
    1. I was thinking the same thing. What is a Nismo oil pump plate??

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    2. Sorry guys, that's a typo! Corrected: Oil pan baffle plate.
      Thanks for stopping by...and the sharp eyes!

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  3. Thank you for taking the time to publish this information very useful! engines

    ReplyDelete