Saturday, May 19, 2018

Project CRS Part 4 - The Engine

After throughly checking the chassis and frame of the car (Part 3 of this series), Ochiai-san moved on to the engine.

This, again, is an area where I had no concerns whatsoever, since the car had just been at NPTC for maintenance few months back. Not only Yamada-san, one of the master mechanics, had fitted a new timing belt, water pump and thermostat, but also changed several hoses and parts that are prone to time out. After running a full diagnostic I have peace of mind that the engine is in great shape.

We didn’t run any check this time, but moving the car in the workshop area, revving it a bit and listening to the exhaust noise was enough for Ochiai-san’s well trained eyes and ears to give the engine a clean bill of health. He did, however, show me the results of recent inspections of customer cars, where a malfunctioning turbocharger was detected by analyzing anomalies in the airflow voltage. Specifically, significant discrepancies were measured between the front side (top purple line) and the rear side (bottom green line) of the airflow intake.

When decreasing (yellow arrow) the rear side quickly drops, while when increasing (red arrow) it struggles to keep up. Once fixed you can see both front and rear keeping up with each other and being perfectly synchronized. These results were also published on Nismo blog few weeks back - I always enjoy learning new things.

But why check the engine if a new one will go in? Great question that deserves a few dedicated posts in the future. I do have a dilemma though, and Ochiai-san surely didn’t help much as he said “I know you want more power, but you should seriously think before replacing this engine - it’s quite special”.

This definitely struck me (especially coming from somebody who is technically supposed to “sell” me a new engine) and I couldn’t help to think he is right. Although the final power output is no different from a standard RB26, the N1 engine is much more than a calibration exercise and a gold colored cam cover. Nissan developed a significant amount of new components for the N1 spec, including testing in the Super Taikyu series and the Nürburgring 24 Hours. I think it’s truly a defining component of the car and I need to find a way not to lose its spirit in my project.

Omori Factory doesn’t offer tuning services outside the three standard packages currently on sale: F-sport, S2 and R2. For example, they won’t fit R35 injectors or R1 turbines on a standard RB26. Very Japanese. At the same time, these engines also are quite a few years old and I am on a mission to find out what (or if) replacements are on their way. Maybe a R3 is in the works and it’s worth waiting a bit longer? Given that Nismo has shown no signal of slowing down in developing new parts this is a scenario that I would not exclude.

After all, at Nismo Festival 2016 an Omori Factory representative confirmed that a new BNR34-based democar was in the early conceptual stages, this time more focused on street usage rather than circuit, since less owners are tracking their GT-Rs nowadays. Nothing has surfaced yet, but I’m also not sure that this is in line with my vision of achieving full-on ultimate performance. In the meantime I’ve been keeping myself busy reading and researching the history of Nismo engines, aiming to find the best option that would fit my project.

I am also planning another visit to Omori Factory in June for some more consultation and to gain new inspiration for my car. Any suggestion? Please feel free to leave a comment!

Until next time.

16 comments:

  1. Hey Ale, do you have a link to the aforementioned Nismo blog?
    I suspected its in japanese though, so google translate to the rescue? ;-)

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  2. Sure, here you go!

    https://ofblog.nismo.co.jp

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  3. I Think i would keep the NUR engine in storage and buy a new one from Nismo for this project if i had the finances.

    Chris.

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  4. AFAIK the "R1 turbine" is actually the R34 N1 turbo. The R2 engines are not too different from an R34 Nur engine, some tweaks like head gasket, cams, injectors, etc... but not all that different.

    Personally, I think the Nismo engine builds would not be cost-effective. You may as well keep your current engine and do a few minor bolt-on modifications (that can be easily reverted) and turn up the boost with an ECU tune.

    The Nismo air inlet pipes are a good idea to reduce turbulence/turbo shuffle on the way into the compressor. If you really want to throw down some money the Nismo plenum would fix the lean cylinder 6 issue too. Maybe an intercooler upgrade if you find intake air temperatures are getting too high from ARC or Nismo. Nismo also has their complete Weldina NE-1 exhaust, tons of other options out there. R35 injectors + Nismo or comparable fuel pump for fuel delivery, R35 coilpacks to avoid misfire issues, R35 MAFs to meter the extra air, Haltech ECU to run everything. You could probably get up to 450 HP without a ton of trouble this way.

    All of this would be easy to revert as well, you shouldn't have to cut up anything or open up the engine. I believe the Supertec R35 coil conversion requires you to trim the cam cover to fit but you can probably find a spare and paint to match your current engine.

    I wouldn't really know where Nismo plans to go for an "R3" though. The obvious route is intake-side VVT to seriously improve response and emissions but I don't really see this happening any time soon.

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    1. Let’s wait and see: I have time to think about this throughly and I think I can find the best option for my needs.

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    2. This is definitely one aspect that is worth researching obsessively. To better understand these things I actually started tuning engines myself to understand things like what features are important in an aftermarket ECU and what can go wrong with an engine build. I would say it is best to avoid modification for the sake of modification though as the more things are changed the harder it is to ensure OEM-like driveability and reliability.

      For example, tubular exhaust headers are almost always going to crack and cause exhaust leaks in response to heat due to oxidation and thermal cycling. OEM is far more durable as a result due to their use of thick castings without any welds.

      Another example of the problem I'm talking about is aftermarket ECUs. DCD seems to be a big fan of deleting the AFM/MAF sensors, but with ITBs such an approach will actually hurt the driveability of the car as fueling at initial throttle (~1 to 15% throttle) will be extremely hard to get right all the time. A lot of ECUs for the RB26 don't actually support the dual MAFs of the RB26, among other issues like properly reading the Nissan CAS sensor which is extremely high resolution. The Link G4+ is rather notorious for requiring a crank trigger kit on the RB26 even at stock rev limits.

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  5. I apologise in advance if I missed a part of your blog about this, but I just have to ask; by CRS you mean you're having it converted (not sure if this is the right term) to Clubman Race Spec, including the Z-tune like aero, down to the Nismo Lmgt4s? If so, that would be very awesome.

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    1. Hi, thanks for stopping by! Yes, the car will receive the full Nismo aero upgrade. More details to come soon.

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    2. Wow I must say congratulations, your car will surely turn out to be more awesome than it already is!

      As a regular reader of your blog and also of Speedhunters, I'm pretty sure your R34's transformation to a CRS deserves project car status on SH, just like Mr. Aki's R33 is.

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    3. Thanks for following the blog!

      Well, Speedhunters has already covered the CRS in a dedicated post...also I’m not sure as the content might overlap since I’m already writing here. But who knows...maybe something will come up in the future?

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  6. Doesn't the R2 engine use the N1 block as a base anyway? I'm assuming you're not considering S2 because you mentioned in an earlier post that the S2 is more useful if you own an R32 or R33.

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    1. Actually both S2 and R2 engines use the N1 block and they can equally fitted on all three Skyline generations. None of them is specifically suited for one model: the basic difference is that the S2 is more street focused while the R2 is a bit more track oriented. So, it really depends on what character you want to give to your car.

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  7. Initially, I support your decision to do CRS conversion on your car. But that sentence of this being a special engine also hit me. I'm on the fence about seeing your getting done now.

    It would be cool to see go through it, but also sacrilege since it's so rare. But then again, doing it and driving it matters the most. Hoping to see the Updates this June!


    PS. Can you do a post about the whereabouts of the Midnight Purple III Z-Tune, I'm GTR fans and geeks would love to know it's origins and it's current owner and state.

    Keep it up! Always a fan of your blog. Greetings from Thailand.

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    1. สวัสดี! Thanks for stopping by!

      From what I have heard from the guys at Omori Factory the Midnight Purple III Z tune is not in Japan anymore, so unfortunately looks like the chances of spotting it are quite low...

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  8. hey there,
    do you have any info on what the f-sport spec is?? It seems pretty rare, I don't think I've ever seen anyone online with one while S-tune and R-tune cars do pop up on forums from time to time.
    thanks

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    1. Hey there! Yes, I did write a dedicated post to this engine, here you go:
      http://www.bnr34gt-r.com/2017/06/nismo-works-special-f-sport-engine.html?m=1

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