joshuaho96

I'm aware that it's a DI motor with VVT + VVL and a number of other changes. My point is that even now when BMW has the option to ship a single turbo for an I6 in their 500 hp+ models they elect to continue with twin mono-scroll turbos instead. Clearly it's not as cut and dry as is being claimed by Andrew Hawkins et al. The RB26 turbo shuffle is a problem but isn't intractable, it seems like much of the problem is related to the twin turbo pipe and the near 90 degree merge. I don't think that alone really justifies the expense and headache of figuring out how to retrofit a single turbo to a motor that never shipped in that configuration.

It matters in the sense that it's easy to hide bolt-on twins when they're crammed under a bunch of heat shields and piping, unless you've really attracted some serious attention for whatever reason nobody is going to be trying to carefully read off what the turbo says to identify it as stock or not. Similarly, no one is going to be opening up an ECU or removing the kick panel to verify that you are actually running the stock ECU. As long as the exhaust gas sniffer says you passed and nothing is clearly wrong it's not hard to pass. Rolling up with a high mount single is going to be a very different story. It's also weird to me that you would make this comparison between being born deformed and the twin vs single turbo choice. Clearly there is still value to twin mono-scroll turbos as seen in the BMW S55 and S58 I6TT engines and they manage a far wider powerband than anything an RB30 is capable of with better BSFC everywhere, higher knock threshold everywhere, significantly lighter weight, and overall much better refinement. Clearly there's something there that is not as simple as single turbo good twin turbo bad. I'm not advocating for cargo cult engineering here but I'd like to know why BMW engineers would elect to go with twin turbos on the S55/58 and single turbo on the N55/B58 when they have the resources to spec a larger single on the higher spec models.

I'm not speaking about what will and won't pass the local emissions laws. As far as most places are concerned the instant you modify anything between the air filter and the last catalytic converter you've failed emissions. But looking at the header design it seems pretty clear to me that the exhaust manifold on a high mount single RB26 is going to have a longer path from exhaust valve to a catalytic converter. Cold start emissions is a big problem with these engines and I'm pretty confident that will make the problem worse. To me that is a problem but YMMV. A low mount manifold could in theory do better but everything out there doesn't look like a good fit for the use case I'm thinking of. Everything else is true if you're talking about a clean sheet design. Single turbos are easier to package, less headaches regarding how to merge the two turbos. Modern engines use twin scroll single instead of bothering with this twin turbo nonsense. But this isn't a clean sheet design, the two paths are bolt-on twins vs a single turbo conversion. The bolt-on turbos are a known quantity and the OEM engineers have already gone through the effort of making sure it meets their internal metrics for quality. A single turbo conversion is just not going to measure up to that if the goal is to play it safe and try and keep it as reliable as OEM, if not more so.

But why bother for such conservative power goals? The HKS GT3-SS turbos are pretty good at modernizing the mid-range of the RB26, the rest is just the limitations of fixed valve timing and low compression ratio that comes with an engine designed in the 80s. I'm not arguing against the logic that a larger single turbo is more efficient and you can run a more modern single turbo to get better response. But I think top mount single raises questions in my mind regarding emissions compliance, long run durability, thermal management, and proper intake design. I think the answer isn't as clearcut as that Motive video makes it out to be. If the only metric of value is how much power the engine can produce across the RPM range then the answer is simple but there are more variables to consider.

Twin turbos make sense if your power goals are something like 300 kw.

Why would OP mention a resistor box then? Sounds like something is interesting there.

Depends on the resistance of the injectors. If they're near stock like 2-3 ohms then you need them. If they're 12 ohm injectors you have to bypass the resistor box.

I was under the impression that the cam signal is not particularly difficult to parse and could be left alone, it was really just the crank signal that was particularly problematic. Has anyone tried running the OEM cam signal + aftermarket crank trigger?

http://www.jimwolftechnology.com/wolfpdf/VG30DETT_CAS_COUPLING_MISALIGNMENT.pdf You need to repair the CAS regardless if you want to run a PowerFC. Also I would recommend keeping the CAS for its actual purpose, which is a cam sensor. The OEM CAS is great at syncing the engine quickly during cranking as it has distinct home signals for each cylinder.

As GTSBoy said if you're planning on modifying the car further you may as well just skip the AFMs. You could put them in a different pipe size to get more power out of them but you will compromise low airflow resolution. Also for single turbo 700+ hp it's worth considering going single throttle body just to run pure speed density instead of ITB blended modes. I think the benefits of ITBs are significantly overstated especially in RBs where torque response, especially in big turbo builds, is entirely limited by the response of the turbo. ITBs make sense as long as you're staying near stock config, at most -9s or -7s and keeping AFMs. Pushing way beyond what Nissan engineers envisioned for the engine means you should think carefully about what should be kept and why.

Check the glove box for any plastic pieces that are relatively loosely held in place. That can often be the source of rattles.

I would recommend the R35 MAFs if you don't plan on going further but I also don't like the thought of using TPS as a load scale ever. Some are more comfortable with that than others.

AFAIK the R32 sills are especially soft. Nissan reinforced them on the R33 and R34.

On a good day in California it costs 3.3 USD/gal for 91 octane, E10. Some of the worst gas in the country, every modern turbo car pulls some timing because of it. On a bad day it spikes to 4 USD/gal, up to 4.5 USD/gal if things get bad.

If the blue R34 really does check out then I would go with that and save some money.

My personal thoughts on the matter is modified cars need to have the right mods. When I was searching for restoration candidates anything with hacked up harnesses, mods that I didn't like were a pass. Stuff like gauge pods, relocating the HVAC to the ashtray, deleting airbags, pods, etc... It really is a matter of personal taste when deciding what the "right mods" are though. You may want these things.

The VSpec 2 is stiffer (irrelevant due to coilovers), the hood gets a NACA duct to help cool the rear turbo and is made of carbon fiber. The rear brake rotors are a bit larger. Personally I would not take a VSpec 2 over the VSpec 1. But rarity influences market value more than functional differences. And the big money is in pure stock, low mile rare variant cars. But the RB26 is frankly a dinosaur of an engine with weak low-end torque. It shows age in stock form, really badly. I also would not consider these cars to be an investment unless you plan to sell in a few years. I am really tired of everyone framing these cars as an investment because they really are not unless you're buying multiple and selling them off. Buying a single car now is just hedging risk, not investing in the hopes of making money. If you want to realize the gains you have to sell the car, which will only happen if it isn't totaled first and you no longer have the car. If you want to have an R34 because you want to drive the thing you can't realize any capital gains from owning one.

Nismo S1 is not much to write home about, it's basically just turning up the boost and some special cams. If you really value special nismo cams then yeah the S1. The exhaust is also not that special, nor is the MFD. Between the two I would pick condition first. Condition above all. Rust is expensive to fix, broken body/trim pieces are expensive to fix. Unwinding bad mods is also extremely expensive, any sign of a hacked up harness and I would walk.

Honestly someone like that needs to be named and shamed, there are way too many tuners out there that won't own their mistakes and have no clue what they're doing. Massive egos abound.

Those are tough to get, try kudos motorsports.

Massive thread bump but I got curious and looked this up a year or so back, the documents are rehosted on this gov site: https://www.regulations.gov/document?D=NHTSA-1999-5507-0015

It is American fueled, there's zero doubt. There are some good aspects. The heritage parts program and a massive revival of the RB26 GT-R aftermarket, a lot of "wobblers" that needed a lot of work to clean up again that would've normally been parted out are now getting restored. Nissan developed an entirely new technology to replicate body panels just for the heritage parts program. For people that got in before all of this happened it's been a great thing for the most part. There are bad aspects though. Yes, there are instagram kiddies claiming their lemonade stand paid for their R32 GT-R but frankly those are surface issues. Those people will get bored and move on to the next fad. The bigger issue is the rise of theft for these cars in Japan. Clean GT-Rs are being stolen from owners in Japan and exported before they have a chance to figure out what has happened. The export-focused companies are also shady as all hell, companies like JDM Expo, Japan Partner, etc are basically buying up rust buckets with blown engines and doing the absolute minimum to get them presentable to sell off to some person at 2-3x mark-up. Even the "reputable" exporters still export cars with crash damage, etc every so often. Companies like Trust Kikaku are also playing games with the parts market, they've had people do videos about how they're trying to "preserve" these cars for normal people but if you go through their yahoo auctions you can easily find parts marked up double the list price in nissan epc data/amayama. There is also the problem of these cars being exported en masse from Japan but I think many of the best examples are kept in private hands in Japan, it is exceptionally rare to see a truly clean R32 or R33 make it stateside and they often command a premium well above what it would cost in Japan. Just my thoughts though as a big dumb american.

How many cam degrees? From the most retarded position you can only advance 30 crank degrees before valve contact happens. Looks like the answer is yes, looking at your cam gear has like 80 degrees of adjustment.

Mines ECUs are kind of notorious for blowing up engines, the Japanese get pretty high quality gas compared to most of the world so they haven't really validated knock maps or anything like that.

https://www.nzefi.com/product/nissan-r35-gtr-mass-air-flow-meter-upgrade-kit/ R35 MAFs are known to be good, just size the tube it's in appropriately for your power goals.