Understanding my Nismo Turbo Compressor Map.

Hi everyone.

I will keep it short and sweet. I have a RB26DETT still with the twin turbos. It has upgraded Nismo Turbos. 14411-RS580.

It been quite hard to find information on these turbos due to there age but I have attached all the info I could find.

The Japanese documentation says 300ps x2 and the English says 540ps. Not sure why there is a difference.

I am currently running 1.2bar and love them. I want to know how hard I can push there turbos. This is a weekend car. It's very laggy and I love it like that.

I worked out my theoretical airflow of the RB26 to be 310.75ft/min at 8000rpm.

Am I right in thinking I can push the turbos into a more inefficient compressor island with the downside of creating more heat? The reason I ask this is might not be a bad idea seeing its a street car and I do pull here and there. As oppose to a track car that is constantly under full boost.

Appreciate the help.

The compressor map is for a large turbocharger capable of delivering enough air for 550-600 hp. Are you sure you have 2 of those installed and not 2 smaller ones?

Sadly I found it on a old website. It's likely its a compressor map for a different turbo. I was worried that this might have been the case as there is no writing on the compressor map saying RS580 Turbo.

So my next question will be. How do I find the limits of my turbos? Would I get a reply email from Nismo Japan.

Well, from my experience Japanese sites reply 50/50. To be honest I'm not familiar with Nissan engines much but I would think the answer to your question is well known on Nismo forums - this engine is no stranger to tuning community and there are shouldn't be any secrets left about it. My rough guess is that it would be OK to push stock turbos up to 1.4-1.2 Bar but again, I'm not Nissan expert...

Those turbos are from the Nismo 400R

They are just a little bit different to a normal n1 turbo. I've only had experience with these turbos on one vehicle, and they were flat out at 1.5bar.

You might find a bit more out of them pushing to 1.3-1.4bar, but you would really want to check on a dyno to be able to measure the gain.

To get the most out of any turbo, reduce exhaust restrictions, ensure minimum intake/filter drop and as close to ambient temp to compressor inducer, then AI to increase pre-turbo air density.