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R35 MAF pipe diameter

Blue

By Blue,
in R35 GTR

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Blue Enthusiast

Blue

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OK, I have spent half an hour trawling search results without concluding anything. 

Is anyone able to definitively state the stock MAF pipe diameter for an R35? I am looking at using a single R35 MAF (I assume they have one for each bank, never looked) in another application altogether. It may not even end up used in the final tune of my car.

My ECU has a table of voltage versus grams/sec airflow for a MAF which I like a lot better than at least the early Nistune/Nissan table of MAF percentage that has been kludged back to a HP figure not an air mass, but I have not yet found the pipe diameter Nissan used to validate the data for my setup. Another option would be a HPX MAF as they provide a spreadsheet to scale the output to any pipe diameter you like with the output in various formats, but they cost maybe 50% more than the R35 unit.

I am looking at it for my HR31 track car, which has an Emtron KV8 ECU. I am looking at it for light load use in the tune, blended out to speed density at higher loads, but also to validate data and refine a table related to throttle body mass flow calculations used elsewhere in the ECU and potentially for some turbo dynamics stuff (Data nerd here) 

Fundamental to the lot is knowing what diameter pipe Nissan used so that the MAF table in my ECU matches reality. If I cant define that I will be better off spending the extra hundred bucks or so for a HPX and be done with it.

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https://www.sau.com.au/forums/topic/475557-r35-maf-pipe-diameter/
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Blue Enthusiast

Blue

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I am guessing after a good few days with no response that I am on my own on this one. Pity, but it makes the money on a HPX look like the better option. When I am am aiming to nail down one known good data point in the setup to swing a number of tables off it makes no sense to go guessing. 

I am betting no Nissan dealer is going to be very keen on letting me take the inlet apart on an R35 to find out for myself ?

Edited by Blue
  • 2 weeks later...
  • 3 months later...

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