Uprev; its tuning software that lets us reprogram the factory ECU and fully tune it. Makes a big difference even on a completely stock Z.

There are 3 ways to do it: 1) the DIY tuner version where you do all the tuning yourself, 2) go to a supported shop and have them tune it in person, or 3) do it over email with a tuner who specializes in remote tuning. You just need a windows laptop to upload the files and record datalogs while driving.

 

I just recently started tuning my 2010 Altima coupe VQ about a week and a half ago. It is NA, custom 3 inch long tube intake, 75mm throttle body, upgraded intake plenum, custom test pipes, and custom exhaust. I'm currently at around 290 whp according to digital dyno(did a run on stock map before tuning and it made 230 which is spot on for stock, so I feel its at least somewhere in the ballpark), and my limiting factor is fuel, or so I think. Still have ignition timing left to work with and possibly cam timing, I just do not want to go further without having fuel to add. It has stock injectors, which are the same as the ones in HRs to my understanding. Injectors are at 93% duty cycle at 7200 rpm, running 12.5ish AFR. I have rebuilt the maf table so that my fuel corrections are all +/-5% or so. I've also adjusted the k multiplier up by 15ish percent if I remember correctly(before rebuilding maf, maybe that's bad?) to accommodate for the larger throttle body and larger intake plenum. I've heard many times that the stock HR injectors are good for essentially any NA build/power you are going for. If that is the case, why am I at 93% duty cycle? 3 possibilities I can think of, and am looking for a bit more guidance. One of them is my tune. I'm not an expert by any means, but I feel like I have the basics down well. There's a solid chance I am missing something important in the software or my tuning knowledge. I can upload some data logs or tune files if that helps any of you. Another possibility is I am actually at the limit if the injectors, but that doesn't seem quite right to me. The last possibility is either my injectors are clogging up, or my fuel pump is not putting out as much pressure as it should. Any advice on things to immediately look at in the tune before digging in too deep to the mechanical side? Any advice is greatly appreciated.