'93 Maxima 5 speed manual, VE30DE, trying to finish my turbo project. Yesterday, I shipped my ECU off to AutoVaughn Performance in Tennessee to get the Nistune install.
I will be running a Z32 MAF and 575cc injectors and 255 lph Walbro pump. I'm "only" looking to make low 300s whp.
My question is - is an adjustable FPR necessary? It seems Nistune would circumvent the need for that, but I want to make sure.
Thanks for any help
Newbie question: do I need an adjustable FPR?
Moderator: Matt
Re: Newbie question: do I need an adjustable FPR?
probably not with the lower flow rate injectors you are using.
sometimes adjusting the FPR helps balance idle mixtures with larger injectors 700+cc's on 2L etc.
sometimes adjusting the FPR helps balance idle mixtures with larger injectors 700+cc's on 2L etc.
Re: Newbie question: do I need an adjustable FPR?
Often people think they need an adjustable FPR when in fact they don't. They can be useful if somebody has injectors that are almost big enough for the job - a small increase in fuel pressure will sometimes get them over the line. Rather than go to the effort and expense of upgrading to bigger injectors. Not to mention the tuning problems that can result. Particularly if they've cheaped out and gone with one of the many drilled out horror stories that are so common these days. "Your solution for difficult tuning, dodgy cold start, rough idle, crap fuel economy, and general poor running". 
Although these days we have a better range of *real* injectors to choose from at often quite reasonable prices.
The other time I've seen a need is when a big fuel system has been fitted and the stock FPR just can't bypass enough fuel to keep pressure under control. In this case an aftermarket FPR will often fix the problem - but not cos it's adjustable, but rather cos it is capable of flowing more fuel. The adjustable part kinda comes along as part of the deal.
They're also handy for making a car driveable just to get it to the dyno. I've sometimes made up a base tune for an ECU on the bench and sent it back. The customer then relies on my base tune to get to the dyno. If the base tune isn't quite where it should be then it can be adjusted using the FPR just to make it driveable.
PL
Although these days we have a better range of *real* injectors to choose from at often quite reasonable prices.
The other time I've seen a need is when a big fuel system has been fitted and the stock FPR just can't bypass enough fuel to keep pressure under control. In this case an aftermarket FPR will often fix the problem - but not cos it's adjustable, but rather cos it is capable of flowing more fuel. The adjustable part kinda comes along as part of the deal.
They're also handy for making a car driveable just to get it to the dyno. I've sometimes made up a base tune for an ECU on the bench and sent it back. The customer then relies on my base tune to get to the dyno. If the base tune isn't quite where it should be then it can be adjusted using the FPR just to make it driveable.
PL