qes78

Dear All,

I've just purchased an adjustable fuel pressure regulator.

I'm curious though, what would be the optimal fuel pressure for a 1993 NA6? Mostly stock cept for K&N cone filter, some plugs and wires, and a free flow exhaust.

Also, I'm not very sure I needed a fuel pressure regulator for a stock miata. Anyone can extol the virtues of having one? And anyone know the pressure that i should set?

olderguy

iTrader: (19)

The stock fuel pressure regulator on the end of your fuel rail is all you need for a non FI car.

zoom2zoom

iTrader: (5)

yeah, the Miata runs rich from the factory, so you are fine with those minor mods.

magnamx-5

iTrader: (7)

well i am gonna slightly dissagree if you lower the pressure a smidge you will lean out the mix and make more power the way you are i would try 37 psi and work out from there, depending on how it feels. Our motors run almost 10-1 in NA form and could benefit quite abit from leaining out up top for more powaah. So just monkeyh with it abit. And BTW a guage onthe return is useless you need one on the feed to tell what the atual pressure is. GL man

Braineack

iTrader: (62)

unless you remove the oem fpr, you arent going to see under 50psi at WOT

qes78

I've removed the oem FPR.
Lean it out at the high rpms?
how low a pressure are we talking about here?

qes78

Another quick question, does having too high a fuel pressure result in higher operating temperatures. I boosted the fuel pressure up to 35psi and i realised that my car was running at around 103 deg celcius instead of the normal 93....this is at a constant speed of 100kmh
turning it back down to 30 resulted in 93 deg again.
I'm running about 16deg of timing...

magnamx-5

iTrader: (7)

well the leaner mix willl make for a more complete burn but cylinder pressures etc will go up as well cuase you dont have the extra heat absorbtion of the fuel. 35 Psi might be a little low you might try 45 -40 and see how it does you mentioned nothing on performance with the different FP. Elaborate please.

qes78

As far as I can tell, there's no discernible difference in power between the 2 settings. The only difference I could tell was that the temperature seemed to rise when I increased the fuel pressure.
and the car seems to take longer to crank and start up.....

92Black&Tan

iTrader: (2)

We were experimenting on the dyno one day when I was taking a baseline on my 1993 car prior to installing the turbo and we leaned out the mixture by tightening the clock spring on the mass air sensor about 7 clicks. We picked up 3-5 horsepower... and it didn't cost anything.

qes78

Thanks for the information.
I'm really getting worried here though, car seems to be running really hot..
Help