I have a 86 Na that has been, rebuilt, street-ported and Tb mod by Kevin @ Rotary Reserection. Also with Rb pipe and silencer with split air pipe attacthed, no cats and oem catback. I want to install a aftermarket fuel pressure regulator with gauge. Later I plan on installing a CAI, RB catback, pineapple port sleves,walbro 255 pump, aftermarket billet style fuel fiter with SS lines, crane HI-6S Ign box and a RTEK S4 Na stage 2 ECU upgrade. What should I set the fuel PSI for with my present configeration?

 

You don't need an aftermarket FPR and a fuel pump that will support 400HP when your car won't break 200HP.

 

Are in of the mods I want to perform in the future practical? Any suggestions on improving performance?

 

There isn't much point installing a Crane box. Your stock coils are quite powerful if working properly.

The TB mod really doesn't offer anything on the NA as long as the throttle body was working properly. Once the engine is warm, the tertiary throttle plates are held wide open.

As for the rest of your stuff (CAI, exhaust, RTek), it sounds fine.

 

how about a T2 fuel pump with the aftermarket fuel regulator, and I raise the PSI?

 

If you raise the fuel pressure and go with a pump that flows better at high pressures (like a TII pump), you'll be adding more fuel to the mixture. This is the opposite of what you should be doing. There are a number of NA cars that have gained a decent bit of power by leaning out the upper RPM range slightly. Here is one S5 NA example that's actually posted on Pocketlogger's site: http://www.pocketlogger.com/index.ph...age=2&ecu=S5NA

Stock AFRs: http://www.pocketlogger.com/images/r...o_af_stock.jpg
Tuned AFRs: http://www.pocketlogger.com/images/r...yno_af_mod.jpg

10-11 AFRs on a naturally aspirated engine is excessive, so it's no surprise that the engine responded to a more appropriate mixture.

 

What is a Good Air\Fuel ratio on my present setup? What is the psi rating?

 

Fuel pressure specs are in the free FSM (fuel and emissions section): http://www.rotaryheads.com/PDF/2nd_gen/index.html. Off the top of my head, at zero manifold pressure (vac line disconnected from FPR) the spec is about 34 - 40 psi. That's actually a fairly wide range, but in the real world I've measured 41 psi @ zero pressure.

Click the links I provided and you can see that engine was tuned to the low 13 AFR range at WOT.

 

Don't try to adjust AFRs by altering fuel pressure.

 

How do I do it?

 

The easiest and cheapest way is to use a piggyback like the S-AFC to alter the signal from the AFM, tricking the ECU into supplying more or less fuel. The S-AFC will allow you to adjust the fuel curve based upon throttle position and RPM.