Jump to content
SAU Community

Recommended Posts

Would pay to get the mixtures checked out. Obviously dropping the fuel pressure reduces fuel flow. Wouldn't want to melt pistons due to running lean.

OP this is a very good idea.

If you're in sydney you could ask Johnny to do it, he might even set your fuel pressure properly for a small fee

I have a top mount fuel rail with 750cc injecorts and a plenum waiting to go in Along with a hypergear atr43ss2 turbo z32 afm and a powe fc so i think i may need one when it comes to tuning in the future

I have a top mount fuel rail with 750cc injecorts and a plenum waiting to go in Along with a hypergear atr43ss2 turbo z32 afm and a powe fc so i think i may need one when it comes to tuning in the future

Nope. Don't need one.

yeah what ben said....adjustable fuel pressure regulators were a thing when upgrading injectors was an expensive proposition, you should only ever need a stock regulator if you run the right pump for the right injectors....most if not all injector flow rates are tested at 43.5psi....your fuel pump just needs to be able to keep up that pressure when the injectors open.

i doubt the stock reg will fit in that rail though. forget rising rate too, just set and forget

possible, if you use those EFI Hardware adapters..

I was going to do that, but thought what the heck.. fit an external and have control over the rail pressure.

What is the point of a rising rate reg? something about squeezing more fuel out in the top end or something?

That's right. They kind of had a use when ecu's couldn't be tuned.

Now they have no real use. Get correct size injectors and tune away.

That's right. They kind of had a use when ecu's couldn't be tuned.

Now they have no real use. Get correct size injectors and tune away.

eh?

All fuel regulators are rising rate.. as you increase boost pressure, fuel pressure is increased.. it's only NA cars that just run 3bar (or whatever) when there's no vacuum.

The purpose of a normal fuel pressure regulator is to maintain EXACTLY the same pressure drop across the injectors regardless of what the downstream (manifold) pressure is. So, it doesn't matter if the manifold is in vacuum, at atmospheric, or boosted to 2 bar, if the reg is referenced to the manifold pressure then it will make the fuel rail pressure go up and down with it, maintaining the same delta P. This is desirable because the spray pattern generated and the quality of the atomisation is a function of the delta P.

That could be thought of as rising rate, but it's not really, as it is completely linear. A true rising rate reg will add MORE pressure to the fuel as the manifold pressure rises. As has been mentioned before, this was a common cheat to get more flow out of injectors without ruining the idle and low load mixtures when adding more power.....back in the bad old days.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • I wasn’t able to replicate the sound anymore. It was a one time sound so maybe it was just coincidence but it was like small pebbles being dropped in a coke can.   should I try cleaning the MAF? It could be it’s functioning but dirty? I don’t know.
    • Update 4: Hi all. The car drives again! Haven't driven for long, only to store it in the garage again, but the test drive was successful. The coolant and oil leaks seem to be fixed for now. Temps on the engine were also very good, while moving I never even saw 80C water during the approx. 30 minute drive. Ate up all the coolant in the reservoir though so will have to fill that even more when I go to the car next time. One thing that pisses me off is that the RPM gauge is still f**ked, I even resoldered the board twice and used copper paste on the silly screws that are used as connections. Next time I take it out I'll take apart the board and fit new components, I'll see if I can get a replacement IC for it.  I have an appointment set for 22nd of September for the engine tune to 370hp. Alignment also still needs to be done. My hope is that I can get all the legal stuff over with by the end of this season. Anyone of you have advice regarding intercoolers? Currently there is an APEXI core fitted, one of those weird hybrid ones, 600x270x76. I don't think it's bad but it's not new and now I still have the chance to change it now to legally include it in the paperwork. Only issue is that the only options that would arrive in time are a HKS Type R intercooler or generic Ebay spec intercoolers comparable to a JustJap one. Ideally I'd order a Plazmaman but it takes over a month to receive which would mean making the car legal has to wait until next season. Would love to hear some input on this. Same story for my injectors, the previous owner was a nunce and put ID 1050x on the engine. They work but are obviously not ideal at "normal" power levels. But I don't see a reason to change them unless the tuner says it's necessary. I read online before buying a different exhaust that the top secret style rear diffusers won't fit due to the size of the rear resonators. My buddy and I made it work by slightly "adjusting the shape" of the mounting bracket and making some spacers out of 3d print for the mounting bolts. Fits like a charm. Just putting this here in case someone has this problem. Even the hefty HKS Silent Hi Power rear can fits without hitting anything.
    • Well they got my money but they are not getting my gearbox ! 
    • It's needed for rolling idle up, and I think it is a decider on VCT also.
    • I mean, not really. Link ECU's can absolutely still have errors from the ECU thinking it's getting a sensor it's not expecting. I would imagine the speed at the ECU level in Nistune does absolutely nothing anyway? I assume the ECU does not do any fancy TC stuff with regards to front+rear wheel speed or anything of that like anyway. Someone who uses Nistune may be more fluent in it. 
×
×
  • Create New...