I will be installing a zex nitorous kit this weekend on my d15 all I have is I/H/E I only want to spend about $300 more I want to gt something to help increase the fuel what should I get....I am doing a swap this winter that is why I want to keep a budget on this engine....I will spend more money on things that can be carried over to the swap but can't see spending to much $$$ on stuff I won't be using after this winter.

what should I get injectors??? fule pump??? chip????

 

Just get an adjustable fuel pressure regulator. On your d15 you can run the Zex kit with a completely stock fuel system, however and adjustable FPR isn't a bad idea to up fuel pressure a tad. Just make sure you run one step colder NGK copper plugs, gap them at .030" for nitrous use, and retard ignition timing according to the zex chart.

 

If I get a fuel pressure regulator...how much can the stock intectors take...I was thinking of upgrade the injectors instead of getting a regulator...I thought bumping the fuel pressure up w/ stock injectors I would be asking for injector failure... what do you think

 

I'm not sure if this answers your question, but I'll give it a shot anyway. If you take a look at DRAG turbo kits, or any turbo setup that uses an FMU and stock injectors, fuel pressure under boost is pretty high. Let's say someone was running 7lbs of boost with a 12:1 FMU. If you take a static fuel pressure of 40psi, and add 72psi(12 x 7), that equals 112 pounds of fuel pressure under boost. Granted this isn't the best way to supply fuel to a boosted engine, but many are using FMU without any injector failure problems.

 

The zex kit doesnt use such extreme fuel pressures, stock injectors are fine. You don't really need anything except colder spark plugs and tuning for the zex kit.

 

would I see any benefits from a s-afc or other air fuel controller? w/ my pretty much stock set-up?

 

An AFC would help if you're running rich up top, since you can use it to lean things out as necessary. If you're running lean, don't expect to be able to do that much with an AFC, since you'll throw a MAP sensor code if you try to add more than a 10-12% value or so. All of this should be dyno tuned, of course, preferably with a wideband O2 for A/F readout.

 

It is important to approach nitrous as you would any other forced induction application. You are introducing a greater amount oxygen available for combustion which means you need to increase fuel delivery accordingly to avoid running lean, and as we all know, running lean can lead to major engine problems such as excessive combustion temperatures and detonation.

You can increase fuel delivery two ways. By increasing the pressure of the fuel system via a regulator or by installing larger injectors. There are also some concerns regarding the performance of the fuel pump, but in most applications the stock pump is more than capable of delivering the required pressure and flow.

It is important to remember that the required pressure is going to be proportional to the square of the flow required. So pressure will increase dramatically faster than flow will. For dramatic increases in pressure, the reliability and proper performance of pump and injectors comes into question. Increase pressure means increase power demand by the pump and injector solenoids to open the injectors, which requires an increase in current, and heat generated by these devices. And heat is one of the biggest reliability concerns when it comes to electronics. There is also the possbility of leakage through the injectors or seal failure. As a secondary concern, the extra heat generated by the pump and injectors also heats the fuel; adversely affecting charge density and power just as air temperature does.

I would suggest getting larger injectors that can provide the required fuel flow at or near stock fuel pressure. An adjustable fuel regulator may be necessary if you can't find anything that should operate properly near stock fuel pressure, and it allows for some fine tuning

Items such as a fuel rail, larger fuel filter, and improved plumbing primarily reduce the pressure drop over the fuel system and even delivery to the injectors. The primary advantage being less power required by the pump and cooler fuel. A new fuel pump is only necessary for large increases in power, or simply to have a pump that operates more efficiently at the fuel system parameters, once again resulting in cooler fuel

Hope this helps

 

With a Zex kit, you do not need any additional fuel upgrades. It is designed for use with a stock fuel system. I ran a 75 shot for a year on stock injectors, pump, fpr, fuel rail, etc. Just premium gas, colder plugs, and retarded timing. Now over a 75 shot, we are talking about fuel/ignition upgrades.

 

WeaselGSR- On current ['88-present] Honda fuel systems, poor atomization at higher injector pressures is a far greater concern than injector and fuel pump failure. Additionally, you will increase the temperature of the fuel through the fuel pump if you run below half a tank on a regular basis on any pump-in-tank system. You'll lose more power to a hot day heating your fuel than you will from heat conducted from the pump to the fuel. In fact, fuel has to be heated to atomize anyways, and this can happen in two manners: 1.) The fuel is already heated and converts into a gaseous state once it's released from pressure [which helps avoid the vapor lock problems of yore], or 2.) The fuel is heated by the intake air, which drops the overall temperature since the fuel must absorb heat from the air to atomize.

Overall, thanks for the response, but the question has been answered, and there was no need for a "lesson" on nitrous tuning that has missing parts , there are very capable people in this forum that have answered these questions time and again, so please only answer questions asked.