Actually, those are fuel dampers NOT regulators.

The fuel pressure regulator is contained in/on the fuel pump housing in the tank on VQ35s.

I wouldn't rely on those for your fuel pressure.

There are plus/minus to a return vs. returnless fuel system, however I'd keep the return system.

 

Yes, but if you're doing a full 3.5 swap w/ECU you need that.

 

Will the 00-01 rail fit into the 3.5 lower? If this is the case, wouldn't I bet better off using the dek injectors also? If this is true, its great news for me

EDIT: I just read that these are the fuel dampers:


The difference between these and a FRP? me=noobish

 

Yes, injector physical dimensions are the same.

Fuel damper goes UP stream of the injectors to smooth the fuel pumps pulsing. Basically, it is a diaphragm with a screw that adjusts travel.

Fuel regulator goes DOWN stream of the injectors and acts like a dam blocking flow, which creates an upstream pressure in the fuel rail.

 

your right one way i have tried dek rails and injectors in a 3.5 lower ...injectors line up perfect one bolt mount only lines up though. But when i use the dek on a 3.5 lower in the future ill just dremil room for the bolt to go in the lower and the side of the bolt will hold the tabs down there that close.

 

The VQ35 fuel regulator is in the FUEL TANK.




Again, you guys shouldn't be wasting your time with the return style systems. The returnless system is better and is there for a reason. Use it instead.

Why go backward with technology? That's like people installing carburators because they don't understand fuel injection.


I guess i will be the first and only person doing the opposite and converting cars to returnless.

 

Why are the big boy 350z's using the return style fuel rails.

 

I have already answered that question. People fear what they do not understand.

 

Why are they the big boys? We been reppin the VQ before them...

 

'Cause they're RWD. And having a 350z makes them cooler than maxima owners

 

4th gen fuel pump--> fuel filter --> all 3.5 rail--> aftermarket FPR + block off the return hose? Will it provide enough fuel for the 3.5 or will I have fuel issues (lean/rich) with this? (running on stock 4th gen ECU w/o any tuning)

Is this your current setup? And do you have any fuel probs?

 

You don't have to narrow it down to a specific fuel rail or fuel pump. Nissan has already engineered the setup. Don't reinvent the wheel, just use what they've provided. Find a VQ35 fuel pump assembly and use it. The FPR is included and runs at 3.5 BAR.

And you should always expect to tune.

 

In 2 days everything i have said will be forgotten and 10 more people will ***** at me for keeping secrets

 

So if I use the 3.5 fuel pump, will it bolt up to the tank? what about the fuel level sensor?

 

Shouldn't you use a Walbro? There's a GD on them - 85$ shipped.

I have a hard time seeing what 5-letter profanity would fit there but whatever.

Vasily's running on a 96 fuel pump, do you think this causes his a/f ratio to be less ideal than what a stock '02 max would have? (Although it's already not-so good, especially at high RPM's)

 

I said use the assembly. Specifically you would use the parts you need from it such as the internal FPR. If the 4th gen parts are too vastly different you can simply put an external FPR right at the fuel tank.

Having a returnless system greatly reduces rising fuel temperatures. Many race teams are going to this setup because of dyno proven power.

 

I actually do use a 255HP Walbro which is capable of supplying enough fuel for normal WOT operations and has enough left over for a rediculous shot of nitrous. All at 3.5 BAR.

I recently made an adjustable in tank FPR that I am going to test. I will then tune to 4.0 BAR as an experiment.

BMW motorsport injectors run at 5.0 BAR. And I trust that BMW has a very good reason for this.

 

Give us the results when you do

I was worried my '95 fuel pump couldn't handle 240 or 250-ish whp.

190lhp-ish instead of 255lhp like the Walbro if I am not mistaken...

 

Only if you can come up with the two theorys as to why this could potentially make more power.

 

It wouldn't make more power, unless it was a ceiling for your "ridiculous nitrous shot", but I don't think you're that over-the-top yet. Unless our injectors are really much crappier than I think they are

 

Don't expect me to keep you updated then.

 

Return style is much better ,better for high HP to.
someone makes a kit to change the 3.5 to return.

Im def going with a return fuel rail because im using a return system

 

I'm not gonna lose sleep over it either way ....speaking of sleep......

 

Return style isn't better. You guys keep disbelieving me and I'll keep kicking your butts on the dyno and at the track.

As I said before. They are converting because they do NOT understand the significance. I do. And so does Nissan, BMW, Ford and even Turner Motorsport.

 

Wow its nice too see everyone gettin along so well here. Its all a matter of opinion on the fuel return or non return. A return system is easier to adjust FP with a regulator.

 

What i'm going for is ease of installation, it's ok for me if I don't make the absolute most power I can. Just as long as it makes the engine work.

 

it is going to be more work to convert a 3.5 to reurn so just stick with what is already there because it is proven to work better.

 

But it hasn't been proven reliable on a 4th gen. I'm gonna try DEK injectors and rail.

 

dek injectors and rail on a 3.5? and then you goign to try to use the IM also? use what is already there.

 

Well in order to "use what is already there", I would have to get a 3.5 fuel pump assembly. This would also bring up the issue if the actual assembly would fit perfect and bolt into the 4th gen tank, if my fuel gauge is still going to work, and how the 4th gen ECU will react to the setup. You running the 3.5 pump assembly in you tank?

I will be using the 3.5 IM. Possibly with some of my own secret sauce.

 

I mean big boys like 400- 500 whp+ .

They are all upgrading to a return style fuel system. They seem to be running lean even with 550+ cc injectors. But once they switch, they run rich.

 

i am using a 96 Fuel pump assembly and i never had a problem with fuel. i have a extra 2k2 fuel pump assembly but never put it into a 4th gen tank. and if you are going to do a complete 3.5, the fuel gauge will work cause mine is and so is te trip computer that tells me how much fuel is left in the tank.

 

But wait, if you are using a 96 pump assembly.. where/what FPR are you using? Aftermarket?

 

That is because of the tiny feed orifice coming out of the fuel pump assembly. That part needs to be upgraded for high power levels.

And I wouldn't call a downgrade in HP potential an upgrade. Sure they upgrade the fuel system as a whole but the end result is old technology that will make less power in the end. If they would simply upgrade the returnless system in the places that it needs their problems would be solved and they would have the luxury of running more consistantly at higher boost and power levels.

A return based system can heat the fuel in the tank upto 120º F. Why is it that everyone seems to think this is better than 70º (or outside air temp) fuel, ESPECIALLY for FI where charge temps. are VERY critical.

 

http://www.findarticles.com/p/articl...10/ai_n9426858

 

^^ Great article

 

Indeed. One problem here is that if Vasily simply used the returnless fuel system, then where is his fuel filter located now? Certainly not in the tank like it says in the article, he says he didn't touch the pump/tank.

 

my fuel filter is located the same place where it was located before.

 

But where is your FPR?

 

i dont have a aftermarket one but the stock fpr are on the 2k2 fuel rails. i took apart a fuel pump today and there is no regulator in it. just the pump and a filter.