370z Fuel System, and Upgrades
 

Its been about a year I think since we took an in-depth look at the 370z fuel pump assembly and made some upgrades to it. We felt it was a little ahead of its time though, since no one was getting to the point of out-running the stock components yet. So we never really mentioned it to anyone other than tuning shops. The situation is probably still about the same, but the need for greater fuel supply will continue to grow. I figured its time we at least mention to people that the parts exist for when they need them.

Quietly in the background, the parts have been installed and tested by a couple sponsors here and have made their way into a few twin turbo 370zs.

When 370z first came out, our friends at Performance Motorsports sent us a brand new assembly to go through and give it the works.

The result was our Walbro 255lph upgrade kit, and a Return Fuel Conversion (we call it a return correction kit), and this little tech article for gurus who haven’t torn their pump apart yet;

http://cj-motorsports.com/370zpump.htm

To compliment this, we actually have an entire line of fuel system products either being tested or finishing up development. We have complete return fuel conversion kits being tested on a pair of twin turbo 370zs. Billet rails, twin fuel pump assembly... etc. But the next item we hope to post up about is a road racing fuel pump assembly with large displacement in-tank surge can.

Ultimately I just wanted to mention the walbro upgrade kit, and the tech article for the geeks like me to soak up.

Thanks!

I just found this via Google a few days ago but the pictures where not up yet on the catalog page.

I did have a question. Why couldn't the fuel pressure regulator nozzle just be drilled out larger? Why the need to cut out the whole assembly and replace it with a new nozzle?

I can answer that.

You are confusing 2 different purposes. So far, through testing in a couple cars, there have not been any issues with the stock fuel pressure regulato being overwhelmed and needing modification (even after using the walbro install kit to upgrade the pump) such as the 350z required. This is probably because the factory regulator already has a slightly larger output than the 350z did, and the 370z also has a pressure relief valve in the venturi plumbing to prevent pressure bottlenecks from the pinhole venturi nozzles. So you can just install the walbro and run an otherwise stock fuel system and completely ignore the part of the modifications where we removed the factory regulator.

What are you seeing us replace the regulator with a new billet piece is to actually eliminate the factory regulator all-together. The only reason you would do that is to convert the fuel system into a return fuel system with an adjustable regulator in the engine bay or wherever else you mount it. The new billet "nozzle" as you referred to it, is to create a way to send the return fuel into the factory venturis. If you simply returned the fuel to the pump assembly without routing it into where the factory regulator used to dump, the over-tank siphon would die and your car would run out of fuel at a half tank on the gauge because all the gas on the driver side of the "saddle" shaped tank could not be accessed. The new billet nozzle sends the fuel to the factory venturis, and also blocks off the opening in the fuel filter housing that used to feed the factory regulator.

So basically you are seeing two entirely seperate modifications done to the fuel pump assembly in that article. You have the option to do just one or the other, or both, depending on your fuel delivery needs!

I hope that answers your question

Thanks

will this help with fuel starvation in right hand turns on the track?

Mike,

Upgrading the fuel pump or converting the pump assembly to a return fuel unit will not help control the placement of fuel inside the tank or pump assembly.

However, the good news is... I am currently at the shop right now working on one of our next 370z product releases, which is a road-race fuel pump assembly. Its essentially a large displacement in-tank surge can that houses a single 255lph pump. It features additional siphoning that will pickup fuel as it passes by the pump assembly to refill the canister.

I will need a little time to finish this up. I am going to get one to Forged Performance as soon as I can for track testing, and at the same time will install into my 370z for street testing.

How about getting two to forged for testing? :) or getting Sharif to let me be the guinea pig!

Regardless, as soon as it's ready, I want one

Welcome to the forum phunk :tiphat:

I remember you guys did wonders for the 350z fuel system. Looking forward for the road-race fuel pump assembly. I'm buying one as soon as your done with the test.

Good luck.

Thanks, Valentino.

There is a tricky part to overcome with this road race pump, but we already know how we are going to do it... I will keep everyone posted!

Will keep you posted! Thanks!

Looks like you have a lot of cool stuff going on Phunk. Welcome to the boards!

That did clear up a lot, Thanks.

Phunk, how's the road-race fuel pump going...Sorry to be impatient and rude, but I'm eagerly waiting for it. I'm having the same problems with fuel starvation as some of the other guys like Mike and Travis. It wasn't so bad when I started, but I'm starting to get annoyed by the constant filling up and losing time. Once, the engine cut out during one of my small practice races with an Elise. Keep posting man!!!

Its coming along great! We had to take a big pause from working on it because we became massively back-ordered on 350z products, but we are caught up on machining parts for the 350z, and we got back on new projects a couple days ago. Last week I finished part of the road race pump project... we have a couple days left on it, hopefully the next few days we are able to get to it.

Cool, and btw, don't let my impatience sway you. I'm just like this sometime, no rush man, take your time...