Fuel System Upgrades

[Akfahad]

Jim,
You said you have your car tuned at 45psi at idle and 60psi at full throttle. My question is, what's the ideal amount of fuel flow during these two different pressures?

[Ian]

I just got the URD fuel pump. For those that have it, how long it took you to install?

After reading the instructions, the task looks a bit daunting for me. I don't think my mechanic will do it because of the modifications required.

All I can think of is blowing up.

[Akfahad]

^^^Ian I hear ya...I didn't even bother doing it myself. I had my shop do it plus I needed them to do my injectors. They told me they had to do some modding to the pump, but it's been working fine.

On a side note, anyone know the answer to my previous question?

[Astro]

I just got the URD fuel pump. For those that have it, how long it took you to install?

After reading the instructions, the task looks a bit daunting for me. I don't think my mechanic will do it because of the modifications required.

All I can think of is blowing up.

It didn't take long at all, maybe 20 mins (but I had my rear seat out already). It's just splicing the new wires, trimming some plastic with a dremel, and connecting everything. I'm not that mechanically inclined, but I found it pretty easy.

[Ian]

^^^Ian I hear ya...I didn't even bother doing it myself. I had my shop do it plus I needed them to do my injectors. They told me they had to do some modding to the pump, but it's been working fine.

On a side note, anyone know the answer to my previous question?

Where is your shop located? I'm in SoCal.

I just got the URD fuel pump. For those that have it, how long it took you to install?

After reading the instructions, the task looks a bit daunting for me. I don't think my mechanic will do it because of the modifications required.

All I can think of is blowing up.

It didn't take long at all, maybe 20 mins (but I had my rear seat out already). It's just splicing the new wires, trimming some plastic with a dremel, and connecting everything. I'm not that mechanically inclined, but I found it pretty easy.

Rats! 20mins. I have reread the instructions like 3 times and I'm still uncomfortable with the idea of splicing wires and gasoline. I admit it, I'm chicken.

[JavaJoe_2]

Rats! 20mins. I have reread the instructions like 3 times and I'm still uncomfortable with the idea of splicing wires and gasoline. I admit it, I'm chicken.

Just be sure to disconnect the battery....BEFORE.... installation.

[Akfahad]

^^^Ian I hear ya...I didn't even bother doing it myself. I had my shop do it plus I needed them to do my injectors. They told me they had to do some modding to the pump, but it's been working fine.

On a side note, anyone know the answer to my previous question?

Where is your shop located? I'm in SoCal.

Sorry Ian, I'm in NC....There's gotta be a shop in Cali that'll do it. What about UPFD?

[Ian]

^^^Ian I hear ya...I didn't even bother doing it myself. I had my shop do it plus I needed them to do my injectors. They told me they had to do some modding to the pump, but it's been working fine.

On a side note, anyone know the answer to my previous question?

Where is your shop located? I'm in SoCal.

Sorry Ian, I'm in NC....There's gotta be a shop in Cali that'll do it. What about UPFD?

Shortly after I posted that question to you, I saw your location under your avatar.

I might try UPFD since I did get my CAI from them. I'll give them a call and see. Thanks.

[jim@foreignaffairs]

I have my fuel pressure set at 48 psi at idle, it goes up to about 60 at full boost. I haven't measured the amount the fuel pump is flowing as that is not of interest. What is important to me is that there is no loss of pressure at full throttle max boost and from idle to redline. That proves the pump as well as the entire fuel delivery system is keeping up with demand. Otherwise pressure would drop. The only way to test the system completely is with a fuel pressure gauge you can watch as you run.

As for the pressure Vs flow argument, you can't move anything without provinding some outside force, including fuel. The outside force is the pressure imbalance from one side of the pump to the other. The dictionary definition of "pump" is "a machine for forcing liquids, air, or gas into or out of things". Anyone can understand then that the pump applys force to the fuel. The maximum amout of force it can provide is measured as pressure. You have to have pressure behind the fuel injectors or nothing will come out. The more pressure the more comes out. Just like your garden hose nozzle.

But I'll be the first to say who cares? All that really matters to us is that we use a pump that will maintain pressure and flow no matter our motor's demand. You want to know if your Walbro 190lph pump is big enough or if you should get bigger. I don't know because I haven't tested it, but as long as boost is no more than 5.5 psi I am willing to bet it is. If you go to a return style system as you should, I would use something bigger. The fuel upgrade you have does wonders, but to really properly dial your fuel system you have to have a return style system. Then your system will automatically dial in more pressure as it sees boost, and you can easily adjust base pressure.

Bottom line: Get a fuel pressure gauge!

[Akfahad]

Bottom line: Get a fuel pressure gauge!

I think I'll have to wait when I get back....

[808Camry]

Thanks Jim for the write up. My question is if I'm too chicken to go to the next level, would ordering the new fuel filter in this upgrade to be used with the original fuel line upgrade work or would it not make that much difference with just the fuel line upgrade?

[jim@foreignaffairs]

The Golan filter is super nice but not necessary and I am sure by adding it alone you won't feel any difference in performance. The -6 size will attach directly to the fuel mod I sent you, but the input end will hve to be adapted. It won't be worth the trouble and expense but it would LOOK good!

Jim

[Ian]

Finally! I got the URD pump put on and I like it. The car runs faster and smoother on acceleration. There are no more hiccups in acceleration at any rpm, which must mean that there is no more retarding of timing. This is how I envisioned it would feel. (The only thing I need now is the exhaust system. )

Can't believe I drove all this time without the upgraded fuel pump.

Also, to my surprise there is no whining noise. I was expecting the noise based on what everyone else reported, but there is none so far. Hopefully it will stay that way.

So, the fuel upgrade answer for anyone supercharged up to 6 psi is:

1. URD fuel pump kit; and
2. Jim's fuel kit.

[Akfahad]

Glad to hear everything is working fine