Fuel Supply Guru: What fuel management device(s) f

**Hybrid EG** · September 27th, 2000, 05:31 PM

Here's a question for everyone.. (I am sure similar questions had been asked million times already, but I need more specific info for this application). Any input is greatly appreciated!

I am planning to run 8psi on the charger in the future, but staying at 6psi for now.

There's a set of RC 320 injectors and I would like to install them on my B18C in preparing for the 8psi upgrade.

The fuel management parts I have right now is JR regulator and JR fuel pump (Walbro LP?). No Cartech, and no CommandFlo. I am wondering after adding the 320 cc injectors, what device(s) can I use to tone down the fuel pressure, and yet versatile enough for future 8psi upgrade? I am thinking of Cartech and by pass the factory regulator.

Is CommandFlo necessary in this case?

There will be a electic FP gauge, and A/F gauge to monitor the fuel supply.

I will likely get a BTC for the 8psi upgrade as well.

Thanks everyone! Thanks for the bandwidth!

Derek

[This message has been edited by Hybrid EG (edited September 27, 2000).]

**Holden** · September 27th, 2000, 06:47 PM

Get the Cartech 20005 FPR. It comes with 5/8" nipples. All the fuel hoses on your car are smaller than that (1/2", 3/8"??? I don't remember).

Anyway, when you install the Cartech, replace the outlet nipple with one from the JR FPR so it fits the existing return hose.

Leave the big nipple on the Cartech inlet, tap the JR fuel rail adapter to 1/8" NPT and screw in the other big nipple (removed from the Cartech) into the JR adapter. Then run 5/8" ID hose from the fuel rail to the Cartech.

You should be able to get pressures down into the teens (way lower than you'll need!).

Mr Rogers and Lundgren should be able to provide sample fuel pressures to start with. They also have RC 320's.

Tune from there with the A/F gauge.

Good luck,

Greg

**Hybrid EG** · September 27th, 2000, 07:07 PM

Great Holden! This is exactly the info I need!

I am wondering what gives the lower fuel pressure? The larger ID hose between fuel rail and Cartech? That's why we switch to 5/8" nipples right?

So there is no need for stock fuel pressure regulator or CommandFlo? And I can ditch the JR FPR after the operation right? I guess..

Thanks again for the great info!

Derek

**Holden** · September 28th, 2000, 02:27 AM

Well, you use the 5/8" nipples because you have them. May as well use them!

The drop in minimum pressure is due to removing the OE FPR. It's outlet is so small that it is the limiting factor.

Because the B&M Commandflo doesn't replace the OE FPR outlet, it can't lower the minimum pressure much.

The Cartech completely replaces the JR FPR.

Greg

**JRCivic** · September 28th, 2000, 02:38 AM

Greg,
You are quoting the barb size incorrectly... the diameter is 5/16", NOT 5/8" !!! So, the hose needed between the fuel rail and the Cartech inlet is a 5/16" INSIDE DIAMETER hose.

The OE size is 1/4", which you also quoted incorrectly, but you did notate that it is actually smaller.

EG, the only reason that the OE regulator is necessary with a supercharger is if tip-in detonation is a problem in your particular car. If it is, then the B&M Command Flo (or similar regulator) is necessary to adjust the ramp point of the fuel in vaccuum.

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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.68 at 110 mph