Just ordered some RC 440cc injectors and tuned ecu. Can the stock Honda ('97 Civic LX-d16y7) fuel pump handle the fuel needs for the upgraded injectors?

 

You are going to have to provide more info on your setup.

I hope you are talking about a turbo system.

 

1997 Civic LX D16Y7
IHI Turbo (Fairly Small turbo)
Spearco Intercooler
Custom IC Piping
Custom Turbo Manifold
Chipped P06 ECU
RC 440cc Injectors
DSM Bov
Running at 8psi
Stock Block, Everything else.

 

you should be fine

 

how big is the fuel pump on a 97 Civic LX anyways?

 

Don't know. Thats why I wasn't sure if the stock fuel pump could handle 440cc injectors.

 

well I did some quick calculations:

I figure at 85% duty cycle those injectors are flowing 380cc / min

380 x 4 = 1520 cc / min for all 4 injectors

So the fuel pump has to be able to provide at least 1520 cc / min or 91 liters per hour (lph).

So you figure the fuel pump should be able to flow at least 100-120 lph. However running 8 psi of boost decreases the amount of fuel the pump can flow. To be safe I would say a 15-20% decrease in pump loss. So the fuel pump would have to be at least 130-140 lph. Minus pumping losses that brings it back down to 100 lph to 119lph. So your stock fuel pump needs to have a rated capicity of approx. 130-140 lph.

If you didn't understand any of what I just said, then maybe you should buy a Walbro 190 lph fuel pump which can be found for $79 new.

 

They're cheap, and the extra insturance is never a bad thing. Here's one for less than $100 free shipping.

http://cgi.ebay.com/ebaymotors...wItem

 

i have one for sale for $60 shipped... walbro 255lph link is in the sig

 

link doesnt work

 

https://honda-tech.com/zerothread?id=1416997 try that one

 

So, do you think my stock fuel pump can handle the needs? Does anyone know for certain?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BlueShadow &raquo;</TD></TR><TR><TD CLASS="quote">well I did some quick calculations:

I figure at 85% duty cycle those injectors are flowing 380cc / min

380 x 4 = 1520 cc / min for all 4 injectors

So the fuel pump has to be able to provide at least 1520 cc / min or 91 liters per hour (lph).

So you figure the fuel pump should be able to flow at least 100-120 lph. However running 8 psi of boost decreases the amount of fuel the pump can flow. To be safe I would say a 15-20% decrease in pump loss. So the fuel pump would have to be at least 130-140 lph. Minus pumping losses that brings it back down to 100 lph to 119lph. So your stock fuel pump needs to have a rated capicity of approx. 130-140 lph.

If you didn't understand any of what I just said, then maybe you should buy a Walbro 190 lph fuel pump which can be found for $79 new.</TD></TR></TABLE>

Yes, this makes sense. Where can I find the capacity info for my stock fuel pump?
And, How does boost decrease fuel flow?

 

Sorry, dude I cant help you with the capacipty of your stock pump. Maybe the guys in the EK forum can help (or whatever year you car is).

Now as far as fuel pressure affecting flow. AFAIK fuel system pressure affects your pumps overall flow, the other thing that affects it is the amount of voltage going to the pump itself. I read it I think on Aeromotives or maybe Walbros site, but when you increase the fuel pressure you decrease the flow of the fuel pump. I forget exactly what causes it, but below is a chart of the Walbro 255 and 255 HP pumps and their different flow rates at different fuel pressures. I also included a pic of the Aeromotive A1000 pump for comparison.

You can raise and lower fuel pressure with an adjustable FPR...now AFAIK your stock FPR and non rising rate FPR's have a 1:1 ratio. So for every pound of boost the fuel pressure goes up one psi, same concept as a 8:1 or 12:1 FMU. So say your base fuel pressure is 45 and you are running 15 psi of boost. Your new fuel pressure at full boost will be 45 + 15 or 60 psi of fuel pressure. Another example is if you had your base fuel pressure set to 50 psi with an adjustable FPR and you are running 20 psi of boost. Your fuel pressure at full boost would be 50+20 or 70 psi of fuel pressure. The regular Walbro will only flow 113 LPH at 70 psi of fuel pressure. The Walbro 255 HP (high pressure) will flow 181 LPH at 70 psi of fuel pressure. And the Aeromotive A1000 will flow about 225 LPH at 70 psi of fuel pressure and 12 volts.

Remember how I said voltage affects fuel pump flow as well? AN A1000 flows about 225 LPH at 70 psi and 12 volts. But at 13.5 volts it will flow about 280 LPH. This is why it is important to make sure your fuel pump is getting as much voltage as possible and that there is no voltage drop in the pump wiring. If your fuel pump is not getting all the voltage it is supposed to then this will also decrease the amount of fuel your pump can flow.

Anyways here is is some info for you:

Walbro 255 and 255 HP


Aeromotive A1000 pump


http://216.242.145.16/products...pk=11

 

is saving $60 really worth the chance of your engine? think about it...