I am having an issue with my fuel pressure decreasing under high boost.

Setup is

intank pump> fuel filter > surge tank > 2x 044 pumps>2x filters Y in 8AN > 4x 2000cc ID> 6AN into FPR (aeromotive) and 6AN return line to surge tank

Have fuel pressure set at 65psi bar at idle, once boost kicks in 32-35psi pressure goes up accordingly then falls to 43psi (lower than base pressure) from around 7400rpm up to 8500rpm.

I use E85, trying to raise the boost higher but this issue is holding me back and I cant figure it out. I have checked voltage to the pumps and they see a solid 13v, are my lines too small?

Surgetank hold around 6 liters, have checked filters all clean.

 

Check your wiring.

 

wiring to what? pumps?

 

Pumps to relays to battery

 

all seem ok, voltage is constant. Boost comes in at 5000rpm, it all works ok up until the higher rev range

 

I had an issue with fuel pressure dropping at high rpm/high boost and I swapped out my wiring to -8 and my issues went away and the car mad 100 extra whp at the same boost

 

so you went with thicker wiring and that cured the issue?

 

Yessir

 

I am using 3mm thick wire with 3 separate relays for each pump, wire is rated at 30 amp and relays 40 amp.

 

Why 3 relays per pump? I use 1 relay per pump

 

Wow you kids need a basic lesson on electricity...

It is not all about the Volts... it is about the AMPS too!!! The longer the wire the greater the resistance which results in Amperage loss.

Volts = Pressure
Amps = Current/Flow
Ohms = Resistance
Watts = Rate of Transfer

For a distance of 7-13 feet and a draw rating of 25-35 amps I would highly recommend having -8 gauge cable.

 

Kids? Ok buddy

 

Unless you are within 10-15 years of me, yes you are a child to me. So, are you in your 50's?

 

Your too old to be on honda tech. Lol what a loser

 

The easiest way to determine the drop that you are getting is to put your volt meter on the same wire. Sounds weird, but do this:

Positive lead of your volt meter to your power source for your dual pumps (pick one)
Negative lead on the same wire on your pump itself.

When the system is under load (operating), what is the reading on your meter? If there is no issue, it should be around .5 volts. Over 1 volt, you start having what is called a VOLTAGE DROP. I have done many diagnosis like this to find corrosion in wires which would reduce the amperage the circuit requires. In essence, the wire was too small (not enough strands) to allow the FLOW (AMPS) required.

Think of it like water, it's one of the ways that helped me get it right.

You have a big wheel you're trying to turn, you can have all the pump in the world, but if the hose connecting the two is not big enough... you'll never get the speed that wheel should turn at, even if you put on 3 pumps....

LMK how it works out.

 

Haha, thanks... at least I am a very successful loser. When you have engines running in Top Fuel, NASCAR, derby cars, circle track cars, NHRA classes, ect - then come talk to me... I am on these forums to try and keep up to date on trends. I am on around 15 different forums and this is the ONLY rice burner one. Either way I am flattered that you wasted time in your life to respond to me, you are the one that is truly pathetic.

PS - It's "you're"... stay in school kid.

 

Rofl!!! Shlapped

 

HAHA I've grown to love/hate that dude!! LOL but I always read his posts a little more carefully.

 

Yea recommend upgrading try -8an return and -10an feed

 

You're just too old in general. :p

 

Hah, just keep paying into Social Security!

 

Care to share how old you actually are ? I remember reading something that you brought "WW2" into which you said you were around for which left a HUGE ? over my head. If you are as old as I'm thinking, you've sure watched the world change... and lived through some tense moments....

 

Oh come on now, I am not that old. I was.born in 1949... WW2 ended in 1945. The effects were still felt even 20 years later. I most likely said the tail end anyways haha... Kind of the same way old war buddies talk about 'Nam. Either way the past is the past and I have always been fascinated with technology and the way it advances. Now I am not going to start an autobiography or what have you, so lets just say I am old as dirt and get on with the *** chewings! Although, I do get told to act my age by my wife quite often, that has been going on for almost 40 years. HAHAHA!!! I am a kid at heart... you are only old as you feel, and I am ready to whip some ***.

 

What was it like owning the first honda civic back in 73 :p

 

Haha, no thanks... my First Honda was actually a Y49 CRX Si back in 1990. For some reason it "spoke" to me... I was intrigued and already bored with SBC Fieros by that time. I wanted another small "sporty" car. It eventually wound up, over the years with TONS of various combinations, with a 12:1 GSR Nitrous engine and gave it to my son. So he brings up the "curse of the Y49", which until that time I had never heard of, a couple months later it was totaled...

I am feeling generous, here is ONE picture... 20+ years down the tube in a few seconds. It was near mint condition without a spec of rust.