Question about wiring upgrade for fuel pump.

[Chief Gilly]

Hopefully someone can chime in with an answer to my question. Here's my situation; The Vortech pump that comes in the V3 SC kit ("00 GT) fuel pump duty cycle (fpdc) was pretty much at it's limit on the dyno @ 6000rpm. I made my own air to water intercooler and reduced the pulley size to 3.33. Back on the dyno my latest mod added 26rwhp and 30rwtq, now I have 390rwhp 380rwtq. Now the Vortech pump was at 100% fpdc at 5200rpm. I installed lethal performance's 340lph fuel pump. After another dyno pull I go 100% fpdc at 5900rpm. Not much gain there with the new pump.
So I'm looking to do the wire upgrade as my battery is in the trunk now anyways.
My question, is the fuel pump in a '00 mustang GT modulated by variable voltage or pulses? Does the typical wire upgrade that uses a 30-40 amp relay, splice the green/yellow wire to energize the relay, run 10awg wire to common contact on relay (pin 30 I believe) and increase wire size to fuel hat, still allow this variable voltage/pulse to work correctly? Or does my year ('00) fuel pump get constant 13.5 volts all the time?

I know I explained a lot in details but I want to be sure this question is answered properly before I do the upgrade.

P.S. In researching this dilemma I found that the 255lph pump should handle 390rwhp. I found a good approximation of fuel requirement is HP X .47 for forced induction engines. 390 X .47 = 211.5lph. Why is a 340lph pump falling short? Did anyone find similar results with such a setup?

Thanks in advance for anyone reading/understanding my question and providing an answer!!!

 

[01GT2V]

I'm wondering the same thing because my 340 pump is maxed also at 6000rpms

 

[Aristeros]

I'm having the same problem wIth my setup. I'm making 401whp and running my pump at max at 5200 rpm. Im also using the divisionx 340 that lethal sells. I have my holes cut in the basket my fuel filter and strainer are both clean. I was beginning to think I just have a faulty pump. But maybe these pumps just can't handle it. So I just bought a cobra tank an hat with pumps that I'm waiting on the mail for.

 

[Chief Gilly]

I'm wondering the same thing because my 340 pump is maxed also at 6000rpms

So it's not unique to my car, we both have exactly the same issue. This 340lph pump should be supplying enough fuel for 550-600 hp, but it's not. Reducing the resistance in the wiring will get some duty cycle back. I am believing though that our pumps are pulse width modulated. IF the FPDM provided that modulated pulse width then I see the typical wiring upgrade will work. Increasing the fuel line up to the fuel rail would buy some duty cycle back also. Maybe in a return style setup the pump works better, :idk: Company's show you graphs and charts but don't say HOW there product was tested pisses me off. 20 hp CAI?, 15 HP COPs?, 12 HP throttle body spacer?

Anyways I'l do the wiring upgrade and then datalog and see what I get, hopefully this weekend.

 

[On Edge]

Wow .... I hope something is wrong .... Well, let me re phrase that ..... That it isn't the division x 340 pump ....
Because I bought one and installed it in preparations for my SC.

From what all I have read ..... And what you guys thought .... The divisionx 340 should be more than enough, without any other mods or electrical upgrades.

Also, I have cleaned the screens, drilled holes in my basket, deleted the pprv and ran different submersible fuel hose. And I have experienced the warnings ..... Don't punch it at 1/8 tank, because the pump will suck it dry ..... The holes in the basket is a double edged sword ..... It allows you to suck more fuel, but it also doesn't keep fuel in the basket .... That is the whole point of the basket.

So, if you guys max out at xyz rpm's ..... What happens when you go over that ?
Because I like to shift 1st at 6000 and 2nd at 5800.

***** chief gilly .... I believe your install was done by Dan at real speed.....what did he say and what was his feeling ?

 

[On Edge]

Also, I am a member on another forum, and they all use the divisions 340 with great success. That's why I bought it.

To the above 3 ..... Do you guys have pics of your install. I'd like to compare ...

 

[Aristeros]

Also, I am a member on another forum, and they all use the divisions 340 with great success. That's why I bought it.

To the above 3 ..... Do you guys have pics of your install. I'd like to compare ...

I have three half inch holes spaced out on the sides of my basket which was done by Dan at real speed. After I went with a pulley change and a retune an found the fueling issue I pulled the pump out to check the strainer and added two more 1/2" holes directly under the pump strainer. It didn't help at all. I also had the pprv delete done by dan.

The few pictures I did take wouldn't really help you out too much in comparing anything though.

I too have read good things about the division x on moddedmustangs but from my experiences this thing is only good for 400whp

 

[Chief Gilly]

Wow .... I hope something is wrong .... Well, let me re phrase that ..... That it isn't the division x 340 pump ....
Because I bought one and installed it in preparations for my SC.

From what all I have read ..... And what you guys thought .... The divisionx 340 should be more than enough, without any other mods or electrical upgrades.

Also, I have cleaned the screens, drilled holes in my basket, deleted the pprv and ran different submersible fuel hose. And I have experienced the warnings ..... Don't punch it at 1/8 tank, because the pump will suck it dry ..... The holes in the basket is a double edged sword ..... It allows you to suck more fuel, but it also doesn't keep fuel in the basket .... That is the whole point of the basket.

So, if you guys max out at xyz rpm's ..... What happens when you go over that ?
Because I like to shift 1st at 6000 and 2nd at 5800.

***** chief gilly .... I believe your install was done by Dan at real speed.....what did he say and what was his feeling ?

No I didn't have it done at Realspeed. The pump is plu and play, no modifications necessary.

See, How that divisionX pump is bench tested for their claims is unknown to us. They might have submerged the pump on a bucket of water and checked it.s output like a return style setup which could yield more flow.

 

[On Edge]

I have three half inch holes spaced out on the sides of my basket which was done by Dan at real speed. After I went with a pulley change and a retune an found the fueling issue I pulled the pump out to check the strainer and added two more 1/2" holes directly under the pump strainer. It didn't help at all. I also had the pprv delete done by dan.

The few pictures I did take wouldn't really help you out too much in comparing anything though.

I too have read good things about the division x on moddedmustangs but from my experiences this thing is only good for 400whp

***** Aristeros ..... Yes, modded mustangs. So why are the MM users getting more than 400 rwhp from the X.....and we are not ??

***** chief gilly .... The X is not plug and play ..... It's taller , so the basket had to be modified and the wire pigtail is different. Do you have a different pump ?

Did any of you guys change the hose, or tried using the existing hose ?
I changed mine. If you tried using the existing hose with the clamp, maybe you have a kink or the hose is split ..... Causing you to leak fuel, thus not having enough.....just wondering

 

[Chief Gilly]

Maybe, just maybe the fuel injectors are a source of the problem. I say that because @5700rpm my 39lb injectors are max duty cycle also. It may be a problem because is the injectors are staying open too long it may slow the flow. I believe 39lb injectors are near their limit at 450 crank HP which is what most of us here, talking about this, are near. Joe @Mustangmagic set my injectors to 100% to be on the safe side @ 5700rpm+. I don't want to spend the money on bigger injectors to find that's not the problem though.
I had mustang magic install the 340 pump so there wouldn't be an issue with the installation plus I needed it dyno'd anyhow, I trust they did it right.
It also may just be that it's installed on a return-less system.
Is there anyone who did not have this issue around 400rwhp with this volume, or less, of a fuel pump? I hope they would chime in.

*****On Edge, like I said MM did the install I know they had to do a small modification and there was a new pigtail.

 

[Aristeros]

Maybe, just maybe the fuel injectors are a source of the problem. I say that because @5700rpm my 39lb injectors are max duty cycle also. It may be a problem because is the injectors are staying open too long it may slow the flow. I believe 39lb injectors are near their limit at 450 crank HP which is what most of us here, talking about this, are near. Joe @Mustangmagic set my injectors to 100% to be on the safe side @ 5700rpm+. I don't want to spend the money on bigger injectors to find that's not the problem though.
I had mustang magic install the 340 pump so there wouldn't be an issue with the installation plus I needed it dyno'd anyhow, I trust they did it right.
It also may just be that it's installed on a return-less system.
Is there anyone who did not have this issue around 400rwhp with this volume, or less, of a fuel pump? I hope they would chime in.

*****On Edge, like I said MM did the install I know they had to do a small modification and there was a new pigtail.

Actually, I have 60# injectors. So injectors are not my issue. And Jose at mustang magic is the one who actually found the problem and pointed it out to me while on the dyno.

 

[Chief Gilly]

Actually, I have 60# injectors. So injectors are not my issue. And Jose at mustang magic is the one who actually found the problem and pointed it out to me while on the dyno.

You cleared that thought quickly! Joey did my dyno pull and said the pump improved, or better said, moved my issue from 5200rpm to 5900rpm. I think the wire upgrade will make it safer and I can call that "good for now". That's all I really want anyhow because I'm at the limit of a stock 2V and have it live a long life. I still would think going from 255lph to 340lph would have done better than that.

 

[Aristeros]

You cleared that thought quickly! Joey did my dyno pull and said the pump improved, or better said, moved my issue from 5200rpm to 5900rpm. I think the wire upgrade will make it safer and I can call that "good for now". That's all I really want anyhow because I'm at the limit of a stock 2V and have it live a long life. I still would think going from 255lph to 340lph would have done better than that.

Yeah basically my 340 is acting as if it's only a 255. A wire upgrade I don't think will be enough for me so that's why I chose the cobra setup. I already blew my motor and put in a forged shortblock from dss racing engines. My goal is 500whp at 15psi. Running out of fuel pressure above 9 psi is what's stopping me.

 

[Chief Gilly]

Yeah basically my 340 is acting as if it's only a 255. A wire upgrade I don't think will be enough for me so that's why I chose the cobra setup. I already blew my motor and put in a forged shortblock from dss racing engines. My goal is 500whp at 15psi. Running out of fuel pressure above 9 psi is what's stopping me.

340 acting slightly better than a 255. I was getting 12 psi Vortch V3, on stock pulley and no after-cooler. I don't know what my max boost is with 3.33" pulley with after-cooler but I am at the limit of the 340 X pump. I think the wire upgrade should/hopefully get me into the 90% fpdc range @ 6000rpm. I will soon find out. I can data-log once I'm done.

 

[Aristeros]

340 acting slightly better than a 255. I was getting 12 psi Vortch V3, on stock pulley and no after-cooler. I don't know what my max boost is with 3.33" pulley with after-cooler but I am at the limit of the 340 X pump. I think the wire upgrade should/hopefully get me into the 90% fpdc range @ 6000rpm. I will soon find out. I can data-log once I'm done.

Definitely report back. I'm curious to know how much further you can push that pump. And how much the upgrade helps out. I plan on doing it with my cobra setup.

 

[On Edge]

340 acting slightly better than a 255. I was getting 12 psi Vortch V3, on stock pulley and no after-cooler. I don't know what my max boost is with 3.33" pulley with after-cooler but I am at the limit of the 340 X pump. I think the wire upgrade should/hopefully get me into the 90% fpdc range @ 6000rpm. I will soon find out. I can data-log once I'm done.

If you can , please take pics of your wire upgrade process. That could help us out. Thanks.

 

[Chief Gilly]

So, if you guys max out at xyz rpm's ..... What happens when you go over that ?
Because I like to shift 1st at 6000 and 2nd at 5800.

***** chief gilly .... I believe your install was done by Dan at real speed.....what did he say and what was his feeling ?

I try not to rev higher than 6000rpm, especially in 1st gear. My HP is still climbing at 6200rpm but torque starts dropping at 5200rpm. If you look at my dyno sheet you will see that and my A/F ratio start to go up at 6000rpm from 11.5:1 up just a little, but an upward trend none the less. So I believe the wire upgrade, which I did do today, should at least keep it at 11.5:1 to 6200rpm. My motor has close to 100K miles on it. Knock on wood it still runs like a champ. At it's age it doesn't really need to go over 5500rpm, unless I stole something and the cops are coming, of course.

 

[Chief Gilly]

If you can , please take pics of your wire upgrade process. That could help us out. Thanks.

Sorry, I didn't see your request for pics and I completed the upgrade already. My battery is now in the trunk one foot away from the FPDM. What I found was that the green w/yellow stripe wire that came from the front of the car and was connected to the safety inertia switch. Then a pink w/blk stripe wire went to the FPDM connector from the inertia switch. Some pics I saw showed it to be a green w/yellow stripe wire all the way to the FPDM. Mine was pink/blk going from the inertia switch to the FPDM. Before doing the mod remove the negative cable from your battery, positive also if you want to be double sure. I removed the wire loom at the FPDM connector to have better access to the wires. Cut the pink/blk wire leaving at least 2in of wire for you to work with on each end of where you cut. Attach the pink/blk end from the connector of the FPDM to pin 87 on a 30-40 amp relay, which is a normally open contact. Attach a 30 amp fused wire from your battery to pin 30 of the relay, which is the common of the normally open contact.
Now you have created 13.5vdc directly to the input supply of the FPDM which through the FPDM will go to the pump. This step is the abundance of voltage drop issue.

To energize the relay connect the other end of the pink/blk wire, which you cut initially, to the coil of the relay which is pin 86 of the relay. Ground pin 85 which is the ground of the coil.

Now instead of the green/ylw wire supplying the voltage that ultimately will supply the pump is now just energizing your relay. Our pumps are pulse width modulated but as long as you use the relay the 13.5 volts still goes through the FPDM to be modulated.

I did not run a wire to the tank. I used a voltage drop calculator to see what changes will happen.
If anyone sees a discrepancy in my instructions please let me know and I will correct it asap

Prepare to be schooled

I estimated a 25 foot length of 18awg wire with a 4 amp load will have 1.28 volt drop.

I then only changed the length from 20 foot to 5 foot (18awg) and now is a .26 volt drop. (battery in trunk)

Next I changed the 18awg to 10awg at 5 foot length and now the voltage drop is .04 volt drop. (battery in trunk)

If you ran a wire from the battery being up front going all the way to the tank via the inertia switch (10awg) and ending at the tank (20ft) would be a .16 voltage drop.

I would only gain 0.10 volt if I went 10awg to the tank. I'm not goin to worry about that. Having 18awg wire for 5ft going from the relay to the tank is not the end of the world. 18awg wire can handle 5 amps up to 25ft, 15 amps to 15ft and 24 amps up to 5ft.

18awg wire has 6.5 to 7.5 ohms every 1000ft. Don't worry about a 5ft run to the tank with 18awg wire.

Nuf said?

I didn't put all the kick panels back, if you want pics of what I did I can take pics tomorrow.