Link To Fp Rewire Retaining High/low Pump Speed .

[discopotato03]

Hi all , I found this link when looking into DW300 turbine pumps and fuel pump rewires .

http://forums.evolutionm.net/evo-engine-turbo-drivetrain/590352-fuel-pump-wire-high-low-voltage-circuit.html

The aim I believe was to avoid "over running the std FPR" when using high volume fuel pumps .

I found it before starting work this morning and have only gotten a couple of pages in . The thread may be of interest to those with an advanced understanding of volts n amps a so forth .

Enjoy , A .

[scotty nm35]

Meh.

The Solid state relay will lose you 1V so you are dropping the total voltage supplied to the pump by that amount. I want to get more voltage to my pump, not less... 16-18V would be good.

Are you over running the stock FPR yet?

[discopotato03]

Not that I know of but I'm running std GTS25T wiring and an R33 GTR pump , have set the pump voltage change at about 1300 revs .
Would have looked into the reg business but had a train to work . Do the Nismo ones flow more or are they just adjustable ?

A .

Edited August 27, 2013 by discopotato03

[discopotato03]

This is a link off the above Evom thread that goes into overrunning the standard FPR .

http://highboostforum.com/forum/showthread.php/28719-TESTED-Stock-Evo-8-9-FPR-Capabilities?

Fuel systems get deeper and deeper . Not sure if there is an easy answer to regs if you don't like glitzy looking aftermarket ones .

I was wondering a while back what would happen if you ran a second OE style FPR in the line before the rail and spliced it into the standard return . In theory both would close up as manifold pressure rose but have double the flow arera of the std single one . Also in theory not all the supply runs through the warm rail .

That aside looked at Britax large spade 80a relays today and need to find a supply of non insulated 9.5mm terminals and insulators for them .

A .

[GTSBoy]

I wouldn't use two regs. If I wanted to achieve the regulator goals you talk about without running the risk of dead-heading the fuel rail with hot/vapourised fuel, I'd simply replace the standard reg at the outlet end of the rail with a small orifice that will pass fuel 100% of the time and place the big aftermarket reg wherever it needs to go before the rail (so that could be in the engine bay or it could be immediately after the pump.

In this way you will always circulate fuel through the rail and back to the tank, but the vast majority of it will never go there.

The problem with two separate regulators doing the same job in parallel is that they will never have the same setpoint. They will always be slightly different. So when the pressure rises to the setpoint of the lower set reg it will open and allow fuel to spill and the other reg will stay shut. If the flow area of the lower reg is insufficient then the pressure will rise above its setpoint and the higher set reg will start to open. This means there will always be some fluff in the fuel pressure setpoint. It will go up and down. If the regs are really close to each other then this won't be a problem. But there is a chance that the difference will be big enough to cause some issues. A permanent very small bleed solves the problem without bringing any real problems of its own.

[discopotato03]

If you have to resort to a higher flowing FPR which are the better ones ?

A .

[GTSBoy]

I dunno. Names like Sard tend to be respected.

[scotty nm35]

I have been using an SX reg for quite a few years on ethanol.

Watch for the Sard copies...

[discopotato03]

I searched the SX ones and they claim to have better diaphragm material to suit alternative fuels like ethanol . I didn't see any pics of them in Skyline engine bays , do you have any of yours Scotty ?

Really the way forward looks like doing the top feed conversion to EV14s then the reg and pump and sort the pumps wiring .

Scott would you go with Xspurt shorty 740s / XS reg / DW300 pump in a GTS25T ? I doubt I would see more than 340 or so wasps at the wheels just to give you a number .

Cheers A .

[scotty nm35]

I will try and get some pics, unless this engine bay shot is good enough?

That sounds like a good setup for around that power.

[discopotato03]

I stumbled on these insulated bulkhead power terminal bolts to get higher current reliably into your fuel tank .

http://www.efihardware.com/products/1593/submersible-pump-bulk-head-terminals

I searched long and hard for this kind of thing a few nights back without success .

A .

[scotty nm35]

They look handy, as they have an Oring seal.

[Ben C34]

I stumbled on these insulated bulkhead power terminal bolts to get higher current reliably into your fuel tank .

http://www.efihardware.com/products/1593/submersible-pump-bulk-head-terminals

I searched long and hard for this kind of thing a few nights back without success .

A .

They look good, but couldn't the fuel leak through the actual thread? Unless the nylic nut seals it off? I am going to machine up something similar, but solid so there are no chance of leaks. Well take some pics when done, hopefully tomorrow.

[discopotato03]

I think the white nylon spacers with the O rings top and bottom may be threaded though anyone's guess how neat a fit they are on that bolt . I suppose a very light smear of a suitable sealant may stop tank pressure feeding up through the threads .

For an R33 you don't need it to be insulated because the tank lid and ring aren't metallic . A modified brass or stainless bolt could probably be made to work with a dowty seal . Jamb nut to clamp it up and some means of fitting an eye fitting to the head .

I've been looking into Britax relays - R4-1280R is an 80a on/off with 9.5mm terminals and 6.3mm coil spades . They have a resistor in them to protect computer circuitry whatever that means .

They doing a mount base with brass non insulated terminals as well Pn 99025 .

A .

[Hanaldo]

They have a resistor in them to protect computer circuitry whatever that means .They doing a mount base with brass non insulated terminals as well Pn 99025 .A .

Means the low load circuit would have a built in resistor to protect the ECU from any surges.

I don't see the advantage of this relay to your standard 60a horn relay though? 60a is thoroughly overkill, and I use a 30a inline fuse. So 80a is unnecessary. The posts sound like they are a similar size too.

[discopotato03]

Just a little overkill and hopefully reliability . I think I know a way to parallel the std high low system using the original relay and FPCM to trigger a heavier duty system . From what I can tell the only thing stopping us from rewiring the std system is the current carrying ability of that FPCM which is a glorified protective (for ECU) switch .<br /><br />From what I gather R33 GTRs have the twin FPCM/resistors in a single assembly and they are famous for overheating and failing . The GTS25T has the single FPCM in the same place but the resistor (heat) is near the std jack .<br /><br />A .