EVO8LTW

iTrader: (41)

The way I see this, the single 450 would require the same amount of effort on the rewire and hobbs switch as the double with more current going through the additional wires for the singe 450 than a second 255 (more heat/fire potential), less predictable base fuel pressure, modification to the stock hanger to add a bulkhead fitting to eliminate the internal wiring clips (I don't trust them at higher wattage with some people experiencing melting), modification to the hangar for the siphon, modification to the stock hangar to fit the longer 450 pump (and still questionable clearance between the pump sock and the bottom of the tank).

The double route would require an inline filter (but I want that anyway with the crazy expensive 1650 injectors and more people having issues with E85 fuel), the same amount of rewiring as a single setup with less wattage through the rewire, retain base fuel pressure with stock regulator and unmodified siphon, no worries about pump clearance to the tank. Equal or more headroom for power since I could always up size one or both pumps.

Am I wrong on anything? I know I'm factoring in things on the single route that most people don't consider necessary, but if something can go wrong, it will for me and I'd rather add that fuel filter and bulkhead rewiring on the single.

Biggiesacks

The pumps need to be on separate circuits. Only one can be hooked up to the OEM wiring or you will be sending power to both during low speed operation and that would be bad. That's what would happen if you hooked them both up to the same hobbs switched triggered relay. So you need to use at least 2 relays and individual power feeds to each pump. You can trigger both relays with one hobbs switch though, and you could feed both relays with one large power feed. I would want to fuse each pump though so your looking at 3 fuses in that scenario, one at the battery and one at each relay. A sufficiently sized ground could be shared by both pumps.

As far as the filter goes, its an inevitability anyway. If your evo lives long enough you will need to eventually replace that OEM filter with something, and its either buy another OEM hanger or add in your own filter. I went the latter route.

If you know what your doing, sizing your wires properly etc. there is no danger of fire from additional current. You really just need to know what you are doing, and if you don't have the humility to recognize that and have a professional do the wiring install. Fires are no joke and a poor install could absolutely result in dying in a fire.

EVO8LTW

iTrader: (41)

I was assuming that the two pumps in the double would be on separate circuits. Stock wiring for the primary pump and a rewire with Hobbs for the secondary. Maybe I said it wrong in my previous message. I wouldn't need to rewire the primary, I wouldn't think unless I went larger than a 255 primary. So, only one relay to add and the reliability of the stock wiring and lower wattage for the primary. As far as wiring a 450, I would do the bulkhead fitting and run probably 10-12 gauge wire right to the pump directly through a bulkhead fitting (similar to what most double pumpers have), which is a safer route I think than most of the shops are doing where they piggy back on the stock wiring inside the hanger. Honestly, the lowest quality work I've had on any of my cars has been from shops. I don't have an English Racing or a RS Motors where I live, so I tend to do everything myself for peace of mind.

LetsGetThisDone

iTrader: (1)

Two pumps makes it harder to work on, and has larger potential failure.

You're retuning the car for different injectors anyways, it doesn't matter. It's a whole new tune regardless.

And a single pump setup is way less money.

EVO8LTW

iTrader: (41)

Okay, you convinced me. Now to find a non-counterfeit Walbro 450lph/274!

Biggiesacks

Even just a 255 pulls more power than the stock wires can supply. So just a single 255 install requires a relay/hobbs switch.

Balrok

iTrader: (15)

I've been on the same 255 with stock wiring for about 13 years now lol.

kaj

iTrader: (60)

I've been on mine for about seven or eight years now. And had them on all my other cars. Hm.

Biggiesacks

I didn't mean it wouldn't work. It's just not optimal. You get voltage drop with stock wiring and the pump is not performing to its potential.

I guess I should have said "requires to get your moneys worth / full performance"

You could wire up a 450 to the stock wires and it would kinda work, it would just fail at higher demand.

kaj

iTrader: (60)

So, a rewire will get me more HRSPRS???!!

Biggiesacks

Only if a lack of fuel is whats holding the ponies back. If thats not the case though, the reason to do it is to reduce the heat on the stock wires. The Resistance of the stock wires is what causes the voltage drop which is basically creating heat. That heat will accelerate the degradation of the wires over time.

kaj

iTrader: (60)

I'd have to review my logs.. it's been about two years. I *think* I ran out of fuel pump, but not sure. I have 1050s on e85 at right around 450whp or so. I don't want to completely tax the system. I wouldn't have a problem if I needed the rewire just to make things easier on the car.

LetsGetThisDone

iTrader: (1)

Order it from a Motorsports vendor. STM, ExtremePSI, etc

Balrok

iTrader: (15)

If they have it in stock, a quick look and all my sources say backorder with no eta.

However the black flag version seems to be available. BF450

EVO8LTW

iTrader: (41)

I ordered one from MAP, who claimed to have them.