iain atkins

Just wondered if there are any pictures of this about.

I understand the setting up etc (i.e. run pumps in parallel etc etc), but just wondered on the oe wiring side after the pumps. Is is just a case of a slightly bigger fuse and off i go? Or will i need to run a dedicated feed?

I have some stainless tie wraps to strap them together etc, and a nice high flow brass y piece etc.

How much more flow will i create, and all the disadvantages and advantages please from the people that have done this.

Thanks v.much


Iain

harvey

iTrader: (48)

Don't want to be negative but it sound like an unnecessary complication. Complication = unreliability. Why do you need to do it when a Walbro 341 is good for at least 450 plus bhp from personal experience and a Bosche unit is good for 600bhp or more?

David_Wallis

Id disagree with the above but thats just me.. (i wouldnt try going above 450 on OPTIMAX)

I run two Large walbaro's in the petrol tank and with std wiring over 160 -180mph no matter what we do we cant get any more fuel in due to the volts dropping off on the pump and the wires getting a 'little warm'.. they need a different feed, Ie some 4 -6mm cable and a couple of large relays (30A), might also be worth checking what the flow down an 8mm tube is at a given pressure, (ie base pressure + max boost) doubt it may be a prob though, but if your using two pumps and a sx reg it makes sense to feed each rail with a pump and seperate feed, and then return them to the SX and back to the tank.

Most of the high powered cars use twin bosch pump setups. (i also have two 044 bosch pumps)

Andy says his car is struggling with the fuel pump now, Steven (p20spd) is also having problems with his fuel pump.

I do have some pics at home though.

David

john banks

David, what can a single Bosch pump handle over the GSS341? Presumably not much if you end up with two of them after further power increments?

I've not had any trouble with the GSS341, but my turbo isn't big enough to expect trouble with the limited power it makes on Optimax.

P20SPD

iTrader: (1)

John, my Walbro has worked flawlessly over the last 2 years, only recently, ie out mapping for TOTB3 and to now has it started to struggle under load. Its now dropping off upto 0.6 bar as revs and load rise.

Fortunately, the in car FPG tells me this, and i remember to lift off/ease off.

I am fitting 2 new walbros as replacement to the old single walbro, as i dont want to chance it.

I would put money on the fact that my car isnt massively over 400, thats if it is over 400, so i certainly wouldnt run a single pump for 450 or higher, but thats my own choice.

Hasnt Bob had problems with the Walbro?

I wonder if once power is above a certain level, and therfore the fuel requirement is higher, that the life of the walbro is shortened greater as the fuel demand increases. Consequently, below say 380, the walbro will work fine on an everyday car with everyday fuel, however above this level its ability diminshes greatly.

?

john banks

I recently put a new one in anyway whilst fault finding a pressure drop which was actually the FSE reg. Have in car fuel pressure and wideband so can watch it OK.

Bob Rawle

I have had problems with the one in the STi5, but it has done 40,000 miles, it loses pressure right across the whole load range not just at the high boost when the fuel level drops enough for it to come out of the fuel (ie it gets hot), also seen problems with three others, having said that seen same problems with the Bosch 044 so pays your money, I'm putting a fresh Walbro in pending sussing something better. I use the SX reg so was a pump issue.

bob

iain atkins

Cheers guys

Gives me something to think about. I was thinking about it from a safety point of view, but i guess i'm not at quite that level just yet.

I will watch this post with interest though.

Cheers all



Iain

P20SPD

iTrader: (1)

Bob, thats about the mileage mine has done, and it is as you say, sufferring across the whole rev range, even in 2nd gear.

PICKLE

Surely for the sake of £130 odd it costs for a new Walbro, it'd be worth changing it for a new one after all the other hard work you've done to yours Steven! Piece of mind if nothing else.

Or, get Wallis to sort you out with a couple of his 'specials'

bren@apex

iTrader: (20)

£130? Is that the going rate for the GSS341s for Subarus?

P20SPD

iTrader: (1)

Pickle (think its James ) i have 2 new ones sat on my workbench in the garage (They arrived on Monday). Waiting for my fuel rails to be finished (wallis if your listening ) before they go in, together with the new braided hoses etc, which i have now had since April.

I wish my engine bay looked as clean and tidy as yours

Not sure on going rate bren, not paid for them yet