FCar2000TA

iTrader: (7)

I know that a Walbro 450LPH will fit the stock pump bucket with a little cutting on the bottom of the bucket, but what about this new 525LPH pump?

131mm long
39mm main housing
50mm lower housing
11mm in
11mm out

gametech

iTrader: (1)

If you need that much fuel, the idea of a stock bucket is ludicrous. Even cutting the bucket for smaller pumps is a really bad idea, as it completely negates the idea of a stock fuel bucket. Skimping out on a few hundred in parts and a few hours work on plumbing an adequate fuel system is a good way to spend thousands on a new motor and dozens of hours of work.

FCar2000TA

iTrader: (7)

I don't need the higher fuel output yet, but since the fuel tank is going to be out for the mini-tub kit, I might as well upgrade the pump and regulator. I'm looking for the most I can go with stock lines.

JoeNova

I was under the impression that it was the same externally as the Walbro 450.

gametech

iTrader: (1)

If you are pulling the entire fuel tank to do a mini tub kit it would be a perversely wrong hot rodding **** up to not just do a proper return fuel system.

FCar2000TA

iTrader: (7)

That is the other option. I was planning on doing the C5 filter/regulator kit from Hawks. The future is a resleeved LS2 454 NA. I thought that the stock fuel lines would support that, but I am thinking that just doing a high pressure filter and an adjustable return/regulator at the fuel rail might be a better plan.

eaglegoat

It's the same pump as the F90000274 drawing more amps to make more flow. It's way more pump than you'll ever need for an NA 454. You don't need to be fancy with your fuel system. Simple is easier and cheaper.

FCar2000TA

iTrader: (7)

So, stock fuel lines, C5 fuel filter/regulator, and a Walbro 450 will work for E85 and a resleeved LS2 454?

Mavn

iTrader: (3)

I run a drop in wally 450 stock lines/reg on my 02 Camaro . its a 416 ci that makes a touch over 550 tire and we've never had a fuel issue

JoeNova

Walbro 450 and C5 regulator don't play well together. Your fuel pressure will be over 70 PSI.

ddnspider

iTrader: (26)

you can tweak the air/fuel tables to account for that. You don't HAVE to run at 58 psi.

FCar2000TA

iTrader: (7)

Eh, I think I will just start looking at info on how to install a return style system with an adjustable regulator.

JoeNova

Its inconsistent though. You'll have 70+ at idle, and it will drop back to 58 when you start making power. You end up with a lot of odd circumstances where a given cell in the VE table may not be proper fueling based on fuel pressure.

ddnspider

iTrader: (26)

That just means it won't be linear in the tune. you can still account for the change in fuel pressure. I'm not saying its the theoretical "right" way to do it, just that it can be accounted for.

eaglegoat

It's honestly not much more expensive and not that difficult.

You cannot compensate for erratic fuel pressure in the gen 3 computers.

ddnspider

iTrader: (26)

Fuel pressure drop is typically not erratic, it's usually linear unless something is failing. Because it's usually linear, you can compensate for it with the MAF transfer function or VE table. Again, not perfect but it'll work.

eaglegoat

In a situation where your pump just isn't quite big enough sure. In this situation where you have a regulator not working correctly it's a bigger crapshoot and more likely to be erratic.

Either way it's less than ideal.

ddnspider

iTrader: (26)

If you're going to talk about a regulator that isn't functioning properly then anything is possible and you've got a problem either way. At that point all bets are off anyways.

JoeNova

Works fine for vacuum referenced regulators. If its a static pressure regulator and the PCM has no way to determine that fuel pressure has increased, you're basically leaving it up to fuel trims, etc.

ddnspider

iTrader: (26)

My assumption is that it hasn't already been tuned and you know about it at the time of turning, not that something has changed after the fact. There are plenty of ways to blow a motor if we're talking about something changing after the fact.