I have the combo in my sig. and am going to add a 150 shot soon. Estimated HP is 550 with the nitrous. Will the Walbro in-tank high pressure 255 ltr/hr fuel pump be ok with this? Is there a better fuel pump I should consider?

 

Just wanted to let you know that I used to run a combo similiar to what you are with the same pump. When I ran the 150 shot it seemed like I was running a little lean in the upper end. You might want to consider sumping your fuel tank and running some bigger externals. I've also heard of some people rigging two of the in-tanks together. Just thought I would let you know.

 

Sump the tank? Do you really think this a a cost effective alternative?? What do you mean by bigger externals? Larger lines?

 

you could try one of the inlines like is used with the blower kits. using this with the stock intank could give you the delivery you need.

 

As far as cost effective......I'm not sure there is any such thing as cost effective when you're trying to obtain reliable HP and 1/4 times. When I say externals I mean external fuel pumps as opposed to in-tank fuel pumps. I've seen guys get low 10's on the stock fuel lines so I would think that the fuel lines are fine as long as you have a good pump. I'm just saying that with the combo he's talking he's probably pushing the limit of the 255 ltr and I was just offering a suggestion as something that I would do.

 

one other option could be a Kenne Bell "boost a pump" it raises the voltage to the pump.

If you want, there's a old post all about in-fuel pumps, and also some about sumping the tank...

let me see if i can locate them...

later
larry

 

I've known of others as well as myself in the past that have run Walbro 255s with a 150 shot on similar combos to yours with no probs at all.

Don't forget to install a fresh fuel filter with your new pump, and check all hardlines for kinks, flattened places, etc. and check rubberlines for internal swelling, kinks etc., basicaly anything that might pose a restriction. Monitor fuel pressure at least on your first few passes.

Heres a thread from the past wth a few different opinions on fuel systems. Even though it was primarily about applications with manifold boost it still has relevent arguments.

 

That's the post i was looking for!!!! thanks...

later
larry