Fuel Surge Issues?

[No Crust Racing]

CA18 track car, not fast but potentially fast enough to move fluids around too much. I'm assuming it's fuel surge. Walbro 400lp/h pump.

Car will cough, splutter and miss coming out of right hand corners when the tank is below 1/3rd -so fuel moves to the left.

It's now happening with the tank half full/a little under half.

Still likely to be fuel surge or more likely a wiring issue?

The pump is hose clamped to the hanger as low as I could get it without it touching, I also remove the lower mounting surface from the arm so it was not obstructing the picking.

Surge tank time or something else?

And if surge tank, what's the easiest/cheapest way to achieve this?

[scotty nm35]

High G force turns on slicks will pretty much ruin any chances of keeping the fuel around the pump pickup. Looks like you need a decent surge tank setup. I guess now you need to decide on a budget, because braided teflon and fittings aren't cheap... Will you be looking at an external pump, or trying to fit the walbro into the surge tank?

[No Crust Racing]

Only using 235 RS-Rs

I thought with half a tank in it, there should be enough fuel but maybe not.

Budget would be as low as is safe. It doesn't need high end stuff as it's only tracked from time to time and it doesn't use a heap of fuel so flow is not a big problem.

No idea about pumps, whatever is cheapest and easiest. I know I need a second pump but I was under the impression the second pump could be basically anything?

[scotty nm35]

It depends where the surge tank is mounted, if it's inside the car I would want motorsport fittings, not push on rubber lines. Underneath, there are still rocks and crap flicking up...

Or just run with a full tank like I do.

[No Crust Racing]

Fair enough, the standard tank has push on rubber hose into hard lines, can't be that bad.

That said, can't hurt to look at prices.

I'll do some searching for some diagrams to show me how all this stuff is supposed to work/be mounted.

[boostn0199]

Fair enough, the standard tank has push on rubber hose into hard lines, can't be that bad.

That said, can't hurt to look at prices.

I'll do some searching for some diagrams to show me how all this stuff is supposed to work/be mounted.

Nothing wrong with just efi hose and push on fittings. Ive used it on my surge setup for 3 years no issues and ive actually not been able to take off the lines off the barbs its that tight so no safety issues for it coming off. Cheapest way just get a surge tank and your basic speedflow push on fittings and some efi house and whatever pump you want and problem will be solved for a few 100 dollars.

[No Crust Racing]

Any special pump required for external mounting?

Also where doors the "good" pump go? Feeding the surge or feeding the engine?

[KiwiRS4T]

Well the better pump should feed the engine as it has to build pressure so just get a cheap pump to use in tank,

You can get heaps of info and diagrams on surge tanks by Googling but you could easily spend $1000 although it could be done for less.

I would tend to go with Scotty's advice - just buy a couple of 20L containers and keep your tank full.

[No Crust Racing]

Yeah I've got 2x 20L but with the upper half of the tank being another 20L or so it means there's only really 60L of fuel, or just over 1 full tank worth.

During a full track day, up to 150ks plus I can easily go through a full tank and almost both 20L containers.

I could just buy a 3rd 20L container but it's a pain in the ass carting them around.

Not to mention carrying an extra 20-30kg i don't need.

Edited June 30, 2014 by ActionDan

[boostn0199]

Well the better pump should feed the engine as it has to build pressure so just get a cheap pump to use in tank,

You can get heaps of info and diagrams on surge tanks by Googling but you could easily spend $1000 although it could be done for less.

I would tend to go with Scotty's advice - just buy a couple of 20L containers and keep your tank full.

how is that a good solution? It doesnt solve hes problem cause now you have half capacity of your tank, you have to muck around with bringing more fuel, potentially still having the problem occur if you let it drop again and if your racing around you want to get all the free weight off you can. He can solve thos problem for under 500 and be able to run it down til the light comes on if you wanted to.

[scotty nm35]

If it's trailered to the track, I don't see an issue with the surge. If he drives it... Perhaps not a great idea. I would run the surge as the best option, but hide it well if used on road.

[No Crust Racing]

It's trailered.

Also a mate just offered me a free surge tank and I remembered I have a spare stock pump I can use as a lift.

Do I need to put a plate on the rear firewall to seal the boot in?

[scotty nm35]

Why not just leave the Walbro intank? You will need an external pump of some sort.

[No Crust Racing]

I assumed I i'd use it to feed the engine but your comment implies it can't be externally mounted?

[boostn0199]

If it's trailered to the track, I don't see an issue with the surge. If he drives it... Perhaps not a great idea. I would run the surge as the best option, but hide it well if used on road.

Yeah that was kind of the reason I had for suggesting surge is best option since he said its a track car so I assumed street stealth wasnt an issue but if it was a street car with occasional track then yeah you would sacrafice a little bit and live with having to fill it up.

I assumed I i'd use it to feed the engine but your comment implies it can't be externally mounted?

Just leave it in tank and atleast you know you have a overkill lift pump that you dont have to worry about failing. Pumps are pretty cheap these days so take your pic to whatever you want to use as your surge feed pump. I personally use a 044 but yes they are old and there are better pumps out there but I got a few for cheap and they do the job for me.

[No Crust Racing]

So correct me if I'm wrong.

Green - Feed from surge tank through additional fuel pump (to be purchased) that feeds the engine.
Red - Return from surge tank to fuel tank.
Blue - Can be either feed from fuel tank to surge tank or returning from engine
Yellow - Can be either feed from fuel tank to surge tank or returning from engine

Also, standard fuel hose is 5/16th?

Black circle is a hole I'll likely have to cut into the spare wheel well.

Do I need to section off the boot from the cabin now?

Edited July 6, 2014 by ActionDan

[boostn0199]

So correct me if I'm wrong.

Green - Feed from surge tank through additional fuel pump (to be purchased) that feeds the engine.

Red - Return from surge tank to fuel tank.

Blue - Can be either feed from fuel tank to surge tank or returning from engine

Yellow - Can be either feed from fuel tank to surge tank or returning from engine

Also, standard fuel hose is 5/16th?

Black circle is a hole I'll likely have to cut into the spare wheel well.

Do I need to section off the boot from the cabin now?

IMG_20140706_143156 - Copy.jpg

Yeah thats correct, I personally run the return from surge to fuel tank on top but yeah either works whatever you prefer. Youll have to other seal off rear boot from in cabin or make a enclosure for the tank.

[No Crust Racing]

Same thing was suggested in another thread actually.

[No Crust Racing]

Question regarding the feed from the surge to the pump.

Given the feed out of the pump and into the fuel system will be 5/16 EFI fuel hose like what's already there, can the feed into the pump be the same or must it be bigger?

I ask only because that fitting is 10AN compared to the 6AN used everywhere else.

My plane was simply to buy AN to 5/16th barb fittings like these. Though I'm having trouble finding a 10AN to 5/16 barb to so I might have to go 10AN to 8AN then to 5/16.

http://www.ebay.com.au/itm/Speedflow-5-16-8mm-Barb-to-6AN-AN6-AN-6-Female-Hose-Fitting-Adapter-Push-On-/271437188344?pt=AU_Car_Parts_Accessories&hash=item3f32eaccf8&_uhb=1

And then just use something like this hose for everything and these clamps.

http://www.ebay.com.au/itm/370906965297?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

http://www.ebay.com.au/itm/160749548016?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

[scotty nm35]

Most large external pumps will require 10an at least to feed them, to stop them cavitating.