So you’ve installed an upgraded fuel pump, you run big boost and you need lots of fuel flow and you still get fuel surge.

One option is to install a swirl pot, sure- lots of pipework and probably a little more complicated, also costs more then $10.

The other option is to modify your standard fuel pump return venturi.
I touched on this years ago in my tuna-tech article, but here is a little more information anyway.

First thing is to understand what the venturi does; its primary function is to pull fuel from the passenger side of the fuel tank over to the driver’s side, it does this by using the return fuel flow from your fuel pressure regulator.



With your stock fuel pump, at stock boost there is usually enough fuel on the return line to create enough vacuum to get the venturi working. When you upgrade your pump or increase boost, this venturi can create a choke point, or does not flow enough and does not promote enough fuel to come over from the passenger side of the tank. Net result, fuel surge.

To overcome this, a rarely mentioned trick is to open the choke point up with a 3mm drill bit, this allows the most amount of fuel to be extracted from the passenger side of the tank to keep the driver’s side of the tank topped up.

To do so, remove the fuel pump from the tank carefully.



wiggle off the venturi from the assembly



take a look at the nozzle, there is the restriction.



so, grab your drill with a 3mm bit, drill it through, being careful not to go too far and drill into your hands!



and there you see the restriction is removed.



reassemble and fit back to your car.

Enjoy!

disclaimer-

If you are clueless.

Do not attempt any of these modifications.

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Long live the WRC

Like!

Loving the Tuna Tech, especially when they are easy to do and cheap!! Keep em coming Stace, if for nothing else then to broaden my knowledge base

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Now handles like a cat on carpet

Amazing! Well done!

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Huge range of extinguisher brackets for cars!

http://kap.industries/

Brilliant, had I known this when I fitted my Walbro about 6yrs ago it would have saved me getting a lift to a servo and buying a tin and petrol....went fast up a steep r/h drive into work with very low fuel (about 5 L but always drive it that low) and it threw what was in the tank over the hump to the left, I must have made it to the parking space with what was in the lines not giving the system time to throw enough fuel back to the drivers side, went to start car after work and empty so lesson learned, this mod could have pushed that little bit I needed over to start the car.

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Beaten up old 98 Gen 2 Liberty, 13.0, stock V3 STI running gear.
07 Transit motor home
69 VF & 70 VG Valiants needing full restoration
Yamaha Zooma 50cc rocket hopefully going with the Transit.

forgot to mention this mod is probably only applicable for RS/GC/Early GD's

i'm not completely familiar with how the GH/GR fuel pumps are configured.

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Long live the WRC

Loving these little DIY mods Stace. Is this worth doing on a car that is likely to only run stock boost?

only if you get the odd surge and have a larger fuel pump.

i think half the 'surge' issues people have are just the clogged venturi anyway!

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Long live the WRC