Fuel surge

[ChrisMParticipant Melbourne VicVN Calais LS1 View build HERE Member since: August 16, 2017 Posts: 140]

Hi All, I have a 8olt drop tank in my car and the car runs really well until i get to the last quarter of a tank then it starts to surge a little bit. dose anyone have an idea what would cause this issue?

[Anonymous View build HERE Member since: January 1, 1970 Posts: 0]

Slosh maybe, or the pickup might be high in the tank.

[cava454Moderator 93 VR BT1 View build HERE Member since: February 20, 2015 Posts: 2 390]

Check the internal rubber return hose is still intact and connected

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

As above, but do you mean a stock tank or custom made?

[ChrisMParticipant Melbourne VicVN Calais LS1 View build HERE Member since: August 16, 2017 Posts: 140]

It is a factory drop tank. I might have to remove the sender unit and check it.

I was thinking maybe the swirl pot was the issue.

[ChrisMParticipant Melbourne VicVN Calais LS1 View build HERE Member since: August 16, 2017 Posts: 140]

Just an update:

I have bought a surge tank. Last week i started to lose fuel pressure when over 1/4 acceleration. I am replaceing the walbro pump in the tank with a areoflow standard pump to use as a lift pump. Then running a Proflow 380Lph external inline pump. The surge tank is made to go under the car.

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

Nice, I am interested to see pics of it installed.

[ImmortalityParticipant 97 HSV Senator 185i 02 VX L67 Calais View build HERE Member since: August 31, 2015 Posts: 535]

^^^  I’ll 2nd that.

[ChrisMParticipant Melbourne VicVN Calais LS1 View build HERE Member since: August 16, 2017 Posts: 140]

I have some pics of how they mount. I will also add photos of mine once its done.

These tanks are meant for a VL but i have seen these mounted to a VN.

[cava454Moderator 93 VR BT1 View build HERE Member since: February 20, 2015 Posts: 2 390]

Surge looks good. But the pro flow and Aeroflow fuel pumps are rubbish. I’ve seen several fail in mates vehicles

[ChrisMParticipant Melbourne VicVN Calais LS1 View build HERE Member since: August 16, 2017 Posts: 140]

i hope they dont fail haha. my walbro is failing atm.

[cava454Moderator 93 VR BT1 View build HERE Member since: February 20, 2015 Posts: 2 390]

Genuine walbro?

[ChrisMParticipant Melbourne VicVN Calais LS1 View build HERE Member since: August 16, 2017 Posts: 140]

Yeah it is a genuine walbro. I started to lose fuel pressure under load

[ChrisMParticipant Melbourne VicVN Calais LS1 View build HERE Member since: August 16, 2017 Posts: 140]

Hi all. Just an update the surge tank is fitted. I had to cut the rear brake line holder bracket. But she’s in ready to be plumbed up.

[ChrisMParticipant Melbourne VicVN Calais LS1 View build HERE Member since: August 16, 2017 Posts: 140]

Here is a picture of the surge tank mounted underneath the car for anyone interested.

[ChrisMParticipant Melbourne VicVN Calais LS1 View build HERE Member since: August 16, 2017 Posts: 140]

Hi All.

Thought i would do a little write up for anyone interested in doing the install. I bought my surge tank from JD Custom Automotive in Mornington Vic for $250. The surge tank is made for a VL. It fits up under the drivers side in front of the diff where the fuel filter sits.The top 3 fittings on mine are -6an and the lower one for the fuel pump is -10an. He can customize the fitting to what you need.

The first step was to jack up the car and place the jack stands under the rear control arms to ensure your diff sits as it dose on the ground so you can ensure the tank is above the control arm height.

The second step is to remove you fuel filter and you will need to cut out the rear brake line holder bracket and relocate once the tank is in and mounted.

The third step is to make sure you have coldies on hand. Maybe an extra set of hands.

The fourth step is to remove the rear seats, hold the surge tank up so all three bracket mount to the floor. This will take a little bit of fiddling. Then drill a hole for the first bolt from underneath the car . You might need a second person to help with the bolt so you can put the nut on from underneath. Once that is secure do the remaining bolts.

The fifth step is to cut down the fuel lines to your desired  length depending on the external fuel pump and fitting you use. For mine i used 4x Aeroflow -6an 90degree 5/16th barb fittings and a -10an to -10an female coupler. I will list the part numbers that i used. The top connection is you feed from the fuel tank. the right connection when facing the flat back is for your  overflow to the fuel tank. The left connection is the return from your rail. (see attached diagram)

The sixth step will be to wire up your external fuel pump and reinstall your rear seat.

 

Aeroflow Fittings that i used.

-6 to 5/16” 7.93mm – AF413-06-05BLK x4

-10 straight coupler – AF131-10S x1

 

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

Nice write up mate, forgot you had a live axle, gives more room.  Nice work.

[ChrisMParticipant Melbourne VicVN Calais LS1 View build HERE Member since: August 16, 2017 Posts: 140]

Thank you.

Yeah but it has its good and bad being live axle.

 

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

Yea won’t lie, I am not a massive fan of the design job Holden did on the IRS on these cars.  Massive camber change built into the design, plus the weight of the subframe, that is also prone to cracking.  I would much prefer live on mine unless of course, you have the fab skills of IJ and design your own set up from scratch

[ImmortalityParticipant 97 HSV Senator 185i 02 VX L67 Calais View build HERE Member since: August 31, 2015 Posts: 535]

VRSenator065 wrote:

Yea won’t lie, I am not a massive fan of the design job Holden did on the IRS on these cars. Massive camber change built into the design, plus the weight of the subframe, that is also prone to cracking. I would much prefer live on mine unless of course, you have the fab skills of IJ and design your own set up from scratch

 

Holden designed nothing, they borrowed it but removed the toe link arms it came with which only re-appeared when HSV re-introduced them for the GTS to improve traction and became standard during the VX.

I’m not sure about the cracking issues, seems to be more prevalent in the early version, it’s not something you hear about in the later models (not that I’m aware off anyway).

 

I’ve driven both and the IRS has it’s advantages but if you are interested in drag racing than semi-trailing is definitely the way to go.

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