Installed surge tank last night

[z-ya]

I installed a surge tank in my turbo 240Z last night. Not sure if anyone has done this, but I used one of the steel expansion tanks as the surge tank. So far it looks like it's working perfectly. Mounts in the stock location, as if it were designed to be there (ahem, it was ).

 

Here is basically what I did, I'll take some pictures tonight and post.

 

I used the stock ~3/8" barb on the bottom to feed the high pressure pump. The large side barb I soldered in a right angle 3/8" barb and ran it to the low pressure pump outlet. The 5/16" barb on the top of the tank is the return back to the primary tank. I then soldered in another 3/8" barb in the bottom for the return from the high pressure regulator. I drilled three holes to the rear of the filler hose and installed grommets. I rasn the new hoses through them.

 

I'm using a EFI pump as the low pressure lift pump. It seems to pumping lots of fuel. I'm asuming its is OK. I figure that with litttle to no pressure, it sould flow a lot. Here's a question, will an EFI pump flow more at zero pressure than the normal 43psi they are measured at?

 

I haven't had an expansion tank in there since I've owned it (all of the tank vents are connected together with pipe fittings, and connect to the hole in the filler hose). I've always been able to fill the tank OK.

 

I won't know for sure if this fixes my NHIS turn 6 starvation problem below 1/2 tank until late May. Hopefully this fixes it.

 

Pete

[Xander]

I have build a small surge tank. Now my MSD 2225 pump is a lot more quiet since it is below the fuel level at all times. Works great.

It never really fixed my fuel starvation problem because that was caused by a rusty fuel tank. I have fixed this by derusting and coating the inside of the tank.

 

I did not have a stock tank that I could have used. My european spec 260Z didn't come with any.

[Tim240z]

Pete,

Which tank did you use. I am planning to do something very similar so I can turn the fuel cell around and face the outlets forward so that they are hidden. I was going to just use a cheap low pressure carby pump to transfer from the cell to the tank, and run the return line from the rail back to the tank instead of the cell. I was thinking about actually making up a tank out of aluminum, with one -8 outlet at the bottom and three fitting on the top...1 for incoming fuel from the cell, 1 for incoming fuel from the fuel rail return, and one overflow back to the cell.......

Is that about how yours is set up?

 

 

[edit] Just re-read your post...did you use the emissions tank from the passenger side quarter panel?[/edit]

[Owen]

I'm watchiing this thread.

[z-ya]

Yes, I used the steel expansion (EXP) tank that is on the passenger side, behind the rear wheel.

 

I couldn't do three fittings on top because there isn't room. There is an existing one on the top that I used for the return back to the main tank (stock 240Z). The lift pump (low pressure) pumps fuel into what was the large hose barb to the rear of the EXP tank (that used to connect to the rubber filler hose), it's about 2/3rds of the way up the EXP tank. The main feed to the high pressure pump is connected to the existing 3/8" barb at the bottom of the EXP tank. I then added another 3/8" barb to the bottom of the tank for the high pressure return (from regulator). The last remaining stock hose barb I squished flat on the end, and then soldered it. I checked the tank for leaks with a vaccume pump, and it held the same vaccume for 3 hours. Solder all your fittings to assure you get a good seal.

 

Yes, you definetly want the return from the fuel rail to go into the surge tank. It's 4 new hoses running around under there, so it's kind of a rats nest, but it should work OK.

 

Pete

[RB26powered74zcar]

I'm watchiing this thread.

 

ME TOO.....

[z-ya]

Couldn't get the camera last night, so I drew a schematic of how I connected the expansion tank as a surge tank. The drawing is in my photo album.

 

The surge tank seems to be working fine so far. I'll let everyone know if I have an problems with it in the future.

 

Pete

[pparaska]

Me Three

 

And Pete, to answer your question about flow volume versus pressure, here's an example:

 

A low pressure pump might be a better idea for a lift pump. I plan on using a really low pressure carb pump (like 3-5 psi) to lift to the surge tank.

 

I hadn't thought of using that vapor tank, but I think mine leaks anyway . Cool idea though!

[z-ya]

OK, drove it to work today , and took some on and off ramps pretty hard (got my 245-45ZR16 Toyo RA-1s on there). No problems to report. I had about 1/4 of a tank, and watching my O2 display, it never leaned out.

 

The lift pump I'm running is a Bosch pump that I picked up on Ebay new for $20. It was supposedly used in a Renalt. I think it is going to be fine for the street, but on the track it may not be able to keep up. It looks just like my big Bosch pump, but just a little smaller (little brother). It seems like they operate at the same RPM, because it still sounds like I've got just one pump under there.

 

Pete, looking at the plot you posted, it looks like a high pressure pump should be fine as a lift pump. It looks like that pump will deliver another 10+GPH at zero PSI as compared to 40PSI (~22% more), and the current draw is way down too. There should be zero PSI in the surge tank, it's all flow, no pressure.

 

Pete