Hot Surge Tank

[RB30TI]

Hey all, my car has been playing up lately when i drive it (RB30et), the things thats happening is that it feelings like its missing some times even befor boost and feels like crap untill i back off, last nigth i was driving and was running shit i didnt have much fuel in the car to i put some it and it did run better but still not great.

I pulled over and felt my surge tank which is located in the boot and it was f**king hot. the fuel set up i have is standard pump pumping to the surge tank then 1 x 044 pumping to the motor, now i recon coz i only had abit of fuel in the car it was curculating (not sure on spelling) the fuel around the system alot quicker then if i had alot of fuel in the car thats why i recon when i put more fuel in it ran better.

Any one had this problem? also im pretty sure i had the surge tank in the car last summer also. so not sure why its started now?

Any Idea people? and i know sure tanks should be mount external of the car.

cheers for any help.

[paulr33]

hot fuel can make it run like ass

check the pump setup you have isnt too big, ie the relay surge pump isnt pumping fuel flat out when the fuel rail doesnt need

this makes the fuel come back and circulate around, and like you said, it gets hot doing this

[discopotato03]

I would have thought that an 044 is going to have a lot of fuel doing the roundies between the engine bay and the pot , actually if it was plumbed to the fuel tank it would probably be the same . It may pay to insulate any exposed sections of steel fuel line in the engine bay and this can be as easy as slitting large bore rubber hose and fitting it over the rail etc and retaining with zip ties . The less exposure the steel lines get the better as they have a fair bit of surface area and a lot of fuel racing around to conduct the heat to . It goes round and round in circles so much that it warms up over time and can form bubbles if it boils .

When you car acts up try cracking the fuel filler cap to see if there is considerable pressure in the tank itself .

A .

[The Mafia]

can you give us a little more detail in your mods?

You might need a fuel cooler.

Also, do you really need a surge tank? Do you drift \ race? Are you making over 500hp?

[Russco]

Best fix I found to this problem was to run a small Permacool fuel cooler in the return line (low pressure side) between the regulator and surge tank - works a treat. Just make sure it has ample airflow and you mount it within the chassis rails for safety.

Edited October 30, 2009 by slapper

[blind_elk]

Don't understand why you are using a high pressure pump to keep the surge tank topped up. A low pressure, low volume pump is more than sufficient.

Does the surge tank overflow back into the main tank? (it should).

[Cjmartz2k]

Don't understand why you are using a high pressure pump to keep the surge tank topped up. A low pressure, low volume pump is more than sufficient.

Does the surge tank overflow back into the main tank? (it should).

Agreed, but I don't see how a high flow lift pump would make the heat problem worse than normal. I think it's just to much going to the engine bay during low speed cruising.

[timsr33]

i have the same problem and the problem is that the fuel return line is running back into the surge tank the way to fix is to have the return line go back in to the fuel tank hot the surge and get a lift pump that can out flow the bosch 044 thats what im doing anyway

[RB30TI]

The Mafia: Yes i do really need a surge tank, motor is RB30et fully built bottom end, pretty standard head with after market cam, the stock pump in are shit house in the r31s it was maxin out so i put the surge tank and bosch 044 in.

blind_elk: I am using the bosch after the surge tank not befor it. i have the standard pump in the tank pumping to the surge then from the surge tank it gets pumped out by the bosch 044, the return from the motor goes into the surge tank, the over flow for the surge tank goes into the main tank. this helps keep the surge tank as full as possible, if it was going from the motor back to main tank this means theres less chance of keeping the surge tank full.

Cjmartz2k: I partly agree with the low speed cruzing being a factor with this.

I Have Most of the parts togeather for my RB30DET so i will deff be needing the surge tank and bosch 044 when i get it up and running.

Also is there anyway the standard fuel pump could slowly dying? that would mean when i give it abit it uses what fuel is in the tank and wont fill up properly??? just an idea.

Edited October 30, 2009 by RB30TI

[shanef]

i have the same problem and the problem is that the fuel return line is running back into the surge tank the way to fix is to have the return line go back in to the fuel tank hot the surge and get a lift pump that can out flow the bosch 044 thats what im doing anyway

Doing it that way could caus airation issues that could lead to fuel surging. Not the best idea.

[RB30TI]

this it the pump and tank befor i put it in, if i took the foam off it would help but i doubt thats what causing ALL the heatin issues.

[tets]

last time i was in japan, i saw fuel coolers on a few track cars. great idea but i cant think what would happen it u have a hard front on impact.

[RB30TI]

id say you would try and mount it high underneath the chassis.

Any other ideas why this problem is happening? i put half a tank in last night but only drove it for abit and it wasnt to bad at the start but then it started to get shit towards the end.

[R31Nismoid]

remove the surge from the loop and go for a drive.

if the same thing happens then it's up the front end

Doing it that way could caus airation issues that could lead to fuel surging. Not the best idea.

Agreed - pretty silly idea.

[rob82]

Hmmm there is a reason that most jap cars generally run a two speed fuel pump control.

The issues you have are from sending too much fuel to the front of the car. Have you thought about making a one way fuel system and pissing off your return line?

[blind_elk]

The Mafia: Yes i do really need a surge tank, motor is RB30et fully built bottom end, pretty standard head with after market cam, the stock pump in are shit house in the r31s it was maxin out so i put the surge tank and bosch 044 in.

blind_elk: I am using the bosch after the surge tank not befor it. i have the standard pump in the tank pumping to the surge then from the surge tank it gets pumped out by the bosch 044, the return from the motor goes into the surge tank, the over flow for the surge tank goes into the main tank. this helps keep the surge tank as full as possible, if it was going from the motor back to main tank this means theres less chance of keeping the surge tank full.

Cjmartz2k: I partly agree with the low speed cruzing being a factor with this.

I Have Most of the parts togeather for my RB30DET so i will deff be needing the surge tank and bosch 044 when i get it up and running.

Also is there anyway the standard fuel pump could slowly dying? that would mean when i give it abit it uses what fuel is in the tank and wont fill up properly??? just an idea.

The "standard" pump is a high pressure EFI pump.

[discopotato03]

There is one school of thought that if the transfer pump can move enough fuel to keep up with the main one then the rail return can return fuel to the main tank . I guess the idea is to sent any heat back to the main tank with the fuel doing the roundies .

Trouble is that it just takes longer to heat up however much fuel is in the main tank and puts you back to square one later dependant on how full the main tank is .

The way I see it heat can only come from the engine bay and the pumps themselves so the go I reckon is to not overkill with pumps and find ways to insulate the heat from exposed steel/aluminium fuel rails etc .

If your engine is std I'd try just using the std R31 pump alone as an experiment to see if the problems go away .

Also the surge tank or swirl pot , it only does you any good if you can get the cornering forces that could give fuel surge problems at the fuel pickup in the main tank . Is this isn't happening the pot stuff is achieving SFA .

Do R31's have a tank surge issue ? Can the tank have baffles or a larger internal swirl pot fitted ?

Cheers A .

Edited October 31, 2009 by discopotato03

[SirRacer]

This problem is incredibly common with RB's and 044's. I myself have this problem with my car. I put in a fuel cooler in front of the grill to temporarily see whether it worked and it does, however im still not too confident about having a few litres of fuel hanging off the front of my car.

By doing this, my surge tank no longer retained the heat it use to, and my caviation and fuel cutting problems seemed to go away. It would still occasionally cut when the car got quite hot. Ive since changed pumps to one i know doesnt cut and will remove the fuel cooler and test to see whether it was perhaps just a dodgy pump.

[RB30TI]

R31Nismoid: I wouldnt like to take it off and take it for a drive because the stock pump wasnt keeping up thats one of the reasons i pump the 044 in.

rob82: One Way fuel system??

blind_elk: They may be high pressure standard pump but there shit house. what part of THE STANDARD PUMP WOULDNT KEEP UP didnt you get?

discopotato03: Yeah its fairly common in the 31's to surge, i have two mates that have had the same problem with theres and also have had to fit a surge tank. Motors not standard, but its not puttin out a great deal of power either.

Id prefur not to run a fuel cooler unless its a last resort.

i cant take the surge tank off and pump off and take it for a drive, well i can but i wont be able to go fast. and if i did take it all off and take it for a drive and it was the problem i would still need more fuel to my motor. id also still need a surge tank as i dont like driving around with over half a tank.

I Think to start with ill try wraping the fuel rail with something and see if that helps at all.

[rob82]

You could try a one way fuel system - what alot of modern cars are using.

Basically you mount the FPR at the rear of the vehcile so that the fuel gets pressurised sent to the front - that way fuel only goes forward and not cycled around and around.