View Full Version : Cup racer FUEL SURGE - Northy ???
Had my first event in the cup car at the weekend and went really well. The only negative on the day was a surge problem (I think) cough and splutter then go again, exiting left hand corners from what i can remember. Had a blast on the road and can not get it to do anything.
The petrol gauge swings up and down link nobodies business and i have just read this thread.
http://www.williamsclio.co.uk/forum/viewtopic.php?t=16018&highlight=fuel+starvation
Was there a solution in the end ?
any pics from the event, how did you get on?
Sounds like you may have to drop some anti surge foam into the car, dont suppose the clio cups had this problem as they were not going round bends that sharp etc etc
Hi Steve
I have done 3 trackdays since i first noticed the fuel serge problem. It still hasnt gone away though.
A new fuel sender unit cured one problem i had last year at angelsey. (The sender stuck in the housing which didnt allow the pump too prime) With that changed the car was better - although the spluttering was less it was still there. Long left corners are worse than short ones i noticed.
Initally i cured it by running the car between 1/2 a tank to 1/4 tanks...anything below 1/4 and it started to splutter on a decent left hand bend.
I have been working on the fuel system since feb although i havent used the car for 6months. So far ive washed out the tank (some muck and grit was in so that wouldnt of been helping) fitted a new fuel filter and checked all the wiring.
I have bought a new fuel pump last month that is rated to 500bhp to see if that helps but the problem is caused by the fuel draining away from the pump. not the pump itself. But a uprated one wont hurt.
The standard tank has a kind of baffle as standard but im am suprised to hear yours has the same problem as mine.
If the new pump and clean tank doesnt sort mine i am going to install an aftermarket swirl pot to the car. (Inline after the pump) That will sort the problem out.
Only other modification i may make is to force some fuel foam / sponge into the tank to stop the fuel from moving around so much. I think it happens with cup races due to the light g-force and extra grip of the slicks.
Im not sure if anyone else has had this problem (evouk, richy, bayliss) Carnt ask matbrown as he hasnt driven his yet :winkey:
The design of the tank isnt the best but i would be suprised if all the mk1 cups suffered this problem when they were racing in 91 - 95. Maybe the removal of the aux tank makes the serge problem worse.
If i was you - buy a swirl pot and fit it to your car. Are you doing croft on the 5th of may ?
yes i have the same problem when below a 1/4 tank...
I think the foam in the tank is the cheaper option
Has anyone used the foam ? successfully ?
not in a standard tank, gaztwo runs the stuffin his tank but thats a custom tank incar mounted.
I am tempted by the foam now while the tank is out but im not sure how much i could get in as the only accsess is on one side of the tank (sender)
Fit a swirl pot mate - then u can tell me if its cured it!
Will have to do something - foam or swirl pot.
Does your do it when its over half full ?
Anyone fitted a swirl pot ? where in the fuel system does it need to go ?
Does your do it when its over half full ?
No - between 1/4 & 1/2
http://img99.exs.cx/img99/1834/fueltwo3dc.jpg
Is that 2 different options ? Where is that from ?
a swirl pot will definatly solve that problem
yes i have the same problem when below a 1/4 tank...
I think the foam in the tank is the cheaper option
How would you get it in the tank ? do you need to completely fit it with foam ?
a swirl pot will definatly solve that problem
Jack and Jill style where would you put the swirl pot and do you need a second pump ?
hybridhughes
17-04-2008, 17:05
i have this problem to on left hand bends but only if the car has below 1/2 a tank. to be fair at cadwell and donnington as there mostly right handers it tends not to suffer but there is a certain piece of road near me that it does it on almost every occasion. it like the car is being starved of fuel until you have straighten up out of the corner for a few seconds then the power comes back on. it did it also with the1.8 in aswell as the 2.0 so im thinking either the fuel pump is weak or the fuel is being sloshed around in the tank. wouldnt mind sorting it out though.
a swirl pot will definatly solve that problem
Jack and Jill style where would you put the swirl pot and do you need a second pump ?
right basically you need a lifter pump (low pressure) in the tank, then run that to the swirl pot, then you need a sender pump (high pressure) from the pot to the fuel rail with a filter in between.
the pot will go anywhere in car (just depends how long your fuel lines are) but over the top of the tank is a good start. ill try and get a pic of my mates old nova LET swirlpot setup
a swirl pot will definatly solve that problem
Jack and Jill style where would you put the swirl pot and do you need a second pump ?
right basically you need a lifter pump (low pressure) in the tank, then run that to the swirl pot, then you need a sender pump (high pressure) from the pot to the fuel rail with a filter in between.
the pot will go anywhere in car (just depends how long your fuel lines are) but over the top of the tank is a good start. ill try and get a pic of my mates old nova LET swirlpot setup
Nice one - what about this one from tweeks can you just have it gravity fed ?
http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=FSECCP001
a swirl pot will definatly solve that problem
Jack and Jill style where would you put the swirl pot and do you need a second pump ?
right basically you need a lifter pump (low pressure) in the tank, then run that to the swirl pot, then you need a sender pump (high pressure) from the pot to the fuel rail with a filter in between.
the pot will go anywhere in car (just depends how long your fuel lines are) but over the top of the tank is a good start. ill try and get a pic of my mates old nova LET swirlpot setup
Nice one - what about this one from tweeks can you just have it gravity fed ?
http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=FSECCP001
http://www.demon-tweeks.co.uk/resources/images/zoom/FSECCP001.jpg
no you still need the lifter pump, the gravity feed is from the pot to the high pressure pump
What about these?
Can you get to the tank body ? do you just take the sender / pump out and put them in ?
http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=EXP10L
What about these?
Can you get to the tank body ? do you just take the sender / pump out and put them in ?
http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=EXP10L
im guessing that would work the same as in tank foam, yea just take the pump out and pour them in.
What about these?
Can you get to the tank body ? do you just take the sender / pump out and put them in ?
http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=EXP10L
im guessing that would work the same as in tank foam, yea just take the pump out and pour them in.
Would you completely fill the tank with them ? How big is the tank as it could work out quite expensive.
What about these?
Can you get to the tank body ? do you just take the sender / pump out and put them in ?
http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=EXP10L
im guessing that would work the same as in tank foam, yea just take the pump out and pour them in.
Would you completely fill the tank with them ? How big is the tank as it could work out quite expensive.
now that bit defeats me lol
i doubt you completly fill the tank as you'd loose out on its volume??
not had any problems on track yet with mine, and the williams was always ok but never ran on slicks etc like current car is, even when theres sod all fuel its been ok
i dont think you would be able to fill the standard tank with foam, even if you got a bit in it would move about!!
i dont think you would be able to fill the standard tank with foam, even if you got a bit in it would move about!!
that stuff in the link isnt foam its like alu pellets
Swirl pot = :D (will basically solve the problem).
Other options are to baffle your tank, foam as suggested, or relocate the tank (will need a new one), or mount a vertical tank so that fuel surge is vastly reduced. Swirl pot is always good to have though :) (Just adds to the expense of it all though).
Depending on where you race you may need to enclose (firewall) it all though, or have a double skinned tank.
Matthew
i dont think you would be able to fill the standard tank with foam, even if you got a bit in it would move about!!
that stuff in the link isnt foam its like alu pellets
i know, but the original thread link gaztwo posted a few years ago is....
i dont think you would be able to fill the standard tank with foam, even if you got a bit in it would move about!!
that stuff in the link isnt foam its like alu pellets
i know, but the original thread link gaztwo posted a few years ago is....
aahh i see didnt click the link in the first post
i still say swirl pot ftw
it costs more for the setup but fueling can then be accuratly controlled
i dont think you would be able to fill the standard tank with foam, even if you got a bit in it would move about!!
that stuff in the link isnt foam its like alu pellets
i know, but the original thread link gaztwo posted a few years ago is....
aahh i see didnt click the link in the first post
i still say swirl pot ftw
it costs more for the setup but fueling can then be accuratly controlled
Would be great if you could get a pic of a set up.
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