Built Fuel Systems

Postby **NitroDann** » Sun Oct 16, 2011 9:30 pm

Hey guys,

So im getting fuel surge a lot lately.

Something is wrong.
Ive checked pickup filter orientation.

Ill replace the fuel filter and check all the in tank seals tomorrow. Maybe im sucking air or something. I honestly cannot put my finger on it.

Its surging. Always on left hand turns, just like it should (pickup is on left hand side of tank).

Lately Ive been able to get it to surge with 1/3 tank of fuel.

Been running E85 for almost a year.

........ Dont know what to do next.

Where do I get cheap walboros?

Thanks,
Dann

Postby **NitroDann** » Mon Oct 17, 2011 12:21 pm

Ok so I just replaced the fuel filter. It was pretty filthy. And cleaned the in tank pre filter. Everything else was fine.

We will see how it goes. If this isnt it I need to do some datalogs and make sure its not a sensor thats wire has a break or a short. Ive considered that it might me a wire shorting as i turn left. But also its fuel surge

Dann

initial D · Postby **initial D** » Mon Oct 17, 2011 12:23 pm

E85 is bad stuff i heard

Postby **NitroDann** » Mon Oct 17, 2011 12:27 pm

You heard wrong. It all looks fine inside my tank and my lines are like new.

Been 12 months now.

Dann

Postby **NitroDann** » Wed Oct 19, 2011 8:16 pm

Problem solved, filthy fuel filters.
24 bucks later its fixed.

Surprised I didnt get more responses about serious fuel systems.

Dann

Kobsy · Postby **Kobsy** » Thu Oct 20, 2011 12:38 pm

I think nobody wanted to post here because most people don't know jack about E85 yet. I've had nothing to do with it yet myself. My bet is it will become a lot more popular in a few years.

Just curious to know how long those filters lasted. I'm assuming 12months?

Postby **NitroDann** » Thu Oct 20, 2011 2:50 pm

The filter was on for 12 months after the E85. Having said that the filter hasnt been changed in the period Ive owned the car (2-3 years now), and looks much much older than that.

The fuel system is actually very healthy, just had blocked filters.

The bit im surprised about is that I didnt get anyone talking about surge tanks and fuel pumps etc.

Dann

Hellmun · Postby **Hellmun** » Thu Oct 20, 2011 3:31 pm

Didn't seem appropriate, issues suddenly started which implied a problem rather than the requirement for an improvement. I'd have done the same thing and replaced the fuel filter then cut it apart to check it, check the pump sock filter pick-up and if that didn't fix it flow-test the injectors. Fuel system upgrades are for Drag and race cars though so I wouldn't expect many people to be that interested. This forum is likely what, %99.5 street cars?

As far as serious fuel systems I have a few plans for post-turbo but I still don't know enough as I'd like yet. My favourite event of the year is the Wakefield 300 and with a basic engine tuned on 98 we can't actually make the 300km's on one fuel stop. 260km looks like the absolute limit on full RPM racing on 80 litres in my car .... Post turbo I was planning on seeing if I can fit a 40-60 litre fuel cell in the spare wheel well, swirl pot and 2 additional pumps. I've heard the turbo cars are already struggling with surge by half-full on the stock system on very hard left hand turns and I'd like the ability to go full-speed the whole race. So fuel cell with low pressure pump with a switch on the dash to fill the stock tank, standard pump left in the standard tank plumbed to a swirl pot, then high pressure walbro to the fuel lines from the swirl pot. Should be a nice expensive exercise...

Postby **NitroDann** » Thu Oct 20, 2011 3:48 pm

yeah what you said just now covers most of my thoughts.

I reckon you would want that tank on the passenger side floor.

I first noticed it at the track though, my first circuit event, and the first sustained high speed cornering on semis, which was my concern.

Dann

Hellmun · Postby **Hellmun** » Thu Oct 20, 2011 4:22 pm

I appreciate it's good weight distribution, especially offsetting the driver weight nicely but I'd really rather not be sitting next to a big fuel tank. If you got unlucky and got king-hit in the passenger side of the car your going to get covered in fuel. I haven't read the fuel section in the CAMS manual lately but I'd bet they require a certain distance from the driver compartment, certain distance from the edge of the car or atleast some massive shielding. I can't help but look at what happened with that Lambo and Lotus at Eastern creek earlier in the year, the lotus driver did nothing wrong but he got smashed by someone elses mistake. It's part of racing and surviving > a few tenth's from low cg and better weight distribution.... I haven't corner weighted by car yet either which I hope to do it when I get the turbo in and I imagine the turbo, mani, oil cooler, intercooler etc are probably going to screw up the weight dist anyway so maybe some rear weight will be good.

With the clean filters you may not have it next trackday, the gunk would've built up to a point. Are you running stock fuel pressure and just big injectors for the E85? Does the stock NA6A have a returning fuel rail? From memory the 8B fuel rail isn't but the 8A one is so you get light starvation on cylinder 4 due to the pressure waves as the fuel hits and bounces back off the end of the rail. I was recommended to swap to the 8A one but am planning on using an M-tuned instead later. Hopefully the 460CC injectors I already have and stock fuel pressure will be enough for around 130-150kw. I'm less worried about power and more about reliability at this stage.

Postby **NitroDann** » Thu Oct 20, 2011 4:34 pm

Stock pressure. 550cc injectors.

Your 460s will hit over 200rwhp so you will be fine.

Yeah I think its fixed now, but I cannot work out how a blocked filter would surge on lefts...

Dann

Hellmun · Postby **Hellmun** » Thu Oct 20, 2011 6:35 pm

Reduced flow rate from the partial blocked filter combined with in-tank sloshing reducing output from the main pump might be just enough to lower the fuel pressure temporarily and cause lean-out, you need a lot more flow at the same pressure on E85 so I'm not surprised it's more sensitive. An electric fuel pressure gauge would give you an idea but that's a few hundred bucks for a warning you may need to clean again. Pick-ups in the worst spot when turning left and stock cars just don't pull enough fuel to reduce the pressure enough to cut injector flow. Consider it to stock SE's at the fishhook getting surge, they have no more grip just higher fuel needs and can't run the tank dry without encountering surge.

tbro · Postby **tbro** » Sat Oct 22, 2011 2:02 pm

Dan,
What you also need to remember is that most who run race cars here are running 2F regs which doesn't allow swirl pots or even extra fuel tanks.

2B, such as the mighty CT runs can run what they like to a point, they have all been there,done that and wrote the book, so to speak and know of all the fuel pump probs encountered in racing.

I'm building my new fuel rail atm and will run a seperate Sard regulator, was going to try out a inline cooler in the return line but will need to study the regs a bit before hand.

What I'm looking at doing

return line in the middle with hose going to fpr.

plate the old fpr hole and silver solder the fittings at each end. Run a t piece in the inlet line to each end of rail. I don't know if no 4 does run lean at race conditions and I don't really care to find out. That should be hopefully all I need to do.

Terry