One-Nut_McGee

Ok, this has been talked about before and I'm not trying to ask about if you guys have had it happen to you (I know you have if you're in this section. )

What I'm looking for here are solutions. My last outing I was making it starve at like 40% fuel left in the tank and I don't even have the grippiest tires. There are a couple of turns that I absolutely 100% cannot have the fuel starve out so I'm trying to find out some way to get an effective solution in place for the upcoming season.

I've seen the fuel offerings out there from Ptuning and Descendent, but both of them are just for higher fuel flow/pressure and neither of them have anything in the way of a surge tank or swirl pot. (Plus Ptuning's is pretty expensive for what it is and I wouldn't want to add MORE money on top of that for their eventual surge tank setup)

Does anyone have any experience or have a current swirl pot/surge tank setup on their tC? (I don't know if the xA,B,Ds have the same problems as us)

I'm considering upgrading the OEM fuel pump as well as add a surge tank and then an inline fuel pump after the tank, but I'm not sure if that's the ideal setup. Thoughts?

ack154

iTrader: (7)

My first thought is to talk to Dan Gardner... but thinking about it, he likely has to run an actual fuel cell.

One-Nut_McGee

I actually am considering a fuel cell, honestly. It's way more expensive than what I think a swirl pot/surge tank setup might be, but it'd fix all the problems and allow me to race in a league that races around me...(well, once I get a cage...)

Here's the fuel cell I was looking at from Fuel Safe:

8 gal tank: 20.125" x 12.125" x 8.625" = $796.58

adg016

I have got the answer. =)

We do currently have a custom three pump setup, BUT what we did prior to that which worked very well was a shroud that ATL made. It's probably $300, but it will let the car go MUCH longer before starving. Give them a call. Other questions, ask.

draxcaliber

an 8 gallon racing fuel cell?

if i an understanding this correctly, this would make no sense at all.

you're saying that you are experiencing fuel starvation at 40% fuel tank capacity. well, for a 14.5 gallon fuel tank, 40% is 5.8 gallons, so you would run through 8.7 gallons of fuel before you start experiencing fuel starvation on the remaining 5.8 gallons of fuel.

if you have a fuel cell that only holds 8 gallons, you're going to have to fill up so much more often that i would think the benefits of negating fuel starvation would be completely ofset by the additional pit stops you would make for fuel.

i only autocross and i always do it on a full tank, so i don't have much experience with fuel starvation on the track, but when doing aggressive cornering on the streets, i've only experienced fuel starvation when below 1/4 of a tank.

adg016

On an actual racetrack, even with reasonably sticky tires, the car WILL starve early without a modification. The ATL piece is the most cost-effective solution. It worked for us for an entire year. We only made radical changes once we decided to take on the endurance format with Grand-Am.

Jan06xB

You guys ever hear of a fuel accumulator - they were used on old VW Rabbits to smooth out fuel pressure - something like that on the pressure side with maybe a bleed back off the top to vent the air that gets pumped in the turns should keep fuel flowing. A simplier solution would be a flexable moving fuel pickup in the tank feeding the fuel pump or some really good baffels added into the fuel tank.

blown_xa

Our Spec ss fuel system does not have a swirl pot, but the Spec RS does have a swirl pot. We don't have it listed yet but have it in stock, it is not officially released yet until we come up with detailed photo instructions and pricing. Please feel free to call and ask about it, I am installing this kit on a tC within a week or so.

If you call ask to talk to Mr.C or Toan (Twan) and they will give you detailed information about the Spec RS fuel system

One-Nut_McGee

Thanks Dan! Didn't know you still checked this forum. Can you explain the shroud a little? It sounds like an in tank solution something like a drop-in baffle maybe?

Also, who is ATL? Got a link or phone number that I could reach out to?

Drax,

Your numbers are correct, but for the most part you're talking about the stock tank's starvation problems. With the fuel safe cell the pickup is located in the middle and you can get them in a baffled config (I think, need to double check) so that there is always fuel near the pickup even under cornering.

I agree entirely about reducing the overall capacity in regards to pit stops, but for the most part I think I should be ok as I'm not going to be in an endurance league. I think the longest they run is a 55 minute race, which is still decently long for a short race, but I should be fine with only 8 gallons. On my last race day we ran a full tank at start and did 158.4 miles to the tank (so that's what, 10.92 mpg?). So at 10.92mpg*8gal= 87.36miles. The course is 2.25 miles long so I can do ~38.82 laps with the smaller fuel tank at an uncorrected/estimated fuel consumption rate. Not too bad, but it's about a 60% loss of range.

This uncorrected MPG doesn't keep track of the weight loss from the extra 6.5gallons of fuel removed from a full fuel load. A quick bing search and I came up with 5.8-6.5 lbs for 1 gallon of fuel. So we'll be generous and go low and say 6.5gallons*5.8lbs= 37.7lbs of weight savings. Not too shabby!

For no fuel starvation, fuel tank meets tech/saftey inspections, and the weight savings this fuel cell is looking better and better.

Weren't the fuel accumulators just a little ball that held extra fuel and a little air, just like a swirl pot? I don't remember, 'cuz it's been a loong time since I've looked at an old VW, but I think that's what it was.

A flexible pickup is actually a really good idea. Any idea on what it'd take to adjust the rigid pickup to something that could slide around in the weird shape of the fuel tank? Would something like that kink up and pinch?

One-Nut_McGee

Interesting, I didn't think you guys had finished this up yet. I'm still a little leary on the price of the whole thing as when I broke down the parts that you had listed (SS kit) and priced them out I found pretty much everything for a decent % cheaper than you guys are selling it for. I won't list the % or the links to the site as I don't want to step on toes here as I totally understand you guys are trying to run a business.

That said, even with the cost, I'm still considering it (especially now that it might have a swirlpot) because it's actually a pretty good looking kit considering you can just buy it and drop it in from one vendor instead of having to go to a couple different places and then do the extra work to fit them it to the tC.

I'm definitely interested, but I can only assume that adding the swirlpot will likely add some more money on top of the original cost of the fueling system itself and funds are low for us non-sponsored self-supported budget racers.

Jan06xB

The accumulator is a spring loaded diafram used mainly to smooth out the fuel pump noise but if you can find a big one it would add fuel flow when the pump sucks air. The VW version was designed for some pretty high pressure like around 90psi so it may be over sprung for tC use.
As far as a flexable pickup all it would take would be a length of fuel proof hose mounted on the fuel pump pickup with maybe a small ball bearing or weight on the end of the hose to allow it to roll around the tank assuming the bottom of the tank is level enough and open enough to allow movement. The g-forces would flip the hose to the low side of the tank where the gas is forced from the turn.

adg016

Yeah, I come by from time to time to offer advice. =)

This is the solution you want. Yes, it's just a little rectangular box you drop in that goes around the pump assembly. There is a fold-over lip that prevents fuel from splashing out and away from the pickup.

The rest of the options people are discussing are far more complicated. ATL (Aero Tec Laboratories) is a company pro teams use for fuel system components...their competition is Fuel Safe.

Here's the contact info:

http://www.atlinc.com/contactus.html

They made these for the celeb cars as well.

blown_xa

I assume you priced out the nylon braided lines, an fittings, factory quick connects, cnc fuel rail, fpr, fuel pump, tools to install an fitting onto lines. By the time you add all those things up... and put the time and effort to make the lines and measure/cut them to lengh, install line ends, get fuel rail made, then you are looking at more money anyways. This kit is plug and play for the tC. The labor to install it would make up more than the money you save buying and sourcing out the same compenents and fabricating it to work. That is the whole purpose of this fuel system The hard work is done, just add to cart lol.

vettereddie

At my work we call it NRE, non-recurring engineering. Basically the cost for us to design stuff to be a drop in fit, we then have to amortize that over the total production run to offset it.

I still can't figure out how the license plate hanger costs $70 though unless you're having to go through the dealer to get donor tow hooks.

I feel sad now, a full race setup built for weight savings is 8 gal. and I'm stuck with a 10 gal from the factory, I need an external fuel pod or something.

blown_xa

cnc machined billet As a company we develope parts to cater to those who want the best product made with the best components. We are not making products to be a "bargin", if so the toe hook plates would be mild steel with similar backplate like Stillen does. It costs more to make, so we have to charge more. If somebody were to ask a machine shop to re-produce one toe hook rod it would cost well over $120 Im willing to bet.
A Majority of the Scion community is perfectly content on looking at a pricetag without regard to apprecitation of a product, this is a known fact. I mean, we do drive $13,000 vehicles so It's understandable.
Megan racing does not make products for Ferrari's and Porsches, there is a reason for that.



On the xA and xB1 fuel starvation is not an issue.

One-Nut_McGee

blown_xa,

I did actually price out every single part you guys had listed (didn't include the swirl pot..). I do all my own labor with my crew and have access to the majority of the tools needed for this type of work so that keeps my costs down. Luckily my crew works for beer, so that helps too.

Obviously this isn't an option for everyone (likely the majority will have to pay for labor...), but in my case I try to save as much as possible so that I can continue to keep myself on the track. Tires, fuel, and entrance fees stack up pretty damn quick when you're a self-sponsored runner so I really have to watch my budget.

To be clear I'm not trying to say that this is a bad kit or that the price is obscene. In fact (like I said in one of my posts) I think the kit is a great product because of how easy and complete it is and I'm still considering buying it (with swirl pot). Something I haven't mentioned before is that I'm consistently impressed with the high level of quality that you guys over at Ptuning put out.

Frankly I think all three of the big shops currently supporting the Scion world are doing a bang up job. There are plenty of other car groups that have shady shops that do nothing to help their communities and are just in it for the quick buck. We should all feel pretty damn lucky we have such good shops on our side.

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Dan,

Thanks for the heads up on this part. I've skimmed the catalog and will try to give them a call soon to see what the deal is on a shroud.

I really appreciate that you come to this site and are willing to help out. It's absolutely awesome to be able to talk to you, even if it is via text on a computer screen.

adg016

No problem at all. This isn't an item you'll likely find in their catalog. Dave over at ATL knows exactly what this is if you tell him what you want. If you ever need to ask a question, you can also reach me at scionracing.com. Scion pushes questions to us weekly there. =)

Hope you get a chance to make it to a race sometime!

alienvictim

this has been a refreshing thread.

blown_xa

you are like me, I do all my own work to my car. My car would be pretty close to stock if I had to pay for somebody to do all the labor. I get by with what I can afford and even then sometimes it's a sacrafice. I have a love for track time, and all I do to my car is to make that track time more enjoyable.

mrexotica

The only time I've ever starved in my xA was in extended cornering when I run below 1/8 tank. I have heard of tC's starving around 1/4 tank.

By the way, Dan, congrats on your 2009 season!