Midcorner fuel starvation?

Discussion in 'Modifications & DIY how-to' started by GTscoob, Mar 14, 2007.

  1. GTscoob

    GTscoob Black is Beautiful

    I'm sure you track guys would have a much better experience at this than I do but it seems like my car loses a lot of power mid corner when playing around on the streets. For example, taking any hard turn in 2nd gear I'll notice power pulling back around 4K-5K revs, most of the time the car will start sputtering around then and I'll just push the clutch in. Its highly inconsistant but happens on a somewhat regular basis (if that makes any sense at all), most of the time its when I'm around 1/4 tank of gas or less but today it happened with just over a half tank of gas.
     
  2. clemsonscooby

    clemsonscooby Active Member

    Yeah, thats why they recommend 1/4 tank or less for drag, and 3/4+ tank for autox/track. It could be a good idea to replace the fuel filter as well, because that could cause a restriction.
     
  3. GTscoob

    GTscoob Black is Beautiful

    Fuel filter has maybe 5K on it. I'm pretty sure I've still got a boost leak somewhere in the system, doesnt feel like the clutch is slipping at all either.
     
  4. FTZ

    FTZ ^.^

    My car did that at and Auto X once. I was trying to run with as little gas a possible, to save weight, as if it dropping a couple pounds would actually help my times. But anyways, I had under a 1/4 of a tank, and when I would make a hard right turn, the car would bog down for a second, and then when I hit the straight again, I would be back to normal. Talked to SS and he said it was definitely fuel starvation. I believe the pickup for the fuel line in the gas tank is on the bottom in the back. When you corner hard, all the remaining gas gets pulled to the side of the tank, and for a few seconds, the fuel pickup acts like you are out of gas, causing a hesitation.
     
  5. slowwrx

    slowwrx Supporting Member

    Welcome to the wonderful world of Subaru fuel starvation.

    Matt

    Oh run a full tank
     
  6. Do they make a baffled fuel tank? Or would a fuel cell be the only choice here?
     
  7. GTscoob

    GTscoob Black is Beautiful

    Yeah I figured it was relatively normal but happened twice recently after not happening for a long time, but then again its summertime and I've been driving a little more aggressively:wiggle:
     
  8. Greg

    Greg Active Member

    Just throw a big sponge in the tank ;)
     
  9. Alex

    Alex Community Founder Staff Member

    Im not sure if its a design issue with our tanks or what but its always been an issue when it splashes.
     
  10. Slowsoul

    Slowsoul Member

    not quite. ;)
     
  11. Alex

    Alex Community Founder Staff Member

    Thinking about it, there are much better ways to cut weight than not running with a full tank. Around 72 degrees or so, gas weighs roughly 6.25lbs. Obviously, if its colder, it is a bit mode dense so the weight increases.

    Assuming 70 degrees-ish, with a 15 gallon tank would mean 94lbs, a very important 94 lbs at that.

    1. Spare tire is 29lbs.
    2. Jack is roughly 5lbs.
    3. The spare tire cover and tool is 4lbs.
    4. All the trim in your trunk is 4lbs.
    5. Rear seat is 6.5lbs.
    6. Middle seatbelt is 5lbs.
    7. Drain your washer fluid (3L @ 2.204684 = 6.6lbs)
    8. Stock battery is 32lbs (get a light weight one)
    9. Your exhaust shed some lbs Im sure. I weighed the TSX RFL muffler when I had it vs the stock one, it was something like 11 vs 24, respectively.

    Doing 1-7 will save you 60 lbs or so. That makes up for the half tank you'd normally run without during an event.
     
    Last edited by a moderator: Mar 15, 2007
  12. Doug@DBW Motorsports

    Doug@DBW Motorsports Active Member

    Yup, its very common under cornering. There is an easy fix for it though. You can modify the pumps pickup.
     
  13. GTscoob

    GTscoob Black is Beautiful

    Link to writeup?
     
  14. Doug@DBW Motorsports

    Doug@DBW Motorsports Active Member

    No write up as of yet... maybe when I do the next one I will take pics and do a write up.

    Edit: Something similar to this [​IMG]
     
    Last edited: Mar 15, 2007

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