Fuel Starvation?

[Icecreamtruk]

How many lateral Gs and for how long do you guys sustain it to get fuel starvation? I havent hit it myself but I run in fairly small tracks, no long sweepers, just wondering for the future (there is one big track with a long sweeper in my calendar this year).

[Lunatic]

Originally Posted by georgiafrsguy

you def had fuel starvation at half tank with your setup for sure. welcome to the club. gonna have to keep full tank or get surge tank setup. couldn't run Atlanta motorsports park n/a with half a tank without starving

Yup, full tank from now on.

[Lunatic]

Originally Posted by Icecreamtruk

How many lateral Gs and for how long do you guys sustain it to get fuel starvation? I havent hit it myself but I run in fairly small tracks, no long sweepers, just wondering for the future (there is one big track with a long sweeper in my calendar this year).

I can't answer your question directly but I have seen over 1 G at different tracks.

[Icecreamtruk]

Originally Posted by Lunatic

I can't answer your question directly but I have seen over 1 G at different tracks.

Maybe its something to do with the banking in the corner? I see between 1.1 and 1.4g on every corner, and just last week I ran until the car had almost no fuel in it (3 laps past the fuel light) and no issues. So it seems the pickup for the fuel pump is enough for NA on normal gas but FI or E85 or both seem to have this issue. I guess you would have no option but to run a surge tank. Its a close to 100lbs of fuel you need to haul around otherwise

[avishenoy1]

You are experiencing fuel starvation. This is a well known issue for left hand turns in boosted cars and there are a few threads with more details and solutions.

I have the Vortech supercharger and have the same issue on turn 3 at Palmer Motorsports Park. It is a sweeping left hander which I am going through at full throttle. If I am below 3/4 tank I see my revs start to drop at full throttle and my AFR goes full lean. This only started happening after I switched to 17x9 with 245 Direzzas and swapped out my sway bars. With these mods our cars are pulling significantly more lateral g's than the fuel tank was designed for.

The only solution I have heard of that has been documented to work reliably is a surge tank in the engine bay. This is a cumbersome and expensive modification that requires an additional (noisy) fuel pump and a tank that is vented to atmosphere (get used to smelling gasoline). And of course there is a greatly increased chance of fire when adding fuel lines in the engine bay.

I have heard mention of having a Holley Hydramat installed in the fuel tank, or an installing an additional in-tank floating fuel pump but have not seen anyone who has done either of these on the forum yet.

Until then I suggest you lift or risk destroying your engine.

[Lunatic]

Originally Posted by avishenoy1

You are experiencing fuel starvation. This is a well known issue for left hand turns in boosted cars and there are a few threads with more details and solutions.

I have the Vortech supercharger and have the same issue on turn 3 at Palmer Motorsports Park. It is a sweeping left hander which I am going through at full throttle. If I am below 3/4 tank I see my revs start to drop at full throttle and my AFR goes full lean. This only started happening after I switched to 17x9 with 245 Direzzas and swapped out my sway bars. With these mods our cars are pulling significantly more lateral g's than the fuel tank was designed for.

The only solution I have heard of that has been documented to work reliably is a surge tank in the engine bay. This is a cumbersome and expensive modification that requires an additional (noisy) fuel pump and a tank that is vented to atmosphere (get used to smelling gasoline). And of course there is a greatly increased chance of fire when adding fuel lines in the engine bay.

I have heard mention of having a Holley Hydramat installed in the fuel tank, or an installing an additional in-tank floating fuel pump but have not seen anyone who has done either of these on the forum yet.

Until then I suggest you lift or risk destroying your engine.

Thank you, now that I know what's happening I'll run a full tank and lift if necessary.

[Lunatic]

Originally Posted by avishenoy1

This only started happening after I switched to 17x9 with 245 Direzzas and swapped out my sway bars. With these mods our cars are pulling significantly more lateral g's than the fuel tank was designed for.

What sway bars did you go to and did they reduce your lap times?
And if I may ask, what spring rates are you using.

[avishenoy1]

Originally Posted by Lunatic

What sway bars did you go to and did they reduce your lap times?
And if I may ask, what spring rates are you using.

Hotchkis front and Rear and yes, the sway bars definitely reduced body roll and gave me more grip in corners. Can't say exactly how much they reduced my lap times but with the front at stiff and the rear at medium soft plus new wheels and tires I was going through corners about 5-10mph faster than I ever had before. I was running RCE yellows which are 4.5k front and rear and Bilstein B8s, so not too aggressive.

I've since put the sways back on the softest setting to try to alleviate the fueling issue but still if I'm below half tank I get starvation in that one turn at full throttle so now I just ease off early and brake very late into the next corner.

I would assume that if you bias damping settings/tire pressure on one side of the car or go with softer sways to increase body roll it might make a difference but at the expense of speed.

@CSG Mike would know more about the issue and talked about it in the thread below

http://www.ft86club.com/forums/showthread.php?t=33991

[Lunatic]

Originally Posted by avishenoy1

Hotchkis front and Rear and yes, the sway bars definitely reduced body roll and gave me more grip in corners. Can't say exactly how much they reduced my lap times but with the front at stiff and the rear at medium soft plus new wheels and tires I was going through corners about 5-10mph faster than I ever had before. I was running RCE yellows which are 4.5k front and rear and Bilstein B8s, so not too aggressive.

I've since put the sways back on the softest setting to try to alleviate the fueling issue but still if I'm below half tank I get starvation in that one turn at full throttle so now I just ease off early and brake very late into the next corner.

I would assume that if you bias damping settings/tire pressure on one side of the car or go with softer sways to increase body roll it might make a difference but at the expense of speed.

@CSG Mike would know more about the issue and talked about it in the thread below

http://www.ft86club.com/forums/showthread.php?t=33991

Thanks for the info. I'll read the thread you posted for me. Thank you.

[avishenoy1]

Originally Posted by Icecreamtruk

How many lateral Gs and for how long do you guys sustain it to get fuel starvation? I havent hit it myself but I run in fairly small tracks, no long sweepers, just wondering for the future (there is one big track with a long sweeper in my calendar this year).

Can't say for sure but I would expect that anyone experiencing this issue is sustaining at least 1.1 lateral g's. On turn 3 at Palmer I'm probably sustaining that level of grip for 3-5 seconds.

245 or wider, 200TW or stickier, boost, a stiff suspension, and downforce will get you there. This chassis is incredibly well balanced.

[avishenoy1]

This looks like it would help: http://www.radiumauto.com/Fuel-Pump-...T86-P1142.aspx

Definitely not a guarantee against starvation but looks like it would have much better pickup than the oem or a drop in pump.

This plus a surge tank would be the full fix for a high horsepower track monster.

[Lunatic]

Originally Posted by avishenoy1

This looks like it would help: http://www.radiumauto.com/Fuel-Pump-...T86-P1142.aspx

Definitely not a guarantee against starvation but looks like it would have much better pickup than the oem or a drop in pump.

This plus a surge tank would be the full fix for a high horsepower track monster.

Thank you, I'll look into that.

[Lunatic]

Here's the corner where I had the problem. Right after I hit the straight you can hear the engine quit revving and me short shifting.
https://www.facebook.com/steve.joneli?fref=ts

[Jonsey]

Moto-East has a plug and play surge kit that is the best option on the market right now in my opinion.

http://www.ft86club.com/forums/showthread.php?t=105934