Fuel Starvation on High G Corners?

[SYT_Shadow]

Originally Posted by nicknaz

one easy "mod" is frequency of fill up the gas tank... e.g. start with 50% of a tank or more?

I get that's a bit annoying.

In my case this is an impossibility. We double track the car, so he (my brother) gets out of the red session and I enter the black immediately after. Barely enough time to change the driver.

[SYT_Shadow]

Originally Posted by redpriest

Presumably retrofit the GTS setup for the fuel system.

That could be a solution. Apparently a friend of a friend has a GTS on its way.

[redpriest]

Originally Posted by SYT_Shadow

In my case this is an impossibility. We double track the car, so he gets out of the red session and I enter the black immediately after. Barely enough time to change the driver.

Presumably this happens after 50% or less - meaning, you could still get 2 good sessions before you'd have to refill.

[larryn]

Originally Posted by nicknaz

one easy "mod" is frequency of fill up the gas tank... e.g. start with 50% of a tank or more?

I get that's a bit annoying.

I have had this happen at 1/3 tank remaining at the Ridge. That's 1 1/2 sessions at 30 minute sessions.

[SYT_Shadow]

Originally Posted by redpriest

Presumably this happens after 50% or less - meaning, you could still get 2 good sessions before you'd have to refill.

Several people have had this happen on their second session while starting with a full tank

[paradoxical3]

bump...any fix for this? Anyone managed to get their hands on the GTS fuel pickup?

[larryn]

Originally Posted by paradoxical3

bump...any fix for this? Anyone managed to get their hands on the GTS fuel pickup?

I had my SA look into it, and he said it was the same part number.

I just make sure I never run to a quarter tank.

[dreamwonder]

Just adding data points. Had the car on 1 autocross and 2 different track days recently (Sat, Sun, Mon).

1. Devens Airfield autocross. 12 runs no issues.
2. Palmer Motorsports. No issues, started the day with near full tank of gas and had fill up after 2nd session.
3. Club Motorsports.
a. When at quarter tank, car went Drivetrain Malfunction twice, going up turn 2. Threw the following codes: B2AAA, P0087, P10FB, P142E. Issue went away after filling the car up to full.
b. No issues for next 2 sessions till tank was at slightly above 1/2. Nearing the end of the straight when car is at about 120mph, experienced what I think is sudden fuel cut. Happened twice. At this point I called it a day and when home.

Club Motorsports have some pretty intense elevation changes, more so than Palmer. Car is completely stock running Federal 595 RS-RR tires. Running roughly 1:52-ish, it was a preview day for instructors and advance solos.

On a side note, tracked a F30 328i 10 days straight (Palmer 1, Mont Tremblant 3, Calabogie 3, Watkins Glen 3) no issues.

[CanAutM3]

I have to say, I am a bit disappointed in this aspect of the F8X, where I cannot go on track for a session unless my tank is at least half full. Anything below that, I will not be able to complete a 25-30 minute session without going into limp mode due to fuel starvation. This means I can only do 2 sessions with one tank at my local track. When I was at the Glen in May, this meant I had to tank after every session .

[CSBM5]

Originally Posted by CanAutM3

I have to say, I am a bit disappointed in this aspect of the F8X, where I cannot go on track for a session unless my tank is at least half full. Anything below that, I will not be able to complete a 25-30 minute session without going into limp mode due to fuel starvation. This means I can only do 2 sessions with one tank at my local track. When I was at the Glen in May, this meant I had to tank after every session .

I've always wondered how "interesting" it could get fully loaded up in a very high speed corner, under power, right on the limits, perfectly balanced...just nailing it good...and then it fuel starves. I would assume the immediate loss of a significant amount of power would of course immediately decelerate the car, transfer weight forward, and create a "nice moment" for the driver to show how experienced she/he is at the wheel.

[CanAutM3]

Originally Posted by CSBM5

I've always wondered how "interesting" it could get fully loaded up in a very high speed corner, under power, right on the limits, perfectly balanced...just nailing it good...and then it fuel starves. I would assume the immediate loss of a significant amount of power would of course immediately decelerate the car, transfer weight forward, and create a "nice moment" for the driver to show how experienced she/he is at the wheel.

I think you would need a very long corner for that. At my local track, I only get starvation about one fourth down the back straight after a long 180deg carousel. The car only stutters once in a straight line, I've never encountered stuttering while cornering.

[chetrickerman]

What do you think about surge tanks?

[redpriest]

I got the drivetrain malfunction because I literally almost ran out of fuel at Laguna Seca going down into turn 5. Hadn't experienced it anywhere else, but I always manage to fill at half tank.

[paradoxical3]

Originally Posted by CanAutM3

I think you would need a very long corner for that. At my local track, I only get starvation about one fourth down the back straight after a long 180deg carousel. The car only stutters once in a straight line, I've never encountered stuttering while cornering.

This is exactly, down to a T what happens to me.

Mid Ohio, coming out of the keyhole. All through the keyhole I am fine pulling serious grip...get on the throttle and power out of the turn. About two seconds after full boost on a straightaway out of the corner, limp mode.

Never happens in the middle of a corner; always just slightly after it when you are full throttle.

[larryn]

I think it depends on the track. For me, I dont get it anymore, because I always make sure I have enough gas, but I used to be able to reproduce it easily. Very high speed right hand compressing uphill sweeper. It's the biggest pucker-factor turn at The Ridge Motorsports Park (turn 9), and with enough nerve, you can do it full throttle, which is ~116mph at the track out cone.

As you approach the track out cone, the car dies, error message happens and while you're managing the car, you quickly take a look that there's nobody in your rearview mirror about to collect you.

[chetrickerman]

Originally Posted by redpriest

Presumably retrofit the GTS setup for the fuel system.

What is different about the GTS fuel system vs the regular M3/M4?

[dreamwonder]

More data points.

NJMP Thunderbolt Sat and Sun.
Drivetrain malfunction going up hill after turn 3. This happened with 4/5 tank, half tank, and 1/3 tank (at time of incident).
There are 3 other F8x that reported no issues. 2 DCT in beginner and intermediate group. 1 manual in instructor group.
Weather was mid 60s, high wind. Car was in sport plus, DSC off, and most aggressive setting for DCT.

In all cases (njmp and club motorsports) it happened after 2 high speed turns follow by wot on the straight section.
Car is going into dealership.

[ibimmer954]

I just completed a weekend at Big Willow in Willow Springs with a 2015 M3. Didn't have any kind of drivetrain errors or any power hiccups. Turn 8 is pretty high G's since it a high-speed sweeping turn (110-125 mph). I got the fuel down to about the last mark before empty which is the 1/6th point I believe. But then I came off track since I going through fuel pretty quickly

[larryn]

Originally Posted by chetrickerman

What is different about the GTS fuel system vs the regular M3/M4?

I had my very knowledgeable SA bring up both parts diagrams, and there were no part differences between any of the versions of the M4 for either the fuel pumps or the tank and fuel pickup.

[md-370z]

stock

[dreamwonder]

Originally Posted by dreamwonder

More data points.

NJMP Thunderbolt Sat and Sun.
Drivetrain malfunction going up hill after turn 3. This happened with 4/5 tank, half tank, and 1/3 tank (at time of incident).
There are 3 other F8x that reported no issues. 2 DCT in beginner and intermediate group. 1 manual in instructor group.
Weather was mid 60s, high wind. Car was in sport plus, DSC off, and most aggressive setting for DCT.

In all cases (njmp and club motorsports) it happened after 2 high speed turns follow by wot on the straight section.
Car is going into dealership.

Update: Problem was finally resolved. Fuel tank and pump was replaced. Dealer found sugar like crystals near pump suction. After fix, was able to drive to 1/4 tank without triggering drive train malfunction at Lime Rock.

Also, the issue caused fuel to leak from charcoal canister vent when car is tracked. Long story short, first dealer spend 3 weeks and couldn't figure out the issue. BMW NA took the easy way out, and ultimately said something along the lines of: works as designed, drive-train malfunction and gas leak is OK since it only happens at the track. 2nd dealership was much better, found and fixed the issue in a week.

[mcvaughan]

I still make it a point to fill up if I'm down to 1/3 of a tank. It's annoying when your range is saying 3 miles when you're in the middle of a session.