Track report

[Gomeler]

Originally Posted by FormulaMMM

Sound advice, but this was definitely an ECU intervention. 18 mile range indicated, gong, and power cut simultaneous. Was 1/2 way down a straight.

I've been ~1/8 tank before on road and it's given full power. The calculated/indicated range was the difference here.

Fuel starved on accident yesterday. Maybe 1/4 tank indicated, ~22 miles range, and it starved in 4th going down a level straight. Surprised the hell out of me, I thought I had broke something. The downside of no sessions, I went from 7/8th tank -> fuel starve in ~50 minutes.

[Mandi90TT]

Originally Posted by FormulaMMM

Sound advice, but this was definitely an ECU intervention. 18 mile range indicated, gong, and power cut simultaneous. Was 1/2 way down a straight.

I've been ~1/8 tank before on road and it's given full power. The calculated/indicated range was the difference here.

It was fuel starvation. The gong happened because the sloshing in the tank lowered the measured level enough for the gong to go off, and also lowered it enough for fuel starvation to happen.

[FormulaMMM]

Originally Posted by Dave 90TT

It was fuel starvation. The gong happened because the sloshing in the tank lowered the measured level enough for the gong to go off, and also lowered it enough for fuel starvation to happen.

Indicated range is drastically reduced on track. I’d have 2-3x 18 mile range at that point in the tank when driving normally on road.

If traveling similarly straight down a highway after normal driving, with ~1/8 tank (~40 mls range), the car will give full power.

Before the 18 mile range indication, gong, and power cut on the straight, I’d just been through a series of 1+g corners including a 3rd gear hairpin coming onto the straight. Likelier points for true fuel starvation.

Sure the ECU doesn’t intervene based upon adjusted, anticipated rate of use? To guard against starvation? Seems like a basic protection they might have programmed — both for the pump/components and to help the driver’s dumb ass get to a fuel station. The alternative being, after thousands of track development miles, the car has no programmed protections against starvation. Probably more likely their programming would kill all fun at the point there’s any risk of damage/warranty repair, no?

Here's a ECU/DME protection feature from the 997 in the event of flow control valve failure. Not sure why a more modern performance car wouldn't have protections due to low fuel.

If the flow control valve fails the Siemens DME (ECU) goes into emergency mode, allowing the engine to operate in a limited manner, but with only low fuel pressure of 5.0 bar (72.5 psi). In this situation the integrated bypass valuve in the pump assembly opens, providing a direct route from the low-pressure fuel side (electric fuel pump) to the high-pressure side... The bypass valve is also activate when an empty fuel rail requires filling: new car or after major engine maintenances.

Could have overlooked, but can’t recall a word about this in any modern “factory track car” literature. If it’s mechanically hazardous to performance drive under 1/2 tank, Ford, GM, Porsche, would mention in their track prep and instruction guidance. Let me know what I’m missing. I'm not trying to damage the pump, etc. but also don't care to visit the pump every 1.5 sessions.

[Mandi90TT]

You can think whatever you want to think, but it is definitely fuel starvation due to G load. It was an oversight on BMW engineers, I suspect.

Visit the fuel pump as often as you want, but keep in mind, that yes, when you do this, it is damaging to the pump and not good to your engine.

[FormulaMMM]

Originally Posted by Dave 90TT

You can think whatever you want to think, but it is definitely fuel starvation due to G load. It was an oversight on BMW engineers, I suspect.

Visit the fuel pump as often as you want, but keep in mind, that yes, when you do this, it is damaging to the pump and not good to your engine.

Yeah, I don't want to think anything. Like I'm invested in the idea it's harmless and I'd annihilate my fuel pump to prove a point..

provided more feedback hoping you'd substantiate the claim that <1/2 tank is harmful. You're suggesting that BMW didn't engineer in any protection, but based on what not sure.

Negligible g load at the time of the power cut vs. 1.0 - 1.2 in brake zones and corners moments earlier, no starvation. Car was running like a champ for the entire lap before power cut -- I was a couple tenths up on my best at the time.

Trying to determine how cautious I need to be. In a decade+ tracking, I've run <1/4 tank countless times, never experienced a low fuel related mechanical failure.

[FormulaMMM]

Profi XL in and out a final time to adjust seat angle.

Here's the view from the back of the setup looking forward along the tunnel. Note the BK slot pushed as far right as possible, side mount is inward of the right edge of the floor mount.



Front seat fabric is rubbing along the carpet on the tunnel. Really can't get any tighter and I'm pretty much centered to the wheel now.



For anyone thinking about stacking the BK mounts and floor mounts, believe you'll have to select the top height setting on the side mounts, and probably no lower than the midpoint in the tilt options to get bolts into the floor mounts at all 4 corners. Seat sits very low to the mounts and floor even on these settings.

[littlebully]

Originally Posted by SYT_Shadow

I would return what you received and get the BK stuff

I coded the lights myself. You are welcome to come see the car, we aren't that far

What did you use to code the lights yourself?

I might have to take you up on your offer. Will let you know.

Don't think direct mount will work because I would like to still have sliders. Can't due 2-3 hour trips to tracks and not be able to change leg position.

[FormulaMMM]

Originally Posted by littlebully

What did you use to code the lights yourself?

I might have to take you up on your offer. Will let you know.

Don't think direct mount will work because I would like to still have sliders. Can't due 2-3 hour trips to tracks and not be able to change leg position.

https://www.bkauto.com/R_9280_Seat_M...s_p/r-9280.htm

[SYT_Shadow]

Originally Posted by littlebully

What did you use to code the lights yourself?

I might have to take you up on your offer. Will let you know.

Don't think direct mount will work because I would like to still have sliders. Can't due 2-3 hour trips to tracks and not be able to change leg position.

E-sys

I have sliders on all my seats. Oem sliders

Pm if you want to swing by. I'm at the track next weekend but we could try to do it during the week

[Gomeler]

Originally Posted by FormulaMMM

https://www.bkauto.com/R_9280_Seat_M...s_p/r-9280.htm

is what SYT_Shadow had mentioned. I think the BK OEM rail side mounts + sub bar + harness lap belt mounts for the side mounts will get the job done. Like you guys said, the 3-point is compromised, but it's a compromise in the direction of the higher risk activity in the car.

I need to research 3-points a bit more, could you feed the bottom of the b-pillar belt through the seat to at least get some anti-sub behavior/waist support out of the 3-point? Combined with feeding the buckle through the seat, it'd kind of work? I'm guessing that's what you guys are talking about a floppy buckle, some replacement buckle that would feed through the seat's lap belt hole. I've never bothered to retain the 3-point in the past, since past cars were 100% track oriented.

[SYT_Shadow]

Originally Posted by FormulaMMM

https://www.bkauto.com/R_9280_Seat_M...s_p/r-9280.htm

FormulaMMM, it is fuel starvation. The M4 GT4 also suffers the same issue

[SYT_Shadow]

Originally Posted by Gomeler

is what SYT_Shadow had mentioned. I think the BK OEM rail side mounts + sub bar + harness lap belt mounts for the side mounts will get the job done. Like you guys said, the 3-point is compromised, but it's a compromise in the direction of the higher risk activity in the car.

I need to research 3-points a bit more, could you feed the bottom of the b-pillar belt through the seat to at least get some anti-sub behavior/waist support out of the 3-point? Combined with feeding the buckle through the seat, it'd kind of work? I'm guessing that's what you guys are talking about a floppy buckle, some replacement buckle that would feed through the seat's lap belt hole. I've never bothered to retain the 3-point in the past, since past cars were 100% track oriented.

Although my 3pt buckled up is routed through the outside of the seat onthe buckle side, it is routed 'inside' the seat on the B pillar side

I've retained the pyrotechnics on the stock 3 pt so although the way the belt is routed on the buckle side isn't ideal, the pyrotechnic makes it a decent solution

[FormulaMMM]

Originally Posted by SYT_Shadow

FormulaMMM, it is fuel starvation. The M4 GT4 also suffers the same issue

Check this out. Again, just trying to determine how much caution is warranted.

Had fuel pump failure in my old S4. Know what that feels like. What the GTS did wasn't a hesitation, momentary interruption, it was a full power shutdown timed immediately with the 18 mile range indication. Felt very programmed, not mechanical, like the car just said "nope."

12.2.1. Fuel supply A voltage signal is sent from the low pressure fuel sensor to the DME based on the system pressure applied between the electric fuel pump and the high pressure pump. The system pressure (fuel pressure) is determined using the low-pressure fuel sensor before the high pressure pump. In the DME, a constant comparison of the nominal pressure and the actual pressure is carried out. In the event of a deviation of the nominal pressure from the actual pressure, the engine control unit increases or reduces the voltage for the electric fuel pump, which is sent as a message via the PT-CAN to the electric fuel pump control unit (EKP). The electric fuel pump control unit transforms the message into output voltage for the electric fuel pump. The necessary delivery pressure for the engine (or the high pressure pumps) is adjusted. In the event of a signal failure (low pressure fuel sensor) the electric fuel pump is pre-controlled with terminal 15 ON. If the CAN bus fails, the electric fuel pump is operated via the electric fuel pump control unit with the system voltage. The high pressure pumps increase the fuel pressure between 50 to 200 bar. The fuel reaches the rail via the high pressure lines. The fuel is stored temporarily in the rail and distributed to the fuel injectors.

[FormulaMMM]

Originally Posted by Gomeler

is what SYT_Shadow had mentioned. I think the BK OEM rail side mounts + sub bar + harness lap belt mounts for the side mounts will get the job done. Like you guys said, the 3-point is compromised, but it's a compromise in the direction of the higher risk activity in the car.

I need to research 3-points a bit more, could you feed the bottom of the b-pillar belt through the seat to at least get some anti-sub behavior/waist support out of the 3-point? Combined with feeding the buckle through the seat, it'd kind of work? I'm guessing that's what you guys are talking about a floppy buckle, some replacement buckle that would feed through the seat's lap belt hole. I've never bothered to retain the 3-point in the past, since past cars were 100% track oriented.

Yeah, I just hadn't routed the 3 pt at the time of the photos. Doing that you at least get approximately proper positioning across the left shoulder/chest and left midsection.

Think the flappy buckle that routes through the seat must be a better solution than what I have going on, which is an aftermarket buckle, improperly positioned, no pyro

[SYT_Shadow]

Originally Posted by FormulaMMM

Check this out. Again, just trying to determine how much caution is warranted.

Had fuel pump failure in my old S4. Know what that feels like. What the GTS did wasn't a hesitation, momentary interruption, it was a full power shutdown timed immediately with the 18 mile range indication. Felt very programmed, not mechanical, like the car just said "nope."

12.2.1. Fuel supply A voltage signal is sent from the low pressure fuel sensor to the DME based on the system pressure applied between the electric fuel pump and the high pressure pump. The system pressure (fuel pressure) is determined using the low-pressure fuel sensor before the high pressure pump. In the DME, a constant comparison of the nominal pressure and the actual pressure is carried out. In the event of a deviation of the nominal pressure from the actual pressure, the engine control unit increases or reduces the voltage for the electric fuel pump, which is sent as a message via the PT-CAN to the electric fuel pump control unit (EKP). The electric fuel pump control unit transforms the message into output voltage for the electric fuel pump. The necessary delivery pressure for the engine (or the high pressure pumps) is adjusted. In the event of a signal failure (low pressure fuel sensor) the electric fuel pump is pre-controlled with terminal 15 ON. If the CAN bus fails, the electric fuel pump is operated via the electric fuel pump control unit with the system voltage. The high pressure pumps increase the fuel pressure between 50 to 200 bar. The fuel reaches the rail via the high pressure lines. The fuel is stored temporarily in the rail and distributed to the fuel injectors.

Whenever the car is under 1/2 this can happen. When it fuel starves it does not just go into limp mode, sometimes it'll turn off and won't turn back on for a good while.

The E46 would just have a hiccup, the F8X throws 30 CELs, drivetrain malfunction, etc.

The car has been towed in multiple times with this issue. Now when I'm double-tracking the car I'll put a 5gal bottle in between sessions

[SYT_Shadow]

Originally Posted by FormulaMMM

Yeah, I just hadn't routed the 3 pt at the time of the photos. Doing that you at least get approximately proper positioning across the left shoulder/chest and left midsection.

Think the flappy buckle that routes through the seat must be a better solution than what I have going on, which is an aftermarket buckle, improperly positioned, no pyro

Ah so our setups aren't identical. I have the OEM 3 point buckle.

I'm not sure how to code it so the pyro works and I don't get a dash light. It sounds like you have to disconnect everything from the bottom of the seat and code it out for the car to stop whining

[FormulaMMM]

Originally Posted by SYT_Shadow

Whenever the car is under 1/2 this can happen. When it fuel starves it does not just go into limp mode, sometimes it'll turn off and won't turn back on for a good while.

The E46 would just have a hiccup, the F8X throws 30 CELs, drivetrain malfunction, etc.

The car has been towed in multiple times with this issue. Now when I'm double-tracking the car I'll put a 5gal bottle in between sessions

So you experience CELs, limp mode, and other trouble after fuel starvation in the CS? Nothing like that in my case.

Originally Posted by SYT_Shadow

Ah so our setups aren't identical. I have the OEM 3 point buckle.

I'm not sure how to code it so the pyro works and I don't get a dash light. It sounds like you have to disconnect everything from the bottom of the seat and code it out for the car to stop whining

Yeah, I just left the stock seats fully intact. Bolted in this one https://store.vacmotorsports.com/vac...kit-p2072.aspx

Not sure on the pyro, I have everything unplugged and the airbags coded to function driver & passenger side. No warning lights of any type.

[Gomeler]

Originally Posted by SYT_Shadow

Although my 3pt buckled up is routed through the outside of the seat onthe buckle side, it is routed 'inside' the seat on the B pillar side

I've retained the pyrotechnics on the stock 3 pt so although the way the belt is routed on the buckle side isn't ideal, the pyrotechnic makes it a decent solution

Originally Posted by FormulaMMM

Yeah, I just hadn't routed the 3 pt at the time of the photos. Doing that you at least get approximately proper positioning across the left shoulder/chest and left midsection.

Think the flappy buckle that routes through the seat must be a better solution than what I have going on, which is an aftermarket buckle, improperly positioned, no pyro

Originally Posted by SYT_Shadow

Ah so our setups aren't identical. I have the OEM 3 point buckle.

I'm not sure how to code it so the pyro works and I don't get a dash light. It sounds like you have to disconnect everything from the bottom of the seat and code it out for the car to stop whining

BK parts ordered, R-9281 bracket that looks to be the correct size for my Momo Daytona Evo. R-9259 sub belt + R-9289 lap belt attachments. Going to just remove the passenger seat and see what I think about the Brey-Krause components.

I presume you guys are talking about coding out the side-impact seat airbag?

[FormulaMMM]

Originally Posted by Gomeler

BK parts ordered, R-9281 bracket that looks to be the correct size for my Momo Daytona Evo. R-9259 sub belt + R-9289 lap belt attachments. Going to just remove the passenger seat and see what I think about the Brey-Krause components.

I presume you guys are talking about coding out the side-impact seat airbag?

In my case it was coding out everything associated with a full disconnect -- airbags, seatbelt.

[FormulaMMM]

Originally Posted by Gomeler

BK parts ordered, R-9281 bracket that looks to be the correct size for my Momo Daytona Evo. R-9259 sub belt + R-9289 lap belt attachments. Going to just remove the passenger seat and see what I think about the Brey-Krause components.

I presume you guys are talking about coding out the side-impact seat airbag?

Also, believe that even if you just briefly unplug then replug you'll throw a code. Don't take that to the bank, but think that's what BPM Sport indicated. Maybe even if the car is off... Sorry if that's completely wrong, but you might want to check if you're trying to avoid all warning lights

[Lienrocs]

Originally Posted by FormulaMMM

In my case it was coding out everything associated with a full disconnect -- airbags, seatbelt.

Same in my case. The belt doesn't even need to be plugged into the connector in the floor.

[Gomeler]

Ok, I need to grab an OBD dongle so I can code out the airbag. Hopefully I can get all this installed before the next lapping day on the 23rd.