Sepang Videos E46 and E92 M3

[Ascendant Motorsport]

Jeremy (Rastaman) takes Haf for a couple laps. Haf must have left the mount completely untightened because in the portion where it rotates you can see the washer hanging free with about a .200" gap. These mounts never come loose, even at 240 km/h or 4G. Nice to see Haf having such fun after working so quickly to take all those awesome photos at the trackday.

[YOUTUBE]http://www.youtube.com/watch?v=W23QlDbUY6E&ap=%2526fmt%3D18[/YOUTUBE]

[YOUTUBE]http://www.youtube.com/watch?v=JymT5LbcHjE&ap=%2526fmt%3D18[/YOUTUBE]

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Shaun takes Ryan Lee for a couple laps. First time driving any E92 and first lap a 42.3 with DSC left on (data and third party). Was extremely pressed for time (track session was about to end) and did not get to adjust seat and wheel to satisfaction. Completed only 1 hot lap before traffic and session conclusion got in the way.

DSC extremely intrusive and does not allow throttle roll on till very late in a turn. Seems to be heavily dependent on steering angle. To minimize DSC effect on lap time as much as possible requires different strategy in the real tight low speed sharp turns vs the big sweepers for various reasons, and all steps taken will result in a slower lap if DSC were off. IOW, it rewards certain driving errors and can end up reinforcing certain bad habits if the driver is not aware. Have data to show DSC over-interference extremely clearly. Will post in future. Twice in the lap you can hear "DSC" mentioned twice where it cuts in most severely, but besides that it affects all turn exits (you can even hear it in the video, T4, T14, etc.) except for T3. Having experienced Z4M DSC previously on track had started to work to figure out what BMW DSC was looking at to do its work and a way around it. Narrowed it down to 2 main areas and this recent drive in the E92 narrowed it down to a single main factor that now can be dealt with.

Car as it was at that trackday was capable of a 40.7 using 6 sets of 5 non-compromising segments in total, from 2 drivers, back to back. Most of T5 was compromised as you can see in the video with leftover oil dry . Estimate at least 6 seconds improvement from turning DSC off. Other lesser powered cars with less intrusive forms of TC have saved anywhere from 4-7 seconds by turning it off as long as driver knows roughly what he's doing.

Friend who has worked for Toyota as a chassis evaluation engineer in Europe, including all benchmark and competitor marque cars like Merc, BMW, Audi, came along for a ride and was amazed at the grip and body control that a car that heavy possessed. "Incredible" he said.

[YOUTUBE]http://www.youtube.com/watch?v=dEwX_Evwp6U&ap=%2526fmt%3D18[/YOUTUBE]

 

[TripleM]

Re: Sepang Videos E46 and E92 M3

Friend who has worked for Toyota as a chassis evaluation engineer in Europe, including all benchmark and competitor marque cars like Merc, BMW, Audi, came along for a ride and was amazed at the grip and body control that a car that heavy possessed. "Incredible" he said.

Spot on..exactly how i felt when i tried Eggz car and that was on street tires.

From the vid , it seems that the M3 gearing is quite long. I notice u didnt have to shift up to g4 when u are pulling from T9 to T10 before cutting the apex on T11.

Good driving...and yes it seems that the steering was too far from your seating position...

 

[Ascendant Motorsport]

Re: Sepang Videos E46 and E92 M3

Spot on..exactly how i felt when i tried Eggz car and that was on street tires.

Hi Jack, yeah this guy has lots of unique ways of subjectively testing out road cars - feeling certain things (different frequencies, the order in which lateral acceleration, yaw, and roll ought to arrive, etc.) as well as areas he looks at that get completely passed over in racing because it does not apply there. All to keep the typical road car driver happy. I hope he'll share with us in more detail what he felt.

To me the car does not give away its weight in handling or braking. It does those things well. It is the tall gearing, weight, and DSC that hides its true power somewhat.

From the vid , it seems that the M3 gearing is quite long. I notice u didnt have to shift up to g4 when u are pulling from T9 to T10 before cutting the apex on T11.

Yes, actually haven't come across a road car yet that requires a shift to 4th before T11. Elise, Exige, S2K, Z4M, GT3 with final drive, Cayman, E46 M3, etc. Though I must say the E92 M3 gearing is slightly taller everywhere vs those mentioned.

Having looked in detail at the data, would like to mention that T5 and 6 in the E92 M3 can be taken in 3rd gear instead of shifting to 4th. It is the thought of having RPM hanging around upper limits for extended duration not really doing much (in the near steady state portion of T5 and 6, that prevents execution. If really pushing, the lower gear is worth time mainly in coming off T6, but also in the short straight just prior. This is provided TC is off since it can easily negate the wheel torque advantage if is triggered either by slight wheel slip, or by increased action as a precaution (ECU watching engine speed relative to wheel speed, so it knows which gear you're in, etc.).

This was already seen in sector times at T14 where 2nd or 3rd with DSC on made no measurable difference due to interference. Basically it makes you lame-ride out the gear at much low inline acceleration than the car and gear is capable of, and then you still have to shift up and that costs time. The video lap shows the downshift to 2nd whereas the other lap I tried 3rd. The interference experienced in 2nd gear caused the narrow exit since as you unwind the wheel and roll on the throttle, you expect a speed and therefore lateral acceleration gain, yet you get none. As such, your line does not widen as much as you expect. You can react to this to reclaim some turn radius, but not entirely because power return is not as predictable as rolling on the gas yourself. As mentioned earlier the power return can be keyed to a large number of factors, either individually or combined. Road speed, lat. acc., steering wheel angle, gear, engine speed, yaw rate, etc. With DSC off, 2nd off T14 in the E92 M3 is the right gear for best sector and lap time.

Evidence of bad traction control interference, here: http://www.bmw-sg.com/forums/ascend...-sepang-international-circuit.html#post426919

Good driving...and yes it seems that the steering was too far from your seating position...

Yes as mentioned was rushed last 10 minutes of the session. Would have been a waste for the session to be red flagged before the warm up lap could be completed. Thankfully completed a hotlap and the session was red flagged before the end of the second hot lap. Will gladly correct if given the chance to repeat laps in same or identical car

 

[centurion]

Re: Sepang Videos E46 and E92 M3

entered hyperspace just before T9?

 

[Ascendant Motorsport]

Re: Sepang Videos E46 and E92 M3

No, gave logger the finger, cos the sector time sucked

 

[Ascendant Motorsport]

Re: Sepang Videos E46 and E92 M3

3 ways of assessing driver efficiency and/or vehicle performance including interference from electronics like TC, etc.

http://www.bmw-sg.com/forums/ascend...-sepang-international-circuit.html#post427615

http://www.bmw-sg.com/forums/ascend...-sepang-international-circuit.html#post427619 (the major loss area on the excel graphs in this one show exactly what happened at the 59-61 second mark the E92 M3 video (you can hear it happen YouTube - BMW E92 M3 first lap Sepang ) .

 

[Ascendant Motorsport]

Re: Sepang Videos E46 and E92 M3

Attached is a plot of some lame braking. ie not trusting entirely, the brakes on 1.7 tons of mass powered by 420 hp, hence first lap just 85% of braking potential. That Gallardo T14 horror story...
So anyway second lap I got on it a little more (closer to 100% potential) , unfortunately traffic and red light got in the way. Going all out would have meant touch ABS on the last pre-hotlap braking event, remembering roughly what it takes, and applying it to every major braking event in the hotlaps (~4 per lap)... not laming out out at 80 or 85% which costs tenths of time.

Was also short shifting on the laps.. orange part of the tach, before redline.

Separately, the T12-T14 stretch can be done in 3rd. Double positive in terms of better acceleration along T14, as well as one less downshift to make before exiting T14. It's just the mechanical sympathy side of the engine handing around in the upper RPM doing little in the near steady state portion of T12. Thankfully much shorter than T5 though.

Cheers

 

[nonono]

Re: Sepang Videos E46 and E92 M3

Anyone has any idea how much did he bleep the throttlw when he downshift from 4,3,2 on the first corner?

Must be running about 5 to 6k revs?

 

[ACS6]

Re: Sepang Videos E46 and E92 M3

I thought Blipping comes standard on the M? It sure is in my e64 SMG.

 

[nonono]

Re: Sepang Videos E46 and E92 M3

I thought Blipping comes standard on the M? It sure is in my e64 SMG.

Are you serious? Or you didn't watch the video?

The M car featured in the video is a manual version.

 

[Ascendant Motorsport]

Re: Sepang Videos E46 and E92 M3

Anyone has any idea how much did he bleep the throttlw when he downshift from 4,3,2 on the first corner?

Must be running about 5 to 6k revs?

Hi Nono,

Looking at the data collected, the last downshift to 2nd gear can be seen as a short interruption to the standard gradient change to the longitudinal G trace, this matches up with the reference point of turn-in in the video where the lateral G starts to build. At this point the car is doing 90 km/h.

2nd gear tops out at 101 km/h (8400 RPM), so by proportion, the resultant RPM of the shift to 2nd gear was just under 7500 RPM. A short while later mid T1 speed is down to 63 km/h and just before the short burst of accel. before braking for T2, we're at 5300 RPM, which is a decent part of the power range to start to pull from. If driver were to stay in 3rd, 3400 RPM is where you'd try to pull from which is kind of low on this type of engine, on top of losing the torque multiplication of the lower gear.

 

[nonono]

Re: Sepang Videos E46 and E92 M3

Hi Nono,

Looking at the data collected, the last downshift to 2nd gear can be seen as a short interruption to the standard gradient change to the longitudinal G trace, this matches up with the reference point of turn-in in the video where the lateral G starts to build. At this point the car is doing 90 km/h.

2nd gear tops out at 101 km/h (8400 RPM), so by proportion, the resultant RPM of the shift to 2nd gear was just under 7500 RPM. A short while later mid T1 speed is down to 63 km/h and just before the short burst of accel. before braking for T2, we're at 5300 RPM, which is a decent part of the power range to start to pull from. If driver were to stay in 3rd, 3400 RPM is where you'd try to pull from which is kind of low on this type of engine, on top of losing the torque multiplication of the lower gear.

No doubt about the e92 was using the right gear. Impressive driving. And thanks for the info provided. Nice one!

 

[Ascendant Motorsport]

Re: Sepang Videos E46 and E92 M3

No doubt about the e92 was using the right gear. Impressive driving. And thanks for the info provided. Nice one!

Thanks and you're welcome nono, actually that lap was the driver's exploratory first hotlap ever in an E92 of any kind, with DSC full on and cutting in all over the place for nothing.

More recently same driver same car, again with passenger, and went 41.1 with DSC on an intermediate setting (major improvement in freedom to drive the car normally) and despite having to pass two cars (one on the line near T3 apex and the other obstructing T12 entry after safety margin considered - both can be seen in the video). Sector time compromise as a direct result of traffic was 0.9 seconds, so lap would have been right next to flat 40. Driving was conservative to the point that the tires never protested at all through the lap, except very slightly around T7, so there is no doubt that even with DSC interfering slightly on intermediate level, low-mid 39s are right there to be picked up if pushed. With DSC completely off and no passenger, certainly 37s. There is a lot left on the table.

The tricky thing with the car is that the lap has to be clicked off early since you don't get a second or third chance as at this level the brakes and tires start to go away early on. If you were to keep pushing the car another two laps beyond initial first hotlap I'm sure they would start to fall away much quicker. It's all that mass and power it has to deal with, but operation of this type is not typical at all so there's no real reason it has to be made to take consecutive hot laps. It is a great road car.

Video of the 41.1 lap will be uploaded soon, perhaps overlaid with data. Many thanks to generous owner.