01-10-2018, 06:59 PM | #1 |
Rocky
412
Rep 3,085
Posts |
F90 M5 roll run M button set ups
So I am thinking for roll racing from 70 mph to have M1 set with MDM off or on, AWD/softest suspension for weight transfer, then a few seconds into the run M2 set to stiffest suspension, DSC off, and RWD. Am I on the right thinking track?
__________________
22 Audi RS E-Tron GT
21 Model S Plaid |
01-10-2018, 07:07 PM | #2 |
Perennial PFC
336
Rep 1,275
Posts |
I'm no help for an answer, but it brought up the thought of how the drivetrain reacts to the transition from AWD to RWD under full power? How is the disengagement accomplished?
|
Appreciate
0
|
01-10-2018, 07:30 PM | #3 |
Rocky
412
Rep 3,085
Posts |
|
Appreciate
0
|
01-10-2018, 07:43 PM | #4 |
Perennial PFC
336
Rep 1,275
Posts |
I haven't been looking for specs on the F90, but I wonder if details are available for the drivetrain yet, beyond the generalities in the sales pitch? None of the current x-drive BMWs have the RWD option, do they?
|
Appreciate
0
|
01-11-2018, 08:51 AM | #5 |
Captain
320
Rep 843
Posts |
At 70mph in dry conditions the stock F90 M5 should be fine to run RWD the whole roll race. Wouldn't think starting off in AWD and switching would change anything.
Also, not sure how the AWD system works yet but i would assume from a roll you would lose power to the ground using AWD compared to RWD. |
Appreciate
1
Madvillain160.50 |
01-12-2018, 04:49 AM | #6 | |
Rocky
412
Rep 3,085
Posts |
Quote:
|
|
Appreciate
0
|
01-12-2018, 09:06 AM | #7 |
Lieutenant General
19365
Rep 10,166
Posts |
I guess the question would be is; can the 2nd M button even be programmed to 100% defeat the AWD. And then if so, can this change (deactivated the front axle) occur while moving. Then if all these line up would there be any boost loss from the switch since and how much tq split really is being pulled from the front to the rear at higher speeds. I have to think that the ECU/TCU is relatively smart and has already shifted alot of the split to the rear post launch. Based on the trap speeds of the F10 with a less efficient tranny than a DCT- I would say its a very efficient power to the ground split.
__________________
2024 BMW M3 CS Frozen Solid White
2023 BMW M8 Coupe Competition Alpine White 2022 Porsche Carrera GTS Coupe Shark Blue 2020 Audi R8 V10 Performance Suzuka Gray 2012 Mercedes Benz C63 AMG Black Series Obsidian Black |
Appreciate
0
|
01-12-2018, 11:59 AM | #8 |
Major General
2873
Rep 7,885
Posts |
I'm not sure about any boost loss during a transition from AWD to RWD mode but here's what I do know.
Yes you can switch from AWD to RWD on the fly while driving fast in forward motion however there are some catches. What you can do is program the M1 button for the AWD Sport mode which will be RWD biased. After the initial roll on acceleration as would occur in a roll race situation, one can then press the M2 button which has been preprogrammed for RWD Mode. The catch is that in order to configure RWD Mode you must turn off DSC completely. And like the F10 M5 M1 and M2 button operation if you configure either of those buttons for DSC OFF you have to press twice to confirm. Therefore in the F90 you will lose a precious second while switching between the 2 M buttons because you will need to press the M2 twice in order to confirm DSC OFF for the RWD Mode. I'm sure one can practice pressing button twice as fast as you can but there will always be a delay because of the inherent design of the system. I think the best thing to do for roll racing the F90 in the future would be to just keep the car in AWD Sport Mode. In this mode it will try to send as little power to the front wheels as it can. But yes with AWD systems there will be drivetrain losses in power. It's a trade off. I look forward to seeing the F90 square off against some of the fastest cars on the planet in the future.
__________________
|
Appreciate
0
|
01-12-2018, 12:40 PM | #9 |
F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph
1087
Rep 1,968
Posts |
I am sure there will be a F90 at the next 1/2 mile in April... will line up against it
|
Appreciate
1
Madvillain160.50 |
01-12-2018, 12:58 PM | #10 |
Major General
2873
Rep 7,885
Posts |
Looking forward to seeing you destroy some stuff.
__________________
|
Appreciate
0
|
01-12-2018, 01:15 PM | #11 |
F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph
1087
Rep 1,968
Posts |
|
Appreciate
0
|
01-12-2018, 06:35 PM | #12 | |
Lieutenant General
19365
Rep 10,166
Posts |
Quote:
I think Dave is right, just trust the electronics and drive the car in the AWD mode. There wont be much parasitic loss from the front drive train as I had mentioned since the split will be all in the back by them one gets up to speed.
__________________
2024 BMW M3 CS Frozen Solid White
2023 BMW M8 Coupe Competition Alpine White 2022 Porsche Carrera GTS Coupe Shark Blue 2020 Audi R8 V10 Performance Suzuka Gray 2012 Mercedes Benz C63 AMG Black Series Obsidian Black |
|
Appreciate
0
|
01-15-2018, 02:32 AM | #14 | |
Major General
1125
Rep 6,067
Posts |
Quote:
If I were you, I would set the M button to RWD and stiffest setting from the beginning (70 mph) since you would have enough traction. Also keep in mind AWD has more power loss (at wheels) than RWD.
__________________
Current : 2020 F92 Black Sapphire M8 - ZF8
Gone : 2018 F80 Mineral Gray M3 - 6MT Gone : 2016 F82 Austin Yellow M4 - 6MT Gone : 2013 F13 Sakhir Orange M6 -7DCT Gone: 2013 F13 Alpine White 650i -ZF8 |
|
Appreciate
0
|
01-15-2018, 11:26 AM | #15 |
Lieutenant General
19365
Rep 10,166
Posts |
Welcome back my friend--- hope the holidays were good to you.
__________________
2024 BMW M3 CS Frozen Solid White
2023 BMW M8 Coupe Competition Alpine White 2022 Porsche Carrera GTS Coupe Shark Blue 2020 Audi R8 V10 Performance Suzuka Gray 2012 Mercedes Benz C63 AMG Black Series Obsidian Black |
Appreciate
0
|
01-16-2018, 01:19 PM | #16 |
Major General
1125
Rep 6,067
Posts |
Hi Vic. Thank you so much. Hope you had fun too...
__________________
Current : 2020 F92 Black Sapphire M8 - ZF8
Gone : 2018 F80 Mineral Gray M3 - 6MT Gone : 2016 F82 Austin Yellow M4 - 6MT Gone : 2013 F13 Sakhir Orange M6 -7DCT Gone: 2013 F13 Alpine White 650i -ZF8 |
Appreciate
0
|
02-03-2018, 11:19 AM | #17 | |
Colonel
249
Rep 2,202
Posts |
Quote:
Agree RWD bias is essentially what the GTR is doing. You are using the AWD when needed and less and less as you go. I think you're far better off using the biased option but having that dash of AWD to help, than trying to drive, switch between buttons, whatever hiccup or delay that causes with the computer. And at 70 mph, in warm temperatures if the tires are already warmed up, unless you just have trouble controlling a RWD car it should be perfectly fine staying straight. Maybe when you start hitting 700whp+ with summer tires where the tires are the limiting factor where you need that little bit of AWD. I don't see why it wouldn't be fine. |
|
Appreciate
0
|
02-14-2018, 04:06 PM | #19 |
F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph
1087
Rep 1,968
Posts |
|
Appreciate
0
|
02-14-2018, 04:52 PM | #20 |
Rocky
412
Rep 3,085
Posts |
|
Appreciate
0
|
02-14-2018, 06:00 PM | #21 |
Rocky
412
Rep 3,085
Posts |
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|