02-28-2024, 12:13 PM | #24 | |
Lieutenant
298
Rep 407
Posts |
Quote:
A 280 pound difference, based on published specs, won't matter or be noticeable to 99.9% of the drivers on the road. |
|
Appreciate
0
|
02-28-2024, 02:30 PM | #27 | |
Lieutenant Colonel
1321
Rep 1,647
Posts |
Quote:
So if I have a RWD 30i my car would be in the neighborhood of 500 pounds lighter than an XDrive 40i? That might help explain why my 430i is an absolute rocket. |
|
Appreciate
0
|
02-29-2024, 05:48 AM | #28 | |
Brigadier General
2730
Rep 3,348
Posts |
Quote:
So our next step was looking at instrumented data since from driving the G80 M3 6MT vs the M340i ZF8 experience, I had this feeling I couldn't shake really. Using C&D test data on the two cars, the 0-60mph is M340i 3.8 seconds, G80 M3 6MT 3.9 seconds. 0-100mph, M340i 9.4 sec, M3 6MT 9.2 seconds. The 1/4 mile is M340i 12.3@114 vs M3 6MT 12.2@117. So my feeling was somewhat spot on in that the performance of the M340i wasn't significantly different from the 6MT M3 (although 3mph higher trap on the M3 is definitely significant in the drag racing world!). Of course this is the somewhat neutered 6MT version of the G80 M3 as the G80 M3C with ZF8 gives 2.8, 7.0 and 124mph trap for those numbers! The second "of course" is that obtaining those acceleration figures for the 6MT M3 requires DSC off, launching it just right and shifting extremely quickly (helps to have decades of drag racing experience for both of those). The B58 is an outstanding combination of huge power while at the same returning outstanding cruise economy in 8th gear. I love the thing. The M340i is only 0.2 seconds slower to 100mph than our M2C 6MT, and in the M2C you'd definitely need to nail the launch perfectly (DSC off, manage hookup just right, it's not easy) and shift 1-2, 2-3 very fast to have a chance at getting that C&D tested number. In so many ways the M340i reminds us of our E39 M5 we had for 15 years but sold back in 2018, but of course it significantly exceeds the performance of the M5 in every category.
__________________
Current Stable:
2024 G20 M340i Melbourne Red/Cognac 2019 F87 M2 Competition 6MT, LBB, slicktop, exec pkg 2007 E91 328i Silver, slushbox, Eibach fr/E93 M3 rear sway bars, ARC-8 |
|
02-29-2024, 07:03 AM | #29 |
Lieutenant
298
Rep 407
Posts |
The weights I listed are for 2WD. The xDrive models weighs approximately 117 pounds more.
|
Appreciate
1
toddwalton1321.00 |
02-29-2024, 07:13 AM | #30 | |
Portimao Blue G22
39
Rep 34
Posts |
Quote:
|
|
Appreciate
0
|
02-29-2024, 08:14 AM | #31 | |
Lieutenant Colonel
1321
Rep 1,647
Posts |
Quote:
|
|
Appreciate
0
|
02-29-2024, 11:36 AM | #32 | |
Major General
1511
Rep 5,091
Posts |
Quote:
330i RWD 3536lb 51.2/48.8 (1810lb/1726lb) M340i RWD 3834lb 52.3/47.7(2005lb/1829lb) M340i xDrive 3951lb 53.3/46.7(2106lb/1845lb) So 330i RWD is 298lb lighter than M340i RWD, and 415lb lighter than M340i xDrive. I haven't driven the M340i RWD, but the M340i xDrive does feel nose heavy at corners, and the numbers show that M340i carries extra 296lb at its nose. |
|
Appreciate
1
toddwalton1321.00 |
02-29-2024, 01:05 PM | #34 | ||
Lieutenant
298
Rep 407
Posts |
Quote:
Quote:
However I still stand by my statement. The average driver will not be able to tell the difference. Even a 415 pound difference. |
||
Appreciate
0
|
03-01-2024, 12:25 AM | #36 | |
Major General
1511
Rep 5,091
Posts |
Quote:
The 330i with 51/49 has the CG close(r) to the midpoint, so the lateral force of front and rear tires should be close too, and the car feels more balanced and natural at the corners than M340i xDrive. |
|
Appreciate
1
RoGo330i144.00 |
03-01-2024, 12:37 AM | #37 | |
Lieutenant
494
Rep 578
Posts |
Quote:
|
|
Appreciate
0
|
03-01-2024, 04:44 AM | #38 | |
Brigadier General
2730
Rep 3,348
Posts |
Quote:
__________________
Current Stable:
2024 G20 M340i Melbourne Red/Cognac 2019 F87 M2 Competition 6MT, LBB, slicktop, exec pkg 2007 E91 328i Silver, slushbox, Eibach fr/E93 M3 rear sway bars, ARC-8 |
|
Appreciate
1
Montaver2210.50 |
03-01-2024, 06:25 AM | #39 |
Portimao Blue G22
39
Rep 34
Posts |
I’m sure the weight definitely plays a part, but the 130 horsepower difference is really where I feel it. 130 hp is a huge jump. Don’t get me wrong the 430i is a fun car but for me the m440i is just on a whole other level. I’m so glad i made the jump, no regrets 💙
|
Appreciate
1
Dan B297.50 |
03-01-2024, 08:21 AM | #40 | |
Lieutenant
298
Rep 407
Posts |
Quote:
It is also common for engineers to dial in understeer for passenger cars. Much safer for the average driver than oversteer. This can be done in many ways. Tires, suspension geometry, sway bars.. Basically, the average driver is really more of a passenger than a driver. |
|
Appreciate
0
|
03-01-2024, 11:14 AM | #41 | |
Major General
1511
Rep 5,091
Posts |
Quote:
I think the extra front moment of M340ix vs 330i can be calculated based on how far the CG of the car is in front of the midpoint. M340ix 53.3/46.7 says its CG is 3.696 inches to the front, or 0.308 ft. 330i rwd 51.2/48.8 says its CG is 1.344 inches to the front, or 0.112 ft. M340ix front 2106llb x 0.308 ft = 648.6lb-ft at front 330i rwd front 1810lb x 0.112ft = 202.7lb-ft at front If these numbers are correct, then M340ix has 3x front moment compared to 330i rwd. Is there any auto engineer on these forum? Maybe that can explain why 330i rwd has an eager nose, and M340ix has a heavy nose. Last edited by bavarianride; 03-01-2024 at 11:49 AM.. |
|
Appreciate
1
awh59.00 |
03-01-2024, 11:45 AM | #42 | |
Lieutenant
298
Rep 407
Posts |
Quote:
|
|
Appreciate
0
|
03-01-2024, 11:56 AM | #43 | |
Major General
1511
Rep 5,091
Posts |
Quote:
Also, there should a difference of performance(weight transfer benefits and such), vs. the car's feel of being balanced/neutral(in terms of not disturbing inner ears!) E.g. I reworked the math in post#41 and there seems to be a 3x difference in front moment between the 2 cars. BTW this appears to be an interesting read: https://www.suspensionsetup.info/blo...e-car-handling |
|
Appreciate
0
|
03-01-2024, 12:21 PM | #44 | |
Lieutenant
298
Rep 407
Posts |
Quote:
1. Air temp 2. Surface material 3. Surface temp 4. Tire specs. 5. Tread depth 6. Tire pressure 7. Corner weights 8. Speed of car 9. Rate of deceleration 10. Slip angle There are a few more but this is a good start. |
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|