[Draxxas]

Originally Posted by Jnyvio

I understand that. 😊👍

However, most folks don’t realize the fact that the only advantage the M850 has over the M8 is that the M850 has 3.40 rear gears and the M8 has 3.15.

As for engine specs the S63 is the better engine. Although, this newest N63 is miles better than its earlier versions.

If the M8 had 3.40 rear gears it would be even quicker 0-60 and in the 1/4 mile.

*These images were taken directly from their respective window stickers under “mechanical”.

have 35 plus years drag racing. I'm not most folks and understand everything about drag racing and what gears do. Going off your reply you are very new to this. There is so much more here that I honestly care to explain but I'll just inform you on the gearing change and that slight difference, it will matter none. Forget about 3:15 and 3:40 . In order to fully know the difference you need to also consider diameter of the tires. Lower gearing helps if it keeps you in your power range better. These days we use 6 gears to go through the 1/4 mile. Also lower gearing can help with getting 4500 pounds out of the hole if it hooks . So in this case it does not help with the kind of power this 9.0 car has so I can almost guarantee you , just like me , he uses 2nd gear . So there goes your theory. Old Days yes, we would go from 2.73 in fox body to 3:73 -4:10s. That big of difference was a couple tenths only.
As far as most people don't understand, that statement is always funny to me. You will always be correct using it. Unfortunately you are included in the most people part due to the fact you have no experience dealing with gearing and what it can or can't do. It's not putting you down it's just saying have you had experience at this you would have never stated that. 😊

[ViO]

Originally Posted by Draxxas

have 35 plus years drag racing. I'm not most folks and understand everything about drag racing and what gears do. Going off your reply you are very new to this. There is so much more here that I honestly care to explain but I'll just inform you on the gearing change and that slight difference, it will matter none. Forget about 3:15 and 3:40 . In order to fully know the difference you need to also consider diameter of the tires. Lower gearing helps if it keeps you in your power range better. These days we use 6 gears to go through the 1/4 mile. Also lower gearing can help with getting 4500 pounds out of the hole if it hooks . So in this case it does not help with the kind of power this 9.0 car has so I can almost guarantee you , just like me , he uses 2nd gear . So there goes your theory. Old Days yes, we would go from 2.73 in fox body to 3:73 -4:10s. That big of difference was a couple tenths only.
As far as most people don't understand, that statement is always funny to me. You will always be correct using it. Unfortunately you are included in the most people part due to the fact you have no experience dealing with gearing and what it can or can't do. It's not putting you down it's just saying have you had experience at this you would have never stated that. 😊

I appreciate your reply… Unfortunately you’re totally wrong. I’ve had plenty of racing experience and engine building experience (porting & polishing heads, setting up cams etc etc I’ve done it all) as well.

I’ve also set up plenty of rear ends in my time.. And have a box full of leftover shims to prove it. 😂

Sure, if you have, say a Doug Nash five speed with a super low 1st, 2nd, you can get by with a 2.73 or a 3.08 final. That’s for another topic.. lol

But the transmission in the M8 and M850 are very close (ratio wise).. No pun intended and I know you’ll get that one! 😂

3.15 vs 3.40 does still matter and yes along with tire differences.. Which I fully know are part of the equation! Even if you prefer to race in 2nd gear (agreed) 3.15 vs 3.40 still matters.

Just don’t be so snarky to call out someone’s experience. That’s all… I understand, you don’t know me that good and I don’t know you that good. 😊

Btw… I purchased my M8 convertible just to enjoy it and take it on long relaxing drives as a normal car just won’t cut it! I personally did not buy this car to mod or race. This one is my Sunday driver. I will be keeping her for a long time. 😊

Regardless, I stand by all of my prior statements. Of course, it’s a free country and your entitled to have your own opinions as well. ☮️

[Tenac]

I never realized the gas tank size was different too.... That just seems odd. lol I guess that just reinforces when people say cars by same brand same series just different model are not so similar after all.

[fmzip]

Originally Posted by Draxxas

You may want to reconsider your statement. A M8 tuned with stock turbos can't come close to producing 1100 + whp that it would take to turn a 9.01 1/4 mile ������
You also may want to check dragy history on M8 comp and fastest times achieved. ����‍♂️

Which platform is the fastest? I'm not sure. The gearing is a key difference in 1/4 mile times for sure. Not sure ever car guy on the planet uses dragy

If I was out to have the fastest 8 series, I wouldn't be testing my luck with the 850i platform. The engine internals of the M can handle far more stress than a non M.

My local Indy shop has a few cars tuned cars with blown motors in there and they are all non M's. Not implying M's are non destructible but it's all fun until you blow it up and or, crash it.

This guy is lucky to see another day, no roll cage nor proper seat belts with a 9 second car. Whatever you do, be safe. Public service announcement for the day

[AmooManiak]

To be fair, if you want the fastest for your $, you wouldn't be picking any 8 series (M8 or M850i) as the foundation. These are first and foremost GT cars. Low 10s is good enough. Otherwise one can just get a much lighter M3 and make it much faster for less $, if that's the primary purpose.

[fmzip]

Originally Posted by AmooManiak

To be fair, if you want the fastest for your $, you wouldn't be picking any 8 series (M8 or M850i) as the foundation. These are first and foremost GT cars. Low 10s is good enough. Otherwise one can just get a much lighter M3 and make it much faster for less $, if that's the primary purpose.

Agreed.... the OP is comparing the two 8 series.

[Torettoshifts]

Guys the m850 has a 2.81 differential gearing not 3.40 gear as it’s final drive.

https://www.bimmerpost.com/goodiesfo...ries-specs.pdf


https://www.press.bmwgroup.com/unite...85EN_GB/430153

All g series n63 cars have a final drive of 2.81
The 3.15 ratio diff will increase torque to the wheels by 12% over the 2.81 diff. And 2nd gear has 66% of the torque multiplication of first gear,So the m850 is at disadvantage to a m5 or m8 or any recent m series car with the 3.15

Car and driver has it wrong.

[Jasinedward]

Originally Posted by fmzip

Agreed.... the OP is comparing the two 8 series.

Just for aftermarket purposes really…. The m850i is my wife’s car. She’s made a few passes at the dragstrip but isn’t a die hard racer. I think I’m going to get her a jb4 and call it a day…. Maybe a titanium exhaust for a bit more sound.

Most of my budget is going into my m4.

[ViO]

Originally Posted by Torettoshifts

Guys the m850 has a 2.81 differential gearing not 3.40 gear as it’s final drive.

https://www.bimmerpost.com/goodiesfo...ries-specs.pdf


https://www.press.bmwgroup.com/unite...85EN_GB/430153

All g series n63 cars have a final drive of 2.81
The 3.15 ratio diff will increase torque to the wheels by 12% over the 2.81 diff. And 2nd gear has 66% of the torque multiplication of first gear,So the m850 is at disadvantage to a m5 or m8 or any recent m series car with the 3.15

Car and driver has it wrong.

I was comparing the convertible. It clearly has the M850 Convertible listed as having 3.40 gears. I’ll post an images of the window stickers from a M850 convertible. It is the same for all of them. IDK.. Perhaps the M850 coupe gets less gearing??

*Under mechanical all three of these convertible M850’s have 3.40 rear gears. Again, I’m not sure about the Coupe?

*I’m going by what I’m seeing….

[Torettoshifts]

The convertible has the same gearing as all of them the data published on car and driver is incorrect and it does not change by body style of m850.
Also if you read the first post it indicates it’s a m850 convertible in the link . There is another forum where some guys went through the same thoughts.

[ViO]

Originally Posted by Torettoshifts

The convertible has the same gearing as all of them the data published on car and driver is incorrect and it does not change by body style of m850.

Maybe everyone else is wrong and your correct..

However when you run the vin and decode the options all of the 2019, 2020, and 2021 convertibles they all come up with having 3.40 gears.

[Torettoshifts]

It’s very odd. But yes.

[ViO]

Originally Posted by Torettoshifts

It’s very odd. But yes.

If you think about it and the extra weight of the convertible it makes sense to have more gearing. This wouldn’t be the first time a manufacturer has done this.

Again, you may be correct and all of these facts are wrong…

*My racing days are over now but back in the day…

We would just chalk mark the driveshaft and chalk mark the backside of the tire and spin the tire one full revolution and count how many times the driveshaft spun around back the chalk mark. If the driveshaft spun around 3.75 times it was 3.73 gears etc..

[Torettoshifts]

https://www.bmwpartsnow.com/oem-part...xoCAH0QAvD_BwE

https://www.ebay.com/itm/14562428288...SABEgK4KPD_BwE

Here is a part number for question

[ViO]

Originally Posted by Torettoshifts

https://www.bmwpartsnow.com/oem-part...xoCAH0QAvD_BwE

https://www.ebay.com/itm/14562428288...SABEgK4KPD_BwE

Here is a part number for question

What is that off of?? Coupe or Convertible??

Honestly, at this point you could just call up any BMW parts dealer and give them one of the three convertible vins I posted and they will tell what the gearing is. 😊

[Torettoshifts]

If you do a quick look up on eBay or real Oem you can cross verify
They are simply writing the wrong information there

[Torettoshifts]

This was looked up by a convertible vin
* WBABC4C53KBJ35802

https://www.realoem.com/bmw/enUS/sho...diagId=33_2227

[Torettoshifts]

https://www.ebay.com/itm/156247204188

[Torettoshifts]

https://www.press.bmwgroup.com/globa...86150EN/445834

https://www.bmwpartshub.com/oem-part...iABEgLO9PD_BwE

https://www.ebay.com/itm/18629988693...yABEgJu9vD_BwE

[Torettoshifts]

https://www.ebay.com/itm/14590663498...FgeTUz9aUdKGXc

[Torettoshifts]

https://www.automobile-catalog.com/a....php#gsc.tab=0

Here’s the technical specs listed here as well to compare to all the used rear diffs online and from esys and ista. When programming the rear diff
This is the 2024 cabriolet m850
Also if the m850 had a different final drive it would result in different horsepower and torque figures at different rpms when compared to the m550 with the same final drive ratio.
They have the same power numbers and shift at the same speed due to the same rear diff front diff and transmission and tcase.

[Torettoshifts]

So to everyone the m850 has a final drive of 2.81. Please always use real Oem or check by part number to cross verify. Hopefully this helps everyone that has ever wondered. And they should defiantly fix those window stickers. It’s misleading information and someone needs to tell car and driver to update theirs as well.