Has anyone changed final drive on manual 545 or 550?
05-13-2009, 02:54 AM
#11
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Originally Posted by uheenada' post='876848' date='May 13 2009, 05:51 AM
umm what do you mean by different setups?
MT and SMG use same transmission except smg has a module that controls the clutch.
They both share same parts including gearing and rear differential.
MT and SMG use same transmission except smg has a module that controls the clutch.
They both share same parts including gearing and rear differential.
Ha cannot accept to be the second, LOL!
05-13-2009, 07:21 AM
#12
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Originally Posted by AlexFW' post='877040' date='May 13 2009, 12:54 PM
Ha cannot accept to be the second, LOL!
BTW on SMG it was risky because I didn't know how the SMG would have behaved (it still doesn't work perfectly in some situations), while on the manual he is sure it would work without any risk.
05-13-2009, 08:39 AM
#13
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My Ride: 2005 545i SMG
Originally Posted by AlexFW' post='877197' date='May 13 2009, 08:21 AM
BTW on SMG it was risky because I didn't know how the SMG would have behaved (it still doesn't work perfectly in some situations), while on the manual he is sure it would work without any risk.
Because, when I talked to Dinan about this mod, they said no problems at all with computer.
05-13-2009, 09:28 AM
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My Ride: 2006 550i SMG
Originally Posted by dusandimic' post='874465' date='May 10 2009, 07:14 PM
I'm seriously considering doing this and some feedbackwould be greatly appreciated.
05-13-2009, 10:27 AM
#15
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My Ride: 2006 550i sport package, manual, black on black w/ anthracite trim, pdc, logic 7, cold weather pkg.
Originally Posted by AlexFW' post='877197' date='May 13 2009, 10:21 AM
BTW on SMG it was risky because I didn't know how the SMG would have behaved (it still doesn't work perfectly in some situations), while on the manual he is sure it would work without any risk.
Also, why did you go with a 3.15 as opposed to a 3.38?
05-13-2009, 11:36 AM
#16
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Originally Posted by dusandimic' post='877337' date='May 13 2009, 08:27 PM
If you don't mind me asking, what did it cost?
Also, why did you go with a 3.15 as opposed to a 3.38?
Because I use to travel at 170-180 kmh and now I have 4000 rpm instead of 3600. With 3.38.. 4400 rpm, crazy!
Keep in mind that your consumption (and noise) will increase. Plus our factory 6th gear is 315-320 kmh, suitable for a travel car: now I have 290 kmh and it begins to be too short for long and fast trips.
05-13-2009, 11:48 AM
#17
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Are there any positives? I can't think of any.
05-13-2009, 12:04 PM
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Originally Posted by DD_545i' post='877398' date='May 13 2009, 03:48 PM
Negative Point #1
Negative Point #2
Negative Point #3
Negative Point #4
Are there any positives? I can't think of any.
Negative Point #2
Negative Point #3
Negative Point #4
Are there any positives? I can't think of any.
05-13-2009, 12:06 PM
#19
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Welcome to your messenger
Re:rear diffs
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dusandimic
Re:rear diffs, May 10 2009, 07:12 PM
sorry. I was having some keyboard trouble... what is the final drive ratio of the 550 now? If you keep a limited slip carrier, you should be fine, if you go with a POSI unit and you like taking exit ramps off the highway quickly, i hope you like drifting.
I dont know what the final drive ratio is. if it is a 3.08, then a 3.38 would greatly help acceleration, making your car feel more powerful. first gear will be extremely short, and 6th gear will pull harder. you will be able to hit top speed i suspect (155) but your RPMs will be higher. you will have less traction off the line. additionally, the higher the ratio (3.08-->3.18-->3.38-->3.55-->3.73-->4.11) the worse your fuel mileage. because lets say you typically drive 70 MPH on the way to and from work, your RPMs will be higher then before with your lower gear ratio.
I dont want to make things more confusing, but the HIGHER the number, the LOWER the gear ratio. when i say higher, i am talking about numerically.
so the rules are...
The higher the NUMBER the lower the top speed
The higher the NUMBER the lower fuel MPG
The higher the NUMBER the worse the traction (countered with a good unit and good tires)
The higher the NUMBER the BETTER the acceleration
The higher the NUMBER the HARDER your higher gears will pull
Your traction WILL BE WORSE in the winter time, however, leave DTS activated and you will be fine.
sorry if this jumped around a bit. I just got back to work from 4 days off and have a bit going on. I always have time for a fellow BMW enthusiast though. let me know if you need anything clarified
Re:rear diffs
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dusandimic
Re:rear diffs, May 10 2009, 07:12 PM
sorry. I was having some keyboard trouble... what is the final drive ratio of the 550 now? If you keep a limited slip carrier, you should be fine, if you go with a POSI unit and you like taking exit ramps off the highway quickly, i hope you like drifting.
I dont know what the final drive ratio is. if it is a 3.08, then a 3.38 would greatly help acceleration, making your car feel more powerful. first gear will be extremely short, and 6th gear will pull harder. you will be able to hit top speed i suspect (155) but your RPMs will be higher. you will have less traction off the line. additionally, the higher the ratio (3.08-->3.18-->3.38-->3.55-->3.73-->4.11) the worse your fuel mileage. because lets say you typically drive 70 MPH on the way to and from work, your RPMs will be higher then before with your lower gear ratio.
I dont want to make things more confusing, but the HIGHER the number, the LOWER the gear ratio. when i say higher, i am talking about numerically.
so the rules are...
The higher the NUMBER the lower the top speed
The higher the NUMBER the lower fuel MPG
The higher the NUMBER the worse the traction (countered with a good unit and good tires)
The higher the NUMBER the BETTER the acceleration
The higher the NUMBER the HARDER your higher gears will pull
Your traction WILL BE WORSE in the winter time, however, leave DTS activated and you will be fine.
sorry if this jumped around a bit. I just got back to work from 4 days off and have a bit going on. I always have time for a fellow BMW enthusiast though. let me know if you need anything clarified
05-13-2009, 12:07 PM
#20
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Originally Posted by DD_545i' post='877398' date='May 13 2009, 03:48 PM
Negative Point #1
Negative Point #2
Negative Point #3
Negative Point #4
Are there any positives? I can't think of any.
Negative Point #2
Negative Point #3
Negative Point #4
Are there any positives? I can't think of any.
The shorter 3.91 gearing takes advantage of torque multiplication for a substantial increase in torque delivered to the road. The improved acceleration comes with only a minor increase in engine speeds at cruise and no effective reduction in top speed