3.9 final drives are in
3.9 final drives are in
Re: 3.9 final drives are in
Think carefully about 16.5% rpm increase at highway cruise with AT-------- direct reduction in mpg. Could be as bad as 4 mpg [highway] worse after the change.
But then again what's 120-140 extra gallons per 15,000 miles of highway use compared to a possible 0.3-0.36 seconds reduction in quarter mile times. Assuming you have the redline to not add another gear shift into the mix.
But then again what's 120-140 extra gallons per 15,000 miles of highway use compared to a possible 0.3-0.36 seconds reduction in quarter mile times. Assuming you have the redline to not add another gear shift into the mix.
Re: 3.9 final drives are in
Simple the rear torque gets multipled by 10%, take the cube root of the change..............2.2 .......
14.5 secs x 0.022= ~ 0.32
Thats a massive gain. But on a $ basis it is expensive.
Just like each 10 HP gain knocks ~0.1 second off the quarter mile.
14.5 secs x 0.022= ~ 0.32
Thats a massive gain. But on a $ basis it is expensive.
Just like each 10 HP gain knocks ~0.1 second off the quarter mile.
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Re: 3.9 final drives are in
What is the cost of the gear set?
'03.5 G35 Sedan Premium, Aero & Sport Packages w/Auto
Desert Platinum w/wood dash & cabin trim
Injen CAI, Borla catback exhaust, Tein H-tech lowering springs, UR crank pulley, Technosquare ECU
'03.5 G35 Sedan Premium, Aero & Sport Packages w/Auto
Desert Platinum w/wood dash & cabin trim
Injen CAI, Borla catback exhaust, Tein H-tech lowering springs, UR crank pulley, Technosquare ECU
Re: 3.9 final drives are in
that would cost you 4k in engine mods if you've already got a plenum or other na mods that add 20-30 hp.
2003.5 DP 5AT Sedan
14.2 @ 97.18
Z-Tube
K&N Drop In & Airbox Mod
10 Wire Hyper-Ground
Crawford Plenum (V4)
UR Crank Pulley
Hotchkis Sways (M/M)
Polk EX-3500 Tweeters/Shock Sensor/H-Liner
2003.5 DP 5AT Sedan
14.2 @ 97.18
Z-Tube
K&N Drop In & Airbox Mod
10 Wire Hyper-Ground
Crawford Plenum (V4)
UR Crank Pulley
Hotchkis Sways (M/M)
Polk EX-3500 Tweeters/Shock Sensor/H-Liner
Re: 3.9 final drives are in
Let me be more clear: What is the price (dollars) of the gear set? I am considering a purchase.
'03.5 G35 Sedan Premium, Aero & Sport Packages w/Auto
Desert Platinum w/wood dash & cabin trim
Injen CAI, Borla catback exhaust, Tein H-tech lowering springs, UR crank pulley, Technosquare ECU
'03.5 G35 Sedan Premium, Aero & Sport Packages w/Auto
Desert Platinum w/wood dash & cabin trim
Injen CAI, Borla catback exhaust, Tein H-tech lowering springs, UR crank pulley, Technosquare ECU
Re: 3.9 final drives are in
The gear sets are usually not very expensive [under $1,000]. Finding a EXPERT Differential Technican who will spend the time to install the gear set correctly and precisely [lots of fine accurate measuring and calculating shim thickness reguired]. Lots of trial and error to get the teeth mess shape correct.
I like to spend 4-5 hours with the diff on the bench.......7-8 shop hours in total to precisely install.
Lots of difference between a quicky 12,000 mile warranty and something [work quality] good enough to last 200,000 miles.
I like to spend 4-5 hours with the diff on the bench.......7-8 shop hours in total to precisely install.
Lots of difference between a quicky 12,000 mile warranty and something [work quality] good enough to last 200,000 miles.
Re: 3.9 final drives are in
Most definitely. BMW learned the hard way (and still learning) by outsourcing their K-Bike rear drives to the Eastern bloc for assy. to save labor costs. The result is rear drives failing on about 8-12% of the bikes made from 1999-2001. I have a 2000 K1200 and just replaced the drive under warantee with a fresh german unit. If you think diff failures are no fun on a car, try having one go out on a bike at 75MPH with trucks on either side. Insist on only the best for power transfer or you will likely end up stranded somewhere you dont want to be (try Enid, Oklahoma).
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Frostbite91
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Aug 20, 2015 07:20 PM




