3.45/3.62 short ratio Diff anyone ?? - BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)

Stratus650 · 01-20-2013, 01:45 AM

nearly everything was discussed in terms of tuning the 1M (except RB's i guess

) however I couldn't find anyone interested in a short ratio diff.

Dinan offers 3.45/3.62 diff options which give 9.5% and 14.9% torque increase respectively, which seems nice for a diff upgrade only. these are listed under the M3 DCT which is identical to our diffs.

anyone have experience in this? after some

i found that biglare had this mod on his previous E90 M3.

It would be nice to know everyones feedback!

bdaddylo · 01-20-2013, 02:23 AM

The M3 needs more torque, not the 1M. IMHO we need a higher gear ratio to make better use of our torque.

OneM · 01-20-2013, 03:06 AM

When you cycle a bicycle uphill, you would normally change to a lower gear so it becomes easier to pedal. However, you would not normally use a lower gear to go downhill, which is what it would be like if you were to put shorter ratio gears on the 1M, you'd be shifting constantly on such a high torque vehicle, ..not to mention the loss of traction.

Stratus650 · 01-20-2013, 03:32 AM

Quote:

Originally Posted by bdaddylo

The M3 needs more torque, not the 1M. IMHO we need a higher gear ratio to make better use of our torque.

agreed, this mod might not fully benefit the 1M acceleration from a stand still, but it would help acceleration on the move from higher speeds/gears.

car feels really strong when accelerating from a standstill but once speed increases things get a bit slow; wouldnt a 3.45 be realistic?

another benefit is the car wont be cruising around the drony 2.2k rpm range

maupineda · 01-20-2013, 10:19 AM

I would do it. the 1M has ver long ratios to the point that 6th is just overdrive. I personally like 6 full usable speeds.

I have 3.43 diff in my 130 and find it just perfect. this would make the 1M even more raw.

CarJunkie · 01-20-2013, 10:55 AM

1st gear would be useless.

ozinaldo · 01-20-2013, 11:35 AM

Like everyone posted before, it has plus and minus to add this mod, I would pass it unless the car is "mostly" used on highways where reaching high gears are possible/permitted (e.g. autobahn).

robertm · 01-20-2013, 09:34 PM

Quote:

Originally Posted by CarJunkie

1st gear would be useless.

Isn't it already?

CarJunkie · 01-20-2013, 09:54 PM

Quote:

Originally Posted by robertm

Isn't it already?

Not with better tires, so I hear.

bdaddylo · 01-20-2013, 10:30 PM

Quote:

Originally Posted by maupineda

I would do it. the 1M has ver long ratios to the point that 6th is just overdrive. I personally like 6 full usable speeds.

I have 3.43 diff in my 130 and find it just perfect. this would make the 1M even more raw.

Not sure I understand you. You can't compare a 130 to a 1M. The 1M's 6th gear has more than adequate passing power and is very useable. It is so useable in daily driving to the point where you can skip 5th. I wish 6th was more like an overdrive to improve highway fuel economy.

Stratus650 · 01-20-2013, 10:57 PM

Quote:

Originally Posted by CarJunkie

1st gear would be useless.

a 3.45 will increase the rpm by 200 when cruising and a maximum of 600 at the redline, this is not a huge shift in ratio, i think we will need to control how we press the pedal instead of a sudden flooring hehe

Quote:

Originally Posted by ozinaldo

Like everyone posted before, it has plus and minus to add this mod, I would pass it unless the car is "mostly" used on highways where reaching high gears are possible/permitted (e.g. autobahn).

+1

I usually cruise at 110km/h around the city so im always on 6th at 2200rpm, with a 3.45 it is going to be 2400rpm, again not a huge difference

maupineda · 01-20-2013, 11:00 PM

in this video it seems to reach 250km/k at around 5K rpm. 2000rpm more to go.

bdaddylo · 01-20-2013, 11:37 PM

Quote:

Originally Posted by maupineda

in this video it seems to reach 250km/k at around 5K rpm. 2000rpm more to go.

There's not 2,000 rpm to go in 6th rear with a stock 1M. Max power occurs between 5,500 - 5,900 rpm.

Stratus650 · 01-21-2013, 03:05 AM

Quote:

Originally Posted by bdaddylo

There's not 2,000 rpm to go in 6th rear with a stock 1M. Max power occurs between 5,500 - 5,900 rpm.

with a 3.45 diff it will be already 250km/h @ 5,600rpm, so in the max power range hehe

Superfly · 01-21-2013, 08:57 AM

I was very sceptical about the fitting of a short ratio Diff and I tried a 1M with a short one fitted : it's so nice with it , the car is really faster and feels snappier, yes i know it's not a surprise but the 1M + short ratio diff is a so beautifull combination that i will have one installed in one month.

Stratus650 · 01-21-2013, 12:51 PM

Quote:

Originally Posted by Superfly

I was very sceptical about the fitting of a short ratio Diff and I tried a 1M with a short one fitted : it's so nice with it , the car is really faster and feels snappier, yes i know it's not a surprise but the 1M + short ratio diff is a so beautifull combination that i will have one installed in one month.

Now you're talking !!

so any details? what brand was the diff ? and what ratio if I may ask

any more feedback on your unique experience would be appreciated.

01-20-2013, 01:45 AM	#1
Stratus650 Second Lieutenant Drives: 1er M Coupe Join Date: Aug 2009 Location: Dubai Posts: 259 iTrader: (0)	3.45/3.62 short ratio Diff anyone ?? nearly everything was discussed in terms of tuning the 1M (except RB's i guess ) however I couldn't find anyone interested in a short ratio diff. Dinan offers 3.45/3.62 diff options which give 9.5% and 14.9% torque increase respectively, which seems nice for a diff upgrade only. these are listed under the M3 DCT which is identical to our diffs. anyone have experience in this? after some i found that biglare had this mod on his previous E90 M3. It would be nice to know everyones feedback! __________________ '12 Candy Grey Metallic 1M
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01-20-2013, 02:23 AM	#2
bdaddylo Captain Drives: 2011 E82 1M Join Date: Dec 2010 Location: Houston, TX Posts: 823 iTrader: (0) Garage List 2005 Acura MDX [0.00] 2011 BMW 1 Series M ... [0.00]	The M3 needs more torque, not the 1M. IMHO we need a higher gear ratio to make better use of our torque. __________________ _______________________ 2011 1 Series M Coupe/VO/Convenience Pkg/Premium Pkg/Harman Kardon/AFE Scoops/Berk Midpipes/P3 V2/BMS Catch Can/CF Rear Deck Spoiler/3M Clear Bra/3M Crystalline/Homelink/M Performance Steering Wheel

01-20-2013, 11:35 AM	#7
ozinaldo Colonel Drives: 1M Join Date: Jan 2011 Location: Chile, Santiago Posts: 2,080 iTrader: (0)	Like everyone posted before, it has plus and minus to add this mod, I would pass it unless the car is "mostly" used on highways where reaching high gears are possible/permitted (e.g. autobahn). __________________ 2011 BMW 1M: Euro spec, w/out Nav, manual seats. Evolve Race+N55 mid, Michelin PSS, ER charge pipe, aFe ProDryS drop-in filter, CDVx, BMW-IND trunk spoiler matt cf/VO stripe, BMW blacklines, BMW black grills, IND side gills&rear M logo, silver turn indicator bulbs, anthrazit overlays on side creases and on air curtains, MPerformance steering wheel w/VO ring, BMW steel pedals, custom mats, color matched MPower e-brake.

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01-20-2013, 03:06 AM	#3
OneM Enlisted Member Drives: 1M Join Date: Apr 2012 Location: - Posts: 44 iTrader: (0)	When you cycle a bicycle uphill, you would normally change to a lower gear so it becomes easier to pedal. However, you would not normally use a lower gear to go downhill, which is what it would be like if you were to put shorter ratio gears on the 1M, you'd be shifting constantly on such a high torque vehicle, ..not to mention the loss of traction.

01-20-2013, 10:19 AM	#5
maupineda Private First Class Drives: E87 130i Join Date: Jul 2012 Location: Mexico City Posts: 186 iTrader: (0)	I would do it. the 1M has ver long ratios to the point that 6th is just overdrive. I personally like 6 full usable speeds. I have 3.43 diff in my 130 and find it just perfect. this would make the 1M even more raw.

01-20-2013, 10:55 AM	#6
CarJunkie Lieutenant Drives: Valencia Orange 1-Series M Join Date: Nov 2011 Location: Tri-Cities, Washington Posts: 431 iTrader: (0)	1st gear would be useless.

01-20-2013, 11:00 PM	#12
maupineda Private First Class Drives: E87 130i Join Date: Jul 2012 Location: Mexico City Posts: 186 iTrader: (0)	in this video it seems to reach 250km/k at around 5K rpm. 2000rpm more to go.

01-21-2013, 08:57 AM	#15
Superfly Private Drives: BMW 1M Join Date: Mar 2010 Location: France Posts: 82 iTrader: (0)	I was very sceptical about the fitting of a short ratio Diff and I tried a 1M with a short one fitted : it's so nice with it , the car is really faster and feels snappier, yes i know it's not a surprise but the 1M + short ratio diff is a so beautifull combination that i will have one installed in one month.