M3 DCT diff

k335d · 05-01-2016, 11:28 PM

Thinking about swapping in M3 DCT diff with 3:154 gears. For me the Quaife and Wavetrac are a no go because being in the great white north i need it to lock when on ice. Mfactory clutch type isn't out yet for are cars so M3 diff looks like the best option out there right now.

Im already running taller tires so at 100kph it will only turn 150 rpm more. 150 rpm should not hurt mpg much and 3:154 would get a little more out of the whole.

Any thoughts?

Whitbread · 05-02-2016, 12:53 AM

A wavetrac does fully lock if one tire free wheels. I've installed many of them for lots of happy customers that live in snowy areas

.

k335d · 05-02-2016, 01:26 AM

Quote:

Originally Posted by Whitbread

A wavetrac does fully lock if one tire free wheels. I've installed many of them for lots of happy customers that live in snowy areas

.

this video lead to to believe otherwise. maybe I'm wrong on that

Owen81 · 05-02-2016, 03:24 AM

Hmmm, in that video it looks like he has an open diff still...

Here is another video of the wavetrac:

Keep in mind to use the M3 diff, just going by what the 335i guys have done, it sounds like you need the half shafts as well. And you have to mate half of the stock drive shaft with half of the M3 shaft and get it all balanced.

k335d · 05-02-2016, 04:08 AM

Yeah i think ill look in to the wavetrac more. Just hate to spend $3500 cad to find out its still a one wheel wonder in the winter.

Owen81 · 05-02-2016, 04:23 AM

Well if you want to be sure, and you don't mind spending the extra cash, they will build the OS Giken Superlock into a used 335d diff as well. (I assume you're looking at VAC Motorsports.)

It is my understanding these would be better if you track the car as well, since they lock up under decel and accel. (For the 1.5 or 2 way)

Speed-D · 05-03-2016, 08:59 AM

I was actually thinking about going the other way. I am thinking about the 2.56, it will result in better gas mileage and I have an argument that it could increase the acceleration. I know that changing the gearing in this direction is generally for higher top end and you loose bottom end; however, with the 2.56 you can hit 65 in second. With a second gear launch that's 60 without a shift. Plus I always felt like the car pulled harder when it was loaded down.

k335d · 05-03-2016, 05:12 PM

Quote:

Originally Posted by Speed-D

I was actually thinking about going the other way. I am thinking about the 2.56, it will result in better gas mileage and I have an argument that it could increase the acceleration. I know that changing the gearing in this direction is generally for higher top end and you loose bottom end; however, with the 2.56 you can hit 65 in second. With a second gear launch that's 60 without a shift. Plus I always felt like the car pulled harder when it was loaded down.

Would be a great idea but I'm already running a taller tire so might be a little to much. I like to hit the drag strip a few times a year so leaning more to the 3.15.
Found a company that offers to rebuild the M3 diff with 2.81 gear set. If i can pick up a cheap used one it would be much more to have it rebuilt and correct gear set installed.

http://diffsonline.com/bmw-e9x-m3-dc...l#.VykiV8clf6B

TDIwyse · 05-03-2016, 07:50 PM

Quote:

Originally Posted by k335d

... For me the Quaife and Wavetrac are a no go because being in the great white north i need it to lock when on ice. ...

The Quaife in my 335d spins both wheels on ice.

My OEM setup on ice only spins the driver side:

Quaife on ice spins both:

k335d · 05-03-2016, 08:54 PM

My OEM setup on ice only spins the driver side
Quaife on ice spins both:

Thank you. Did you have to lightly hold the brakes to get it to lock or is that just put in to gear and go?

Owen81 · 05-04-2016, 12:37 AM

Indeed, braking would pre-load the lower traction wheel and lock up the diff.

With the car rocking back and forth after they start spinning, it doesn't look like he was holding the brakes?

TDIwyse · 05-04-2016, 07:11 AM

Quote:

Originally Posted by k335d

My OEM setup on ice only spins the driver side
Quaife on ice spins both:

Thank you. Did you have to lightly hold the brakes to get it to lock or is that just put in to gear and go?

This was on my driveway, which has an incline, and I used blocks on the front wheels so I wouldn't be holding the brakes for this test. Both tests were conducted in this way.

What I didn't do, and want to after seeing the other videos posted, is do the one wheel test (one on ice, the other on dry). But it'll be many months before conditions are such that I can replicate that.

k335d · 05-04-2016, 02:25 PM

Quote:

Originally Posted by TDIwyse

This was on my driveway, which has an incline, and I used blocks on the front wheels so I wouldn't be holding the brakes for this test. Both tests were conducted in this way.

What I didn't do, and want to after seeing the other videos posted, is do the one wheel test (one on ice, the other on dry). But it'll be many months before conditions are such that I can replicate that.

Thanks TDIwyse

Starting to wonder if lots of the other guys posting about not locking on ice are guys who don't have or never tired Quaife or Wavetrac.

05-01-2016, 11:28 PM	#1
k335d Private First Class 80 Rep 163 Posts Drives: 09 335d Join Date: May 2014 Location: Abbotsford Canada iTrader: (1)	M3 DCT diff Thinking about swapping in M3 DCT diff with 3:154 gears. For me the Quaife and Wavetrac are a no go because being in the great white north i need it to lock when on ice. Mfactory clutch type isn't out yet for are cars so M3 diff looks like the best option out there right now. Im already running taller tires so at 100kph it will only turn 150 rpm more. 150 rpm should not hurt mpg much and 3:154 would get a little more out of the whole. Any thoughts?
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05-02-2016, 12:53 AM	#2
Whitbread Banned 144 Rep 316 Posts Drives: 335D Join Date: Jun 2015 Location: Gaylord, MI iTrader: (0)	A wavetrac does fully lock if one tire free wheels. I've installed many of them for lots of happy customers that live in snowy areas .
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05-02-2016, 03:24 AM	#4
Owen81 Lieutenant 83 Rep 432 Posts Drives: 335d, 17/22 TDI Join Date: May 2015 Location: Alberta, Canada iTrader: (0)	Hmmm, in that video it looks like he has an open diff still... Here is another video of the wavetrac: Keep in mind to use the M3 diff, just going by what the 335i guys have done, it sounds like you need the half shafts as well. And you have to mate half of the stock drive shaft with half of the M3 shaft and get it all balanced.
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05-02-2016, 04:08 AM	#5
k335d Private First Class 80 Rep 163 Posts Drives: 09 335d Join Date: May 2014 Location: Abbotsford Canada iTrader: (1)	Yeah i think ill look in to the wavetrac more. Just hate to spend $3500 cad to find out its still a one wheel wonder in the winter.
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05-02-2016, 04:23 AM	#6
Owen81 Lieutenant 83 Rep 432 Posts Drives: 335d, 17/22 TDI Join Date: May 2015 Location: Alberta, Canada iTrader: (0)	Well if you want to be sure, and you don't mind spending the extra cash, they will build the OS Giken Superlock into a used 335d diff as well. (I assume you're looking at VAC Motorsports.) It is my understanding these would be better if you track the car as well, since they lock up under decel and accel. (For the 1.5 or 2 way)
	Appreciate 0 Quote

05-03-2016, 08:59 AM	#7
Speed-D New Member 2 Rep 19 Posts Drives: 2011 335d Join Date: Jan 2016 Location: Georgia iTrader: (0)	I was actually thinking about going the other way. I am thinking about the 2.56, it will result in better gas mileage and I have an argument that it could increase the acceleration. I know that changing the gearing in this direction is generally for higher top end and you loose bottom end; however, with the 2.56 you can hit 65 in second. With a second gear launch that's 60 without a shift. Plus I always felt like the car pulled harder when it was loaded down.
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05-03-2016, 08:54 PM	#10
k335d Private First Class 80 Rep 163 Posts Drives: 09 335d Join Date: May 2014 Location: Abbotsford Canada iTrader: (1)	My OEM setup on ice only spins the driver side Quaife on ice spins both: Thank you. Did you have to lightly hold the brakes to get it to lock or is that just put in to gear and go?
	Appreciate 0 Quote

05-04-2016, 12:37 AM	#11
Owen81 Lieutenant 83 Rep 432 Posts Drives: 335d, 17/22 TDI Join Date: May 2015 Location: Alberta, Canada iTrader: (0)	Indeed, braking would pre-load the lower traction wheel and lock up the diff. With the car rocking back and forth after they start spinning, it doesn't look like he was holding the brakes?
	Appreciate 0 Quote