New Dinan 3.62 FD for DCT

[doba_s]

I had a chance today to check out Dinan facility in Morgan Hill. Very nice place and everyone there looked super busy ... good thing I guess !

Anyway ... I was kind of set on upgrading my final drive and to go with 3.45 that they offer. But decided to ask if they have any plans to release 3.62 final drive, and Chris told me that they can sell me one today ! I was very happy to hear that ! We went to talk to the person who is actually working on it right now and he told me that they have unit that are ready to go, but they are not done yet with R&D and want to test it first on their car to make sure everything will be ok ! So, they are planing to release it in about 1 week or so.

I also went on a drive with one of the guys who has 3.45 final drive and I was very impressed ! So, my guess is that you can expect even more from 3.62.

[Sticky2]

Originally Posted by doba_s

I had a chance today to check out Dinan facility in Morgan Hill. Very nice place and everyone there looked super busy ... good thing I guess !

Anyway ... I was kind of set on upgrading my final drive and to go with 3.45 that they offer. But decided to ask if they have any plans to release 3.62 final drive, and Chris told me that they can sell me one today ! I was very happy to hear that ! We went to talk to the person who is actually working on it right now and he told me that they have unit that are ready to go, but they are not done yet with R&D and want to test it first on their car to make sure everything will be ok ! So, they are planing to release it in about 1 week or so.

I also went on a drive with one of the guys who has 3.45 final drive and I was very impressed ! So, my guess is that you can expect even more from 3.62.

Tell me more about the drive with the 3.45. Should have felt significantly faster.

[doba_s]

I was surprised how the car behaved ... even in D mode it felt like you are driving in M mode ... With 3.45 there is 9.5% increase in torque, and with 3.62 they are saying it will be around 14.5% increase. Sounds good to me !

[labelexec]

what's the eta for the 3.62 to be released?

[M3 996]

More impressions of the test drive please??? I am seriously considering this mod too...

[Sticky]

Originally Posted by labelexec

what's the eta for the 3.62 to be released?

Diffsonline already has it, for less money.

[doba_s]

Originally Posted by Sticky

Diffsonline already has it, for less money.

with 15% rebate from Dinan the difference in the price is not big at all ... plus everything is still under warranty

[doba_s]

Originally Posted by labelexec

what's the eta for the 3.62 to be released?

i called Dinan on friday and left a message ... i will keep you guys posted

[Sticky]

Originally Posted by doba_s

with 15% rebate from Dinan the difference in the price is not big at all ... plus everything is still under warranty

Under Dinan warranty... which is the same thing as the diffsonline warranty. It breaks, you get a new part.

[Mischievous M]

Originally Posted by doba_s

I had a chance today to check out Dinan facility in Morgan Hill. Very nice place and everyone there looked super busy ... good thing I guess !

Anyway ... I was kind of set on upgrading my final drive and to go with 3.45 that they offer. But decided to ask if they have any plans to release 3.62 final drive, and Chris told me that they can sell me one today ! I was very happy to hear that ! We went to talk to the person who is actually working on it right now and he told me that they have unit that are ready to go, but they are not done yet with R&D and want to test it first on their car to make sure everything will be ok ! So, they are planing to release it in about 1 week or so.

I also went on a drive with one of the guys who has 3.45 final drive and I was very impressed ! So, my guess is that you can expect even more from 3.62.

Hi guys,

Pardon my ignorance but what is a final drive? Am i right to guess that it is a throttle body or by pass valve upgrade?

hope i dont sound like a real idiot.

[GregW / Oregon]

Originally Posted by Mischievous M

Pardon my ignorance but what is a final drive? Am i right to guess that it is a throttle body or by pass valve upgrade?

hope i dont sound like a real idiot.

Rear differential--the "final drive" is the set of gears that converts driveshaft speed to wheel speed. A "shorter" gear ratio (higher number) gives more torque in each gear, at the expense of fuel economy and higher revs on the highway in top gear.

[Sticky]

Originally Posted by GregW / Oregon

Rear differential--the "final drive" is the set of gears that converts driveshaft speed to wheel speed. A "shorter" gear ratio (higher number) gives more torque in each gear, at the expense of fuel economy and higher revs on the highway in top gear.

Exactly, and theoretical top speed, but that is obvious.

[Mischievous M]

Originally Posted by GregW / Oregon

Rear differential--the "final drive" is the set of gears that converts driveshaft speed to wheel speed. A "shorter" gear ratio (higher number) gives more torque in each gear, at the expense of fuel economy and higher revs on the highway in top gear.

Originally Posted by Sticky

Exactly, and theoretical top speed, but that is obvious.

thanks guys for shedding the knowledge on final drive... hmm, more torque in each gear sounds like insane fun. I can only imagine the constant grin on the faces of enthusiasts who are considering or have done a pulley and final drive upgrade.

[noxredna]

How badly will the MPG be affected? Anyone has done this mod? How much MPH are you giving away on the car's top speed?

Interesting mod considering that this is my DD and I do a lot of city/road driving, the torque increase would definitely be nice.

[Mickb]

Does this make much of a difference in terms of outright acceleration, or does the car just feel more torquey in each gear?

Presumably while there is more torque at the wheels, the enginer flys through the rev band quicker for any given speed/acceleration and there is a tradeoff in terms of number fo gearchanges required?

I guess this shouldnt matter too much with DCT since the shifts are so fast.

Final question. Can you change the final drive without changing the entire diff?

[kmac1980]

im guessing people who contemplate this mod arent using their m as a daily driver? i mean the fuel economy (more importantly range) already sucks.... this car revs so high in top gear at highway speeds!

id guess the stock final drive is already much more aggressive than my previous e90 330i... this is probably a reason 335i fanboys underestimate the m3, they are stuck on hp/tq vs. weight numbers and dont look at gearing....

[doba_s]

Originally Posted by Sticky

Under Dinan warranty... which is the same thing as the diffsonline warranty. It breaks, you get a new part.

i would go with diffsonline if they were near me , but to pay every time to install/uninstall it would be much more expensive than Dinan's FD.

another thing , did Dan did any R&D ? Did they installed any 3.62s or any other FDs on e92 M3 ? will 3.62 final drive work perfect with car's computer ?

[doba_s]

Originally Posted by noxredna

How badly will the MPG be affected? Anyone has done this mod? How much MPH are you giving away on the car's top speed?

Interesting mod considering that this is my DD and I do a lot of city/road driving, the torque increase would definitely be nice.

not sure how badly, but it definitely will be affected ! i was told it will be in 8-10mpg neighborhood ...

[doba_s]

UPDATE:

I just got a call from Dinan that they have 3.62 ready to be installed. So, if you are looking for one give them a call.

[e36jakeo]

I think you guys are overestimating the positive effects of the shorter gearing. As mentioned a 3.62 will add torque 9.5% more torque per gear, but if , say you are going 85 MPH in 3rd gear you will now need 4th gear. 4th gear is taller than the stock 3rd gear, so until the stock 3rd gear runs out it will be pulling harder than the 3.62's 4th gear.

In other words, there is a give and take as to which will be quicker. Overall the 3.62 WILL be quicker, but by no means will it be pulling 9.5% harder at all times. As mentioned above, sometimes it will be pulling harder, sometimes less hard.

Also consider that with super-short gearing you will completely light up the tires in 1st gear, thus sacrificing your launch. So any standing start (without drag radials) will favor the stock car.

Honestly, with how perfectly and tightly geared the DCT is (7 speeds!!) I really don't understand why this is a very desirable option. Really understand the trade offs before getting it.

The 4.10 gearing for the 6-speed MT makes more sense because I find gears 2-4 to be too widely spaced. However, the too-short 1st gear is still a problem.

[Sticky]

Originally Posted by e36jakeo

I think you guys are overestimating the positive effects of the shorter gearing. As mentioned a 3.62 will add torque 9.5% more torque per gear, but if , say you are going 85 MPH in 3rd gear you will now need 4th gear. 4th gear is taller than the stock 3rd gear, so until the stock 3rd gear runs out it will be pulling harder than the 3.62's 4th gear.

In other words, there is a give and take as to which will be quicker. Overall the 3.62 WILL be quicker, but by no means will it be pulling 9.5% harder at all times. As mentioned above, sometimes it will be pulling harder, sometimes less hard.

Also consider that with super-short gearing you will completely light up the tires in 1st gear, thus sacrificing your launch. So any standing start (without drag radials) will favor the stock car.

Honestly, with how perfectly and tightly geared the DCT is (7 speeds!!) I really don't understand why this is a very desirable option. Really understand the trade offs before getting it.

The 4.10 gearing for the 6-speed MT makes more sense because I find gears 2-4 to be too widely spaced. However, the too-short 1st gear is still a problem.

The reduction is ~13% and I think you are underestimating the positive effects.

You will not light up your tires in 1st gear, any more than you will now. Plus, this is why wider tires exist.

This is an extremely desierable options as with the DCT you don't lose time due to the extra shifts since they are practically instant.

The 3.62 for the DCT makes far more sense than the 4.10 for the manual as the manual has more torque in first gear than the DCT to begin with and it is a larger reduction than 4.10 for the manual.

[e36jakeo]

Originally Posted by Sticky

The reduction is ~13% and I think you are underestimating the positive effects.

You will not light up your tires in 1st gear, any more than you will now. Plus, this is why wider tires exist.

This is an extremely desierable options as with the DCT you don't lose time due to the extra shifts since they are practically instant.

The 3.62 for the DCT makes far more sense than the 4.10 for the manual as the manual has more torque in first gear than the DCT to begin with and it is a larger reduction than 4.10 for the manual.

You really think with 13% more torque to the wheels in 1st gear you won't light up the tires in 1st gear??