Pros/Cons with the 3.62
I am looking at getting the 3.62 for my DCT M3. Can anyone provide me with some pros/cons on such a mod?
This is my 3.62 review from a while ago, I sold the gears and went back to stock:
I said I would go into why I switched back to the 3.15 from the 3.62 and here it is.
Shorter gears are a popular upgrade for a number of reasons. They increase your torque multiplication. More torque is good, right? Well, that is only part of the picture.
The gears make the car feel faster. So, as for a seat of the pants improvement, they feel great. However, there is a trade off.
Here is some data from my car running the stock ratio at the strip:
12.19 @ 115.170 , 1.95 60 foot
That was with the 3.15 that is stock for the DCT.
I blindly went for the 3.62 based on some charts that people such as PencilGeek posted. On paper, the 3.62's show more torque at the axle in every gear. The thing is, once you shift, you lose the torque advantage and the stock gears spend more time at a higher average torque level. So even though you have more torque, it is for a shorter period of time. You feel faster, but you aren't faster.
12.20 @ 114 , 1.78 60 foot.
Even with a superior 60 foot, the 3.62's cost me top end.
I went BACK to the 3.15, and to the strip again:
CONSISTENT 115.5 mph traps, EVERY run, in 2000 Density Altitude (layman's terms, it was way freaking hotter). Corrected, this would be 117+ mph.
Basically, my result is that shorter gears cost me top end. It is a pointless mod for the DCT unless you just want to feel faster. Even a smaller ratio like the 3.4X is pointless for the DCT. I am going to try LENGTHENING my ratio next.
Anyway, back on topic, I believe the manual is geared much better for the top end than the DCT. So from my results, the DCT is superior on the road course as it is geared closer 2nd to 3rd. Past 3rd gear, the manual has better gearing so it will win a high end roll on race and have a higher trap at the strip as it has more torque at the axle past the 1/8 mile.
Also to be noted, a member on M5board by the name of M5Ranger went from 3.62's in his M5 to 3.91's, a much smaller % change than I did, and also lost 2 mph of trap speed. Basically, he came to the same conclusion as I did that the shorter gears hurt the top end where these cars shine.
That's great information. I guess I won't look into getting the 3.62 then.
Hmmmm what should i do next?
Edited: Damn it Shah... lol, you are going to scare everyone away.
Originally Posted by Sticky
Originally Posted by tag824
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