4.875 final drive review

[fooddude]

@drift86: Thanks...great videos. Such a big difference it made with the S2k!

I'd probably just say F-it and go 4.88... 500-600rpm more on the highway doesn't sound too bad; but of course, 4.56 sounds perfect for DD. Just wish there was a cheaper option for 4.67 and wish Weir made that available..4.67 would be a good middle ground.

[GT86_PRAGUE]

Originally Posted by drift86

Here's my review of the Autofactory 4.875 final drive.

...

Conclusion
If you are looking for something that makes the car feel faster, this mod is great. It really does make the car feel at least 19% faster as the torque is increased by that much in each gear and it revs through the gears that much more quickly.

If you are looking to improve your laptimes, then this mod may or may not improve it. It is not the same as increasing the power by 19%. It really depends on the track and the shift points before and after the mod. You will be faster between some speeds but also slower between other speeds as you will now need to use a higher gear.

Thanks for excellent review.
Do you still think 4.88 is optimal for you or would you choose 4.67/5.1 if you could change that?
I am deciding between 4.88 and 5.1 but dont want to overdo it, so I am inclining to 4.88 (japanparts because weir is not responding to my mail) but I dont want to be frustrated few weeks later that I didnt get that 5% more.
[95% city DD]

[fatalelement]

Originally Posted by GT86_PRAGUE

Thanks for excellent review.
Do you still think 4.88 is optimal for you or would you choose 4.67/5.1 if you could change that?
I am deciding between 4.88 and 5.1 but dont want to overdo it, so I am inclining to 4.88 (japanparts because weir is not responding to my mail) but I dont want to be frustrated few weeks later that I didnt get that 5% more.
[95% city DD]

Gotta call weir. I finally got an email response weeks later, and it pretty much said "this is too many questions, call me Monday" (it was 3). Lol.

Sent from my HTC One_M8 using Tapatalk

[Lunatic]

I went to 4.88s in my automatic FRS. I got the gear set from Weir and had a local shop install it. Can't be happier. Best mod I have done to my car for performance. Reduced my 0 to 60 times a full second and reduced my 30 to 70 mph times 1 1/2 seconds. And I still get 30 mpg at 70 on the freeway.

[GT86_PRAGUE]

Originally Posted by fatalelement

Gotta call weir. I finally got an email response weeks later, and it pretty much said "this is too many questions, call me Monday" (it was 3). Lol.

Sent from my HTC One_M8 using Tapatalk

Thanks.

Clearly I have a communication issues.
Where to buy LSD & Final Drive/Gear?

I am not sure if I want to call from Europe to US, how to time that with Spence and I am not comfortable with that, I would prefer to get numbers on "paper".

[troek]

Originally Posted by RehabJeff86

Just to share a key point - For track purpose, 4.56 is ideal because u never want to hit the 6th gear

i almost hit 6th now on fuji speedway. but the corners that 2nd is to low for, and 3rd bogs a little, this mod would more than make up for that last few hundred yards of cruising in 6th.

[GT86_PRAGUE]

Originally Posted by Lunatic

I went to 4.88s in my automatic FRS. I got the gear set from Weir and had a local shop install it. Can't be happier. Best mod I have done to my car for performance. Reduced my 0 to 60 times a full second and reduced my 30 to 70 mph times 1 1/2 seconds. And I still get 30 mpg at 70 on the freeway.

I believe that 4.88 is awesome, I would like to know that if owners of 4.88 doesnt regret not getting 5.1 instead. I have 6MT.

[mad_sb]

Thanks for the review!

I do have to ask though... If the gear reduction is that much, couldn't you accomplish exactly the same thing by always running a gear lower (with the exception of 1st gear of course)? Seems like a much less expensive option to me..

I can understand if you need to maximize every gear for a specific road course or drag race so you hit the top of the desired gear at the desired place on the track, but you said yourself you were not concerned with that.

[GT86_PRAGUE]

Originally Posted by mad_sb

Thanks for the review!

I do have to ask though... If the gear reduction is that much, couldn't you accomplish exactly the same thing by always running a gear lower (with the exception of 1st gear of course)? Seems like a much less expensive option to me..

I can understand if you need to maximize every gear for a specific road course or drag race so you hit the top of the desired gear at the desired place on the track, but you said yourself you were not concerned with that.

I am no expert on this but as I know, you will rev faster.
You also get +19% traction with 4.88
So I will get over that infamous power gap faster.
I am planning to do this with LW driveshaft and flywheel.
Also buying new diff cause I dont want Torsen.

[Lunatic]

Originally Posted by GT86_PRAGUE

I believe that 4.88 is awesome, I would like to know that if owners of 4.88 doesnt regret not getting 5.1 instead. I have 6MT.

For me, with the automatic, and the tracks I run on 4.88 is perfect. I just get maxed out at the end of the straights in 4th. And only need 2nd one one corner. So I can pretty much run the whole track in 3rd and 4th. I wouldn't want the 5.1 my self.

[kodyo]

Originally Posted by GT86_PRAGUE

I believe that 4.88 is awesome, I would like to know that if owners of 4.88 doesnt regret not getting 5.1 instead. I have 6MT.

I would not get 4.88 gearing if you have a 6MT. The automatic gear box has different gearing than the 6MT, and the 4.88 in an auto would be like a 4.38 in a 6MT. A 5.1 in an auto would be like a 4.56 in a 6MT (Correct me if I am wrong on this, hard to find a good approximation).

I have a 4.56 in my 6MT and couldn't imagine going to a higher ratio. RPMS are already high with the 4.56 when cruising highway at 75-80mph (~3700 RPM). Acceleration and shifting intervals feels optimal and it's about the highest ratio I'd recommend for a DD. My personal opinion of course. You'll find that a lot more people go with a 4.56 for the 6MT.

[GT86_PRAGUE]

Originally Posted by kodyo

I would not get 4.88 gearing if you have a 6MT. The automatic gear box has different gearing than the 6MT, and the 4.88 in an auto would be like a 4.38 in a 6MT. A 5.1 in an auto would be like a 4.56 in a 6MT (Correct me if I am wrong on this, hard to find a good approximation).

I have a 4.56 in my 6MT and couldn't imagine going to a higher ratio. RPMS are already high with the 4.56 when cruising highway at 75-80mph (~3700 RPM). Acceleration and shifting intervals feels optimal and it's about the highest ratio I'd recommend for a DD. My personal opinion of course. You'll find that a lot more people go with a 4.56 for the 6MT.

4.56 is +11.2%
4.88 is +18.9%
I want something more significant than 10%, altho I would like to know how the car change if I go 4.88 and then buy LW driveshaft and LW flywheel.
I am not worried about highway comfort, al least I wont be speeding there as much as usual.

[rx3]

If you do get a lighter flywheel you just need to be aware of the fact that you'll most probably end up with some deceleration chatter.
http://www.ft86club.com/forums/showthread.php?t=78333

[GT86_PRAGUE]

Originally Posted by rx3

If you do get a lighter flywheel you just need to be aware of the fact that you'll most probably end up with some deceleration chatter.
http://www.ft86club.com/forums/showthread.php?t=78333

Thanks, I was not aware of this.
Is this really from lightweight flywheel? It seems like some problems in transmission.
I saw many guys here who has lwfw, lw driveshaft, even lw pulleys and even turbo on top (for me a miracle that their engine still works) but I didnt saw single guy complaining about chatter.
I dont really care if it add some noise, but the last thing I want to screw on this car is transmission. My second gear is often unusable until oil gets warm.
And I want TRD clutch, it is not so light.