Do we care about final drive ratio?

[FFRSpec72]

So don't know Subaru's that well yet (but I'm learning), but what is a 4.44 ratio transmission, since we are not using the running gear does it make a difference? In this case its a JDM 5 speed itransmission

[Jaime]

I have a JDM transmission with 4.444 final drive that I'm planning to use in my 818S. I already have a 3.90 ring and pinion to swap in because I'm pretty sure that even a modest power upgrade will turn the car into a tire-to-smoke conversion machine instead of a regular car with 4.444 gears.

[RM1SepEx]

Those 4.444 gears might be well suited to an 818R depending on the track...

[FFRSpec72]

Those 4.444 gears might be well suited to an 818R depending on the track...

Most of the tracks that I race at have about .5 mile straight away with top speed in my Challenge car of 145mph, we do have 1 track that has a .8 of a mile straight, I guess I would be worried that the 3.90 gears would not give me the low end that I need on some of the 180 degree turns we have

[Rasmus]

Do we care about final drive? YES!

When I was mulling this over for my 818R - X Prepared build I made a spread sheet to help me pick what transmission I wanted. I settled on an 2005-2009 Turbo Outback with 4.444 Final transmission (TY757VWAAB).

I attached a zipfile of the ods file and a transmission list I used. Download, enjoy, nerd out.

[Jaime]

My TY754VBAAA has exactly the same gearing as your TY757VWAAB. Are you planning any power upgrades?

[Jaime]

Most of the tracks that I race at have about .5 mile straight away with top speed in my Challenge car of 145mph, we do have 1 track that has a .8 of a mile straight, I guess I would be worried that the 3.90 gears would not give me the low end that I need on some of the 180 degree turns we haveAre you in the market for a 4.444 ring and pinion?

[FFRSpec72]

Do we care about final drive? YES

Thanks, this helps as it looks like the JDM Transmission I'm looking at (TY754VBAAA) has same gear ratios as the 2005-2009 Turbo Outback

[Jaime]

BTW, you'll get even higher gearing if you use an 02-05 US WRX transmission and swap in 4.444 gears. Subaru parts are generally very interchangeable, you can often take the bits you like from different cars to assemble what you need.

[FFRSpec72]

Are you in the market for a 4.444 ring and pinion?

no, as the trans i'm looking at has 4.444 (TY754VBAAA)

[DodgyTim]

Seems like we might all have been nerding out ...in private:eek:
26562

0-60 for my build will require 3rd gear as i dont think I'll see 6950 rpm with the little turbo I'm going to run

[Xusia]

Too funny. I went with taller gears to be better able to put the power down without spinning the tires, and without needing to shift too much.

[Frank818]

Too funny. I went with taller gears to be better able to put the power down without spinning the tires, and without needing to shift too much.

Same for me. Especially my first gear which is quite taller.

[RM1SepEx]

Street use vs track use, very different req. For the track want to max rpm on end of longest straight. Though some tracks can be preferential for certain sections to be at certain gears/rpms etc...

For the street I don't need to maximize acceleration. I went maximum tall gears and taller tires... I don't think that my setup will pull the tallest gear to redline...

[Xusia]

I understand the track concerns - I rarely leave the gearing alone on my motorcycle. I went taller to enhance acceleration from the standpoint of reducing wheel spin (because that's doesn't move the car forward), and reducing shifts. For street use, it can also mean a greater selection of gears for any given corner (when you aren't trying to maximize acceleration off the corner).