3.73 thoughts on 260whp turbo?
 

I'm on a 2018 brz with the 4.3 final drive. What's everyones' thoughts' on going down to a 3.73 if I'm not making too much power?

I'd use the 3.73 either to raise your grip, or for 1/4mile driving to hold a gear longer. I do not think 260whp merits a 3.73. I'm selling mine because it really just makes the car piggishly slow, and I think under 350whp it'll only make you feel slower.

What kinda turbo and how much power are you making? That doesn't seem good. Would you happen to have any videos?

I don't have my turbo installed yet, I installed it on my NA car. There is one video on Youtube of BRZoomTX running it on his 400+ WHP car.

I have experience with other cars and changing the diff to try for longer gears. You can certainly do it, but you'll be surprised how much torque you lose by lengthening the gearing if you're not making enough to take advantage

Yeah his car is ridiculously fast. My first gear is so useless rn lol. On a site note, how much are you selling your diff for?

It's already sold locally, sorry.

It really would be a great tool for helping minimize wheel spin in 2nd, but I think 1st really is a matter of tire, contact patch and boost by gear settings. I definitely don't mean to discourage the 3.73, but I feel that the cost to benefit ratio is not there unless you're going for bigger power.

eventually i'll go for e85 and go for around 320whp. what about at that power?

Choosing a proper FD is highly dependent on your power levels and your usage for the car. Like autox, track, drag, street pulls etc. if it can prevent an extra upshift in the straights or down shifts in the corners it may be a good choice.

Going from 4.3 to 3.73 your gears will be 15.5% longer, also the same amount of less torque multiplication from the gear. So whatever your currently topping a gear out at multiply by 1.155 and see what your new redline speed is per gear. You may find out you just made 5th too long /high of speed for your power and now it’s useless.

A 3.9-4.1 may be a better option for sub 350whp

thanks guys.. I think i'll just stick to my 4.3 then and save that cash for something else such as e85.

86TOYO2k17: or if NA, imho by then close ratio gearset might be better option, as in making longer just 1st & 2nd.

@incutebus: I have it as a factory option in the early European models and I don't make too much power either. It works great on the autobahn with a really strong 5th gear for performance (stronger than the 4.3 fd 6th gear) and a much better overdrive 6th gear for economy. Porsche's are using similar or even longer final drive ratios for decades.

how is your acceleration in 2nd 3rd and 4th?

Personally I like it because it doesn't break traction easy. Power delivery is smoother and longer in same gear. However, it is a setup for high speed driving. The 2nd gear for example tops approximately at 103kph or 64 mph.

I'll be at 450whp soon, thinking about upgrading the fd.. Friend says the torque feel and pulls will feel a lot different. Curious to see how it is with the stock fd lol. Friday is the big day for my tune.