Hoping to get some feedback on if it’s worth following through with power levels above 450.

Have purchased a set and was wondering if it will still be a worth while mod or if I am better off using the original 4.10 or maybe even using a 3.90 instead.

Originally had plan to use it in a stock setup which I know it would shine but when power is factored in would it still be worth it?

 

It completely depends on what you're trying to do and even then you'll get differing opinions - mine is that anything after 350 a 3.9 is very appealing for 1st - 3rd for anything but autocrossing or the like.

 

You won' t like 4.44 with that much rwhp
The 4.44 and 4.7 options are great for STOCK engines ONLY per our experience.

 

No experience with a 4.4 but my car is a 4.7 and had "400"hp. The only thing keeping it manageable was the immense lag from my too big turbo. There were times that it would spin MID PULL. I could not imagine what 450+ would be like.

On the twins it was absolutely incredible. Phenomenal actually. The most incredible. I could cry talking about it. A 4.7 is not a 4.4 but it's close enough I guess. Just something to go off of

 

I think 4.444 is great for the track, but it's overkill for the street, especially with that much power.
Just use the 4.1.

 

At modern highway speeds, I find the 4.1's are a little short for a street car, even with the USDM 5th.

I saw a writeup about track guys switching to 4.7's to avoid extra shifts. They could stay in 3rd or 4th without downshifting.

 

4.77 makes close ratio gearset drivable on the street with tall 1st gear, highway cruise you want 6th (the close ratio T56magnum gearset would be the perfect upgrade with 6th if you are running an OS-G gearset). You could probably argue a broad powerband single would be more usable with 3.9 and factory ratios, but that's also loading 3rd gear even harder which is the flexy fail point in the gearbox.

 

yes... highway with a 4.7 puts you at ~4k around 70-75mph. Super annoying. I tried cruising around 80-85 and my temps started to rise.

Typically they normalize in the mid to high 80s but trying to maintain that speed brought it to mid to high 90s. Still within an acceptable range but I did not feel good about cruising at ~5k+ for that long.

The 4.7 will keep you safe on the highway at least. It has its place but it can get real annoying real fast depending on your driving style and how you use your car. I enjoy it but there's a lot to consider if CHOOSING to use it. My car came with it installed so maybe I learned to love it.

 

Does anyone have experience with the 4.3 final drive and making 400whp? With my 8374 and stock motor, I actually find it hard to get above 5k rpm with how robust my powerband is. I have a spare Torsen diff and a 4.3 final drive from a JDM FD I have been wanting to try when I go to drop my rear-end.

 

Er, unless you're talking about 1st gear, just downshift?

 

I am planning to start my large build shortly. I currently have 4.77 gears with my stock twins and its a lot of fun with ~310rwp. I will get betting a T56 close ratio and shooting for 600-650rwp. I was thinking I would need to go from 4.77 to 4.30 or under. Have you driven a t56 4.77 setup? Curious to hear your feedback if so. As Full Detail mentioned, we are at 4krpm with stock transmission at 70mph.

EDIT-- More specifically, I am looking at the Tremec website calculator and wondering if its correct. LINK

I was looking at either the 2.66 or 2.97 T56Mag. My current tire setup is a 285/30R18 and I have a 4.77 ring & Pinion. Using the 2.66 tranny, at 8500rpm with tire height of 24.73 and 4.77 ring, show top speed in 6th of 208mph.

With stock 4.10 gearing I could hit 242 mph. yikes.

 

Well... you're not going to make that kind of power reliably on the FD diff. You would need an 8.8. So no really concern there 😅😅

 

The first 3 gears of the OS-G and 2.66 1st tremec are near identical, I'd keep the 4.77 gears myself, especially if you drive in traffic much. Otherwise the 2.97 would work better with 4.3 but the ratio splits are unnecessarily wide with that gearset.

 

OS Giken LSD.

 

I just drove US-129 with a 4.44 rear end and the stock trans on my pump gas tune which is around 460hp. I was constantly shifting 2-3-4-3-2 and it didn't feel weird, the car is on 295/30/18 yoko ao52's and boost is set up to be 2 pounds retarded in second gear. I had no traction issues, nor issues with turbo lag.
The friends I cruised with were able to spend a longer time in 2nd gear because they have stock 4.10 rear ends. I probably should have tried one of their cars but I was happy with how mine performed. The 4.44 hasn't been an issue for me.

 

I have it on good authority that 4.4 gears on the dragon in the wet will cause traction issues...

 

You are absolutely right. Enough to make me pucker.