Favorite Gear ratio?

[garagefujimoto]

My question:

I have a 4.10 Torsen case/ring/pinion that was OEM in my car (1JZ, R154)
Differential is obliterated, in the garbage

I also have a complete 4.30 differential.

I had planned to put the 4.10 gearset onto the MA70 differential, but it is costly and labour intensive to set everything back up.

Anyone just running a 4.30 on a 1JZ and having fun doing it?
I enjoyed the 3.9 in my old mA70, but going double the speed limit in 4th gear is kinda a waste of a transmission...

Should I just go 4.3 and spend my money on other mods and enjoy the quicker shifts/engine response?

PS: Will the W58 speedo gear fit in the R154?
I want the speedo to be correct, it has a 4.10 speedo gear currently.

 

[Freshmaker]

My BPU 1jz was amazing with the 4.3 in it. First gear still had plenty of use with BPU power. Now my cars down cause my twins went south. But, I remember thinking, "I just want to drive it like this. I don't need any more power."

 

[foreverpsycotic]

I love the 4.30 with my BPU 1jz, and I'll find out how it feels come mid winter with my new turbo setup :evil2: Top speed at the end of 4th should be around 130mph.

 

[tsuper92]

put a taller tire on the back ,once you burn the old one's off

 

[OneJoeZee]

I like my 3.7. Helps the turbos in the first two gears since they're a bit lazy.

 

[Insidious Surmiser]

^

 

[Bigzavs]

i had 4.30s with my T61 setup, it was fun, but id roast the tires in 1st-3rd and spin em in 4th

i like my 3.73's that i have now with my 72 setup, like joe said lots better in the low gears for laggy turbos, i also like it for the highway for just how long you can hold out the gear

 

[Clint]

yeah Ive been happy with my 3.73's

 

[Doward]

I have a set of 3.91s currently. Honestly, I want a set of 3.4x's, but I know of none for our pumpkin

 

[Turbosidosis]

I have a bpu 1jz with a 4.30 gear in mine.

I don't understand, wouldn't you want a torqueyer gear if you had more lag. To help with driving while not under boost, or for building boost.

 

[OneJoeZee]

I have a bpu 1jz with a 4.30 gear in mine.

I don't understand, wouldn't you want a torqueyer gear if you had more lag. To help with driving while not under boost, or for building boost.

My turbos do not respond like stock twins. In first gear, the gear is over faster than the turbos can hit full boost in that gear. In 2nd, it's better. 3rd, 4th, 5th are fine.

The power isn't like stock twins. I can't just nail the gas anywhere in any gear and expect full power full boost. My power is between 4500ish and 7k. Longer gears help hold out the powerband and get the turbos up to speed better.

With stock twins, it doesn't matter. Higher diffs are ok. You could spool those things to full boost by farting at them.

 

[garagefujimoto]

Good feedback

I like the thought of spinning in 4th gear

BTW engine is 1.5JZ, turbo will be 61-67mm-ish
Nothing too big
There's no drag strip here so I'd rather peel out than go 200 mph

 

[BlackMKIII]

You could spool those things to full boost by farting at them.

:word8kn:

I'm still running my stock 4:30 LSD with my 1JZ, with only IC, piping, and 3" exhaust. Boost is available whenever, wherever. It's actually really hard NOT to boost. :biglaugh:

 

[SupraClaou]

I got a 2jzgte with R-154 and oem 3.73 LSD.
I think it's the best.And it's the longest differential gear set
we can get on our cars.
To tell you the true....I would like a lower diff gear than 3.73,
something like 3.5 :biglaugh:

The N/A mkIV supra had a 3.5 with the W58 trans.Do you think
that this diff could fit on mk3s ?

 

[SupraClaou]

Aaaa....The only thing I hate on the R-154 trans is it's 5th gear!
It is to long :icon_evil
And it takes time to fill up the 5th gear till the redline,which will
never hit.
By the way, is there anyone that hit redline with an R-154 trans
and 3.73 diff ???

 

[annoyingrob]

I run a 4.10 on my 1.5JZ, and it's too short. All it does is roast tires. I also want a taller rear-end so I can cruise at something that isn't 3500+rpm.

A thing to note about larger turbos, a taller gearing is going to put more load on the motor at full throttle, which is going to spool the turbo a little better. Just like Joe said, he can't spool the turbos in the lower gears.


And Doward, and SupraClaou, I've said it several times, if you want a taller gearing for the Supra, Jawsgear has a 3.54 ring and pinion for the MKIIIs, for like $200.

 

[Spaniard]

I got a 2jzgte with R-154 and oem 3.73 LSD.
I think it's the best.And it's the longest differential gear set
we can get on our cars.
To tell you the true....I would like a lower diff gear than 3.73,
something like 3.5 :biglaugh:

The N/A mkIV supra had a 3.5 with the W58 trans.Do you think
that this diff could fit on mk3s ?

you can go lower with 4runner gearing. no problem.

 

[gilberjj]

I have a bpu 1jz with a 4.30 gear in mine.

I don't understand, wouldn't you want a torqueyer gear if you had more lag. To help with driving while not under boost, or for building boost.

if you have shorter gears, you'll start boosting just as you're hitting redline. with taller gears (lower number), it will increase the load on the engine, thus giving you more time in boost. I think Little Red Riding hood would agree, that sticking in the middle of the spectrum (3.90's in my case) is going to be "just right!"

 

[suprahero]

I had the 3.73's and changed to the 3.91's and I like them better. I wasn't aware that we could get 3.5's for our car until now. Thanks for the info.

 

[Supraholics]

It would be nice to get some numbers for the different setups, preferably from the same person whose had different pumpkins:

60 Ft
1/8
1/4
etc....