diff problem please help
#1
Driver School Candidate
Thread Starter
diff problem please help
so I converted frrom auto to manual in my sc4001j, i notice gear ratio is not what it supp to be, whats a diff thats inexpensive that will work apart from the twin turbo supra?
#2
Lexus Champion
What year is your SC4? You might be able to stumble on an Aristo rear diff at a reasonable price but don't expect to find it quick.
Is the gear ratio too tall? Or too short?
Is the gear ratio too tall? Or too short?
#3
Lexus Test Driver
iTrader: (44)
Join Date: Jan 2007
Location: Maryland /Germantown
Posts: 5,139
Likes: 0
Received 7 Likes
on
7 Posts
the stock sc4 rear end should be fine it's a 3.92 i had that on my R154 and it was fine.
The ratio is too short i think, well you can get the diff out of a gs400 which is 3.26 that works great also.
gl
The ratio is too short i think, well you can get the diff out of a gs400 which is 3.26 that works great also.
gl
#4
Lexus Test Driver
iTrader: (3)
Quicksc4 the stock sc4 rear end should be fine it's a 3.92 i had that on my R154 and it was fine.
The ratio is too short i think, well you can get the diff out of a gs400 which is 3.26 that works great also.
gl
The ratio is too short i think, well you can get the diff out of a gs400 which is 3.26 that works great also.
gl
Trending Topics
#8
Driver School Candidate
Thread Starter
you guyz are awesome
first of all , i appreciate all the responses in this day and age i thought everyone was to themselves but neways the car is a 92 sc400, with a 1jz thats was making 440hp automatic on 15 pounds so it has boost, but converted to r154 5 speed and thr lower gears are short it revs so quick but doent go in boost at almost 6000 rpm so i really get nothing out of 1st and 2nd
#15
Lexus Test Driver
iTrader: (5)
http://www.physicsforums.com/showpos...42&postcount=2
Gearing is all about torque manipulation. The JDM is rated 320 ft/lb of torque so I'll use that for this demonstration.
320 x 3.266 = 1,045
v160
3,999
2,466
1,761
1,371
1,045
829
r154
3,397
2,042
1,369
1,045
787
With 3.266 differential you'll lose 600 ft/lb of torque in 1st gear and 424 in 2nd gear.
Top speed is 155 mph @ 6800 rpm in 4th gear.
320 x 3.769 = 1,206
3,920
2,358
1,580
1,206
908
With the 3.769 differential you'll lose only 79 ft/lb in 1st gear and 108 ft/lb in 2nd gear compared to the v160.
Another way of looking is you'll gain 521 ft/lb in 1st gear and 319 ft/lb in 2nd gear compared to the 3.266.
Top speed is 134 mph @ 6800 rpm in 4th gear.
320 x 3.916 = 1,253
4,073
2,449
1,641
1,253
943
With the 3.916 differential you'll gain 74 ft/lb in 1st and and lose only 17 ft/lb in 2nd gear.
Or gain 674 ft/lb in 1st and 407 ft/lb in 2nd compared to the 3.266.
Top speed is 129 mph @ 6800 rpm in 4th gear.
Are you trapping higher 129 or 134 mph? If not the higher speed is compromising your acceleration. If so you're best off going with a v160 and 3.266 differential swap because of the inherent torque loss.
Last edited by account2x; 07-22-11 at 05:11 PM.