[MattOneDime]

Yo..

Just looking for some opinions and experiences with the various rear end options we have on the mk3.. Right now I am running the sport NA (4.11's I think?) and its just not cutting it.. I trap at 127 with the tach at around 7700 through the trap (eeek!).. Honestly I dont think this rear end is helping 60's times either, its just a big tire spin fest if they break loose. I would really like to hear from people trapping in the 120+ range.

PS - If anyone wants to trade for my NA Sport rear lets do it.

 

[BadBoyToy]

The NA rear ends are 4.30s, I would go with a 3.73 unit out of a 89+ Turbo.

 

[Ckanderson]

I like my 3.73. works well with a 1j

 

[toyota_supra_1988]

lol 7700 thats high, i think i would go for a 3.73 too

 

[7mgtemk2]

4.3's are gay because it makes you rip through all the gears soo fast. You get no traction with the 4.3's. 1st gear is useless and you have to shift to 5th gear before the 1/4 is even over. switch to 3.9's or 3.73's bro.

charlie

 

[maeso]

7m= 3:73
1j=3:90

 

[cre3d]

Not to hijack the thread, but what did 87 turbo 5 speeds come with?

 

[MattOneDime]

3.73's I think


And if anyone has a 3.90 for sale hit me up

 

[Justin]

I read somewhere changing your diff jacks up your speed-o-meter... true?

 

[BoostAddctn]

3.73's I think


And if anyone has a 3.90 for sale hit me up

I believe 3.73s are 89+ while the 3.9s are the 87- 88s, I have been trying to find longer gears since at the end of the 1/4 mile I keep topping out of 4th gear that I am close to 5th, let me know what you find out Matt... aight peace :chicken:

 

[Jeff Lange]

86.5-92 7M-GE: 4.30:1
87-88 7M-GTE: 3.909:1
89-92 7M-GTE: 3.727:1
90-92 1JZ-GTE 5-speed: 4.10:1
90-92 1JZ-GTE Auto: 3.909:1

I know the GA70 had 4.54:1 in some cars, not sure what different variations had what (1G-GE, 1G-GTE, 5-speed/auto, etc).

Hope that helps.

I'd go 3.91 or 3.73 if I were you.

 

[MattOneDime]

Good info.. Thanks all

Actually I think I'm just going to go Ford 9" solid axle with a detroit true trac. Well, not the real true track, but the welded spider gears version. :drag:

Bert how are you topping out 4th at 107mph hahah

 

[BoostAddctn]

Good info.. Thanks all

Actually I think I'm just going to go Ford 9" solid axle with a detroit true trac. Well, not the real true track, but the welded spider gears version. :drag:

Bert how are you topping out 4th at 107mph hahah

That I don't know, I think its cause of either the transmission or the rear end, I've been trying to find out why, but no one came up with a good explanation... btw GET ON MSN foo, aight peace

 

[Jeff Lange]

6500rpm in 4th with 3.73 rear end is 128mph....

That's odd. where you're at should only be around 5500rpm.

Only reason it could be different is if the clutch is slipping, or your tires aren't stock size.

What size are your tires?


Have you checked the ratio of the diff?

 

[flubyux2]

3.73 or taller... turbo cars like alot of gear.

 

[becauseican]

I have the 3.90 in my car , I love it, it has good bottom end and a decent top speed. I have gone up to 175mph at about 6300 rpm in 5th with 18" wheels. I normally get about 2.19- 2.25 60 ft times with street tires.
I am swapping in a 1J right now and I have the 4.10 Torsen diff going in. I will use which ever one I like best. People say the Torsen cant hold up to Drag racing with slicks or DR's but I will find out soon.

 

[MRSUPRA]

Trapping at 127mph? Can we get some info on this, or did I miss a post?

 

[BadBoyToy]

Hey Matt you may look into getting a Ford 8.8" rear end out of a Explorer, they are common and they come with disk brakes. They are becoming a popular swap with the muscle car crowd.

 

[VanSupra]

86.5-92 7M-GE: 4.30:1
87-88 7M-GTE: 3.909:1
89-92 7M-GTE: 3.727:1
90-92 1JZ-GTE 5-speed: 4.10:1
90-92 1JZ-GTE Auto: 3.909:1

I know the GA70 had 4.54:1 in some cars, not sure what different variations had what (1G-GE, 1G-GTE, 5-speed/auto, etc).

Hope that helps.

I'd go 3.91 or 3.73 if I were you.

Hey Jeff I see the rear ratio differences in the 1JZ cars between standard and automatic. Are the rear end ratios the same for the automatic 7M powered cars throughout the production years or do they differ aswell? Also is there a wide and close ratio R154?

With the lower gear such as 4:30 you'd get more traction with less tire spin. Taller gears equal more tire spin. I'm thinking of going R154 with the 4:30 LSD. My concern is what my RPM's will be at the end of the quarter and will I be able to finish in fourth?

 

[BadBoyToy]

VanSupra with 225/55/16 tires you would have a top speed of 116mph in 4th at 6500. Heres the calculator I used to find that out. 4th gear is 1:1. http://www.juric.org/mopar/tools/topspeed.php