[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.

 

[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?

 

[Jeff Lange]

You're right drjonez that's what I meant. But I always refer to higher numerical ratio's as lower gear and vice versa. Bad habit I guess.. Everyone seems to be saying more wheel spin with the 4:30's as opposed to 3:73 or 3:9's If this is the case why do all other drag racers(non Supra) use a higher ratio gear such as 4:88 5:13's? I'm getting ready to do a swap into my 88 NA with a 4:30 rear and am now wondering if I need a different rear end? In which case what would be the ideal ratio for strictly drag racing?
Appreciate any comments.
Thanks.

Everyone refers to 4.30:1 being a lower gear than 3.73:1, it's also considered shorter gearing. It also promotes wheel spin. If you understand how gear ratios work, you'd know 4.30:1 means it's multiplying the torque by 4.30 times. Which is why a higher number results in faster acceleration (and thus, more wheelspin). But, then you add a turbocharger into the mix, which boosts faster with more engine load. You can launch with less wheelspin with a taller rear end, and have more boost earlier on in the rev range. It is also better for highway driving as your revs stay lower.

 

[Jeff Lange]

fixed that. lower (numerical) gear put more load on the engine and pulls you into boost earlier.

Oops, typo, that is what I meant.