Manual gearbox ratios vs performance

[-Nemesis-]

Have been doing a little thinking tonight, which led me to an interesting find. My 4Runner which has the 1UZ has the R150F 5 speed as standard and it is what I used for the conversion.

In terms of on road performance, i'm wondering what the different ratios found in it's brother (R154 Supra Turbo) would do to acceleration on a 2 tonne 4WD.

I find that when driving it hard 1st gear revs out so quick, then hitting 2nd it seems to dip slightly under the 1UZ's power band and you have to wait for it to hit its straps again. So looking at the two ratio's side by side, is the Supra Turbo likely to keep the 1UZ more on song when taking off?

R150:

Ratios:

First Gear: 3.830:1
Second Gear: 2.062:1
Third Gear: 1.436:1
Fourth Gear: 1.00:1
Fifth Gear: 0.838:1

R154:

Ratios:

First Gear: 3.250:1
Second Gear: 1.955:1
Third Gear: 1.310:1
Fourth Gear: 1.00:1
Fifth Gear: 0.753:1


I know overall they're taller, but that's not such a bad thing. I have slightly shorter final drive gear than standard anyways. I'm mainly wondering what people think the difference will do to rev matching at full noise launches?


Edit* I know it's big and it's not 'fast' but i'm still chasing frugal performance gains. Also, i'm not fussed about low range as I can adapt a gear driven transfer and get reduction gears anyways...

 

[steveo]

It looks like the R154 gears are better spaced, except for the top gear, which will have a bigger drop than your current gbox going into top.
That just means lower cruising revs and maybe better mileage at cruise.
Also, higher top speed if the engine can pull the gear to peak power in top gear.

The longer first will feel a bit more sluggish getting rolling, and the second may still drop you out of your power band, but the drops as you get into third and fourth will not be as bad...