Changing individual gear ratios?

[CrankyOldMan]

I'll dig up my spreadsheets and see what info I'm missing. I think I accidentally deleted my part number workbook and only have a partial record from a previous version...

[Jerkratt]

Please and thank you I'm gonna have to go scavenger hunting anyway to find the trans 's I need

[CrankyOldMan]

Well, here's what I have so far. One spreadsheet is a list of OEM part numbers, if you want to either buy them new or find what donor vehicles should have them. The other is a sandbox for evaluating different ratios. It's up to you to put in the right values, but it will show you the change in top-end speed for a given setup. The tradeoff for lower top speed is more torque, but this doesn't factor in the torque curve of the 1ZZ. The doc is a collection of different configurations. If you can't see it in MS office formats, I can try and post them as PDFs instead.

[fnkngrv]

Heya Jerkratt - If you end up having to have tools purchased to do the work let me know as I might be interested in going in on it with you for my transmission mods I need to have done!

[fnkngrv]

I have started a new group on Facebook called "Toyota 1NZ Enthusiasts Garage. There is interest on what can be mated with the 1NZ to include I believe even transaxles. I will be posting up this information in a document there as well.

[CrankyOldMan]

So I finally got around to counting the teeth on all the gear sets I've acquired. Turns out there were a few surprises!

C50 (Yaris and xB): as expected
C56 ('03 Celica): as expected
C59 ('07 Matrix): 4th gear actually 0.886:1 (31:35)
Differentials for C56 and C59: may be the same as the xD. RagnaCaT on microimage is in the process of swapping an LSD into an xD gearbox to put on his Yaris and discovered that the xD has a different differential, despite having the "same" C50 gearbox.

Looks like it's time for me to go back over the spreadsheet and find out if I'm using that new 4th gear ratio.

[RagnaCaT]

Something that would be nice to look up is the 2014 corolla 6 speed MT they still have the 2ZRFE and our tranny bolts to them maybe just need XD axles also... Do you know where we can look it up?

[fnkngrv]

As a heads up your original graph is a bit off in the estimates as I have the stock C50 still and currently my top speed on the dyno sits in the mid 160s. This is at the 7k redline.

[RagnaCaT]

Originally Posted by fnkngrv

As a heads up your original graph is a bit off in the estimates as I have the stock C50 still and currently my top speed on the dyno sits in the mid 160s on pump gas and the ~250hp. This is at the 7k redline.

Maybe his qoute is at the 6400 redline thats why its below the 160 I will soon be testing the 3.94 ratio I think its in the middle of performance and economy.

[fnkngrv]

If you look at graph he has presented he does show the continued elevation past the 6250 redline. In some parts of the world it is actually 6500. His graph is theoretical in nature anyway, but I figured that I would share the disparity. He and I have been discussing this topic for months via PM.

We are both very intrigued with the entire scope of the subject. It also has been very educational for me especially when I talk with other parties that have no experience with the powertrain in the car and thinking that it is easy to increase the ability for top speed by changing gearing not realizing that there is very little support for the platform.

[RagnaCaT]

Originally Posted by fnkngrv

If you look at graph he has presented he does show the continued elevation past the 6250 redline. In some parts of the world it is actually 6500. His graph is theoretical in nature anyway, but I figured that I would share the disparity. He and I have been discussing this topic for months via PM.

We are both very intrigued with the entire scope of the subject. It also has been very educational for me especially when I talk with other parties that have no experience with the powertrain in the car and thinking that it is easy to increase the ability for top speed by changing gearing not realizing that there is very little support for the platform.

Your right I was refering to the wrong graph the 1st and didn't notice the rpm's in the second. The wheel size aldo affect the equation what size of tire was taken in to account?
This attachment I made can help you guys made this when hunting for the 3.94 final

[fnkngrv]

Originally Posted by RagnaCaT

Your right I was refering to the wrong graph the 1st and didn't notice the rpm's in the second. The wheel size aldo affect the equation what size of tire was taken in to account?
This attachment I made can help you guys made this when hunting for the 3.94 final

very good point about the wheel and tire configuration. I am currently running 205/55/15.

[RagnaCaT]

Originally Posted by fnkngrv

very good point about the wheel and tire configuration. I am currently running 205/55/15.

My yaris has 195/50/16 this the exact height as OEM 185/60/15, intresting is that with 195/50/15 would give the same affect as 3.94 FD.

[CrankyOldMan]

Originally Posted by fnkngrv

As a heads up your original graph is a bit off in the estimates as I have the stock C50 still and currently my top speed on the dyno sits in the mid 160s. This is at the 7k redline.

The spreadsheet I use has a built-in reduction for "rolling radius" on the tires to compensate for the "perfect" geometry of calculating the tire diameter/circumference. I don't remember what tire size I had selected for that particular screenshot, so that could be a factor, too.

I think the spreadsheet is more useful as a comparison of ratios. As an engineer, I appreciate the value of a mathematical model, but I put more faith in the empirical evidence than the simulation.

[Jason@SportsCar]

Originally Posted by CrankyOldMan

Differentials for C56 and C59: may be the same as the xD. RagnaCaT on microimage is in the process of swapping an LSD into an xD gearbox to put on his Yaris and discovered that the xD has a different differential, despite having the "same" C50 gearbox.

Does the xD have a different final drive and output shaft as well, or just the diff? *I know it is a different ratio, but is it physically different to the point it wont swap...

[CrankyOldMan]

Originally Posted by Jason@SportsCar

Does the xD have a different final drive and output shaft as well, or just the diff? *I know it is a different ratio, but is it physically different to the point it wont swap...

I was able to close the Yaris C50 with a C56 and C59 differential in it, but I never checked the preload. From what I understand of RagnaCaT's project, the xD differential housing is large enough that the final drive ring gear from a Yaris will not seat on it. I took my ring gear off the xB diff--which is the same as the Yaris--but haven't dismantled the C59 or C56 diffs yet to measure their critical dimensions. That said, the C56 pinion shaft seems to mate correctly with the xB's ring gear, but I still have to do the preloads and whatnot.

Are you hoping to use the larger diff and output shafts from an xD for better power handling, or some other reason?

[CrankyOldMan]

I've just realized that up to this point I've been referring to the pinion shaft as the "output" shaft. Now that the output/drive shafts are in the discussion, I should probably stick with "pinion" for the shaft between the input and differential from now on, yes?

[Jason@SportsCar]

Originally Posted by CrankyOldMan

Are you hoping to use the larger diff and output shafts from an xD for better power handling, or some other reason?

No, looking to build my spare trans with a 3.9fd for faster tracks. With the 4.3 and Kaaz gear set I am on the limiter (7500rpm) in 5th at some tracks.