Taller gear transmission options for 2005 Toyota Corolla

[i_am_socket]

[ NOTE from Darin: split this thread off from http://ecomodder.com/forum/showthrea...bsfc-6453.html ]

Hooray! I finally found the gearing specs for my car. So, given that to optimally increase the FE based on altered BSFC from drag reduction I'd have to move to taller gearing, moving from stock automatic to stock manual looks like a win for the Corolla:

.	Auto	Manual
First	3.643:1	3.166:1
Second	2.008:1	1.904:1
Third	1.296:1	1.310:1
Fourth	0.892:1	0.885:1
Fifth	.	0.725:1
Final Drive	2.96	3.25

Of course it would likely help the FE anyway despite drag reduction. Now I just need to wait for my transmission to fry so I can justify the cost...

[Daox]

I'm pretty sure the final drive on an 03-08 Corolla manual transmission is 3.941, not 3.25. 3.25 is the reverse ratio.

[i_am_socket]

I only found the reverse ratio for the automatic, which is 2.977:1; 3.25 was listed as final drive ratio. 3.941 would be better though, yes?


But in any event, it sure would be nice to find a BSFC map for the 1zz-fe that's a little newer than the one from 97-00(?) that is hard enough to find yet seemingly the only one available...

[Daox]

3.941 will give you higher rpms unfortunately. A 3.722 was used in the transmission from the 98-02 Corollas and the other gearing is identical. So, if you were to swap, that would be the tranny to go with. However, that still only drops your cruising rpms by 140 @ 65 mph. At lower speeds the difference would be even less pronounced. So, its not a large gain at all. As far as a stock option, thats as good as it gets.

If you want to venture into custom land, reversing the 2nd gear ratio and using it as a new 5th gear would be a lot of work and money, but far superior. You'd have a 5th gear ratio of .525 and a cruising rpm of 1700 @ 65 mph instead of the stock 2670 @ 65 mph with the 98-02 tranny.

[Funny]

The funny thing is, I was just looking for this stuff not that long ago. I guess we all look to unrealistic modifications when the weather gets cold .

Below are the transmission specs for all Toyota "C" Transmissions (from an Australian forum, I think), which are interchangable. You just have to change the axles in a manual transmission along with the final drive ratio (3.526) from a 2000-2005 Echo to get some seriously tall gearing. Would probably be underpowered, but throw a small turbo on there, and you are in milage heaven... Now I am really talking unrealistic (read: cost prohibitive) mods!

I "think" yours is the C52, but don't quote me, I was looking for the 2002 transmission.

Here are ratios for various C gearboxes:

All C-series transmissions have a 3.250 reverse gear ratio, new generation C55# notwithstanding; they use a 3.214 reverse and 3.944 axle ratio exclusively.

C40/C140
3.545 1.904 1.310 0.969

C50/C150/C50F
3.545 1.904 1.310 0.969 0.815

C51/C151
3.545 1.904 1.233 0.885 0.725

C52
3.166 1.904 1.310 0.969 0.815

C53/C153/C53A
3.545 1.904 1.310 0.969 0.725

C54/C154
3.545 1.904 1.392 1.031 0.864

C155
3.166 1.904 1.310 0.969 0.725

C56/C56M
3.166 1.904 1.392 1.031 0.815

C57
3.166 1.904 1.233 0.969 0.725

C58
3.545 1.904 1.233 0.969 0.725

C59
3.166 1.904 1.310 0.885 0.725

C60/C160
3.166 2.050 1.481 1.166 0.916 0.725

C63
3.166 1.904 1.310 1.031 0.864 0.725

C64
3.166 2.050 1.481 1.166 0.916 0.815

C65/C65M
3.166 1.904 1.392 1.031 0.815 0.725

C66/C66M
3.166 1.904 1.310 0.969 0.815 0.725

C250
3.545 1.904 1.310 1.031 0.815

C251
3.545 1.904 1.392 1.031 0.815

C550/C550A/C550K
3.545 1.913 1.310 0.973 0.804

C551/C551A/C551K
3.545 1.913 1.310 1.027 0.850

Among the available axle ratios of the C-series:
3.526 3.722 3.941 4.058 4.312 4.529



And check out the following website:
Gear-Speed Calculator Program

It provides a calculator program that we all can use to calculate speed, using gear ratios and tire size.

[Daox]

I don't see why you'd need or want a turbo. The whole idea here is to increase engine load at cruise, not increase available torque. You still have the same amount of horsepower available as you did before any transmission mods. You just have to downshift instead of keeping it in 5th gear.

[i_am_socket]

[ NOTE from Darin: split this thread off from DRAG-REDUCTION vs BSFC ]

Good call Was getting pretty off topic.

Cost prohibitive, yes, but still a consideration for when repair/replacement becomes necessary.

I'd have to check what my current 65 RPM is; been a while since I drove that fast. I'm @ ~2100 RPM doing 55 MPH with the current auto.

*edit* that calculator is pretty handy. So, by inference from the calculator, I'd actually want a lower final drive to increase speed at a given RPM?


*edit again* according to the repair manual the 05 has the C59 manual with the 3.941 differential gear size. My auto has a 2.962 differential gear size. By using the calculator and crazy extrapolation, if I could get the 5 speed gear ratios with the auto's differential, I'd be better off?

[i_am_socket]

Almost all the info you could ever hope for about the 04-07(?) Corolla.

Should have just looked there for the gear ratios... too bad the one piece of useful info I've been unsuccessfully hunting (the updated BSFC map) isn't in there.

[Funny]

Originally Posted by i_am_socket

Cost prohibitive, yes, but still a consideration for when repair/replacement becomes necessary.

Indeed, when one must replace a part on a car, AND plans on keeping that car for some time, I say go for the gusto and get the best part within your budget.

Originally Posted by i_am_socket

I'd have to check what my current 65 RPM is; been a while since I drove that fast. I'm @ ~2100 RPM doing 55 MPH with the current auto.

That isn't that bad, however I would prefer to cruise at 1500 RPM at 60-65 MPH.

Originally Posted by i_am_socket

*edit* that calculator is pretty handy. So, by inference from the calculator, I'd actually want a lower final drive to increase speed at a given RPM?

I stumbled upon that when I was on the Australian forum (can't remember it for the life of me. ) I believe it was made by a Korean kid that was interested in swapping transmissions.

Originally Posted by i_am_socket

*edit again* according to the repair manual the 05 has the C59 manual with the 3.941 differential gear size. My auto has a 2.962 differential gear size. By using the calculator and crazy extrapolation, if I could get the 5 speed gear ratios with the auto's differential, I'd be better off?

Long story short, you can't. The automatics use a different system that is not interchangeable, sorry.

[almightybmw]

Originally Posted by i_am_socket

I'd have to check what my current 65 RPM is; been a while since I drove that fast. I'm @ ~2100 RPM doing 55 MPH with the current auto.

*edit* that calculator is pretty handy. So, by inference from the calculator, I'd actually want a lower final drive to increase speed at a given RPM?

Lower final yes produces lower rpm to tire speed. Think of it this way if you ever get confused again: Your engine rotates at 2000rpms. Tire dimensions given say 766rpm (random number). That's a ratio right there, 2000:766, mythical ratio I made up is 2.61:1. Remember, this is all revolutions per minute. If your engine rotates 1rpm, wouldn't you want your car to move forward on the tire 1rpm? That'd be pretty impressive gearing (assuming a reasonably sized tire).

/end ratio tangent.