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Discussion Starter #1 (Edited)
I like the close gear ratio of the c-50 and c-52 trannies, but at the same I don't like cruising on the highway at 4k rpms. Are there any c-series trannies (or any trannies for that matter that can bolt up) with a longer final drive gear? I quote ITA MR2 from another thread: "If you want a top speed gearbox, get one out of a 4AF-powered Geo Prizm (or better yet - a 4AC Chevy Nova)". Is only the final gear longer, or are all of them that way?
I'll also be swapping in a 4agze this summer, so I'm looking for something that is at least equal in strength to a c-50 or 52. I would also be willing to consider a 6 speed, although this would be a more expensive option I'm sure. Thanks!

-Travis
 

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The tranny in the Geo's IS a C-series. The pinion and differential SHOULD be a bolt-in conversion for the C-52. The E-51 has a longer 5th gear - but the ratios are spread more.
 

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Discussion Starter #3
Norm, would you consider the prizm tranny a good option? Are there any reasons that it wouldn't be a good choice? Does anyone have any details on it?
 

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I've got a parts manual, and it LOOKS like the same tranny as in the FWD Corollas (no reason it shouldn't be - since they came out of the same plant), but I can't cross the part #'s because the Geo's use a GM code.
 

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travis brecher said:
I don't like cruising on the highway at 4k rpms. Are there any c-series trannies with a longer final drive gear?
Travis, I installed a new transmission in my 86 a few months ago from a Chevy Nova. See THIS LINK for the post. It was new in a Toyota box from a GM dealer's stock. Less than $300 delivered to my door. I purchased the correct drill bits for the shift linkage conversion.

The ebay link does not work anymore but the seller said it was for a 88 or 89 chevy nova. I recognized the picture of it as a C-52 for a FWD. I am glad to get rid of the C-50 with the 5th gear pop out.

ITA MR2 informed me that the tranny has a 3.54 to one ratio final drive. I was concerned it would be more difficult to get moving from a dead stop without slipping the clutch more however I have found NO drawbacks to installing this transaxle.

Just checked my combination driving MPG tonight and came out with 36.5 MPG. It has been a great upgrade.

John
 

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Travis, if you're not looking for a huge difference you might just put taller tires on the car. When I changed from 195/50/15 to 205/50/15 it was enough to notice a difference for sure. I am using the C-52 with my SC swap (stock boost) and I like the combo.

I still have never driven any transmission more willing than C-52.
 

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BryanH said:
Travis, if you're not looking for a huge difference you might just put taller tires on the car. When I changed from 195/50/15 to 205/50/15 it was enough to notice a difference for sure. I am using the C-52 with my SC swap (stock boost) and I like the combo.

I still have never driven any transmission more willing than C-52.
Agreed, I noticed a slight difference when I put the 195/60's on the rear.
 

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I put in a tall ratio C56 out of a 4AC Corolla, out of the junkyard, and did the shifter swap. I get 38 mpg highway. I also took action and bought one of the NOS Nova transmissions, which are still available on ebay, just search Corolla transmission. The first gear seems to be taller but not too tall, it helps in city traffic. If there is no hurry, there is not really a need to burn the clutch. But if there is a hurry, burn the clutch a little and you're bye bye. The old C52 that came out was low enough that I felt I needed to shift too soon. It is the best mod I've done to my 2 so far. No regrets.
 

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Discussion Starter #11
Thanks for the responses guys. Alot of good info! Fogjammer, the c56 sounds like a good option. I'll look into the ratios. As long as the lower gears aren't really long I would definately consider it. I could go for an E-51, but I just love how smooth my c-52 is. I've also been reading in another thread that people were experiencing e-51s to be much notchier than the c-series.
Tires aren't really an option for me now. I'm running 205/45/16, and I think I would risk rubbing if I go any taller with my current setup. Otherwise I'm pretty happy with my wheel/tire setup (although 15's would be nice). It also seems cheaper and easier to get a "new" junkyard trannny, especially since I'll have the engine out for a swap. Thanks for all good info!

-Travis
 

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The actual gear ratios in the Corolla tranny are the same - just a 20% higher final drive. The overall first gear ratio is about halfway between where first and second are with the stock setup. I've never driven a E-51 in a S/C, but I know the one in my 91-T is a lot heavier / clunkier than any of my C-52's.
 

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Discussion Starter #13
ITA-MR2 said:
The actual gear ratios in the Corolla tranny are the same - just a 20% higher final drive. The overall first gear ratio is about halfway between where first and second are with the stock setup. I've never driven a E-51 in a S/C, but I know the one in my 91-T is a lot heavier / clunkier than any of my C-52's.
Wow that sounds pretty ideal. Come to think of it, first gear could use a little more range anyway. I think I'll start looking for one. This is the c56, correct?
 

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That's the same one (and prbably from the same source) as AustinTXmr2 was talking about. IIRC, that place is right across town from WIWhite87's house. You will have to do the C-56 shifter mods on it, because the linkage is for a FWD application.
 

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travis brecher said:
Is this the c56 tranny?
Travis, I don't know what it is called but it is the same one I installed in my 86. Best mod yet to the car, I recommend it. Of course I do not race my car though.

It look externally just like my original 86 tranny except for the extra starter boss (hump).

John
 

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AustinTXmr2 said:
Travis, I don't know what it is called but it is the same one I installed in my 86. Best mod yet to the car, I recommend it. Of course I do not race my car though.

It look externally just like my original 86 tranny except for the extra starter boss (hump).

John
Besides the shift linkage mod, are there any other things that have to be done to this tranny to make it work in an 85mr2? Will the drive axles swap over?
 

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Discussion Starter #18
AustinTXmr2 said:
Travis, I don't know what it is called but it is the same one I installed in my 86. Best mod yet to the car, I recommend it. Of course I do not race my car though.

It look externally just like my original 86 tranny except for the extra starter boss (hump).

John
I'm glad to hear a positive review from someone who has done it. I won't be racing the car either; if it can still feel quick to me that's all that matters. Thanks for the advice!
 

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The other good news is that your speedometer will still be (reasonably) accurate, since it's a complete unit. :D
 

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cfspinner said:
Besides the shift linkage mod, are there any other things that have to be done to this tranny to make it work in an 85mr2? Will the drive axles swap over?

Besides the shift linkage mod, the only thing that required some work was the fact that the extra starter hump got in the way of a metal coolant line. There was some info about using the lines from a later MR2 to get around this. I took the cheap way out and just used my ol trust pneumatic cut off tool and moded the hump to not interfere with the original coolant line.

The transmission came complete with new clutch fork and throwout bearing which I inspected and I think I used. The clutch slave cylider was a little different so I just slapped the original car cylinder on it. It had a bunch of new brackets and such on it and I just swapped them out for the originals and junked the new ones.

I can't tell you how nice it is to get a NEW transmission for that kinda cash delivered to your door. No fuss or worry about the rebuilder or who's parts of what quality were put in it.

The car is no slug off the line (not any more than it was before) and I can't explain how not having the lower gearing has not made a noticable loss of performance. That 1000 RPM slower engine speed at 70 MPH is sure nice.

I have been reading the acetone thread and believe it is time for me to give that a try. I have documented the MPG on this car for just over a year now and want to see how that helps.

John
 
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