My g/f has a 1986 MR2, 4AGE / 5sp. It is showing the first signs of 5th gear pop-out right now. Rather than spend bucks fixing this trans, we are looking for something that provides a better top gear for highway travel. The engine is spinning near 4000rpm sticking near the speed limit on the interstate, just nuts!
From searching the forum, I've gathered that the transmission is a C50 and that any other Cxx trans should bolt in, right? Unfortunately, I haven't been able to find great data on top gear ratio and final drive ratio for these transmissions and what cars they came in. The wikipedia page is especially lacking final drive info on many of these units. We're looking for something that has the highest gearing (lowest numerical) that will bolt to the 4AGE. The girl has a lead foot and there's a lot of interstate driving around here...
Marc put a 6 speed C160 on Mk1 and has a very thorough page on what is required to do it.
Seems like a decent swap. A bit of a gain on the highway, but Yikes the price! The price/benefit ratio isn't quite what we're looking for. I was thinking of something sold in a US market so we could get one from a U-pull junkyard, more like $50-100 for the trans. Honestly, something with gearing more like on her old B11 Sentra would be great. That setup put the engine at a comfy 3000rpm at 70. Has Toyota made a C-series trans with this sort of gearing? Something with an overall top gear ratio of 3:1 or slightly lower?
I prefer taller gearing than most OEM's. It extends engine life, improves mileage, and since I don't care much for the dragstrip I have found that I like the performance better. Besides, when the engine can comfortably cruise in 5th at 30mph, I know it can pull more gear...
Some AE92 Corollas have the C52 with a 3.722 final drive. I've heard there was also an option for a 3.54 final drive that I believe was in the carbed Chevy Novas and Geo Prizms in '87 and '88.
Besides, when the engine can comfortably cruise in 5th at 30mph, I know it can pull more gear...
Cruising @30mph in 5th gear is not gonna happen. It would take alot of HP. Did you not read asjoseph's post?
Though not impossible, I think it is not prcatical. especially on a limited budget.
On a limited budget you could swap in the final drive from one of those cars I mentioned.
Maybe I'm a heretic but I don't see much wrong with doing so and changing the characteristics of the 4AGE. We're talking about transmissions from other 4A engines, it's not like they're radically different.
Yes, you'll lose some acceleration. There's always a trade-off.
One person who did this reported getting 39 mpg over 7 tanks after changing his final drive. I haven't seen any other numbers or I'd mention them.
Cruising @30mph in 5th gear is not gonna happen. It would take alot of HP. Did you not read asjoseph's post?
Though not impossible, I think it is not prcatical. especially on a limited budget.
Yes, I read asjoesephs post. I just happen to disagree with his philosophy.
As far as the shifting, I'm not saying I'd like that to happen, I'm saying that it does that. On level ground, I will put the car into 5th at 30-35mph if I am not planning on accelerating. The engine runs along around 1500rpm or so just fine. I would rather the car be geared so that 5th isn't useable untill 40mph or slightly higher. Just rolling along at a steady 30mph takes negligible HP, most lawnmowers make enough HP to do that.
Ghostyman, thanks for the tip. I'll have to try looking for those. Being in a domestic branded chassis they should be easier to find here in Mi!
seeing how i was present for the first 6 speed conversion into the MkI MR2, and also having driven it, it can say that it's actually a really great swap.
repair the current trans. BTW: PapoJ who has the 1st 6 speed swap discovered that sometimes the 5th gear pop-out can be repaired by r&r of the bearing in the trans end cap.
second, why bother swapping gears into a trans when final drive gear is affected by the size of tyre/wheels.
Last edited by ToyotaTechGeek; 11-13-2008 at 09:14 AM.
I'm sure the 6sp swap is great, especially for a car that is often taken to the track. But this is a street car and I'd really like something that offers taller gearing on the highway to better suit how the car is actually used. Do not want to repair the current trans because then it would be a rebuilt trans that still has the wrong gearing so little gain.
Yes, tire height changes the overall final ratio, but again I want more of a change. I'm afraid tall enough tires to get the RPM's down to a satisfactory level would have clearance problems and seriously make the car look like a 4-wheeler.
I've got tomorrow off work, so I'll see what I can find in the junkyards!
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