Tallest gear ratios available for ae101

[BLSTIC]

I've been thinking about fuel economy for a while, and along with the purchase of a new vehicle when I get back to NZ I would like to know what the tallest ratio gearbox I can fit is (don't worry, there will be other accompanying modifications to either reduce engine load or increase torque).

So far I have found the C50 gearbox in the ae101 with 4A-FE (the most likely car I will get if I choose to chase fuel economy on the open road) has a 0.815 5th and a 3.722 final drive, making for 3.03 overall in top gear. Although I don't know what rpm that will relate to at 100km/h.

My grandmother has a Ceres (which I assume based on it's appearance and age is based on the 101 chassis) with some type of A-series FE (1.5 or 1.6 I'm not sure) headed engine with an auto box and it pulls 1800rpm at 100. The only gearbox info I can find on that vehicle points me at a 0.89 top gear with a 2.96 final drive, for a 2.63 overall in top, but I'm not sure if that's the gearbox fitted to her vehicle.

Is there a bolt-in manual gearbox that is taller than the 101-series C50? Or am I limited to wheel/tyre selection as my only option? Or can the final drive gears be swapped with something else (although I believe the C50 already *has* the tallest)?

Thanks
Ben

[Hiro]

What is your reasoning behind wanting a taller final drive? My 7AFE/C52 sits at about 3200rpm @110km/h, it's a bit higher than I'd want but you have to remember that these are city cars with relatively small (1.6L in your case) engines, if you change the final drive to give you a ~2000rpm cruise speed on the highway then the car will be gutless pulling away from traffic lights. Autos can get away with it, partly because they are only 4 speed (so naturally are going to be taller geared) and also because the torque converter helps overcome the issue of pulling away at low engine speeds. Fuel economy isn't a problem, I drive reasonably hard and still get ~8-9L/100km around town, ~7/100 on the freeway (factory figures are 8/6.6).

If you're dead serious about it, an E-series gearbox from a 4AGZE has taller ratios, but they are a pig-heavy box and definitely overkill on a 4AFE. And because the ratios are taller, you'll have to work the engine harder to get the same acceleration, so whatever fuel economy savings you get on the freeway you'll lose around town

[BLSTIC]

Purely for fuel economy reasons. However as mentioned before if I purchase said vehicle the engine will be modified and I will be at least rialling some low drag aero modifications.

[ivandude]

If a 7AFE gets ~7L/100KM i can tell you a 4AGE 20V Auto AE101 will get the same as well on HWY (and about 8.5-9L/100 City). They can be just as economic as the 4 door AE101 i find

[BLSTIC]

Hmmm... It's interesting to note those figures, already pretty impressive. Kinda gives me hope of cracking into the 6's on the highway with a few aero modifications (which aren't to everyone's tastes, but hell it's my car). Not that there is much highway in NZ but it's kinda like hp wars, bragging rights not practicality.

[wa5]

Bragging rights? when I ask somebody "what'll she do", (concerning their cars), I'm not interested in fuel economy, only how fast the car goes... but each to thier own.

Why try for increased open road economy, when you say NZ doesnt have much in the way of open road, and your methods will make the car a pig for 90 percent of the time you drive it?

Some import 101s had a deisel in them, that may be more to your taste?

[BLSTIC]

Only the taller box will make the car worse to drive around town, but it looks like the C50 has the tallest ratios of any readily available and cheap box anyway. Which is stock in a few 101's

The diesel thing is a sore point for me. Diesel tax in NZ is based purely on the distance you drive and not the amount of fuel you use. I worked it out a year or so ago and it would mean that to get better economy (financially) your car has to get around 4l/100km LESS THAN the petrol version. When you're talking about a car that uses less than 10l/100km anyway that's quite a feat. Then you have to worry about the increased failure cost of obscure diesel parts.

As for the mods themselves (for those that are interested) initially they would be an undertray, rear spoiler and, depending on what the airflow over the rear windscreen is like/can be made to be, vortex generators. The visual impact on those is pretty mild and, except for servicing, the undertray would go unnoticed. After that I would be looking at engine/ecu tuning. But I'm not sure what gains are there to be had once you go past the usual intake/exhaust/ecu suspects. Maybe there's some porting or cam timing tricks I can pull to get a bit more low-rpm torque happening. Of course then there's the blatantly ugly things one can do like wheel covers, but that will have to be last (and probably only fitted if I want to prove a point or drive a really long way).

Notice all of these have an impact on acceleration too, so they aren't totally useless to the non-economy minded

*edit: I should mention there's a guy (basjoos is what he's known by) who did a host of aero mods to his civic along with installing a lean burn engine. He can stay in lean cruise at some incredible speed like 85mph and his top speed went up something fierce. His car is 8 kinds of ugly though*

[maj]

Skinny tyres and tyre wind deflectors go a long way for starters when it comes to drag reduction, at the cost of handling though in the case of the former.
My missus new Impreza got 7L on the highway despite it being a barge of a thing, with one half flat tyre, as well as having roof racks (although they are wing shaped). Easily would get it down to 5.9L once the above is sorted, engine is at 2,500rpm at 110km/h in 6th gear.

It really comes down to horses for courses. Either you live your life trying to obtain a figure and always being miserable, or you live enjoying what you drive, knowing it's also very well rounded and is in the ballpark of what you want it to achieve.

[BLSTIC]

You could say that, or you could enjoy the challenge of just getting a little bit more out of it, knowing that your car gets better all the time. Much like the constant quest for more power.

TBH except for the wheels, tyres, and brakes the only real difference between modifying for economy and modifying for performance is the size of the engine and the rpm you are tuning for. Hell no-one can argue that more low end torque is less fun around town (and as long as you get that torque without lowering the compression or running stupidly rich, fuel economy won't go down).

[BLSTIC]

I just found an interesting page... http://www.toyoland.com/engines/4A-F.html

It looks like the '93+ 4A-FE engine was a big step over the previous. Enough to hunt for that if I'm truly chasing economy...

[wa5]

Ummm, since you are chasing a 101, not a 92, would it not be running that spec already.... if you are after torque rather than revs and outright power, why not experiment with a 7A (1.8)?

[BLSTIC]

I thought the 101's started earlier than that, I'm probably mistaken though

*edit: nope, the 101 started in '91 and the updated engine didn't start til '92/'93 depending on location*

[wa5]

Started in Oz in 94. wasnt thinking about NZ being chock ful of imports .. sorry

AE92s have 1.4s in them (6A), personally I think they would be working too hard on the highway (espacially with high gearing) but perhaps a little Turbo could make it work?

[Hiro]

All AE101s had the updated 4AFE, just there are different starting years in different countries. Toyoland is American, and they got the 10x series in '93, Japan got it in '91 and Aus got it in '94 (although we already had the same improvements in the 7A in the AE92)

[BLSTIC]

I suppose I just look at where the injectors are to see... The updated ones are in the manifold and don't have 16 VALVE EFI on the rocker cover