C50 gearbox (1.6vvti) swap to C53 (1.4 D4D)

[Adrien]

Hi everybody !

I know gearbox swaps topics are quite commons on internet, but I can't find anything about this one in particular :

Out of curiosity, is swapping a standard C50 gearbox for a d4d C53 possible in a 2003 Corolla 1.6 vvti ?

Rpms at highway speed are quite high (more or less 4000rpm at 130kph) and strongly decrease fuel economy and driving comfort, which are otherwise good. Putting a C53 gearbox will make the car cruise at less than 3000rpm at 130 kph

Comparing the drivings ration, 1st, 2nd, 3rd, and 4th gears would be 7% longer, which is really reasonable for city driving, but 5th gear would be 22% longer, which would really be appreciable at higher speeds., and I believe the car is powerful enough to whistand these new gear ratio.

 

I did some research, and It seems almost the whole gearbox assembly is shared between C50 and C53 (http://www.japan-parts.eu/toyota/eu/2003/corolla-hb-ukp/zze121l-dgmnkw/3_153550_019_/powertrain-chassis/3305_transmission-gear-mtm)

 

Now, I know it's an old car, it's not worth it, and so on... I'd just like to know if it is technically possible, It's a build I'd like to make if I can put my hands on a cheap used d4d corolla.

 

Thanks for your thoughs !

 

 

 

 

 

[oldcodger]

Hi,

Thats always been my thoughts that the standard 1.6 gearbox is rather low and makes it a bit noisey for high speed motorway cruising, though not doing so much of that than we used to.

However it does mean that the lower gears do make your getaway a lot faster than most !  

If you do the swap, and you original box is good ,could be interested in a standard 1.6 gearbox as mine is whining a bit, but not sure if you are in England ?

[Adrien]

Hi,

Yes, I like the acceleration of this car, I never had any problems for overtaking or anything as long as you drop one or two (or three ! 🤪) gears.

I would have been OK to sell you my current gearbox, but I'm in south of France, and you'd have to wait for me to do this hypothetic miracle swap ^^

 

On the topic, I did a bit of research, and I saw that a C59 could be a good match too, but I don't know if it's possible to find those in Europe.

[oldcodger]

When you need to change the clutch its the time to try a swap, but no idea about the different gearbox models and their compatabilty.

Seems decent gearboxes are getting hard to find so if you get chance to get one I would say take it, even if you do not fit it for some time.

Think June sounds about right for a trip to the south of France ....

[Adrien]

Yes, I was planning to wait to change my clutch, I guess I'm still good for a long time...

I checked my speedo, and I wonder what kind of gearbox do I have..

My VIN number plate telle me I do have a C50, and theorically a 3,722 final ratio, however, at 100kph, my rpms are at exactly 3000, at 130kph/4000rpm, 80kph/2400rpm which corresponds closely to a 4.312 final ratio...

 

If anyone has an guess about it...

 

[furtula]

That's the pretty standard gearbox ratio for 1.6, not just for Toyota. Even if you drop in another gearbox, the consumption will suffer.

How much of a drop do you want to have? 

Newer cars that have 6th gear only drop the rpm around 200, not that much, this is in order to get better mpg.

 

[Adrien]

17 hours ago, furtula said:

How much of a drop do you want to have?

I guess 2500rpm at 100kph would be a good improvement over the current 3000rpm.

I'm always in 5th in the city at 50kph, dropping in 3rd if necessary, and I can average beetween 5,4 and 6 L/100km, depending of the traffic.

On 80kph countryside roads, I'm always in 5th, at 2500rpm, even uphill, without loosing speed, and I can average as low as 5,3L/100km on a full tank. I can easily overtake without dropping a gear if the conditions are good, if not, I can always drop in 4th or 3rd in difficult conditions.

On the other hand, on the highway, impossible going under 6,3L/100km, and it's at 100kph (3000rpm) max. If I drive at 130kph (max speed limit here in France) and 4000rpm, FE is around 7,5 - 8L/100km.

 

All this to say that I believe that this car has enough power to either have a 6th gear, or a way lower final ratio ; grazing the throttle at high revs is not at all an efficient way to use the engine, and it is super frustrating too ! ^^

 

After testing different gears at different speed, I can definitely say that this car do not have the standard 3,722 final ration of the C50 gearbox, but a 4,312 final ratio. It's super fun to drive, perfect for mountain or countryside roads. On the highway, I wish I had a 6th gear...

 

 

 

[furtula]

Car might have power, but  it lacks torque. I think it  just does not have raw grunt of a diesel to accommodate for the low rpm cruising at 130 kmh that you want.

The high consumption you get is because of higher wind resistance, and since the car has most of its power in upper RPM range, it struggles more at lower rpm.

Even if you do a conversion, you would be getting worse MPG, if that is the whole point of why you want to do this, then you might be better off putting a 1.4 engine in there.

If we compare the specs of your engine, which has maximum torque of 153Nm at 5200 RPM, with the 1.4 1ND-TV, there's a huge difference,not to also mention the final drive difference, as the diesel has plenty of low rpm grunt to push the car forward, and we should not forget the wind resistance at such speed is a big factor.

1.4 1ND-TV Max. torque:

• 170 N⋅m (125 lb⋅ft) (FGT) at 1800 - 2400 rpm
• 192 N⋅m (142 lb⋅ft) (VGT) at 1800 - 2800 rpm
• 205 N⋅m (151 lb⋅ft) (VGT) at 1800 - 2800 rpm
• 205 N⋅m (151 lb⋅ft) (VGT) at 1400 - 2800 rpm 

Maybe it would be better to get a 09 Auris 6 speed box instead? The engines are more similar, and might be easier to fit + it's made suited for the power your engine has now.

At 130 it should do around 3400 or so RPM instead of 4, but at that speed consumption would still be 7L or more.

Another alternative , since i think on your gearbox you can access the 5th gear without taking the whole thing apart, just the cover at the end of gearbox.

Have you thought about getting a machine shop to mill you special gears with different ratios, to lower the RPM?

[flash22]

I would check the torque rating of the gearbox as the diesel boxes are usually rated high for the low down power, maybe swapping the diff is a better option

Had a look on the epc all the internals of the C50 and C53 are identical but there are 5 diff ring gears

C50. 3.772

C53. 3.47

C56-04C 4.312 (lsd)

[flash22]

https://www.blocklayer.com/rpm-gear.aspx

i don't think you will get any benefit from changing the box, i would be looking at rim and tyre sizes if you want better economy

[Adrien]

5 hours ago, furtula said:

Car might have power, but  it lacks torque. I think it  just does not have raw grunt of a diesel to accommodate for the low rpm cruising at 130 kmh that you want.

The high consumption you get is because of higher wind resistance, and since the car has most of its power in upper RPM range, it struggles more at lower rpm.

Even if you do a conversion, you would be getting worse MPG, if that is the whole point of why you want to do this, then you might be better off putting a 1.4 engine in there.

If we compare the specs of your engine, which has maximum torque of 153Nm at 5200 RPM, with the 1.4 1ND-TV, there's a huge difference,not to also mention the final drive difference, as the diesel has plenty of low rpm grunt to push the car forward, and we should not forget the wind resistance at such speed is a big factor.

I totally get what you are saying about torque, however I'm talking about cruising speed, which certainly doens't require max torque, nor max HP. At 100kph cruising would only requires about 20hp, or 30hp at 130kph.

What counts isn't the max HP or max torque that an engine can give, but what it give at the targetted RPM, which for me would be more or less 2500rpm for 110kph, or 3000rpm for 130kph

This kind of engine has a quite flat torque curve, and I believe it would make around 40hp max at that RPM, which for 100kph is more than enough. At 130kph and 3000 rpm, it would make around 50hp max, which again are sufficient for cruising at that speed.

(cars half as powerful, and as heavy as mine doesn't struggle so much to achieve those speeds, so I guess that even with longer gears, i'm OK)

6 hours ago, furtula said:

Maybe it would be better to get a 09 Auris 6 speed box instead? The engines are more similar, and might be easier to fit + it's made suited for the power your engine has now.

At 130 it should do around 3400 or so RPM instead of 4, but at that speed consumption would still be 7L or more.

Your suggestion of an auris gearbox seems interesting, do you have any more info about it ?

 

5 hours ago, flash22 said:

https://www.blocklayer.com/rpm-gear.aspx

i don't think you will get any benefit from changing the box, i would be looking at rim and tyre sizes if you want better economy

I've already thought about it, however it's illegal in my country, and the insurance wouldn't cover me.

 

As a reminder, it isn's a "serious" modding project on a financial point of view. I have an old cheap car, and it's been some time now that I wanted to put my hands in the engine bay for a fun project to learn a bit about internal working of en engine ;-)

 

[furtula]

10 hours ago, Adrien said:

Your suggestion of an auris gearbox seems interesting, do you have any more info about it ?

Not really,  i just mentioned it because the engines might  be similar, and it might fit with an adapter plate.

It was just a slight upgrade from the standard 5 gear one, with more or less same ratios as you (and i) have, so it should suit the car the most.

I don't understand how different tires sizes are illegal? I mean, i know you cant just fit them and drive (by law), but you should be able to get for example 17" rims with bigger tires, then get some white paper from the manufacturer, get to your inspection place, they check and approve, then it gets written to some paper that your car can use it, and that's it, right?

That's at least where i am, and should be the same EU law, or similar, except it can be a bit costly, but nowhere near getting a new gearbox + fitting and other things.

 

[Gerg]

If you can be guided by the results of an older, smaller car (a Suzuki Swift, but sold in USA as a Geo (GM) Metro) then this thread might be of interest:- 

https://ecomodder.com/forum/showthread.php/metro-taller-transmission-swap-thread-5-efficiency-gain-107-2.html

VW followed a similar path in the eighties with their Golfs and Polos with 'Formel E' models, basically the cars had a regular gearbox but with just a much taller top gear and some aerodynamic and compression ratio modifications:-

http://www.polodriver.com/eco-polos/polo-formel-e-1983-1987/

But the engines were carbureted and had 'non-electronic' ignition with contact breakers and a distributor, and only 8 valves!

In the first instance, I'd just stick some Dynamat under the bonnet!  (£18)  🙂

Also from the diesel/petrol gearbox swap perspective; don't overlook the fact that as well as having a lot more torque, the 1.4 D4D has a heavier flywheel to make pulling away from stationary easier with a taller ratio.

[oldcodger]

5 minutes ago, Gerg said:

 

In the first instance, I'd just stick some Dynamat under the bonnet!  (£18)  :-)

 

I'd second that, after moving from my old Avensis to the Corolla it did seem noisier at motorway speeds so we used some product like Dynamat not only on the bonnet, but all over the boot and down in the tyre well , sides and door panels, it made things much quieter, even without knowing we had done it, other folk also commented how quiet the car seemed..

From the fuel tank top cover forwards to the bulkhead there a thick soundproofing felt there already, but probably space for the thin dynamat if you take the trouble to lift it up, though did not do it on ours.

You will find Dynamat or similar pads a lot cheaper in bulk  than the more often seen small speaker pads .

http://www.caraudiodirect.co.uk/deadening?p=3

Probably a lot cheaper and easier than changing gearboxes and tyres etc, either way extra soundproofing will make it  quieter.

 

 

 

 

[Adrien]

11 hours ago, Gerg said:

In the first instance, I'd just stick some Dynamat under the bonnet!  (£18)  🙂

 

 

11 hours ago, oldcodger said:

I'd second that, after moving from my old Avensis to the Corolla it did seem noisier at motorway speeds so we used some product like Dynamat not only on the bonnet, but all over the boot and down in the tyre well , sides and door panels, it made things much quieter, even without knowing we had done it, other folk also commented how quiet the car seemed..

 

I absolutely didn't expect what both of you answered to me, but it is actually a very good idea ! Thank you for reminding that the simplest ideas are often the best ;-)  I'll seriously look into it.

About the gearbox, well.. I'll see what comes to me, If I manage to find a cheap one, I guess i'll take my chance. The idea of only changing the 5th would be an option too !

[oldcodger]

Hi,

Its hard to appreciate the difference soundproofing can make until you have done it.

The most noticable on mine was the amount of drumming you get from behind the rear seat, though every bit of insulation helps.

There are places that do full soundprooofing kits though probably much cheaper to just use the sound pads yourself simple enough.

Just ensure the surface is free of dust and dirt, gently warm the surface and the pad with a heat gun and press down with a wallpaper seam roller.

We never did the roof on ours as the headlining seems to be a pain to remove and refit without damage, but suspect that could also make a big improvment in noise levels.