5 Spd to 6 Spd Conversion DIY

[H3LlIoN]

Eh. Sweet write up. I'm def interested in this, but I am having serious difficulty sourcing the c160. Been looking for an LSD one, but can't even find the regular!

[rob323]

A few more q's.

Did it throw your speedo out?

What are the chances of using the gearset minus 6th gear (just 1st to 5th) and installing it and the diff into the C150 housings (or if the centre housing is the same, just use the C150 end housing and bell housing)?

[Bluevitz-rs]

I used the speed gears from the C160. There was only a 1 tooth difference that make the speedo read slightly slower than stock, witch in my case is better as I run slightly smaller tires than stock. But I haven't compared it to my GPS yet.

And gears 1-5 would not work in the C150. Half of First gear is part of one of the input or output shafts, I can't remember. And 5th gear tops out at about 165km/h.

[rob323]

Originally Posted by Bluevitz-rs

And gears 1-5 would not work in the C150. Half of First gear is part of one of the input or output shafts

Is the shaft itself too long to fit in the C150 housing?

And 5th gear tops out at about 165km/h.

Which is pretty much perfect for what I want.

[Bluevitz-rs]

Yeah, as you can see in the pictures I took, the input and output shafts are longer to accommodate 6th gear.

It really isn't a big deal to modify the frame to fit the whole transmission in.

[rob323]

I know, but our rules for rally cars state:

3.4 Transmission:
(i) Clutch: The clutch assembly is free provided that the original type of operation is retained.
(ii) Gearbox: The gearbox (and the number of ratios) is free, save for the following:
• no modifications may be made to any bodywork to accommodate a gearbox, save for the drilling of holes to
support components, or to facilitate the fitting of the gear change mechanism;

[Bluevitz-rs]

You could protest the fact that the rule says "body work" because the work needs to be done to the frame.

Or you could do the modification, grind the welds down smooth, re-paint it and make it look like it came that way from factory. I know if I was re-painting mine factory blue you never know I did anything to it. I used a rubber dead blow hammer to pound the metal in place so there's no dints, just a smooth curve and no seams.

[rob323]

Nah, it's not worth the argument. The over riding rule is that you are NOT allowed to change anything unless specifically stated. In other words, it says I can change the transmission, but it doesn't say that I can change the chassis. Can't win.

[Mrhiguy]

So you're saying that the C160 Transmission accepted all the Original Echo motor mount brackets and locations?

[Bluevitz-rs]

Originally Posted by Mrhiguy

So you're saying that the C160 Transmission accepted all the Original Echo motor mount brackets and locations?

The only mount bolted to C160 parts is the front one. the rear one is bolted to C150 parts. Nothing was modified to make it work.

[Mrhiguy]

Do you guys think the Final drive could swap over from a c150 to a c160?

[Bluevitz-rs]

Originally Posted by Mrhiguy

Do you guys think the Final drive could swap over from a c150 to a c160?

Not a chance. The F/D is part of the output shaft.

[Mrhiguy]

Originally Posted by Bluevitz-rs

Not a chance. The F/D is part of the output shaft.

But is it possible to pull the gears off the output shaft?

[Bluevitz-rs]

Originally Posted by Mrhiguy

But is it possible to pull the gears off the output shaft?

Absolutely. That's the only way to do the swap.

The reason you can't swap them is because one caries 5 gears, and the other caries 6. Also, the C160 has an 8 bolt diff and the C150 is a 6 bolt. There would be no point in putting in the diff from the C150. It would defeat the purpose of the close ratio 6 speed.

[Mrhiguy]

Originally Posted by Bluevitz-rs

Absolutely. That's the only way to do the swap.

The reason you can't swap them is because one caries 5 gears, and the other caries 6. Also, the C160 has an 8 bolt diff and the C150 is a 6 bolt. There would be no point in putting in the diff from the C150. It would defeat the purpose of the close ratio 6 speed.

The reason for my question is the idea to use the 6 speed as a better daily driver. Because putting in the 3.526 F/D ratio to the c160 would give it a great o/d 6th gear to keep the revs low but still retain a close to stock 1-5.

Exmple: with 205/55/16 wheels
GEAR=------------------1-------2--------3--------4--------5----------6
c160 with 4.5 FD= 14.9 __ 23.1__ 31.9__ 40.6__ 51.6___ 65.3 @ 3000RPM
C160 with 3.5 FD= 19.2 __29.6__ 41.0__ 52.1__ 66.3___ 83.8 @ 3000RPM
c150 stock3.5 FD= 17.1 __31.9__ 46.4__ 62.7__ 71.7 _______ @ 3000RPM

[rob323]

With the 3.5 final drive, the engine would be far too low in the revs when cruising at 60 mph and probably use more fuel because of the lack of power available at those revs.

[Mrhiguy]

Originally Posted by rob323

With the 3.5 final drive, the engine would be far too low in the revs when cruising at 60 mph and probably use more fuel because of the lack of power available at those revs.

Then just keep it in 5th gear. Here in the states we drive 65-75mph Average even though the speed limits are generally 65-70 mph.

Plus if 3.5 is too low for you. You can get a final drive from a 4 door Echo c150 with a F/D of 3.850.

[Bluevitz-rs]

Yeah, but even at those speeds I still found the 5 speed was revving too low. The 6 speed as it comes make the engine work far less to accelerate the car under normal driving conditions. I'm still getting the same millage I did before the swap, maybe even a little better, if I could keep from driving it hard. My last tank yielded me 685km on 42.8L of fuel, driving on mostly back roads with hills and corners.