D16 Final drive swap?

[Ken_86gt]

I have an 07 Aveo with the D16 tranny and the 3.944 FDR, I would like to swap in the 3.550 FDR from a D20. Are these transmission similar enough to do this? My goal here is to get better fuel economy. Can I swap the D20 strait up for the D16? Any other ideas, thanks.

[Pir0]

I'm not sure about the D16 and D20 but I'm sure you can do it with the F16 and F20, so i'd assume you can

[LacettiGT]

Hmm, that can't be finished with simple swap.

1. pull out 3.944 pinion gear (separate pinion gear from 1,2,3,4th gear)
2. replace it with 3.550 pinion.
3. differential in gearbox should be replaced with 3.550's. (if you don't, u can't assemble it again)

but, gear ratio you want to make is very long for normal vehicle.
it would be best choice for 300 hp turbo to run 270km/h.
I suggest to change D20 close ratio with 3.722 final or D16 medium with 4.176 final on 2.0 n/a vehicle.

[xiaogary]

You mean those 2.0 n.a vehicle's final drive can be swapped into D16?

I would like to get hold of a higher Final Gear Ratio to improve the acceleration. Since my country's road limit is 90km/h on the express way. No point having very high top speed with traffic light every 100-200m.

If anyone want to let go a Final Drive Gear, I am interested.

[Ken_86gt]

My goal for the swap would be to lower engine RPM at highway speeds. The majority of my driving is 70-75 MPH, and the engine goes to fast at this speed. I would like to see the RPM below 3000 at 70-75. If anyone has the necessary parts for the swap or could point me to an online dealer that would be great, I am located in the US. Thanks

[xiaogary]

I have a 3.944 final gear ratio on my 1.4 DOHC Daewoo Kalos.
Will the pick up be better if I change to a 4.176 final gear ratio?

What does it comes with?
Is it a long stick gear and a piece of round gear?
Or only a piece of round gear?

Is the labour coast to change these expensive? Or its better to do it together when I change my flywheel to a lighter after market one which I cam buying soon.

[Ken_86gt]

I have a 3.944 final gear ratio on my 1.4 DOHC Daewoo Kalos.
Will the pick up be better if I change to a 4.176 final gear ratio?

What does it comes with?
Is it a long stick gear and a piece of round gear?
Or only a piece of round gear?

Is the labour coast to change these expensive? Or its better to do it together when I change my flywheel to a lighter after market one which I cam buying soon.

Yes, if you were able to change your ration to a higher number you would likely be able to accelerate more quickly. But the change you mention is so small, 3.944 to 4.176, Its not going to make a big difference. You may not even notice it. As to the cost, since you would likely have to remove the transmission from the car and then take it apart, it would be fairly high due to labor cost.

[xiaogary]

Yes, if you were able to change your ration to a higher number you would likely be able to accelerate more quickly. But the change you mention is so small, 3.944 to 4.176, Its not going to make a big difference. You may not even notice it. As to the cost, since you would likely have to remove the transmission from the car and then take it apart, it would be fairly high due to labor cost.

Hi. thanks for ur advice, I was quoted abt $300us for the 4.176 final drive. Think it came with a stick with some gear teeth on it and a circular dish with gear teeth also. I am waiting for thr shipping. Its from korea. I will update the difference. I also changing to a lightweight flywheel from opel. Hope both combine to make my slow car a better drive.

[gse_turbo]

what did the 4.176 gear come from? do you have contact info and or a part number?

Garrett

[PrecisionBoost]

I have an 07 Aveo with the D16 tranny and the 3.944 FDR, I would like to swap in the 3.550 FDR from a D20. Are these transmission similar enough to do this? My goal here is to get better fuel economy. Can I swap the D20 strait up for the D16? Any other ideas, thanks.

You won't get better fuel economy by changing the ratio...... fuel economy on the highway is directly related to the coefficent of drag and your tires.

If you change the ratio to drop RPM you may end up with worse fuel economy because the engine is more efficent at higher RPM. ( more power per gram of fuel )

So if your going to change the FDR it should be for a reason like "I want my car to be quieter on the highway"


Let me put it to you this way...... if driving down the highway your vehicle may require the engine to put out 30hp to keep it moving in a straight line with no wind and no accleration or deceleration.


Right now you might be doing 4000 RPM at this speed...... and your engine can potentially make 80hp at this point ( at wide open throttle ).

Well... that means that your throttle has to be pressed down about 37.5% ( 30hp/80hp) and that means your engine is using up about 1200 Liters of air per minute


Now if you drop that RPM via FDR to 3600 RPM at that same speed your engine may only have the potential to make 70hp at this point (at wide open throttle )

Now all of a sudden you need the throttle to be open 43% to make that same 30hp required to keep the car going and that means your using up about 1238 Liters of air per minute.


So at 4000 RPM your car is gulping back 1200 Liters of air per minute and now with the change of FDR it's gulping back 1238 Liters of air per minute to produce that same 30hp.


Given that fuel consumption is directly related to the amount of air injested this example would show a decrease in fuel economy of 3.2%


So...... this is just an example..... but I promise you that I"m not far off the mark here.

The only way to increase fuel economy is to increase the efficency of the engine.

The key is finding out where in the RPM band the car is most efficent and then running it at that RPM.

Guess what.... the manufacturer allready thought of that.... that is why your FDR is exactly where it should be.

Now having said that they are going to choose the gearing and efficency based upon some number such as 55 MPH

If your driving on the highway faster than that..... well it may be possible to change the engine efficency so as to accomidate your faster speed.

But having said that the force of air friction increases with the square of the speed..... so by driving faster your ultimatly responsible for your own poor fuel economy.


Hopefully you understand what I'm saying here...... all vehicles require a particular amount of power (derived from air and fuel ) to move foward at a particular velocity.

Changing engines, changing gearboxes.... none of those help..... your still going to require the same power level to move down the highway.

A 2.0L engine may only have to open the throttle 25% to make that 30 hp but it's a bigger engine.... so ultimatly it will still be sucking back the same quantity of air and fuel.

[PrecisionBoost]

Ways to improve efficency.....


decrease weight of car
decrease drag (air friction)
increase engine efficency by removing restrictions in the intake and exhaust systems
increase compression ratio of engine
change oil viscosity and type ( synthetic .... 5W30 )
Change your tires ( some tires are more efficent than others )
Monitor and control your tire air pressure ( can make as much as 10% difference )
Use nitrogen in your tires ( more stable pressure )

There are other ways..... but this is what I can tell you off the top of my head.

[gse_turbo]

I'm not looking for economy, I'm actually trying to help a guy on mig to locate the ratio he is after, any ideas on the application for the 4.176 gear

Garrett

[Efratech]

As far im aware 4.17 came on 1.5 DOHC Nexias/Cielos

Theres a thread somewhere that has pictures of the final drive stamped on the gearbox casting

[Pir0]

I've 2 nexia F16's sitting up in the shed I work at my car in. I should be able to grab a pic of the ratio, if I can find it. Is it alongside where it says F16 [daewoo ones actuaslly have a daewoo stamp on the gearbox beside the F16 stamp too].

All nexia's came with an F16 anyway, a close ratio one I think. I'll be able to check sometime between tomorrow and friday. Probably tomorrow. Just need to know where to look.

[Efratech]

found them pics