020 six speed... is it worth it?

[kane66]

I was cruising craigslist and stumbled across this add

1983 VW GTI VL Enterprises 6 Speed Transmission Almost New
$ 1,800.00

does anyone know the gear ratios in this transmission. Would the final drive be larger than the stock 020 in my 85 jetta.

[burn_your_money]

That's not stock (as far as I know)

There were a couple companies selling conversion kits to convert the 5 speed 020 into 6 speeds. The problem is that the 5 speed is already a 4 speed converted to 5 speed, so adding another gear on the end gets kind of dicey

[kane66]

After some searching I found the conversion kit was provided by a company called VL Enterprises in Hillsborough Oregon. They don't make it any more. The price seems really expensive for transmission... but if the final drive gear was another step up from my stock transmission I could get closer to 1800 rps @ 65 mph on the highway (which is the most fuel efficient rpms)

[burn_your_money]

Who says 1800 is the magic RPM?

[cyrus #1]

If I was going to shell out $1800 on a transaxle, it would be going towards an O2A conversion.  You should be able to get decent ratios and replacement parts are still available.

[kane66]

I did some research a while back. The gist is that at 1800 rpms the 1.6 vw diesel engine uses 264 g/kwh of work.
so......
1hp=.75kw
diesel weighs between 820-950 g/l ~ 885 g/l
1 l=3.79 gl
so if at 1800 rpms it uses 264 g/kwh
885/264=3.35 kwh/l
3.35/.75= 4.46 hp/l
4.46*3.79= 16.92 hp/gal

for every 16.92 hp the engine produces at 1800 rpms it uses 1 gal. of fuel.

I'm trying to make my car more fuel efficient, and short of reducing the amount of energy it needs to travel @ highway speed,and there's not a lot I can do besides try and approach optimum engine performance at the speed I most often travel. (55 65 mph. I would like to gear my car to run @ 1800 rpms in the highest gear. I could increase the tire size until I get there but that reduces the performance in the other gears... But if I could get a transmission with a higher final drive ratio then I could maintain performance in the lower 5 and use the 6th overdrive gear for highway cruising.

[kane66]

I knew someone posted the graph on hear. The original thread we were discussing it in was.
http://vwdiesel.net/phpBB/viewtopic.php?t=15250&highlight=264++kwh

[jtanguay]

don't forget though, that at 1800 rpm a stock 1.6TD will have very bad acceleration.  so with the gearing required to produce 1800 rpm's @ 65 mph, to go any faster, or to hit a hill, you must downshift to 4th (or 5th on a 6 speed box)  if you didn't downshift, you would be putting a lot of stress on the motor, excess soot out the tailpipe and in the oil and high egt's!

now... change the turbo to a nice small K03 or even VNT-15 (for some of that cutting edge technology)  and you should be able to hold 1800 rpm in 5th/6th gear no problem! with the right fueling of course  

but don't forget that the fuel graph will change with the smaller turbo, but it will still use less fuel than a stock 1.6TD if you use lower rpm's.