Gear boxes / transmission suggestions

hi guys,

For the past few months I've been amassing the parts I need to get my Chesil build rolling (less engine). I'm almost at the stage where I need to think about gearboxes (or transmissions as you Americans call them!) and I'd be grateful for your input. 

In terms of engine, I'm looking to put in a 1776 cc with between 80-100 bhp (dependent on the final set up). I won't be doing huge numbers of miles in the car and the driving will mostly be on more windy roads, but I don't want it to be too uncomfortable on the motorway at between 60-70. 

I so far can't decide between these options:

Rancho final drive 3.874:

https://www.vwheritage.com/113...ive-for-irs-vw-spare

and the more expensive 'Freeway Flyer' model (3.875):

https://www.vwheritage.com/ac3...final-drive-vw-spare

I know some of you guys have the Freeway Flyer model but would be interested to hear whether it's worth the extra money. 

Thanks,

John

Original Post

The first option will work well for your setup. The second (.83 4th gear) would probably not, as the gap between 3rd and 4th gear is too wide and the smaller engine would  struggle trying to pull in 4th gear.

VW also made a .89 4th gear which lowers the revs in 4th nominally (and opens the gap a little and that could work for you but I think the .93 is probably best for what you're intending for the car.

With normal wheels and tires, at 60 mph in 4th gear you'll be turning about 3000 rpm. 70 mph will be about 3500.

It's a little noisy and the revs feel a bit high to people used to modern cars but that's just about where these engines want to be.

The first trans you've linked is a late Beetle trans- VW went from .89 to the shorter .93 in 4th when the 3.88 ring & pinion was introduced (late 1972?) because the Beetle couldn't carry the taller gear, whereas the Karmann Ghia's better aerodynamics allowed it to keep the .89. Look at the side by side comparison of the 2 stock gearboxes below- 

 http://www.teammfactory.com/ca.../0/0/3600/3600/1/0/2

A Speedster is a lot like the Karmann Ghia in that it can carry the longer .89 in 4th, even with a 1600. This will be a fun, no hassles combo. Stay away from the "freeway flier"- as Ed has said, the .82 4th won't work, as even a 1776 is too small for the wider than stock spacing. Look below at the rpm drop when you shift from 3rd to 4th at 3500 rpm with the taller gear- a smaller engine doesn't have the torque to carry the car in this gear at this speed, and overheating the engine can result if you're not really, really careful. Guys here (and on the Samba) have reported that, even with  a 2 liter or bigger, the longer spacing with the .82 in 4th is just awkward. 

http://www.teammfactory.com/ca.../0/0/3600/3600/1/0/2

If you think the 1776 will stay in the car for a while, you'd like the car to be as zippy as possible when you're out and about and a high cruising speed isn't a big priority, consider going with a 4.125 r&p- it will make the car a little more fun at lower speeds. Input it into 1 of the gearsets with the .89 4th and see what it does. 

Hope this helps. Al 

@WOLFGANG said- "In looking at trans code charts it looks like all Karmann Ghias came with 3.875 R&P

The KG used the earlier ring & pinions (4.375 and 4.125)and switched to the longer gears at the same times as the Beetles did, as power and displacement went up, Greg. The gearsets in the earlier boxes are the same as the Beetle units until the switch to the 3.88, when the Beetle got the 0.93 4th and the Ghia kept the .89.

 

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