Freeway Flier???

[richtrek]

I have seen ads in VW mags for a "Freeway Flier" transmission. Would putting one of these in my 74 Thing provide a more "Bug-like" performance, and better mileage?

Thanks.

[Bruce]

No. The reason your car is slower than a Bug on the highway is that it is an aerodynamic brick.
Taller gearing will make your mileage worse, not better.
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[klokard]

Bruce, this topic has been kicked in the teeth many times. I personally have the data to back up what I claim here. During my pan off restoration of my 181, I had Super Beetle gearing put in my 181. No change in the R&P. My mileage increased by almost 2 MPG and my oil temp was reduced as well. I now can cruise on the FWY at 65 MPH and keep the oil temp below the pre set point of my Gene Berg oil temp dip stick. This was not possible before with stock gearing.

[uberautowerks]

- - - Install one or don't, but DO NOT be fooled into buying a "Freeway flyer". A late model Beetle trans IS a freeway flyer. Also the late Beetle trans mostley drops right into a Thing. You have to change the nose cone and the drive flanges.
_________________
--- The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair.
- Douglas Adams -
---
'74 Thing (White)
'71 Single cab (White too)
'70 Weekender (White three)
'05 Evolution VIII (White also!!!)
'68 F-250 (White over black)

[Pierre G]

A Thing trans is already a "freeway flyer" as it has 4.12 ring and pinion. On some late IRS trans in super beetles you could find what is considered "freeway flyer" today : the 3.88 R&P. Most of the early bugs (swingaxle or IRS) had 4.37 R&P. So a 4.12 is sort of a "freeway flyer". This combo works very well with a Thing, as you need short 1st and 2nd gear if you wish to go a little bit off road, but the 4.12 is still very driveable on freeways. Don't forget that the early 181's made in Germany had 3.88 R&P on swingaxle trans BUT with the reduction boxes !! Top speed on freeways was then really slow compared to the IRS without RGB's. I had several of these, top speed in 4th : 55-60 mph !

Pierre
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1976 181/Thing, 1967 fastback, 1973 squareback, 1964 microbus, 1967 Double Cab, 1969 westfalia (currently under resto), 1972 LM1C dune buggy, 1974 jean's bug, 1974 1303 (super beetle, currently under reassembly after new paint).

[uberautowerks]

Just FYI, USA spec "Things" had a R&P of 4.125 and the late Beetles had a R&P of 4.375.
_________________
--- The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair.
- Douglas Adams -
---
'74 Thing (White)
'71 Single cab (White too)
'70 Weekender (White three)
'05 Evolution VIII (White also!!!)
'68 F-250 (White over black)

[Towel Rail]

[uberautowerks]

sorry, my bad, wrong line in the book and it should be the final drive ratio listed above
. . . 4.375 (to 1) was only for the 1970 Beetles
. . . while 1973 and later Beetles had a final drive ratio of 3.875 (to 1)
. . . and '73 '74 USA spec Things had a final drive ratio of 4.125 (to 1)

Better?
_________________
--- The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair.
- Douglas Adams -
---
'74 Thing (White)
'71 Single cab (White too)
'70 Weekender (White three)
'05 Evolution VIII (White also!!!)
'68 F-250 (White over black)

[Bruce]

[Towel Rail]

[uberautowerks]

funny, the Orange Bentley disagrees with you. Just so we're clear the size of the R&P is NOT the final drive ratio in forth, the ratio @ forth gear comes into play and VW changed forth gear from time to time.
_________________
--- The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair.
- Douglas Adams -
---
'74 Thing (White)
'71 Single cab (White too)
'70 Weekender (White three)
'05 Evolution VIII (White also!!!)
'68 F-250 (White over black)

[Towel Rail]

[Bruce]

[uberautowerks]

That's what I get for reading, and not doing
I refuse to open VW transmissions, it helps that my local re-builder is VW only and awesome
I'm aware that the bently's don't cover 181's, I thought we were talking about Beetle trannys
And I did say 181's had a 4.125
_________________
--- The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair.
- Douglas Adams -
---
'74 Thing (White)
'71 Single cab (White too)
'70 Weekender (White three)
'05 Evolution VIII (White also!!!)
'68 F-250 (White over black)

[Pierre G]

[richtrek]

You guys know too much!!!! I wish there were more Thing owners in the area to learn hands-on from.

So, on my 74 Thing what is the likely gear ratio? Could it be identified by the Things' serial number? I believe it is stock. Would there be an upgrade that could produce better hwy mileage?

Thanks,

Rich

[Bruce]

Rich, crawl under your car and have a look at the trans code. Here it is:

http://www.thesamba.com/vw/forum/viewtopic.php?t=248742

Originally the code should be AV. This means you got a 4.12 R&P with:
3.78
2.06
1.26
.93

VW isn't stupid when they pick gears. Lots of testing is done. Since your car is an economy car, if they could have gotten better mileage with a simple gear change, VW would have built it that way. Taller gears slow down the cooling fan. Compared to a Beetle, your Thing must make more hp to push it through the air on the freeway. By gearing it slighty shorter, the cooling fan is a bit higher, so it can cool better.
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[Pierre G]

[Bruce]

I have never liked the 3.88 in any VW. For years I used to switch from one car with a 3.88 to another with a 4.12 and always, the 4.12 was nicer to drive.
If you must have taller gearing, I recommend a .89 4th gear. To drop in a .89 to a SSC AV Type 181 gearbox, you must get it from a 1975 Bus gearbox. (BTW, the .82 4th gear only came in Bus gearboxes, never a Type 3) The gap between a stock 1.26 3rd gear and a .89 will not be intolerable since VW built plenty of cars with that combination. A 1.26 3rd and .82 4th will make for a pretty big gap.
If you had a bigger than stock engine (c. 100hp), then I would recommend the .89 4th gear. This is what Greg at German Motor Works does so his customers can keep up to traffic in So Cal. But with a stock engine, the taller gear increases the load on the engine. If you have lots of hills where you live, the stock .93 is the way to go.

There is always a trade-off when you go with taller gears. Acceleration gets slower, hill climbing ability gets worse. Since the load on the engine is increased, it will run hotter. You should be able to cruise comfortably at 60-70 mph (100-115km/h) with no problems with stock gears. How much faster do you need to go?
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[Pierre G]