3:88 or stock (4:12?)

I had a 2110cc with 3:44 final drive and I did 70mph at 3100, others will have to chime with that engine and tranny combo, but 3K Rpm is the sweet spot you want to be at for your normal driving for me that is about 70mph. 

Caretech, thanks for chiming-in! 70 is just too fast for our driving around here. I know we'll be driving in more urban settings but like I said earlier, our freeway speed is 61-62, we're old folks on a perennial Sunday drive!

Will

Will, Well nothing like asking how the freeway flyer will be at 60mph, I actually find myself driving slower at times with my roadster too Ray 

I have a VS with standard tranny. 1600 cc Super twin carbs, doing 3K rpm at 60 mph and it runs nice and cool. It has an external oil cooler as well. Good engine speed. I don't go much faster than 65 anyways.

I've got a 3.88 R&P with standard gearing and I'm at 60mph at 3000 rpms in 4th.  With standard gearing you will be over 3000 rpms at 60 with a 4.12.  If you are getting a 60 hp 1600 cc engine a 4.12 might be the way to go.  Think you'd be much happier with a bit more grunt...say a 1915 cc bolted to a 3.88 R&P.  My 2 cents.  I'd actually like to have 180 hp and a 3.44.  Now I'm just being greedy.

If you really never see yourself doing more than 60-65mph then get the 4.125 ring & pinioned transaxle with the stock .89 beetle 4th gear. The 4.125 r&p came in the 1500 and early 1600cc bugs and the 3.88 came with the later 1600 bugs and karmann ghia's. The .89 is the most common 4th, being in all beetles until they were equipped with the longer 3.88 r&p which at that time they switched the 4th to the slightly shorter .93 (from the .89, which a 1600 can't pull and ends up overheating). The Karmann Ghia, with it's superior aerodynamics, kept the .89 with the 3.88.

 

The longer .82 4th (which some people use, especially in a 5speed) is out of a bus. Some have tried it in 4 speed tansaxles (there are people here- I believe RonO and maybe Stan?) but it makes the 3-4 split too long, and it feels awkward even with a > than 2 liter engine. Al

Bought my VS new in 2006 with 1915 and 3.88.  Money well spent, even for an old guy that didn't think he needed it.  If you want to save money, leave out the stereo.  I have one and have used it once in 9 years.  Get the external oil cooler, battery shut-off and tire upgrade if your budget has room. 

 

Will:

 

I think you've already answered your own question, but running a 1600 - 1815 engine, use a 4:12/.89 transaxle.  Otherwise, you'll be really working on hills to keep up with traffic, even at 60-65mph.  That combo will plant your rpms right in the cooling sweet spot and I think you'll like it.

 

If you up to a 1915-2276, you can opt for the 3:88/.89 or 3:88/.82 rear combo and the engine will have enough grunt to keep up on hills, but will be turning slower so you have to watch engine temps more closely.

 

I would not opt for the 3:44 unless I was running a 5-speed and could really take advantage of it with a custom gear-to-gear spread.

 

gn

Steven,Yorkie, ALB, Tom and Gordon, thanks so much for your thoughtful and informative replies! I think based on my ride this morning in a 4:12 VS speedster and knowing our driving habits, that the 3:88 with or without a big motor Will simply be lugged-to-death at our pedestrian highway pace.

I purchased a Vespa 5 years ago for our wonderful back-roads here on the Central Coast where 45 mph is plenty fast enough for us. Yes, it will take us down 101 all day at 65-70, but why?

I'm sure there may be occasions when a bit more top-end would be nice, but I think the low-end torque and general driveability will more than offset those.

Again, I appreciate all of your responses and thought, youI've helped me make yet another decision as Kathy and I embark on this new adventure!

Will

Hey Will, please tell Eddie that Terry said hi

Terry, will do!

Looks like a 4:12 R&P will suit your needs.  Do you know what Eddie's 4th gear is?

 

Here's some gear ratios to ponder over, using a 185/65-15 tire:

 

4.12 r & p with a .89 4th

speed at 3000 rpm: 60 mph

 

4.12 r & p with a .82 4th

speed at 3000 rpm: 65 mph

 

3.88 r & p with a 89 4th

speed at 3000 rpm:  63 mph

 

3.88 r & p with a .82 4th

speed at 3000 rpm:  69 mph

this combo is not recommended, because of the huge gap between 3rd and 4th gear.

Will- Just call me Al (come on; you know the tune...).

Ron, thanks for that great chart! I'll ask Eddie tomorrow but he said he's turning 3,000 rpm at 60 mph so probably the .89.

Al, Will do, thanks!

The 3.88 with a .89 4th might be a better choice if you're running a mild to high horse power engine.  The 3000 rpm speeds, between a 3.88/.89 and 4.12/.89,  are very close but the 3.88 R&P will spread out your 1st, 2nd, and 3rd a bit more than a 4.12.  Great for an engine with some torque, but not so good for a 1600cc.

If the power plant is in the 1600 to 1776cc range I'd stick with the 4.12/89.

 

Will, you might do best with the stock 4.125. If you ever have to go up the Nacimento Furgeson Highway you'll be glad you did. We drove right past your place in 2011 while heading South from Monterey, there was a landslide that blocked off US1 near Big Sur. Our destination was Morrow Bay so up that hill we went and came out near Fort Leggat Hunter.

 

Either in your town or Pasa Robles there was a Spanish Lady on a corner cooking BBQ chicken. I can still remember that fantastic smell like it was yesterday. Man, where'd the time go, eh ?

It sounds like the 4.12 will suit your needs but I would bump my tire size to 25 inches.  The highway ride will be much better. 185/70 15 would be great but that tire size is not cheap. If you are just tooling around town you can get skinner 165/80 15s.

This whole "Freeway Flyer" thing is often misleading.  It should go beyond just a 3.88 R&P. While the 4.125 R&P is just fine for stock/near stock engine, Freeway Flyer's usually include a refurbished transaxle with a high strength billet aluminum side plate (1), hardened keys, and welded 3-4 gears, super diff, heavy duty shift forks plus often a 5 year warranty (Rancho). Is the alternative is a used 40 year old (non-refurbished) 4.125 with no warranty (or a limited 1 year warranty)?

I agree with all that Greg said above and would add though, I've just put 50,000 miles on my car since late 2010 and most of that with a stock VW 4.125 gearbox mated to a homebuilt Subaru 2.2l engine probably pulling about 115-120 hp out of a possible 137 as advertised new. No problems. I don't drive it hard. Mostly just cruising around town and long distance travel.

The "Freeway Flier" moniker was invented by a company called Transform (big, splashy full page ads in Hot VW's and surprise surprise, not around any more) in the late '80's(?) and the whole idea was (I believe) in response to the Berg 5 speed. IIrc all they did was switch out the stock .89 4th gear for a bus .82. It didn't really work all that well, as it took a larger than 2 liter engine's torque to cover the increased 3-4 spacing. Now, instead of a 3500rpm shift from 3rd dropping to about 2400 in 4th (and the fan moving enough air to cool the engine when it's under power) it went down to about 2200, and a stock engine can't push a beetle in 4th at that engine speed and spin the fan fast enough to proplerly cool itself. Even with a larger engine's torque (and less demands on the cooling system at lower rpm's), guys here report the increased spacing "awkward" and at least a couple have returned to the stock beetle 4th.

 

I was posed this question in another discussion- Why spend extra money (almost $1,000) if I don't generally drive it that hard? 

My answer- Although the VW transaxle seems to be a pretty tough little unit and if driven somewhat conservatively will last a long time even with a somewhat more powerful engine, all it takes is one moment of fun to scramble the thing badly enough that even the case is scrap, and not only are you rebuilding the thing again but you're also needing to now source another core. I'm sure some of the more astute members of this esteemed crowd will guess how I've come by this knowledge, and yes (as usual), I was much younger, and there was beer involved...

 

 

"...I was much younger, and there was much beer involved"

 

     Ahhh...nostalgic memories!!!