Highway flyer trans, question!

[NextGen]

Actually Mikey is one of those guys you find hard to dislike when talking to him. But he sure gave me the run around.

Joe

[aircooledtechguy]

As was hinted at on the final posts... The noise difference is due to the teeth count AND the tooth pitch.

Lest everyone forget that you have a huge squirl fan pointed about 4 feet from your back with a trumpet style opening that makes a good share of the noise from the engine/drivetrain. Higher speeds causes a LOT more noise. I would be more apt top believe that the noise difference between bad bearings in an old tranny and new bearings would cause WAY more noise than course/early and finer late style gears. The old trannys are not noisy unless they have a bearing going bad.

I had the reduction box bearings go bad on me last summer and I couldn't believe how quiet my bus was once I replaced them. It's a noise that sneaks up on you throughout years and then suddenly it's gone.

It's very likely that Joe's old tranny HAD bad bearings which makes the new trans seem extra quiet. Couple that with the lower engine speeds and it's a night and day difference like Joe has said.

[KDF Lad]

This graph shows the comparison between the 2. The taller geared one is the SSC 'box.

[NextGen]

Guys is amazing how the posts change like playing the game telephone.

The noise level was from the sound of the engine at a high RPM. THe change in sound was from a drop in RPM. I guess higher or lower may not make a difference in decibel rating but you can feel and hear the difference between a higher or lower rpm.

No it was not trans noise. And yes bearing noise creeps up on you till you realize you are blasting the radio so you can hear a weather report..

Joe

[Plastermaster]

Joe, Minds are like pots. There are 3 kinds. One is upside down, so nothing can be put into it. Some pots have holes so things leak out. And, some pots aready have something in them so when you add something else it all gets mixed up.

I know you have posted more than once on this thread that the noise level you experienced dropping is from the engine, and that the tach shows a 500 RPM drop. I believe you. I think you have a very tall final drive that we are not sure exactly what it is.

Ron

[NextGen]

Ron,
You forgot the other other Pot. That does something to your mind also,ha.

Actually you guys are great, I guess we won't be here if we really didn't dig in.

Yep tall gear. I didn't give enough info to go with to come to a conclusion and I can't unless I strip the trans. It is what it is, but as aways we all came away with a bit more knowledge about trannys.

Joe

[Bobby74]

When you use a generic term like "noise" to compare 2 transmissions, of course I was thinking transmission noise, not engine noise.

Engine noise is pretty easy to hear...compared to the whine of an early geaset.

VW wouldn't waste all that time and money designing a new transmission for it to make the same amount of sound and weaken the design in the process....if they didn't think it was worth it.

I am having a custom tranny built and I have been in contact with my trans builder about this subject quite a bit. He assured me that the early gearset will make more noise, with the benefit of being a LOT stronger than a early model 3rd and 4th. There's also a 4-bolt bearing retainer type case and the single nut type. That also makes a difference in sound, along with how the gears are carried.

Without jacking up one tire and counting the revolutions vs engine revolutions....you will have no idea what your gear ratios are. All tires have a different circumference, so you can't go off of tire size when making your calculations... chances are you have a 4.12 R&P with a .82 4th or a 3.88 R&P with a .89 4th.

[Bruce2]

74 trans, welded 3rd and 4th gears.

Also said he was going to use some early gears because they had less teeth and were stronger. What and where they were I don't remember.

There is your answer. All Beetle SSCs had gears that were factory furnace brazed. It is not possible to weld them. Thus the gears had to be changed. Since you said they were early gears (that must be welded), it had to be either a .89 4th or a .82 Bus 4th gear. Since you said your speed increased from 60 to 70 at 3k, you have the Bus .82.

Here's some more math:

stock AH 4.12 x .89 = 3.67:1
your SSC 3.88 x .82 = 3.18:1

The difference is 3.67/3.18 = .866, or 15.5%
If you took your original speed (60mph) and increased it by 15.5%, you'd have precisely 69.3mph, pretty close to the 70mph you observed.
Math is your friend.

[NextGen]

Wow the next step would have been me giving you a DNA sample.
Nice work Bruce, that has got to be it.

Math has never been my friend but I am glad it is yours.

My car is blocked by 3 feet of snow so I was really going nuts trying to see if I was going crazy or not. I was starting to doubt myself.

Joe

[A_67vdub]

Math has never been my friend....

You have a Mechanical Engineering degree?????




Steve

[NextGen]

Yep just because you have a Mechanical Engineering degree means you like math. Some industries use very little math for their engineering. Everything is computerized in my business. No more slide rules.

Years ago I did major prints by hand using many different pencils and drafting tools, like Tee squares and curves. Someone would look at my work and say, Joe Cali made that. Now with CAD the flare is gone, you are no longer an artist.. Not saying that CAD is bad, actually it is 100 times better then using pencils, I just feel the art is gone.

95% of what I do is pushing papers and buttons. That's why I have a garage full of machines and love to get my hands dirty. Create and step back when it is done and say nice job.
Work on the other hand never ends.

When you work for a major company you are like one pixel in a 5 meg pixel photo. Remove the one pixel and guess what --- The picture is still there nice and clear.
Joe

[A_67vdub]

True.

I hope you don't think I was bagging on you, I was just surprized to hear you say that. I work at an engineering firm myself. I never completed my ME degree, but I got an AA. I use CAD every day, but I still use alot of math.

That had to be a hellofa tough degree to get not liking math, though.



Steve

[raygreenwood]

Design is what I do and am trained for. Most of the practicing designers I know (Architecture, interior arch, landscape, product design, graphic)....who are actually good....not just functional, but produce well thought out designs....ALL use paper and pencil (and many combinations of that)...to first finish the IDEA and get te visual. CAD cannot do that with the speed and ease of thought process. It also cannot render color "thought processes" as well and cannot produce multiple point, gridless perspective in the ideating process and conceptual phase....like the mark 1 univac "pink' series (brain , hands...eyeballs ). They then move to CAD for presentability and speed of modification..
About 15 years ago, there was a huge movement in the design based industries to "break" designers of the habit of using manual methods.
It was a speed versus money issue in many design studio management types. It worked....both goodly and badly. First off....many more learned cad and it really helped in a lot of areas. But...the designs themselves suffered. Mostly architectural suffered. Too many buildings were built to what the rendering systems were capable of. And they look and "feel" like it. A lot of late 80's and early 90's architecture is like this. Some of the automotive suffered the same fate...mainly in the small "textural" details...like interiors and tactile functions. The auto body forms themselves...did quite well....as they are still....first modelled in clay, to get a "feel" for the shape in 3-dimensional space, after the original concept drawings, no matter what they are drawn with. The CAD then enables the car companies to get the design on the road faster and cheaper, and make next years changes...even before this years production hits the road.
The "only on CAD" trend.....had died among the better design companies. Its getting common again to see work stations with a CAD system taking up the desk area...and a drafting/drawing table right behind it. My Architectural buddies laugh...because the twenty something interns they get say...."deeeewd...whose museum is this"?...when they see the drafting table. They quickly learn two things. (1) The better designers always start with sketches and paper (2) They were not taught how to draw in their schools...well enough to compete.
The schools in the past five years have been franticly adding the advanced drawing classes back in...that they took out in the early 90's.
What comes around goes around. Don't be afraid of paper and pencil....like math...it is your friend. Sorry for the length and the off topic. Ray

[NextGen]

Steve no problem, and Ray I could not agree more. I did not know about schools going back to teach pencil and paper. Don?t forget to spin the pencil to keep it sharp and find your own style. Oh and keep the sand paper handy for sharpening.

By the way I like the Arm to work fast but it took too much room and went out of parallel too fast. So I used the rolling parallel Tee with the string and rollers.

For me the big advantage of CAD was you only drew something once. If I need a elevator machine I just go to my library.

Steve a lesson in life I have found, you may get a degree in Electronic Engineering and study the latest cutting edge electronics but seldom do you ever use every thing you studied.

Elevators, really how much can you do for something that only goes 1800 fpm tops. My watch has more memory then is needed in an elevator system. Yet we have high paid Engineers that never use 80% of what they learned in school. Sometimes when they think about It and they actually get depressed.

But they would not be making the money if they did not have the degree.

[raygreenwood]

Nextgen...you hit on the very reason why engineering has not suffered from CAD...but design has (two very different but interconnected things). If something works and you know the parameters of it, library it and use it again in CAD...instead of re-inventing the wheel each day. Unfortunately, that does not work as well in pure design, or product design or architeture. The act of studying a previously produced design, and re-rendering it in basic design study sketches leads to new styles and ways to use and shape an item. CAD rnders it the same way each time. Nothing new is added unless you purposely import it. Design can stay mechanically sound this way yes...but can also become quickly outdated if the reference isn't resdesigned or retested. Ray