Going 5-speed, I think....

[boygenius]

After driving up to Toccoa I am begining to think that my car could really benifit from a 5th gear to aid in acceleration. After talking to a few people it looks like getting a 5th gear is cheaper than getting the extra hp needed to pull the 4-speed. I am going to most likely build a 2270 now after talking to Jake Raby and Len Hoffman. So what would be a good gear box for an engine like that.


1. 1978 to 1983 915 converted to a push type clutch.

2. 923 gearbox from a rare 1976 912E already designed for the type 4.

3. 901 (flipped 914) with 100mm drive flanges.


P.S. I will also have a new kennedy type 4 to type 1 adapter flywheel and built close ratio type 1 tranny with 100mm drive flanges for sale if I decide 100% to go ahead with the tranny swap. If anyone is interested in the above items the possable sale might motivate the swap. Just want to make sure I can sell what I have to pay for what I want.

[kdanie]

Porsche made each transmission with several different gear sets, the only way to tell what gears are really in the box is to disassemble it and count teeth. Not a fun prospect and not likely to happen as you are trying to buy a used trans.

The trans case has a code stamped on the bottom and that number will tell you what gear ratios were originally in the trans. Porsche printed little pocket guides that were great for this info.... Might be hard to find but you could get the number and call/visit a dealer service or parts dept. they should be able to help.

There was even a 901 with a 1-1 5th gear.... great for racing but not for crusing unless you change the final drive too. If you stumble onto one of those grab it, you can sell it and buy at least 2 other "normal" trans...

ken

[boygenius]

Thanks for the reply Kdanie...


Anybody have any opinions here.
What letter codes for the gears would work good for a 2270cc type 4.
I might have a buyer for my tranny so that would pay for the 5 speed....

Should I keep my kennedy type 4 to type 1 flywheel or get a 215 mm 914 flywheel.?

[kdanie]

For an early Porsche 901/902 5 speed you need the 914 flywheel/clutch. For a 915 trans you need a special flywheel/clutch or convert your release bearing to the early style.
ken

[boygenius]

What is the difference between the 901 and the 902 transmission.?

[kdanie]

I have a 902, it's from a '69 912. I think the only difference is the gear ratios, which I think are a little low for the torque of a type 4.

ken

[yetibone]

I had read that the 914-4/901's were all geared the same, however I'd been told different Go figure on that one, LOL.

Mine's from a '72 914-4.

I believe that as long as it came from a 914-4 your ratios will be fine for your torque range.

[boygenius]

I think I will be cutting my chassis up again for the 5-speed.


I just can't stop myself.

[Michael Ghia]

The 915 clutch setup is so easy to copy onto your Bug that I'd not bother modifiying the gearbox...
The flywheel on a 915 matched 911 engine is a flat plate with holes drilled and tapped for the clutch. The clutch pressure plate goes on first and then the ring-gear bolts on the outside... just make sure you have the distance correct from clutch plate surface to startmotor.. should just be a case of machining a Beetle flywheel down.

The 914 and 901 gearboxes have different ratios as does the 902.
The 914 has a higher 5th gear (as the 4 cyl engine doesn't rev as much)
The 902 box has an X (28:24) or U (26:25) 5th gear
The 901's have any of the following: O (23:28), S (27:26), V (27:25), Y (28:23) or Z (29:23).
The 901 and 902 ratios I have given are only up to '68 when the pull type clutch took over.
I don't have my 914 ratio book to hand... sorry.

MG

[boygenius]

Hey thanks for the input Michael, I'll have to do some research and find the best gear ratios for my bug. I'm leaning toward just using the stock 914 ratios but wonder if they would be too tall for a 2270cc type 4 in a bug. Although I do like to cruise at around 80mph to 90mph on the highway.

[yetibone]

I believe you'll be fine with stock ratios. You should be pulling a little less weight down the road in a Bug, so the torque will still be good. A 2270 will make more torque than a 2.0 anyway, so the tall stock ratios will be better.

You'll only see 5th gear on the highway above 60 anyway.

[boygenius]

I found these ratios for the 1.7 liter 914 on the web. I hope they are correct.
1st. 3.09 :1
2nd. 1.89 :1
3rd. 1.26 :1
4th. 0.93 :1
5th. 0.71 :1
Final is 4.43 :1

[boygenius]

Will a VW shift coupler work with the 901 input shaft or do I need the 911 unit.

[yetibone]

Should work. The selector shafts are equal diameter.

[boygenius]

Originally Posted by yetibone

Should work. The selector shafts are equal diameter.

I thought so since pelican parts sells a tranny gear selector tool for the 901 that is made by Bugpack. hmmm. Well one less part to buy. :agree:


I got an idea for a bolt in 901 conversion shift linkage assembly that I will be working on once I get all the parts.