Porsche 901 five speed ratios Thursday, 20-Jul-2000 13:09:23 Message: 198.23.5.8 writes: A couple of people outside of this forum have asked me about ratios, and since I've never seen them mentioned here this post is for those contemplating the swap. ring/pinion = 4.428 1st 11/34 = 3.091 (13.689 ovrall) 5.50 mph 2nd 18/34 = 1.889 ( 8.366 ovrall) 9.06 mph 3rd 22/29 = 1.318 ( 5.837 ovrall) 12.93 mph 4th 25/26 = 1.040 ( 4.606 ovrall) 16.38 mph 5th 28/24 = 0.857 ( 3.795 ovrall) 19.89 mph 5th 29/23 = 0.793 ( 3.499 ovrall) 21.56 mph 29/23 is 911, 28/24 is 912, mph is approx. with 185x65 15" tires. george brown

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Re: Porsche 901 five speed ratios (Steve Arndt) (20-Jul-2000 13:18:42)

Gears (Steve Arndt) (20-Jul-2000 13:22:36)

It's been a long time but i think 1st and 2nd gear are not interchangable.Eric ballard says he can make em though !!! (n/t) (Mark Reilly) (21-Jul-2000 01:39:12)

Correct. 2nd gear is build onto the mainshaft. 915 transaxles have first on the mainshaft as I understand it. This is just from reading and I could have it basackwards. (n/t) (Steve Arndt) (21-Jul-2000 10:43:23)

Porsche 901 shift pattern is weird, 1st is where reverse is on a VW, then the "H" pattern for 2nd-5th (Chris) (20-Jul-2000 17:33:30)

When we first started driving,an h pattern was weird.After a few weeks it come 2nd nature,no problem.!! : ) (n/t) (Mark Reilly) (21-Jul-2000 01:35:32)

yes the gears can be changed around and i think it's 2nd thru 5th? (1st is different), they really arnt that tuff to do and you don't need a jig to set the forks, just be sure you measure the gasket between the carrier and housing, this comes in different thicknesses to set the pinion depth into ring gear, i've got a line on a 915 box (mo better shift pattern:-) (n/t) (Steve B) (21-Jul-2000 10:50:52)

What are the changes between the mounting of a 901 and a 915 box? Can you still use VW rear mouts on the bellhousing? Does your 901 front mount work with a 915? How much more frame horn clearancing and body dimpling vs. a 901? Shift rod in the same low spot as the 901? How did you seal the shiftrod into the pan, Steve? (n/t) (Steve Arndt) (21-Jul-2000 11:16:30)

I think the 915 is somewhat heavier than the 901, but you might be able to better customize ratios; the shift pattern doesn't matter to me. (n/t) (george brown) (21-Jul-2000 14:03:13)

More Info. . . . . (Steve Arndt) (21-Jul-2000 15:26:55

i can't recall but.. (Steve B) (21-Jul-2000 23:17:23)

I have the main shaft from the airport trans and all the gears spline on, I've heard some were like that for racing? been so long ago but i believe the stock trans used for gears did have a fixed 2nd on the main shaft.....getting old'' (n/t) (Steve B) (21-Jul-2000 23:35:40)

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Re: Porsche 901 five speed ratios

Thursday, 20-Jul-2000 16:18:42

207.70.63.165 writes:

Those are the gears that my 901 has. I have a factory speed vs. RPM chart if anyone needs it. Just the text in the table is helpful though.

Steve Arndt [email protected]

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Gears

Thursday, 20-Jul-2000 16:22:36

207.70.63.165 writes:

I haven't been inside a 901 before, but Mark R. has told me that it is possible to move 3rd 4th and 5th around however one wants. They are all similar gears. This gives you the option of buying a short third gear, using stock 3rd as new 4th, and of course stock 4th as new 5th. This is what Mark ran I believe. I might try doing this if I don't like the RPM drop from 2nd to 3rd. I have also found a source for QUAIFE style anti torque biasing Difs for these boxes.

Steve Arndt

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Porsche 901 shift pattern is weird, 1st is where reverse is on a VW, then the "H" pattern for 2nd-5th Thursday, 20-Jul-2000 17:33:30 172.139.248.183 writes: makes it great to drive at speed, but kinda weird to drive in traffic, the later(much larger) 915 box has the normal "H" pattern for 1st-4th then 5th is up on the far upper right........ Chris

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More Info. . . . . Friday, 21-Jul-2000 15:26:55 207.70.63.165 writes: The 915 uses a clutch motion which is backwards from the early 901 and the beetle. The 70 and 71 901 uses the same clutch motion as a 915. Not conducive to easy mounting in a beetle. The frame horns need more clearancing with a 915 versus 901 which is fairly sleek in the front portion, not bulky. Most people don’t like how the 915 shifts compared to a slick shifting performance pattern like the 901. There are plenty of parts available for the 901 so worrying about that is academic. Limited slips, short gears, syncros, bearings, seals, etc. are all available (for $). I have a decent source for good used 901s on the web, as well as Quaife style differentials. If anyone wants to know, you know whom to ask. http://netnow.micron.net/~motodad/vw/trans.htm Steve Arndt

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i can't recall but.. Saturday, 22-Jul-2000 02:17:23 207.16.24.84 writes: Steve A. sounds on top of this, I'll need to take a good look at the 915 box before going that way, maybe the 901 is the trans for a VW? i like the H & 5th pattern of the 915 vers the dogleg 1 & 2 of the early 901, I've gotten used to it and have no probs shifting but have missed 2nd and found reverse a couple times before and it isn't pretty. the nose cone/pan boot is from a 912 (someone asked?) and i had to weld rear mount bosses to the trans housing on mine but i've seen other 901's with rear mount bosses cast in the housing but not used?.....humm'' the 901 in my car came from a class 5 car that a couple german dudes brought from the fatherland to race the Baja500 back in the early 80's, the dudes blew a couple CV's and went back to germany leaving the car to be sold, a friend of mine picked it up to make a pre-runner out of and quickly decided a porsche 901/5 wasn't made for offroad, we put a 091 trans in the 5 car and i bought the 901 for my street car. the trans was fresh and had a ZF diff with some way to close 2nd thru 5th ratios, must have worked bitchen for pikes peak!! but on the street it was 1st-3rd-5th most of the time. I bought a stock 901 and swapped out 2nd thru 5th...much better!! what i have now is 4:42 r&p, 3.09 1st, 1.89 2nd, 1.32 3rd, 1.04 4th, and 0.89 5th....i think? works very well! I can't remember the ratios for the airport gears removed but it was stupid for the street. later guys Steve B

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Porsche 5 speed in a 64 Notch? Monday, 17-Jul-2000 01:57:08 63.224.135.44 writes: Has anyone out there ever installed a Porsche 5 speed in a street notchback; and if so, what modifications are necessary? Would it even be a good idea, or would I be better off with a VW tranny? Frenchys Son -Marc D- Marc Dehoux

Message thread:

Porsche 5 speed in a 64 Notch? (Marc Dehoux) (17-Jul-2000 01:57:08)

Re: Porsche 5 speed in a 64 Notch? (Terry in TN) (17-Jul-2000 08:25:19)

Re: Re: Porsche 5 speed in a 64 Notch? (Dave Buckholts) (17-Jul-2000 08:51:00)

Should fit no problem, same frame horns as a type1 plus there is a ton of room under their. I conteplated putting one in my 65 notch but went with a full out 4spd (n/t) (Bruce M) (17-Jul-2000 23:47:30)

It's definitly different on an early car and should be easier... (Dave Buckholts) (18-Jul-2000 07:47:57)

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It's definitly different on an early car and should be easier... Tuesday, 18-Jul-2000 07:47:57 167.196.190.144 writes: With the frame horns it is probably going to be very similar to installation in a bug. There are numerous articles on that install. You'll have to make some modifications but I don't believe that would cause you any grief. In my 69 Fastback it's gonna be a little more of a challenge. Took some pics last night of the brace that runs under the torsion housing...It is going to have to be cut to allow the shift rod to be placed correctly. Here's my site... http://www.geocities.com/MotorCity/Shop/1911/ Anyone done this to a late model car? (no frame horns) Later, Dave Buckholts Dave Buckholts

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'67 Porsche 901 five speed on Ebay Friday, 21-Jul-2000 13:59:44 Message: 198.23.5.73 writes: No idea what condition it's in but if anyone wants a rebuildable core it may be a good deal, and it's an aluminum (not magnesium) 901 - which I have been told is better/stronger. george brown

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I was told the later pressure cast mag is better than the early sand cast aluminum. ? (n/t) (Steve Arndt) (21-Jul-2000 14:06:54) Steve, I got my 901 from Mike (owner) of German Performance in Ft. Lauderdale. He told me to stay away from the magnesium cases because they don't have dimensional integrity, e.g., magnesium "creeps", and he said mag cases aren't as strong. His explanation was fairly detailed and convincing, and he could have sold me either one. (n/t) (21-Jul-2000 15:02:30) Which type of casting is a 1969 911 model? The finish is really ugly on mine, it will take a lot of work to get it pretty. (n/t) (Steve) (21-Jul-2000 15:14:46)

Steve, I haven't a clue as to when they changed from alum to mag, but your local Porsche dealer should be able to tell you (shop manual spec). My '73 911 Targa had a mag case and in '74 they went back to alum for strength, if I remember correctly. (n/t) (george brown) (21-Jul-2000 15:28:17)

My '73 911 Targa had a mag case and in '74 they went back to alum for strength, if I remember correctly. (n/t) (george brown) (21-Jul-2000 15:28:17)

Re: 901 aluminum 65-68, mag 69-71; 915 all mag from 72-86 (argh), G50 alum 87 on hallelujah! (n/t) (Tracy) (22-Jul-2000 09:01:55)

I have a 69 I was told, I guess I have the soft case. Which do you think is better Tracy, the pressure cast Mag or sand cast Aluminum 901? (n/t) (Steve Arndt) (22-Jul-2000 10:32:38)

Re: Doesn't really matter which one, but get the billet aluminum intermediate plate that Automotion sells, fixes the weak link. Also 915 changed to alum. in 78, sorry. (n/t) (22-Jul-2000 15:46:24)

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More on Porsche 901 with VW type1 Friday, 21-Jul-2000 16:21:02 198.23.5.73 writes: Steve, I read Michael Ghia's article on type 901 in a VW and noticed his concern about the starter shaft/gear operating range not allowing proper engagement with the ring gear. What about taking 4mm (.157") off of the starter mounting flange and 2mm (.079") off of the matching mounting surface (or some other combination of machining)? That shouldn't sigificantly weaken either part and should give enough engagement to work OK (he says it's about 7mm short). george brown

Here is a better solution. . . (Steve Arndt) (21-Jul-2000 16:42:58)

Autostick starter in 901 been working fine for 15 years now on big motor.. . . (n/t) (Steve B) (22-Jul-2000 02:24:44)

That is just what I had heard before. I'll stash my Autostick starter for when I need it. (n/t) (Steve Arndt) (22-Jul-2000 10:31:11)

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Here is a better solution. . . Friday, 21-Jul-2000 16:42:58 207.70.63.165 writes: Run a Type IV engine with a 914 flywheel. This gives the flywheel the depth needed. OK, I'll quit joking, I know most of you folks hate the big block. I know someone that had the face of the bell housing on the transaxle machined down. This is one way. Your idea would work too. Hey, doesn't the Type IV 210 and 215 flywheel have the outside diameter the same as a beetle 200? This means you could use a VW Autostock starter, or a 914 starter and it would work with your beetle. Right? Another way would be a KEP flywheel for the Type 1, 200mm, but deeper for the 901 trans. Mike Ghia says a 912 flywheel works. I don't see how, they don't have the offset SPG 8 dowel pattern like most folks run do they? Are 912s 4 or 8 dowel? (we are talking 912, not 912E). Steve Arndt