Another thing to note is that the 915 was originally designed for relatively low torque small displacement engines. Also, back then, maybe now Porsche tried to design to a spec to maintain low weight. Didn't one of the fellas once say that if they had known the 911 engine could have been expanded to the size it was he would have told the engineers to go back to the drawing board.

My point is, for another 50 or 100 pounds they could have made the 915 sturdier, but that was not the goal. The 930 is sturdier partly because it is only a 4 speed. I guess the main issue is that it took them too long to redesign, but that may have been due to the issues of the late 70's and 80's.

I like my 915 transmission. Its not as smooth as my BMW's shifter but it gives alot more feedback than the BMW transmission. I have to delay for less than a second between 1st and 2nd but otherwise its fine through the rest of the gears. I cannot race people from stop light to stop light in my 911 but I can have a blast with them on the curvey roads. In my opinion there is nothing easy about a 911. Thats why I like it. It is an art to drive a 911 well, but once youve got it, there is nothing else like it.

Redbeard,

I have been wondering and maybe you know the answer, on a 4 speed 901 tranmission is the first gear cantilivered the same way as in the 5 speed 901 ?

-Don

No. On a 4 speed, 1st gear is where we normally think of second.

5 Speed

R 2 4
1 3 5

4 Speed

R 1 3
() 2 4

James

Thanks for your replies. There are things that I absolutely like about my 915 equipped 911...namely the "feel" that you get from it. Very nice. So, in that sense...it fits the car well and adds to the experience.

The notchiness and bad synchros (at only 65,000) I can do without. So..Im taking the steps to rectify these things as best as possible.

James,

Do you think the 4 speed version of the 901 may be considered a slightly stronger transmission than a 901 5 speed since it doesn't have the cantilever weekness that I read so much about ?

Or does the loss of 1 gear spacing and less flexibility matching to engine speeds make it a moot point ?

-Don

I've had VW bugs which shifted better than my 915 does. People talk about treating it like a lady, being a surgeon, an artist, etc. Fact is you have to do those things or you'll wind up destroying it faster. Who EVER heard of a manual transmission needing a rebuild at 50k miles? At 100k miles? I've driven a stick shift all my life: Fords Mustang, Nissan 200sx, Mercedes 230, BMW 318, VWs, Suzuki Sidekick, etc. And all of these cars shifted like butter and were well over 100k miles. With sooo many wonderful things that came with the 911's, it's PATHETIC that the transmission is what it is.

Beepbeep, I think you're right on.

I doubt that there's a single person on this board who wouldnt like to be able to speed shift their 911 or downshift without double clutching. It's funny to see people defending the 915 like it's their child.

Ok--so what is the fix for the 915? or isnt there one? has anyone rebuilt or customized a 915 to shift better, smoother, easier?

G50

Yeah but you cant put a G50 in the pre 87 cars without a substantial mod...

Good question Jon T.

Ruf.

Well, I wrote to the factory and this is their response:

Herr Harry:

Thank you fer your inquirvey. We haft has dis question before und vee all know zat de Deusche design is zee best der ist. Yo foolshish amerikaners und speed shiftin desire is not vot der Porsche ist about.









:rolleyes:

:D

I've read taking mass out of the gears helps along with some beefier parts like billet bearing retainer plates and forced oil cooling. Jim

I've heard of taking mass out of the relatively heavy G50 gears. Do they do that for 915's also?
-Chris

"Do you think the 4 speed version of the 901 may be considered a slightly stronger transmission than a 901 5 speed since it doesn't have the cantilever weekness that I read so much about ? "

No. The weak points in the 901 are the side cover and the intermediate plate and both are thrust issues. And I think they start from oil starvation.

Lightening gears making it shift better????

I would stick to the basics - Replace shift bushing, align shift rod and shifter, adjust clutch, replace synchro's, dog teeth and sliders.

Oh, and unless someone has spent $3k on a tranny overhaul, there are still (replacable) used parts inside the case. Parts alone are about $2500. Just replacing the synchro's without dogteeth and sliders will only get you so far....

James

Actually i despise 915 so much that we opted for 4-speed 930 tranny in our project car, despite using four-banger engine.

Lightened gears have less inertia so the synchro system has to apply less force (torque) to match speeds and hence works better (and faster) and lasts longer.

Jim

I understand the concept, but I cannot believe that they would much, if any, effect.

James

This is more about economics than anything else. The 911s were selling without Porsche putting money into these improvements (what else explains the faulty door pocket design that lasted what, 20 years). When Porsche wanted to expand into other cars, i.e the 924/944 design, they had to make a superior product as they were not 911s. I had a chance to drive a 1987 924S the other day with close to 300,000 miles on the original engine and tranny and it shifted great - like my old 91 Nissan NX2000. I was shocked and said to the owner ' "You mean Porsche made a smooth sifting transmission like this in 1987?" I have a G50 1987 Coupe with a tranny in very good shape and the 924S shifted way better (oh, and the AC worked as well).

I think the 915 is a great thing - and mine needs more work.

Most people have no idea how to drive a "Sports Car", but they can drive a standard stick. This is a car that can damage itself. Speed shifts aren't a good idea, so learn how to drive it so you don't need to speed shift. This is a car that needs you to adapt to it - not vice versa. If you want a car to drive around you, I have a Civic commuter car that is great - with a little nitro will even compete with anything. I personally would rather not have a g50 - why bother with hydraulics, just not worth it for me.

Oh well - thats my .02$
Anthony