70' 911T coupe with 915?

[hotdogwater]

We just bought a beautiful 1970' 911T coupe that I plan to restore. The car is pretty clean minus some light rust here and there and a battery area needing some help.

I will probably start a separate build/resto thread eventually but I found something a little off and wanted to hear from the experts.

The transmission seems to be a 915 or at least the shift knob/pattern is. I don't see the same pattern as our 74 914 has which I know has a 901 with R being top left above 1st. The 911 has a more typical 1 on top left pattern and R being bottom right which I understand is the 915. Would it be common to upgrade the transaxle on a DD if you had issues with the 901? Should I try to source a 901 though I'm undecided which way I want to take this car build. I have a backup 901 for our 914 racecar but it's side shift not tail shift.

From what I read. the 901 or the Sportmatic were the only transmissions available on the 1970 911T. Does this sound like a swap may have taken place sometime after the car was shipped? I have no service history on this car and I am sending off for the Porsche COA but I was curious if there was an option for the 915 in 70'? Probably not an original so now I wonder if the motor is original.

[911s55]

The 915 was available starting in '72, who knows what your COA will say.

[Peter Zimmermann]

Car was probably a Sporto, and was modified when the original trans became to costly to repair. Check your intake manifolds for extra vacuum sources, and look at the forward, vertical bulkhead of the engine compartment - is there evidence of a large vacuum canister that might have been there? The cannister was almost flat, and measured about 8" by 20" (this is a best, minds-eye guess - I haven't actually seen/touched one in more than 25 years), and mounted near the middle of the bulkhead. Also, check your front brake calipers - are they aluminum "S" type calipers?

EDIT: Post the serial # & type for the 915 and we'll run it down for you...

[Trackrash]

A 915 is a common upgrade for the 70-71 cars, especially those with sportos.

I believe there would also be extra fittings on the oil tank for the sporto trans.

BTW, I have a 901/911 trans sitting in my basement, if you are interested.

As Peter stated, post the engine and trans numbers.

[Peter Zimmermann]

Originally Posted by Trackrash

A 915 is a common upgrade for the 70-71 cars, especially those with sportos.

I believe there would also be extra fittings on the oil tank for the sporto trans.

BTW, I have a 901/911 trans sitting in my basement, if you are interested.

As Peter stated, post the engine and trans numbers.

Dang! I knew I was forgetting to mention something !

[hotdogwater]

Originally Posted by Peter Zimmermann

Car was probably a Sporto, and was modified when the original trans became to costly to repair. Check your intake manifolds for extra vacuum sources, and look at the forward, vertical bulkhead of the engine compartment - is there evidence of a large vacuum canister that might have been there? The cannister was almost flat, and measured about 8" by 20" (this is a best, minds-eye guess - I haven't actually seen/touched one in more than 25 years), and mounted near the middle of the bulkhead. Also, check your front brake calipers - are they aluminum "S" type calipers?

I'm new to this so forgive my dumb questions but Sporto would be a Sportmatic transaxle?
Checked front calipers, magnet sticks so not AL. Their is an open area in front of air box/plenum but nothing that looks like something was taking up space. Not sure if I would know what extra vacuum lines would be on the intake manifolds but there are some hard/soft lines that go from something on carb to the intake man on both sides of the zenith carbs.

Haven't been underneath yet so I don't have have trans # but engine # is 6106700

Oh yea I took a pic. Like this

[fb111]

35 years ago my 70 911S received the stronger 915 gearbox.

[hotdogwater]

Now Porsche is saying since Fax won't answer, the email the COA information. Not too keen on sending my credit card info via email to someone. Anyone know how I can get the COA or just the info from the COA.

[Peter Zimmermann]

I don't see any left over Sportomatic gear in your picture. It would help if you could remove your air filter housing and snap a picture of the bulkhead in the forward area of the engine compartment.

You need to have the car raised to read the trans number/type - if it's really a 915 the numbers will be stamped on a rectangular "boss" near the trans oil drain plug.

[RichardNew]

Don't trust the COA. They're filled with mistakes. Plus, a lot of people are calling Porsche and getting them changed. You can literally create your own PCNA COA.

I got mine directly from Germany. I'm not sure you can do that anymore.



Richard Newton
Historic Racing Images

[Matt Monson]

If it ain't broke don't fix it, yet. A '70 would not ever have left the factory with a 915. If it runs and drives fine now just keep using it.

When the day comes that it requires a rebuild, then ponder the question of going to a 911 type (901 based gearbox but not the same thing. Magnesium and way different gearing. Most similar to a 914 gearbox) to make the car more correct or not.
Some of us like the dog leg shift pattern and lighter shifting of the 901/911/914 family of gearboxes. Others are 915 diehards. On a stock 911t 2.2l the strength difference between the two is pretty inconsequential. If you go hot rod with the car, once you are up over 200hp or so the argument for the 915 becomes a lot more relavent.

[hotdogwater]

Yup, it's a 915 all right. Thanks for the heads up on the location and info guys. I would like to know what the car had originally but not willing to give some crook my credit card info to get it just yet. Trying to determine if we had some rare car before I started tearing into it to make it my own or if I needed to keep it original. Think I have my answer. I don't think I mind the 915, just wanted to know what the story is/was. Good point Matt, I don't plan on making any major changes yet, just want to get this thing running and have some fun first and decide where to go. I have lots of stuff to work on, just trying to get a plan. Service motor, clean fuel system and check compression. Overhaul brakes and check suspension then maybe I will get to drive my first 911.

Here is the engine bay pic sans air filter housing.