901 Transmission Questions.
08-25-2003, 11:30 PM
#1
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901 Transmission Questions.
If you'll [ardon me while I step into your air cooled world for a moment of...air....
Anyway, I like the "racing pattern" transmissions that Porsche designed. I have learned to shift them with my hands tied behind my back and my legs crossed. Well, not really, but you get the idea that it has become second nature to me, and to have to purchase a car without it would not make sense....
The "racing pattern" transmissions of which I speak are obviously any manual made for the 928 type Porsche, and the 901 transmissions installed. Am I correct with the 910 transmssion's pattern design? Down left for first, and then up right for second?
I do believe that these were only installed in the 911 until 1971?
My questions:
1) Can they be "retrofitted" to later 911s, such as the venerable SC?
2) How big can I make the engines in the 69, 70, and 71 911s, if I were to find one not easten by rust down to the very last molecule?
3) Is this 901 transmission in fact what I imagine?
Thank you for your considerations.
Anyway, I like the "racing pattern" transmissions that Porsche designed. I have learned to shift them with my hands tied behind my back and my legs crossed. Well, not really, but you get the idea that it has become second nature to me, and to have to purchase a car without it would not make sense....
The "racing pattern" transmissions of which I speak are obviously any manual made for the 928 type Porsche, and the 901 transmissions installed. Am I correct with the 910 transmssion's pattern design? Down left for first, and then up right for second?
I do believe that these were only installed in the 911 until 1971?
My questions:
1) Can they be "retrofitted" to later 911s, such as the venerable SC?
2) How big can I make the engines in the 69, 70, and 71 911s, if I were to find one not easten by rust down to the very last molecule?
3) Is this 901 transmission in fact what I imagine?
Thank you for your considerations.
08-26-2003, 02:17 AM
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Hi Brendan,
I believe the 901 is more or less plug and play with the 915, as I have heard of people with '70 & '71 911's who have put in a more recent engine in their 911's. After '69 Porsche changed over from a push type, to a pull type clutch, so if you have a pre-70 901 you'll have to make do with the older clutch components.
Now the reason the 915 replaced the 901 was to handle the greater horsepower and torque of the 2.4 911 engine, so although I've heard up to a 3.6 can fit and work, you may have longevity problems if you're doing a 901/3.6 combo.
If you want to put a 901 in a later car, I believe its possible, but I've never heard of anyone doing this. You'd be putting in an older, weaker tranny into a newer car. The 915 is notorious for having weak #1 and #2 syncros, and the 901 has even weaker #1 and #2 synchros than the 915. I have heard of older cars putting in a larger engine, though. If they didn't also replace the tranny, it was probably to save the extra expense.
If you're hooked on the dog-leg tranny and want to use it on a car designed for it, either get a pre-72 911 or any 914. I believe all 914's use the 901. With a 914 and a 928 you'd pretty much have all autocross/track situations covered.
Regards,
Don
I believe the 901 is more or less plug and play with the 915, as I have heard of people with '70 & '71 911's who have put in a more recent engine in their 911's. After '69 Porsche changed over from a push type, to a pull type clutch, so if you have a pre-70 901 you'll have to make do with the older clutch components.
Now the reason the 915 replaced the 901 was to handle the greater horsepower and torque of the 2.4 911 engine, so although I've heard up to a 3.6 can fit and work, you may have longevity problems if you're doing a 901/3.6 combo.
If you want to put a 901 in a later car, I believe its possible, but I've never heard of anyone doing this. You'd be putting in an older, weaker tranny into a newer car. The 915 is notorious for having weak #1 and #2 syncros, and the 901 has even weaker #1 and #2 synchros than the 915. I have heard of older cars putting in a larger engine, though. If they didn't also replace the tranny, it was probably to save the extra expense.
If you're hooked on the dog-leg tranny and want to use it on a car designed for it, either get a pre-72 911 or any 914. I believe all 914's use the 901. With a 914 and a 928 you'd pretty much have all autocross/track situations covered.
Regards,
Don
08-26-2003, 11:48 AM
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Thanks Don. So I am correct in thinking that any 901 will always have the dogleg pattern?
I suppose that with a very good rebuild with some updated sychros, maybe I could make it more suitable to daily use?
I suppose that with a very good rebuild with some updated sychros, maybe I could make it more suitable to daily use?
08-26-2003, 07:08 PM
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Yes, all 901 5-speed trannys have the dog leg. I just recall that some of the older 901's may have come in 4-speed, which is just missing the low gear (thus not dogleg, just normal H).
For the 901 all the synchros rings for all gears were the same (70mm). In the 915 #1 & #2 synchros are beefier (80mm). You can make a 901 work with a larger engine, you just may have to rebuild the #1 & #2 synchros more often.
-Don
For the 901 all the synchros rings for all gears were the same (70mm). In the 915 #1 & #2 synchros are beefier (80mm). You can make a 901 work with a larger engine, you just may have to rebuild the #1 & #2 synchros more often.
-Don
08-26-2003, 11:12 PM
#5
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Guard Gears?