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Guest
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915 Gear Ratios
My 915 seems to be geared differently (lower) than others. I don't think it is the main gear, such as the 7:31 that has been spoken of because my speed/RPM in 5th is not as low/high as reported. This is a Euro car, is the 5th gear ratio different than U.S. spec? The differential between 4th and 5th isn't mutch. At 60mph the tach will fall from 3200 to just over 2800 after the shift into fifth, only ~350 RPM. I have had the speedo checked and it is right on the money - rather unusual. I havn't seen anything in my reference books concerning Euro vs U.S. gearing. Any thoughts?
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06-30-2000, 09:22 AM
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I suspect a previous alteration in gearing. With all of the different gears available ... over 40, total, some previous owner may not have been able to resist the temptation ... to make an 'improvement' in the factory gearing!
------------------ Warren Hall 1973 911S Targa |
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06-30-2000, 01:46 PM
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RarlyL8
I'm guessing a bit here, but I think I have about the same drop. I have a Euro (Uk, actually) 1975 911S, and yours is a 77(?) so it could be the same. A number I know better is 2950 = 70mph (guess who can't see his speedo behind the steering wheel). What is "normal" for anyone in the US? Cam ------------------ ---------------- Cameron Baudinet 1975 911S |
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07-02-2000, 07:42 PM
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My car is a '78. Tach sits around 3200RPM @ 70 mph. You're right about the blocked speedo. I have a Momo wheel and can't see from 60-80 mph without looking around the wheel.
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07-03-2000, 09:55 AM
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RarlyL8
I have lent out my copy of the road tests for my car (we can get copies from down at the public library as they have magazines going back to the 50's with an index system of raod tests - it is so cool!) but I remember that the UK 1974 model had a different final drive (same as '73 I think) and was slightly shorter geared. You might have this transmission set. I will endeavour to check them when I get it back and give you the mph/1000 rpm and max speeds in each gear. Cam ------------------ ---------------- Cameron Baudinet 1975 911S |
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07-03-2000, 01:51 PM
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What is the type number stamped on the bottom rib of the transaxle? ... should be 915/xx, and the xx designates what gearsets were originally in the trans. and the ring & pinion, as well.
------------------ Warren Hall 1973 911S Targa |
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07-03-2000, 08:15 PM
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Thanks for the replies, I'll look up those tranny numbers when I get back in town.
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07-06-2000, 05:19 PM
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