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Discussion Starter #1
Just returned from a great drive in my 1973 1600cc Spider and the rev counter was showing 3000rpm at about 100km per hour in 5th gear. Is this normal or do I have a low reading rev counter.
Many thanks in advance for any info on revs per km as I could not find anything via Google etc.
 

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reading about 8km fast, according to speed calculator
depends on tyre sizes, what rear axle ratio you have etc

this chart was calculated from the following data (my guess at what your 1600 spider has;))
165/70-14 tires
rear axle ratio 4.56 (I think this was standard on the 1600 spiders?)
and your 5th gear ratio is 0,79 (I think all gearboxes are the same, except the 1300 junior where the 5th gear is 0,86 ratio)
speedo.jpg
 

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Discussion Starter #3
Thanks so much! Correct tyre size and car is standard as far as I know so axle ratio and 5th gear probably correct. To be honest the kph might have been slightly lower as I was not focusing on the speedo. Also I guess the speedo might be reading high so I will use GPS next trip and check more accurately.
Thanks for sharing the chart. Most useful!
 

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Those old European metrics are about 82% aspect ratio.
Hopefully spiderserie4 can rerun his calculation.
Joe
 

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the car would have had 165SR14 tyres (in fact optional equipment, as the originals were 155SR15)
checking the classic Pirelli cinturato CA67, they are listed as 165/80-14

that would make 3000 revs in 5th gear = 97,26 km/h
getting closer;)
 

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Discussion Starter #8
Quick update. Spiderserie4 you are spot on. The rears are 165SR14 as you stated and the fronts are marked 165/80-14, again as you stated. So your calculations are dead right. I will check the speed via GPS when out next but at least the tacho readings seem accurate. Thanks again for all your help and for doing the calculations.
 

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Discussion Starter #10
Plus it doesn't leak oil so now I am really worried!!! At least the petrol gauge wobbles all over the place when driving so not all bad!!
 

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It's Italian, so I would say it's because there's no oil in it, amico!
 

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Discussion Starter #14
Bom dia! It is Portuguese although born in Italy so maybe it has oil in but it can't be bothered to leak out!
 
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