|
|
|
|
| Author |
|
|
Registered
|
901 ratios
Hi all... I have noticed that a few guys know a lot about 901 gear ratios etc. My question is this..I have a 901/07 trans. I am running
225 50/15 tires on the rear of my 69S. At about 70 mph, the engine is turning about 4100 rpm. Does this sound right? I am assuming that nobody has changed gears over the years,so 5th gear should be 29:23. Is this correct? Thanks |
||
01-19-2002, 02:19 PM
|
|
|
Registered
Join Date: Feb 2000
Location: London, UK
Posts: 2,349
|
Mike, I think that a 1969 S fitted with the original sized 185/70 tyres would be doing about 86mph at 4100rpm in 5th gear - the engine speed at 70mph being approx 3400rpm.
The overall diameter of your 225/50 tyres is about 5% smaller than the original tyres which will lower your gearing & affect your speedo reading - but I would not have thought that it would make this much difference. Chances are that your speedo is under-reading (in addition to the effect of the tyres). Andy Boyle (UK) '69 911E Last edited by andyjboy; 01-19-2002 at 03:22 PM.. |
||
|
01-19-2002, 03:05 PM
|
|
1990 Porsche 944 S2 3.0 16V
