modulus wrote:dumone wrote:modulus wrote:XXX-1.8T wrote:ok so back on topic will i blow my engine or gearbox do 80mph.
Im running 165's rear and 135's at the front!
With this tyre combination, your speedo will be quite optimistic unless it has been recalibrrated, i.e. an indicated 80 mph would be somewhat less in reality. How are you judging your speed?
hth
speed variations will depend on profile of the tyres, not the width
like wise with rpm and rear tyre profile
[ Edited on 14-2-06 by dumone ]
The height of a radial tyre is determined by the width X the profile; 'speed variations' will therefore depend on the width and the profile. Between a 135 and a 155 front tyre there is about 5% difference in diameter, directly affecting the speedo accuracy, assuming that 155's are equivalent to standard issue. Couple with a relatively large (comparatively) width (and therefor diameter) rear tyre, the actual engine RPM at an indicated 80 mph might be quite low compared with the rpm of s standard tyred bug. Which, after all, is directly relevant to the amount of engine stress at and indicated 80 mph.
If, as XXX-1.8T has indicated above, the front tyres are lower profile than the rears, then the above differences and their effects are magnified.
hth
[ Edited on 14-2-06 by modulus ]
i know, i should of had "and" in there instead of "not" hey, sorry
we should have asked for more info right from the start too
tyre size and profile front and rear...
which 1300 box-the late or early
engine mods-specifically bottom end, cooling aids/mods?................
we are learnning more tho as we get along.
:kiss
[ Edited on 14-2-06 by dumone ]