[TR] TR3 speed Vs RPM

[Randall]

> took a friends TR3 for a ride last night.
> we hit 75mph, but the rev's where at 4500 to 5000 depending on coast or
> maintain speed. 4th gear, no overdrive.
> is this about what the rest of you TR3 owners experience?

What axle and tires does he have?  That rpm is way high with stock tires and
a standard 3.7 axle; but might be somewhat in the ballpark with a 4.1 axle
and shorter tires (assuming you were using GPS or similar to measure speed).

The normal relationship between displayed speed and rpm is almost exactly 20
mph per 1000 rpm (so 4500 rpm should show as 90 mph), assuming you have the
3.7 speedometer.  There is a calibration number on the face of the
speedometer, should be around 1180 for a 3.7 speedo.  A number above 1300
indicates it is a 4.1 speedo.

Just as a side note, my previous TR3A came to me with a 4.1 speedo and 3.7
gears; while my current TR3 came to me with 4.1 gears and a 3.7 speedo.
Seems that most people don't know or care about the fine details when doing
an axle swap :)

> also it has always been my experience that if one gets wheel wobble
> between 55 and 60, its wheel balance.
> slower than 55 is ok, accelerating beyond 60 makes it go away.
> no?

Balance is probably most common, but it can also be wheels, hubs, or tires
that don't run true or variations in tire stiffness.

Lately I've been fighting problems that I think are mostly imbalance in the
hubs and brake rotors.  I'm not quite sure how it's possible, but I finally
had to scrap a pair of new rotors because they were so badly out of balance.
After drilling 6 holes some 1/4" deep into the edge, the balance was getting
better but then they started to warp.

-- Randall