Hey everyone,

When I bought my rx7 the tach was acting up, so when it gave up I replaced it. I used a s5 non turbo tach with a higher redline than the stock TII gauge, so I replaced the face plate adjusted the needle to zero and gave it a go.

It looks like it working great, but I want to make sure it's not over revved.

I looked on the FSM, nothing and online.

I want to know the speed before redline of each gear.

 

At 50 mph in 4th with a 4.1 rear end gear you should be at 3k rpm.

 

Thank's I'll check it out and report back

 

V = (C*RPM)/(1056RnRf)

V = Vehicle Speed in mph
C = Tire circumference in inches (A stock S4 TII 205/55-16 is about 78.15639")
RPM = Engine RPM
Rn = Transmission Gear Ratio (See the FSM for gear ratios)
Rf = Final Gear (2.90, 4.10, or 4.33)

 

Well at 50mph the tach shows 3600rpm I'm not quite sure what the gearing is.

It's a stock TII car with stock tire size 205/55/16

 

http://www.f-body.org/gears/

 

http://www.gearboxman.co.uk/download/gearspeeds.v2.xls

My fav gearing calculator...