Tach Doesn't Work Wondering Whats My Rpm's On The Freeway
 

EVERY SINCE I PUT MY MSD ON MY TACH DOESN'T WORK (TACH ADAPTER ON ITS WAY) AN IVE UP GRADED ALOT ON MY STANG :HEADERS EXAUST 3.73 GEAR SO MY RPM BAND HAS RISEN AN I CANT GO BY THE SOUND OF MY ENGINE ANY MORE OR MY SPEEDO CAUSE ITS WAY OF SO MY QUESTION IS WHATS MY RPM'S AT 70 MHP WITH 3.73'S AN 16-55-245'S................ :rolleyes: :rolleyes: :rolleyes:

Re: Tach Doesn't Work Wondering Whats My Rpm's On The Freeway
 

Need to know tire diameter (in inches) and in what gear are you talking? I'm GUESSING the tires are about 26.25" or so, and assuming you mean overdrive, that puts you about 2300 RPM at 70MPH, according to the calculators here on MW. ;)

Re: Tach Doesn't Work Wondering Whats My Rpm's On The Freeway
 

In Fifth Gear, 26.61 Diameter Tires............thanks

Re: Tach Doesn't Work Wondering Whats My Rpm's On The Freeway
 

Tire diameter is 26.61". The 5th gear ratio is .68. You would be doing 1923 RPM at 60MPH and 2243 RPM at 70 MPH. At 80 MPH, you would be turning 2563 RPM.

Re: Tach Doesn't Work Wondering Whats My Rpm's On The Freeway
 

Thanks Guys Fo Your Reply's

Re: Tach Doesn't Work Wondering Whats My Rpm's On The Freeway
 

WOW! That was a hell of a guess I threw up there! LOL

Even a blind squirrel finds an acorn once in awhile. hehehehehe

Glad we could help you out. Get the tach fixed, that's the best way to tell for sure. ;)