Using RPM for speed
 

If this will work, my speedometer cable is broken. Is there a way to use RPM for MPH? If so if anyone has some free time. Find out what RPM the engine is in with the transmission in 4th or 5th gear for 35, 40, 45, 50, 55, 60, and 65, I would greatly appreciate it. and 25 in 2nd or 3rd, or 4th for school zones. Is this possible, I know the gears are set ratios, so hopefully it works. Any information, or websites just please put up. I will be able to get the cable in a while but not for 3 months probably. I am still checking scrap yards.

I forgot to say it is a 88 non turbo stock. If this helps any.

My cables are broken too, I just go off of those machines that tell you how fast you're going trying to get you to not speed. I've been in 5th at 2500rpm and it said my MPH was 65. I have a turbo tho, and idk if that will make a difference.

I know for sure that in 5th at 2000 rpm im going 45 mph. 87 non turbo.

Thanks a lot guys, I got a chart from another forum, the only problem is the tire sizes are 225 50 16, and mine is 205 55 16. Is this much of a difference in speed?

Here's what I did for my kids car.
I had my bro drive beside me, go ech speed , and then I used some 'white out' to write the numbers at each speed on the tach.

3 for 30mph, 4 for 40mph, etc.