I was wondering what RPM I should be at when I am cruising in 5th gear at 70mph. What do you guys get?

 

it depends on your rear end.

 

If it's stock, and has the 3.08's (like mine) then you should be around 1800, I think. I know when I'm doing 100mph I'm JUST over 2500.

 

Should be around 1750, if i recall, I always remember that 80mph is almost exactly 2000 RPM. I'll check later.

 

Use the calculations section of this site. It doesn't matter what type of motor you have to determine the RPM's.

 

I wonder if the gears in mine were changed...My tach is WAY off to begin with, it says I idle at 1500rpm. So when I'm doing 70 the tach says I'm doing 4000 - 45000...hmmm.

 

Has yours always been that far off? A gear change will not change the tach but it will change the speedo. Your tach should not be that far off and should deff not read that high at 70.

 

maybe time for a speedo gear change or a new VSS (withda proper gear).

 

Sounds like your tachometer is on the fritz. Mine does the exact same thing. It registers about 1000-1500 RPM at idle but I know it is not really idling that high. You might should try installing an aftermarket tachometer and see what it registers (that is what I am going to do).

 

our tachs are horrible, they are known for going bad, and when they go bad, the read very high.

**note** i shift to third, after a 2 mississippi from the time the tach needle hits the dash.

 

Ha. Is that the technical way or would 1 potato 2 potato work?

 

has to be mississippi, or else you will shift too soon.

problem fixed though, i got a $20 Sunpro tach at the local swap meet this week.

 

I want to keep the dash looking stock, so I got a whole gauge cluster off ebay from a 92 RS w/V8. The guy said every gauge including the tach was working to spec. So, I will just try and change out the tach with this other factory tach and hope its on!

 

If you have the ability to run winALDL on it as well that will give you your real rpm's. You can guage that against your new clusters...