79powerwagon wrote:
OD, you can change your gear ratio a bit by installing taller tires on the rear. But before you do that (or call Gear Vendors), hook up a vacuum gauge and drive around a while to see how it responds to your driving habits.
An example, if your driving at 60 and 3000rpms, and you're pulling 15"hg, and then you're driving at 65 and 3200rpms and pulling 17"hg, you are actually MORE efficient at 65 than 60. If the opposite were the case, then you are more efficient at 60mph...
Get what I mean?
Eric
Correct me if I'm wrong but how could you get higher manifold pressure if the only factor that changes is increasing throttle position to increase the RPMs? Wouldn't the increased throttle position lower the manifold pressure?
My understanding is that throttle position on a non-computerized, carbureted vehicle determines manifold pressure. I don't think I have ever seen pressure increases while throttle positions increases unless other factors are involved, like gear changes, or in the instance of newer vehicles timing changes due to computer control, etc.
This is just my understanding and would be very interested in the correct information!
