Plz Help with Trans Gearing

[patrickt]

If your engine demands 2600 RPM there's no question you want the .81 for street driving. Don't even think about it anymore.

[patrickt]

But you still might find the mid to upper 60's to be troublesome. With your setup, fourth gear needs 2800 RPM to hit 65MPH, using a 26.8" rear tire, which is what my MT 295/50 tires are. A shift to fifth at 65MPH drops your revs to 2300RPM, which your engine might not like.... I think I did that math right. The truth is, you really won't know for sure until you have the engine nicely broken in and tuned to perfection.

[Davidless]

Originally Posted by patrickt

But you still might find the mid to upper 60's to be troublesome. With your setup, fourth gear needs 2800 RPM to hit 65MPH, using a 26.8" rear tire, which is what my MT 295/50 tires are. A shift to fifth at 65MPH drops your revs to 2300RPM, which your engine might not like.... I think I did that math right. The truth is, you really won't know for sure until you have the engine nicely broken in and tuned to perfection.

Based on 18" wheels my calculations are a bit different

@ 2800 RPM 4th will cruise @ 72 mph and 5th is 89

@2500 (minimum for happy engine) 4th is 65 mph and 5th is 80 mph, I'm sure on a good tune I can go down to 2400 RPM to cruise @ 76 mph.

Plus I'm using the programmable Progressive distributor so I can tune on the fly, that is if I know what I am doing LOL



So I think the .81 is the way to go

[patrickt]

Originally Posted by Davidless

Plus I'm using the programmable Progressive distributor so I can tune on the fly, that is if I know what I am doing LOL

Here are the instructions: