This is starting to make more sense now. Thanks for all the responses!
4th gear gives 18.6mph per 1000rpm. Suggest a quick check against a garage tachometer. Interestingly, my car has provision for a cable drive tachometer on the engine but runs an electronic unit. Sent from my iPhone using Tapatalk
In that case the photograph in the first post would perfect sense if the car were in fourth gear at the time. If it really was in fifth gear checking the tach's accuracy seems like a very good suggestion.
Here's spec's I have 400 gt 10:43 = 4.3 400 A + i 12:39 = 3.25 Daytona 10:33 = 3.3 C4 11:45 = 4.09 365 QM 8.34 = 4.25 Why are the autos so tall. Is that due to torque converter loss?
The 5-speed5th is an OD gear and final ratio motor to wheels is very similar for Auto and 5-speed. Ken
For any interested. Drove the car to work today. In the photo the car was in 5th gear, and the tachometer is way off.
Jim The 5-speed in the 400 GT is OD giving the final drive ratio almost identical to the auto; diff's are different. That would make the OD 5th about 0.75:1. Can anyone confirm? 4th gear is 1:1 in the GT's. Ken
5th gear is 0.8145:1 so the effective final drive ratio is 3.5:1 compared with 3.25 for the automatic. I have often wondered about fitting an auto diff (and speedo head) to my manual car, this would give 28mph/1000rpm in 5th. Obviously acceleration would suffer but fuel economy would improve vastly, 1st gear would be not much lower than 2nd now. Sent from my iPhone using Tapatalk
I don't think there has ever been a transmission swap on one of these cars but if it could be done with out huge expense and difficulty a swap to a T56 would be a great improvement.
Justin A good friend of mine bought a rebuilt diff from and auto and installed it in his GT; his thoughts same as yours because he does a lot of cross country drives (has about 150k miles on car). He kept it a few weeks and swapped back! It said it was terrible. Good news for me, I bought the diff for a nice price as mine is getting a bit noisy. Ken
